/[pcre]/code/trunk/doc/pcre.txt

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-revision 578 by ph10,
Wed Nov 17 17:55:57 2010 UTC
+revision 579 by ph10,
Wed Nov 24 17:39:25 2010 UTC
 Line 2
  This file contains a concatenation of the PCRE man pages, converted to plain
  text format for ease of searching with a text editor, or for use on systems
  that do not have a man page processor. The small individual files that give
  synopses of each function in the library have not been included. Neither has
  the pcredemo program. There are separate text files for the pcregrep and
  pcretest commands.
  -----------------------------------------------------------------------------
 Line 269 
 REVISION
         Last updated: 13 November 2010
         Copyright (c) 1997-2010 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREBUILD(3)                                                      PCREBUILD(3)
 Line 600 
 REVISION
         Last updated: 29 September 2009
         Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREMATCHING(3)                                                PCREMATCHING(3)
 Line 804 
 REVISION
         Last updated: 17 November 2010
         Copyright (c) 1997-2010 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREAPI(3)                                                          PCREAPI(3)
 Line 1165 
 COMPILING A PATTERN
         pcrepattern documentation). For those options that can be different  in
         different  parts  of  the pattern, the contents of the options argument
         specifies their settings at the start of compilation and execution. The
-        PCRE_ANCHORED, PCRE_BSR_xxx, and PCRE_NEWLINE_xxx options can be set at
+        PCRE_ANCHORED,  PCRE_BSR_xxx, PCRE_NEWLINE_xxx, PCRE_NO_UTF8_CHECK, and
-        the time of matching as well as at compile time.
+        PCRE_NO_START_OPT options can be set at the time of matching as well as
+        at compile time.
         If errptr is NULL, pcre_compile() returns NULL immediately.  Otherwise,
-        if  compilation  of  a  pattern fails, pcre_compile() returns NULL, and
+        if compilation of a pattern fails,  pcre_compile()  returns  NULL,  and
         sets the variable pointed to by errptr to point to a textual error mes-
         sage. This is a static string that is part of the library. You must not
-        try to free it. The offset from the start of the pattern  to  the  byte
+        try  to  free  it. The offset from the start of the pattern to the byte
         that was being processed when the error was discovered is placed in the
-        variable pointed to by erroffset, which must not be NULL. If it is,  an
+        variable  pointed to by erroffset, which must not be NULL. If it is, an
         immediate error is given. Some errors are not detected until checks are
-        carried out when the whole pattern has been scanned; in this  case  the
+        carried  out  when the whole pattern has been scanned; in this case the
         offset is set to the end of the pattern.
-        Note  that  the offset is in bytes, not characters, even in UTF-8 mode.
+        Note that the offset is in bytes, not characters, even in  UTF-8  mode.
-        It may point into the middle of a UTF-8 character  (for  example,  when
+        It  may  point  into the middle of a UTF-8 character (for example, when
         PCRE_ERROR_BADUTF8 is returned for an invalid UTF-8 string).
-        If  pcre_compile2()  is  used instead of pcre_compile(), and the error-
+        If pcre_compile2() is used instead of pcre_compile(),  and  the  error-
-        codeptr argument is not NULL, a non-zero error code number is  returned
+        codeptr  argument is not NULL, a non-zero error code number is returned
-        via  this argument in the event of an error. This is in addition to the
+        via this argument in the event of an error. This is in addition to  the
         textual error message. Error codes and messages are listed below.
-        If the final argument, tableptr, is NULL, PCRE uses a  default  set  of
+        If  the  final  argument, tableptr, is NULL, PCRE uses a default set of
-        character  tables  that  are  built  when  PCRE  is compiled, using the
+        character tables that are  built  when  PCRE  is  compiled,  using  the
-        default C locale. Otherwise, tableptr must be an address  that  is  the
+        default  C  locale.  Otherwise, tableptr must be an address that is the
-        result  of  a  call to pcre_maketables(). This value is stored with the
+        result of a call to pcre_maketables(). This value is  stored  with  the
-        compiled pattern, and used again by pcre_exec(), unless  another  table
+        compiled  pattern,  and used again by pcre_exec(), unless another table
         pointer is passed to it. For more discussion, see the section on locale
         support below.
-        This code fragment shows a typical straightforward  call  to  pcre_com-
+        This  code  fragment  shows a typical straightforward call to pcre_com-
         pile():
           pcre *re;
-Line 1209 
 COMPILING A PATTERN
+Line 1210 
 COMPILING A PATTERN
             &erroffset,       /* for error offset */
             NULL);            /* use default character tables */
-        The  following  names  for option bits are defined in the pcre.h header
+        The following names for option bits are defined in  the  pcre.h  header
         file:
           PCRE_ANCHORED
         If this bit is set, the pattern is forced to be "anchored", that is, it
-        is  constrained to match only at the first matching point in the string
+        is constrained to match only at the first matching point in the  string
-        that is being searched (the "subject string"). This effect can also  be
+        that  is being searched (the "subject string"). This effect can also be
-        achieved  by appropriate constructs in the pattern itself, which is the
+        achieved by appropriate constructs in the pattern itself, which is  the
         only way to do it in Perl.
           PCRE_AUTO_CALLOUT
         If this bit is set, pcre_compile() automatically inserts callout items,
-        all  with  number  255, before each pattern item. For discussion of the
+        all with number 255, before each pattern item. For  discussion  of  the
         callout facility, see the pcrecallout documentation.
           PCRE_BSR_ANYCRLF
           PCRE_BSR_UNICODE
         These options (which are mutually exclusive) control what the \R escape
-        sequence  matches.  The choice is either to match only CR, LF, or CRLF,
+        sequence matches. The choice is either to match only CR, LF,  or  CRLF,
         or to match any Unicode newline sequence. The default is specified when
         PCRE is built. It can be overridden from within the pattern, or by set-
         ting an option when a compiled pattern is matched.
           PCRE_CASELESS
-        If this bit is set, letters in the pattern match both upper  and  lower
+        If  this  bit is set, letters in the pattern match both upper and lower
-        case  letters.  It  is  equivalent  to  Perl's /i option, and it can be
+        case letters. It is equivalent to Perl's  /i  option,  and  it  can  be
-        changed within a pattern by a (?i) option setting. In UTF-8 mode,  PCRE
+        changed  within a pattern by a (?i) option setting. In UTF-8 mode, PCRE
-        always  understands the concept of case for characters whose values are
+        always understands the concept of case for characters whose values  are
-        less than 128, so caseless matching is always possible. For  characters
+        less  than 128, so caseless matching is always possible. For characters
-        with  higher  values,  the concept of case is supported if PCRE is com-
+        with higher values, the concept of case is supported if  PCRE  is  com-
-        piled with Unicode property support, but not otherwise. If you want  to
+        piled  with Unicode property support, but not otherwise. If you want to
-        use  caseless  matching  for  characters 128 and above, you must ensure
+        use caseless matching for characters 128 and  above,  you  must  ensure
-        that PCRE is compiled with Unicode property support  as  well  as  with
+        that  PCRE  is  compiled  with Unicode property support as well as with
         UTF-8 support.
           PCRE_DOLLAR_ENDONLY
-        If  this bit is set, a dollar metacharacter in the pattern matches only
+        If this bit is set, a dollar metacharacter in the pattern matches  only
-        at the end of the subject string. Without this option,  a  dollar  also
+        at  the  end  of the subject string. Without this option, a dollar also
-        matches  immediately before a newline at the end of the string (but not
+        matches immediately before a newline at the end of the string (but  not
-        before any other newlines). The PCRE_DOLLAR_ENDONLY option  is  ignored
+        before  any  other newlines). The PCRE_DOLLAR_ENDONLY option is ignored
-        if  PCRE_MULTILINE  is  set.   There is no equivalent to this option in
+        if PCRE_MULTILINE is set.  There is no equivalent  to  this  option  in
         Perl, and no way to set it within a pattern.
           PCRE_DOTALL
-        If this bit is set, a dot metacharacter in the pattern matches a  char-
+        If  this bit is set, a dot metacharacter in the pattern matches a char-
         acter of any value, including one that indicates a newline. However, it
-        only ever matches one character, even if newlines are  coded  as  CRLF.
+        only  ever  matches  one character, even if newlines are coded as CRLF.
-        Without  this option, a dot does not match when the current position is
+        Without this option, a dot does not match when the current position  is
         at a newline. This option is equivalent to Perl's /s option, and it can
-        be  changed within a pattern by a (?s) option setting. A negative class
+        be changed within a pattern by a (?s) option setting. A negative  class
         such as [^a] always matches newline characters, independent of the set-
         ting of this option.
           PCRE_DUPNAMES
-        If  this  bit is set, names used to identify capturing subpatterns need
+        If this bit is set, names used to identify capturing  subpatterns  need
         not be unique. This can be helpful for certain types of pattern when it
-        is  known  that  only  one instance of the named subpattern can ever be
+        is known that only one instance of the named  subpattern  can  ever  be
-        matched. There are more details of named subpatterns  below;  see  also
+        matched.  There  are  more details of named subpatterns below; see also
         the pcrepattern documentation.
           PCRE_EXTENDED
-        If  this  bit  is  set,  whitespace  data characters in the pattern are
+        If this bit is set, whitespace  data  characters  in  the  pattern  are
         totally ignored except when escaped or inside a character class. White-
         space does not include the VT character (code 11). In addition, charac-
         ters between an unescaped # outside a character class and the next new-
-        line,  inclusive,  are  also  ignored.  This is equivalent to Perl's /x
+        line, inclusive, are also ignored. This  is  equivalent  to  Perl's  /x
-        option, and it can be changed within a pattern by a  (?x)  option  set-
+        option,  and  it  can be changed within a pattern by a (?x) option set-
         ting.
-        Which  characters  are  interpreted  as  newlines  is controlled by the
+        Which characters are interpreted  as  newlines  is  controlled  by  the
-        options passed to pcre_compile() or by a special sequence at the  start
+        options  passed to pcre_compile() or by a special sequence at the start
-        of  the  pattern, as described in the section entitled "Newline conven-
+        of the pattern, as described in the section entitled  "Newline  conven-
         tions" in the pcrepattern documentation. Note that the end of this type
-        of  comment  is  a  literal  newline  sequence  in  the pattern; escape
+        of comment is  a  literal  newline  sequence  in  the  pattern;  escape
         sequences that happen to represent a newline do not count.
-        This option makes it possible to include  comments  inside  complicated
+        This  option  makes  it possible to include comments inside complicated
-        patterns.   Note,  however,  that this applies only to data characters.
+        patterns.  Note, however, that this applies only  to  data  characters.
-        Whitespace  characters  may  never  appear  within  special   character
+        Whitespace   characters  may  never  appear  within  special  character
         sequences in a pattern, for example within the sequence (?( that intro-
         duces a conditional subpattern.
           PCRE_EXTRA
-        This option was invented in order to turn on  additional  functionality
+        This  option  was invented in order to turn on additional functionality
-        of  PCRE  that  is  incompatible with Perl, but it is currently of very
+        of PCRE that is incompatible with Perl, but it  is  currently  of  very
-        little use. When set, any backslash in a pattern that is followed by  a
+        little  use. When set, any backslash in a pattern that is followed by a
-        letter  that  has  no  special  meaning causes an error, thus reserving
+        letter that has no special meaning  causes  an  error,  thus  reserving
-        these combinations for future expansion. By  default,  as  in  Perl,  a
+        these  combinations  for  future  expansion.  By default, as in Perl, a
-        backslash  followed by a letter with no special meaning is treated as a
+        backslash followed by a letter with no special meaning is treated as  a
         literal. (Perl can, however, be persuaded to give an error for this, by
-        running  it with the -w option.) There are at present no other features
+        running it with the -w option.) There are at present no other  features
-        controlled by this option. It can also be set by a (?X) option  setting
+        controlled  by this option. It can also be set by a (?X) option setting
         within a pattern.
           PCRE_FIRSTLINE
-        If  this  option  is  set,  an  unanchored pattern is required to match
+        If this option is set, an  unanchored  pattern  is  required  to  match
-        before or at the first  newline  in  the  subject  string,  though  the
+        before  or  at  the  first  newline  in  the subject string, though the
         matched text may continue over the newline.
           PCRE_JAVASCRIPT_COMPAT
         If this option is set, PCRE's behaviour is changed in some ways so that
-        it is compatible with JavaScript rather than Perl. The changes  are  as
+        it  is  compatible with JavaScript rather than Perl. The changes are as
         follows:
-        (1)  A  lone  closing square bracket in a pattern causes a compile-time
+        (1) A lone closing square bracket in a pattern  causes  a  compile-time
-        error, because this is illegal in JavaScript (by default it is  treated
+        error,  because this is illegal in JavaScript (by default it is treated
         as a data character). Thus, the pattern AB]CD becomes illegal when this
         option is set.
-        (2) At run time, a back reference to an unset subpattern group  matches
+        (2)  At run time, a back reference to an unset subpattern group matches
-        an  empty  string (by default this causes the current matching alterna-
+        an empty string (by default this causes the current  matching  alterna-
-        tive to fail). A pattern such as (\1)(a) succeeds when this  option  is
+        tive  to  fail). A pattern such as (\1)(a) succeeds when this option is
-        set  (assuming  it can find an "a" in the subject), whereas it fails by
+        set (assuming it can find an "a" in the subject), whereas it  fails  by
         default, for Perl compatibility.
           PCRE_MULTILINE
-        By default, PCRE treats the subject string as consisting  of  a  single
+        By  default,  PCRE  treats the subject string as consisting of a single
-        line  of characters (even if it actually contains newlines). The "start
+        line of characters (even if it actually contains newlines). The  "start
-        of line" metacharacter (^) matches only at the  start  of  the  string,
+        of  line"  metacharacter  (^)  matches only at the start of the string,
-        while  the  "end  of line" metacharacter ($) matches only at the end of
+        while the "end of line" metacharacter ($) matches only at  the  end  of
         the string, or before a terminating newline (unless PCRE_DOLLAR_ENDONLY
         is set). This is the same as Perl.
-        When  PCRE_MULTILINE  it  is set, the "start of line" and "end of line"
+        When PCRE_MULTILINE it is set, the "start of line" and  "end  of  line"
-        constructs match immediately following or immediately  before  internal
+        constructs  match  immediately following or immediately before internal
-        newlines  in  the  subject string, respectively, as well as at the very
+        newlines in the subject string, respectively, as well as  at  the  very
-        start and end. This is equivalent to Perl's /m option, and  it  can  be
+        start  and  end.  This is equivalent to Perl's /m option, and it can be
         changed within a pattern by a (?m) option setting. If there are no new-
-        lines in a subject string, or no occurrences of ^ or $  in  a  pattern,
+        lines  in  a  subject string, or no occurrences of ^ or $ in a pattern,
         setting PCRE_MULTILINE has no effect.
           PCRE_NEWLINE_CR
-Line 1358 
 COMPILING A PATTERN
+Line 1359 
 COMPILING A PATTERN
           PCRE_NEWLINE_ANYCRLF
           PCRE_NEWLINE_ANY
-        These  options  override the default newline definition that was chosen
+        These options override the default newline definition that  was  chosen
-        when PCRE was built. Setting the first or the second specifies  that  a
+        when  PCRE  was built. Setting the first or the second specifies that a
-        newline  is  indicated  by a single character (CR or LF, respectively).
+        newline is indicated by a single character (CR  or  LF,  respectively).
-        Setting PCRE_NEWLINE_CRLF specifies that a newline is indicated by  the
+        Setting  PCRE_NEWLINE_CRLF specifies that a newline is indicated by the
-        two-character  CRLF  sequence.  Setting  PCRE_NEWLINE_ANYCRLF specifies
+        two-character CRLF  sequence.  Setting  PCRE_NEWLINE_ANYCRLF  specifies
         that any of the three preceding sequences should be recognized. Setting
-        PCRE_NEWLINE_ANY  specifies that any Unicode newline sequence should be
+        PCRE_NEWLINE_ANY specifies that any Unicode newline sequence should  be
         recognized. The Unicode newline sequences are the three just mentioned,
-        plus  the  single  characters  VT (vertical tab, U+000B), FF (formfeed,
+        plus the single characters VT (vertical  tab,  U+000B),  FF  (formfeed,
-        U+000C), NEL (next line, U+0085), LS (line separator, U+2028),  and  PS
+        U+000C),  NEL  (next line, U+0085), LS (line separator, U+2028), and PS
-        (paragraph  separator,  U+2029).  The  last  two are recognized only in
+        (paragraph separator, U+2029). The last  two  are  recognized  only  in
         UTF-8 mode.
-        The newline setting in the  options  word  uses  three  bits  that  are
+        The  newline  setting  in  the  options  word  uses three bits that are
         treated as a number, giving eight possibilities. Currently only six are
-        used (default plus the five values above). This means that if  you  set
+        used  (default  plus the five values above). This means that if you set
-        more  than one newline option, the combination may or may not be sensi-
+        more than one newline option, the combination may or may not be  sensi-
         ble. For example, PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to
-        PCRE_NEWLINE_CRLF,  but other combinations may yield unused numbers and
+        PCRE_NEWLINE_CRLF, but other combinations may yield unused numbers  and
         cause an error.
-        The only time that a line break in a pattern  is  specially  recognized
+        The  only  time  that a line break in a pattern is specially recognized
-        when  compiling  is when PCRE_EXTENDED is set. CR and LF are whitespace
+        when compiling is when PCRE_EXTENDED is set. CR and LF  are  whitespace
-        characters, and so are ignored in this mode. Also, an unescaped #  out-
+        characters,  and so are ignored in this mode. Also, an unescaped # out-
-        side  a  character class indicates a comment that lasts until after the
+        side a character class indicates a comment that lasts until  after  the
-        next line break sequence. In other circumstances, line break  sequences
+        next  line break sequence. In other circumstances, line break sequences
         in patterns are treated as literal data.
         The newline option that is set at compile time becomes the default that
-Line 1392 
 COMPILING A PATTERN
+Line 1393 
 COMPILING A PATTERN
           PCRE_NO_AUTO_CAPTURE
         If this option is set, it disables the use of numbered capturing paren-
-        theses  in the pattern. Any opening parenthesis that is not followed by
+        theses in the pattern. Any opening parenthesis that is not followed  by
-        ? behaves as if it were followed by ?: but named parentheses can  still
+        ?  behaves as if it were followed by ?: but named parentheses can still
-        be  used  for  capturing  (and  they acquire numbers in the usual way).
+        be used for capturing (and they acquire  numbers  in  the  usual  way).
         There is no equivalent of this option in Perl.
+          NO_START_OPTIMIZE
+        This  is an option that acts at matching time; that is, it is really an
+        option for pcre_exec() or pcre_dfa_exec(). If  it  is  set  at  compile
+        time,  it is remembered with the compiled pattern and assumed at match-
+        ing time. For details  see  the  discussion  of  PCRE_NO_START_OPTIMIZE
+        below.
           PCRE_UCP
-        This option changes the way PCRE processes \B, \b, \D, \d, \S, \s,  \W,
+        This  option changes the way PCRE processes \B, \b, \D, \d, \S, \s, \W,
-        \w,  and  some  of  the POSIX character classes. By default, only ASCII
+        \w, and some of the POSIX character classes.  By  default,  only  ASCII
-        characters are recognized, but if PCRE_UCP is set,  Unicode  properties
+        characters  are  recognized, but if PCRE_UCP is set, Unicode properties
-        are  used instead to classify characters. More details are given in the
+        are used instead to classify characters. More details are given in  the
-        section on generic character types in the pcrepattern page. If you  set
+        section  on generic character types in the pcrepattern page. If you set
-        PCRE_UCP,  matching  one of the items it affects takes much longer. The
+        PCRE_UCP, matching one of the items it affects takes much  longer.  The
-        option is available only if PCRE has been compiled with  Unicode  prop-
+        option  is  available only if PCRE has been compiled with Unicode prop-
         erty support.
           PCRE_UNGREEDY
-        This  option  inverts  the "greediness" of the quantifiers so that they
+        This option inverts the "greediness" of the quantifiers  so  that  they
-        are not greedy by default, but become greedy if followed by "?". It  is
+        are  not greedy by default, but become greedy if followed by "?". It is
-        not  compatible  with Perl. It can also be set by a (?U) option setting
+        not compatible with Perl. It can also be set by a (?U)  option  setting
         within the pattern.
           PCRE_UTF8
-        This option causes PCRE to regard both the pattern and the  subject  as
+        This  option  causes PCRE to regard both the pattern and the subject as
-        strings  of  UTF-8 characters instead of single-byte character strings.
+        strings of UTF-8 characters instead of single-byte  character  strings.
-        However, it is available only when PCRE is built to include UTF-8  sup-
+        However,  it is available only when PCRE is built to include UTF-8 sup-
-        port.  If not, the use of this option provokes an error. Details of how
+        port. If not, the use of this option provokes an error. Details of  how
-        this option changes the behaviour of PCRE are given in the  section  on
+        this  option  changes the behaviour of PCRE are given in the section on
         UTF-8 support in the main pcre page.
           PCRE_NO_UTF8_CHECK
         When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is
-        automatically checked. There is a  discussion  about  the  validity  of
+        automatically  checked.  There  is  a  discussion about the validity of
-        UTF-8  strings  in  the main pcre page. If an invalid UTF-8 sequence of
+        UTF-8 strings in the main pcre page. If an invalid  UTF-8  sequence  of
-        bytes is found, pcre_compile() returns an error. If  you  already  know
+        bytes  is  found,  pcre_compile() returns an error. If you already know
         that your pattern is valid, and you want to skip this check for perfor-
-        mance reasons, you can set the PCRE_NO_UTF8_CHECK option.  When  it  is
+        mance  reasons,  you  can set the PCRE_NO_UTF8_CHECK option. When it is
-        set,  the  effect  of  passing  an invalid UTF-8 string as a pattern is
+        set, the effect of passing an invalid UTF-8  string  as  a  pattern  is
-        undefined. It may cause your program to crash. Note  that  this  option
+        undefined.  It  may  cause your program to crash. Note that this option
-        can  also be passed to pcre_exec() and pcre_dfa_exec(), to suppress the
+        can also be passed to pcre_exec() and pcre_dfa_exec(), to suppress  the
         UTF-8 validity checking of subject strings.
  COMPILATION ERROR CODES
-        The following table lists the error  codes  than  may  be  returned  by
+        The  following  table  lists  the  error  codes than may be returned by
-        pcre_compile2(),  along with the error messages that may be returned by
+        pcre_compile2(), along with the error messages that may be returned  by
-        both compiling functions. As PCRE has developed, some error codes  have
+        both  compiling functions. As PCRE has developed, some error codes have
         fallen out of use. To avoid confusion, they have not been re-used.
  no error
-Line 1517 
 COMPILATION ERROR CODES
+Line 1526 
 COMPILATION ERROR CODES
  (*MARK) must have an argument
  this version of PCRE is not compiled with PCRE_UCP support
-        The  numbers  32  and 10000 in errors 48 and 49 are defaults; different
+        The numbers 32 and 10000 in errors 48 and 49  are  defaults;  different
         values may be used if the limits were changed when PCRE was built.
-Line 1526 
 STUDYING A PATTERN
+Line 1535 
 STUDYING A PATTERN
         pcre_extra *pcre_study(const pcre *code, int options
              const char **errptr);
-        If a compiled pattern is going to be used several times,  it  is  worth
+        If  a  compiled  pattern is going to be used several times, it is worth
         spending more time analyzing it in order to speed up the time taken for
-        matching. The function pcre_study() takes a pointer to a compiled  pat-
+        matching.  The function pcre_study() takes a pointer to a compiled pat-
         tern as its first argument. If studying the pattern produces additional
-        information that will help speed up matching,  pcre_study()  returns  a
+        information  that  will  help speed up matching, pcre_study() returns a
-        pointer  to a pcre_extra block, in which the study_data field points to
+        pointer to a pcre_extra block, in which the study_data field points  to
         the results of the study.
         The  returned  value  from  pcre_study()  can  be  passed  directly  to
-        pcre_exec()  or  pcre_dfa_exec(). However, a pcre_extra block also con-
+        pcre_exec() or pcre_dfa_exec(). However, a pcre_extra block  also  con-
-        tains other fields that can be set by the caller before  the  block  is
+        tains  other  fields  that can be set by the caller before the block is
         passed; these are described below in the section on matching a pattern.
-        If  studying  the  pattern  does  not  produce  any useful information,
+        If studying the  pattern  does  not  produce  any  useful  information,
         pcre_study() returns NULL. In that circumstance, if the calling program
-        wants   to   pass   any   of   the   other  fields  to  pcre_exec()  or
+        wants  to  pass  any  of   the   other   fields   to   pcre_exec()   or
         pcre_dfa_exec(), it must set up its own pcre_extra block.
-        The second argument of pcre_study() contains option bits.  At  present,
+        The  second  argument of pcre_study() contains option bits. At present,
         no options are defined, and this argument should always be zero.
-        The  third argument for pcre_study() is a pointer for an error message.
+        The third argument for pcre_study() is a pointer for an error  message.
-        If studying succeeds (even if no data is  returned),  the  variable  it
+        If  studying  succeeds  (even  if no data is returned), the variable it
-        points  to  is  set  to NULL. Otherwise it is set to point to a textual
+        points to is set to NULL. Otherwise it is set to  point  to  a  textual
         error message. This is a static string that is part of the library. You
-        must  not  try  to  free it. You should test the error pointer for NULL
+        must not try to free it. You should test the  error  pointer  for  NULL
         after calling pcre_study(), to be sure that it has run successfully.
         This is a typical call to pcre_study():
-Line 1565 
 STUDYING A PATTERN
+Line 1574 
 STUDYING A PATTERN
         Studying a pattern does two things: first, a lower bound for the length
         of subject string that is needed to match the pattern is computed. This
         does not mean that there are any strings of that length that match, but
-        it  does  guarantee that no shorter strings match. The value is used by
+        it does guarantee that no shorter strings match. The value is  used  by
-        pcre_exec() and pcre_dfa_exec() to avoid  wasting  time  by  trying  to
+        pcre_exec()  and  pcre_dfa_exec()  to  avoid  wasting time by trying to
-        match  strings  that are shorter than the lower bound. You can find out
+        match strings that are shorter than the lower bound. You can  find  out
         the value in a calling program via the pcre_fullinfo() function.
         Studying a pattern is also useful for non-anchored patterns that do not
-        have  a  single fixed starting character. A bitmap of possible starting
+        have a single fixed starting character. A bitmap of  possible  starting
-        bytes is created. This speeds up finding a position in the  subject  at
+        bytes  is  created. This speeds up finding a position in the subject at
         which to start matching.
-        The  two  optimizations  just  described can be disabled by setting the
+        The two optimizations just described can be  disabled  by  setting  the
-        PCRE_NO_START_OPTIMIZE   option    when    calling    pcre_exec()    or
+        PCRE_NO_START_OPTIMIZE    option    when    calling    pcre_exec()   or
-        pcre_dfa_exec().  You  might  want  to do this if your pattern contains
+        pcre_dfa_exec(). You might want to do this  if  your  pattern  contains
-        callouts or (*MARK), and you want to make use of  these  facilities  in
+        callouts  or  (*MARK),  and you want to make use of these facilities in
-        cases  where  matching fails. See the discussion of PCRE_NO_START_OPTI-
+        cases where matching fails. See the discussion  of  PCRE_NO_START_OPTI-
         MIZE below.
  LOCALE SUPPORT
-        PCRE handles caseless matching, and determines whether  characters  are
+        PCRE  handles  caseless matching, and determines whether characters are
-        letters,  digits, or whatever, by reference to a set of tables, indexed
+        letters, digits, or whatever, by reference to a set of tables,  indexed
-        by character value. When running in UTF-8 mode, this  applies  only  to
+        by  character  value.  When running in UTF-8 mode, this applies only to
-        characters  with  codes  less than 128. By default, higher-valued codes
+        characters with codes less than 128. By  default,  higher-valued  codes
         never match escapes such as \w or \d, but they can be tested with \p if
-        PCRE  is  built with Unicode character property support. Alternatively,
+        PCRE is built with Unicode character property  support.  Alternatively,
-        the PCRE_UCP option can be set at compile  time;  this  causes  \w  and
+        the  PCRE_UCP  option  can  be  set at compile time; this causes \w and
         friends to use Unicode property support instead of built-in tables. The
         use of locales with Unicode is discouraged. If you are handling charac-
-        ters  with codes greater than 128, you should either use UTF-8 and Uni-
+        ters with codes greater than 128, you should either use UTF-8 and  Uni-
         code, or use locales, but not try to mix the two.
-        PCRE contains an internal set of tables that are used  when  the  final
+        PCRE  contains  an  internal set of tables that are used when the final
-        argument  of  pcre_compile()  is  NULL.  These  are sufficient for many
+        argument of pcre_compile() is  NULL.  These  are  sufficient  for  many
         applications.  Normally, the internal tables recognize only ASCII char-
         acters. However, when PCRE is built, it is possible to cause the inter-
         nal tables to be rebuilt in the default "C" locale of the local system,
         which may cause them to be different.
-        The  internal tables can always be overridden by tables supplied by the
+        The internal tables can always be overridden by tables supplied by  the
         application that calls PCRE. These may be created in a different locale
-        from  the  default.  As more and more applications change to using Uni-
+        from the default. As more and more applications change  to  using  Uni-
         code, the need for this locale support is expected to die away.
-        External tables are built by calling  the  pcre_maketables()  function,
+        External  tables  are  built by calling the pcre_maketables() function,
-        which  has no arguments, in the relevant locale. The result can then be
+        which has no arguments, in the relevant locale. The result can then  be
-        passed to pcre_compile() or pcre_exec()  as  often  as  necessary.  For
+        passed  to  pcre_compile()  or  pcre_exec()  as often as necessary. For
-        example,  to  build  and use tables that are appropriate for the French
+        example, to build and use tables that are appropriate  for  the  French
-        locale (where accented characters with  values  greater  than  128  are
+        locale  (where  accented  characters  with  values greater than 128 are
         treated as letters), the following code could be used:
           setlocale(LC_CTYPE, "fr_FR");
           tables = pcre_maketables();
           re = pcre_compile(..., tables);
-        The  locale  name "fr_FR" is used on Linux and other Unix-like systems;
+        The locale name "fr_FR" is used on Linux and other  Unix-like  systems;
         if you are using Windows, the name for the French locale is "french".
-        When pcre_maketables() runs, the tables are built  in  memory  that  is
+        When  pcre_maketables()  runs,  the  tables are built in memory that is
-        obtained  via  pcre_malloc. It is the caller's responsibility to ensure
+        obtained via pcre_malloc. It is the caller's responsibility  to  ensure
-        that the memory containing the tables remains available for as long  as
+        that  the memory containing the tables remains available for as long as
         it is needed.
         The pointer that is passed to pcre_compile() is saved with the compiled
-        pattern, and the same tables are used via this pointer by  pcre_study()
+        pattern,  and the same tables are used via this pointer by pcre_study()
         and normally also by pcre_exec(). Thus, by default, for any single pat-
         tern, compilation, studying and matching all happen in the same locale,
         but different patterns can be compiled in different locales.
-        It  is  possible to pass a table pointer or NULL (indicating the use of
+        It is possible to pass a table pointer or NULL (indicating the  use  of
-        the internal tables) to pcre_exec(). Although  not  intended  for  this
+        the  internal  tables)  to  pcre_exec(). Although not intended for this
-        purpose,  this facility could be used to match a pattern in a different
+        purpose, this facility could be used to match a pattern in a  different
         locale from the one in which it was compiled. Passing table pointers at
         run time is discussed below in the section on matching a pattern.
-Line 1646 
 INFORMATION ABOUT A PATTERN
+Line 1655 
 INFORMATION ABOUT A PATTERN
         int pcre_fullinfo(const pcre *code, const pcre_extra *extra,
              int what, void *where);
-        The  pcre_fullinfo() function returns information about a compiled pat-
+        The pcre_fullinfo() function returns information about a compiled  pat-
         tern. It replaces the obsolete pcre_info() function, which is neverthe-
         less retained for backwards compability (and is documented below).
-        The  first  argument  for  pcre_fullinfo() is a pointer to the compiled
+        The first argument for pcre_fullinfo() is a  pointer  to  the  compiled
-        pattern. The second argument is the result of pcre_study(), or NULL  if
+        pattern.  The second argument is the result of pcre_study(), or NULL if
-        the  pattern  was not studied. The third argument specifies which piece
+        the pattern was not studied. The third argument specifies  which  piece
-        of information is required, and the fourth argument is a pointer  to  a
+        of  information  is required, and the fourth argument is a pointer to a
-        variable  to  receive  the  data. The yield of the function is zero for
+        variable to receive the data. The yield of the  function  is  zero  for
         success, or one of the following negative numbers:
           PCRE_ERROR_NULL       the argument code was NULL
-Line 1662 
 INFORMATION ABOUT A PATTERN
+Line 1671 
 INFORMATION ABOUT A PATTERN
           PCRE_ERROR_BADMAGIC   the "magic number" was not found
           PCRE_ERROR_BADOPTION  the value of what was invalid
-        The "magic number" is placed at the start of each compiled  pattern  as
+        The  "magic  number" is placed at the start of each compiled pattern as
-        an  simple check against passing an arbitrary memory pointer. Here is a
+        an simple check against passing an arbitrary memory pointer. Here is  a
-        typical call of pcre_fullinfo(), to obtain the length of  the  compiled
+        typical  call  of pcre_fullinfo(), to obtain the length of the compiled
         pattern:
           int rc;
-Line 1675 
 INFORMATION ABOUT A PATTERN
+Line 1684 
 INFORMATION ABOUT A PATTERN
             PCRE_INFO_SIZE,   /* what is required */
             &length);         /* where to put the data */
-        The  possible  values for the third argument are defined in pcre.h, and
+        The possible values for the third argument are defined in  pcre.h,  and
         are as follows:
           PCRE_INFO_BACKREFMAX
-        Return the number of the highest back reference  in  the  pattern.  The
+        Return  the  number  of  the highest back reference in the pattern. The
-        fourth  argument  should  point to an int variable. Zero is returned if
+        fourth argument should point to an int variable. Zero  is  returned  if
         there are no back references.
           PCRE_INFO_CAPTURECOUNT
-        Return the number of capturing subpatterns in the pattern.  The  fourth
+        Return  the  number of capturing subpatterns in the pattern. The fourth
         argument should point to an int variable.
           PCRE_INFO_DEFAULT_TABLES
-        Return  a pointer to the internal default character tables within PCRE.
+        Return a pointer to the internal default character tables within  PCRE.
-        The fourth argument should point to an unsigned char *  variable.  This
+        The  fourth  argument should point to an unsigned char * variable. This
         information call is provided for internal use by the pcre_study() func-
-        tion. External callers can cause PCRE to use  its  internal  tables  by
+        tion.  External  callers  can  cause PCRE to use its internal tables by
         passing a NULL table pointer.
           PCRE_INFO_FIRSTBYTE
-        Return  information  about  the first byte of any matched string, for a
+        Return information about the first byte of any matched  string,  for  a
-        non-anchored pattern. The fourth argument should point to an int  vari-
+        non-anchored  pattern. The fourth argument should point to an int vari-
-        able.  (This option used to be called PCRE_INFO_FIRSTCHAR; the old name
+        able. (This option used to be called PCRE_INFO_FIRSTCHAR; the old  name
         is still recognized for backwards compatibility.)
-        If there is a fixed first byte, for example, from  a  pattern  such  as
+        If  there  is  a  fixed first byte, for example, from a pattern such as
         (cat|cow|coyote), its value is returned. Otherwise, if either
-        (a)  the pattern was compiled with the PCRE_MULTILINE option, and every
+        (a) the pattern was compiled with the PCRE_MULTILINE option, and  every
         branch starts with "^", or
         (b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not
         set (if it were set, the pattern would be anchored),
-        -1  is  returned, indicating that the pattern matches only at the start
+        -1 is returned, indicating that the pattern matches only at  the  start
-        of a subject string or after any newline within the  string.  Otherwise
+        of  a  subject string or after any newline within the string. Otherwise
         -2 is returned. For anchored patterns, -2 is returned.
           PCRE_INFO_FIRSTTABLE
-        If  the pattern was studied, and this resulted in the construction of a
+        If the pattern was studied, and this resulted in the construction of  a
 -bit table indicating a fixed set of bytes for the first byte in any
-        matching  string, a pointer to the table is returned. Otherwise NULL is
+        matching string, a pointer to the table is returned. Otherwise NULL  is
-        returned. The fourth argument should point to an unsigned char *  vari-
+        returned.  The fourth argument should point to an unsigned char * vari-
         able.
           PCRE_INFO_HASCRORLF
-        Return  1  if  the  pattern  contains any explicit matches for CR or LF
+        Return 1 if the pattern contains any explicit  matches  for  CR  or  LF
-        characters, otherwise 0. The fourth argument should  point  to  an  int
+        characters,  otherwise  0.  The  fourth argument should point to an int
-        variable.  An explicit match is either a literal CR or LF character, or
+        variable. An explicit match is either a literal CR or LF character,  or
         \r or \n.
           PCRE_INFO_JCHANGED
-        Return 1 if the (?J) or (?-J) option setting is used  in  the  pattern,
+        Return  1  if  the (?J) or (?-J) option setting is used in the pattern,
-        otherwise  0. The fourth argument should point to an int variable. (?J)
+        otherwise 0. The fourth argument should point to an int variable.  (?J)
         and (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
           PCRE_INFO_LASTLITERAL
-        Return the value of the rightmost literal byte that must exist  in  any
+        Return  the  value of the rightmost literal byte that must exist in any
-        matched  string,  other  than  at  its  start,  if such a byte has been
+        matched string, other than at its  start,  if  such  a  byte  has  been
         recorded. The fourth argument should point to an int variable. If there
-        is  no such byte, -1 is returned. For anchored patterns, a last literal
+        is no such byte, -1 is returned. For anchored patterns, a last  literal
-        byte is recorded only if it follows something of variable  length.  For
+        byte  is  recorded only if it follows something of variable length. For
         example, for the pattern /^a\d+z\d+/ the returned value is "z", but for
         /^a\dz\d/ the returned value is -1.
           PCRE_INFO_MINLENGTH
-        If the pattern was studied and a minimum length  for  matching  subject
+        If  the  pattern  was studied and a minimum length for matching subject
-        strings  was  computed,  its  value is returned. Otherwise the returned
+        strings was computed, its value is  returned.  Otherwise  the  returned
-        value is -1. The value is a number of characters, not bytes  (this  may
+        value  is  -1. The value is a number of characters, not bytes (this may
-        be  relevant in UTF-8 mode). The fourth argument should point to an int
+        be relevant in UTF-8 mode). The fourth argument should point to an  int
-        variable. A non-negative value is a lower bound to the  length  of  any
+        variable.  A  non-negative  value is a lower bound to the length of any
-        matching  string.  There  may not be any strings of that length that do
+        matching string. There may not be any strings of that  length  that  do
         actually match, but every string that does match is at least that long.
           PCRE_INFO_NAMECOUNT
           PCRE_INFO_NAMEENTRYSIZE
           PCRE_INFO_NAMETABLE
-        PCRE supports the use of named as well as numbered capturing  parenthe-
+        PCRE  supports the use of named as well as numbered capturing parenthe-
-        ses.  The names are just an additional way of identifying the parenthe-
+        ses. The names are just an additional way of identifying the  parenthe-
         ses, which still acquire numbers. Several convenience functions such as
-        pcre_get_named_substring()  are  provided  for extracting captured sub-
+        pcre_get_named_substring() are provided for  extracting  captured  sub-
-        strings by name. It is also possible to extract the data  directly,  by
+        strings  by  name. It is also possible to extract the data directly, by
-        first  converting  the  name to a number in order to access the correct
+        first converting the name to a number in order to  access  the  correct
         pointers in the output vector (described with pcre_exec() below). To do
-        the  conversion,  you  need  to  use  the  name-to-number map, which is
+        the conversion, you need  to  use  the  name-to-number  map,  which  is
         described by these three values.
         The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT
         gives the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size
-        of each entry; both of these  return  an  int  value.  The  entry  size
+        of  each  entry;  both  of  these  return  an int value. The entry size
-        depends  on the length of the longest name. PCRE_INFO_NAMETABLE returns
+        depends on the length of the longest name. PCRE_INFO_NAMETABLE  returns
-        a pointer to the first entry of the table  (a  pointer  to  char).  The
+        a  pointer  to  the  first  entry of the table (a pointer to char). The
         first two bytes of each entry are the number of the capturing parenthe-
-        sis, most significant byte first. The rest of the entry is  the  corre-
+        sis,  most  significant byte first. The rest of the entry is the corre-
         sponding name, zero terminated.
-        The  names are in alphabetical order. Duplicate names may appear if (?|
+        The names are in alphabetical order. Duplicate names may appear if  (?|
         is used to create multiple groups with the same number, as described in
-        the  section  on  duplicate subpattern numbers in the pcrepattern page.
+        the section on duplicate subpattern numbers in  the  pcrepattern  page.
-        Duplicate names for subpatterns with different  numbers  are  permitted
+        Duplicate  names  for  subpatterns with different numbers are permitted
-        only  if  PCRE_DUPNAMES  is  set. In all cases of duplicate names, they
+        only if PCRE_DUPNAMES is set. In all cases  of  duplicate  names,  they
-        appear in the table in the order in which they were found in  the  pat-
+        appear  in  the table in the order in which they were found in the pat-
-        tern.  In  the  absence  of (?| this is the order of increasing number;
+        tern. In the absence of (?| this is the  order  of  increasing  number;
         when (?| is used this is not necessarily the case because later subpat-
         terns may have lower numbers.
-        As  a  simple  example of the name/number table, consider the following
+        As a simple example of the name/number table,  consider  the  following
-        pattern (assume PCRE_EXTENDED is set, so white space -  including  new-
+        pattern  (assume  PCRE_EXTENDED is set, so white space - including new-
         lines - is ignored):
           (?<date> (?<year>(\d\d)?\d\d) -
           (?<month>\d\d) - (?<day>\d\d) )
-        There  are  four  named subpatterns, so the table has four entries, and
+        There are four named subpatterns, so the table has  four  entries,  and
-        each entry in the table is eight bytes long. The table is  as  follows,
+        each  entry  in the table is eight bytes long. The table is as follows,
         with non-printing bytes shows in hexadecimal, and undefined bytes shown
         as ??:
-Line 1808 
 INFORMATION ABOUT A PATTERN
+Line 1817 
 INFORMATION ABOUT A PATTERN
 04 m  o  n  t  h  00
 02 y  e  a  r  00 ??
-        When writing code to extract data  from  named  subpatterns  using  the
+        When  writing  code  to  extract  data from named subpatterns using the
-        name-to-number  map,  remember that the length of the entries is likely
+        name-to-number map, remember that the length of the entries  is  likely
         to be different for each compiled pattern.
           PCRE_INFO_OKPARTIAL
-        Return 1  if  the  pattern  can  be  used  for  partial  matching  with
+        Return  1  if  the  pattern  can  be  used  for  partial  matching with
-        pcre_exec(),  otherwise  0.  The fourth argument should point to an int
+        pcre_exec(), otherwise 0. The fourth argument should point  to  an  int
-        variable. From  release  8.00,  this  always  returns  1,  because  the
+        variable.  From  release  8.00,  this  always  returns  1,  because the
-        restrictions  that  previously  applied  to  partial matching have been
+        restrictions that previously applied  to  partial  matching  have  been
-        lifted. The pcrepartial documentation gives details of  partial  match-
+        lifted.  The  pcrepartial documentation gives details of partial match-
         ing.
           PCRE_INFO_OPTIONS
-        Return  a  copy of the options with which the pattern was compiled. The
+        Return a copy of the options with which the pattern was  compiled.  The
-        fourth argument should point to an unsigned long  int  variable.  These
+        fourth  argument  should  point to an unsigned long int variable. These
         option bits are those specified in the call to pcre_compile(), modified
         by any top-level option settings at the start of the pattern itself. In
-        other  words,  they are the options that will be in force when matching
+        other words, they are the options that will be in force  when  matching
-        starts. For example, if the pattern /(?im)abc(?-i)d/ is  compiled  with
+        starts.  For  example, if the pattern /(?im)abc(?-i)d/ is compiled with
-        the  PCRE_EXTENDED option, the result is PCRE_CASELESS, PCRE_MULTILINE,
+        the PCRE_EXTENDED option, the result is PCRE_CASELESS,  PCRE_MULTILINE,
         and PCRE_EXTENDED.
-        A pattern is automatically anchored by PCRE if  all  of  its  top-level
+        A  pattern  is  automatically  anchored by PCRE if all of its top-level
         alternatives begin with one of the following:
           ^     unless PCRE_MULTILINE is set
-Line 1846 
 INFORMATION ABOUT A PATTERN
+Line 1855 
 INFORMATION ABOUT A PATTERN
           PCRE_INFO_SIZE
-        Return the size of the compiled pattern, that is, the  value  that  was
+        Return  the  size  of the compiled pattern, that is, the value that was
         passed as the argument to pcre_malloc() when PCRE was getting memory in
         which to place the compiled data. The fourth argument should point to a
         size_t variable.
-Line 1854 
 INFORMATION ABOUT A PATTERN
+Line 1863 
 INFORMATION ABOUT A PATTERN
           PCRE_INFO_STUDYSIZE
         Return the size of the data block pointed to by the study_data field in
-        a pcre_extra block. That is,  it  is  the  value  that  was  passed  to
+        a  pcre_extra  block.  That  is,  it  is  the  value that was passed to
         pcre_malloc() when PCRE was getting memory into which to place the data
-        created by pcre_study(). If pcre_extra is NULL, or there  is  no  study
+        created  by  pcre_study().  If pcre_extra is NULL, or there is no study
-        data,  zero  is  returned. The fourth argument should point to a size_t
+        data, zero is returned. The fourth argument should point  to  a  size_t
         variable.
-Line 1865 
 OBSOLETE INFO FUNCTION
+Line 1874 
 OBSOLETE INFO FUNCTION
         int pcre_info(const pcre *code, int *optptr, int *firstcharptr);
-        The pcre_info() function is now obsolete because its interface  is  too
+        The  pcre_info()  function is now obsolete because its interface is too
-        restrictive  to return all the available data about a compiled pattern.
+        restrictive to return all the available data about a compiled  pattern.
-        New  programs  should  use  pcre_fullinfo()  instead.  The   yield   of
+        New   programs   should  use  pcre_fullinfo()  instead.  The  yield  of
-        pcre_info()  is the number of capturing subpatterns, or one of the fol-
+        pcre_info() is the number of capturing subpatterns, or one of the  fol-
         lowing negative numbers:
           PCRE_ERROR_NULL       the argument code was NULL
           PCRE_ERROR_BADMAGIC   the "magic number" was not found
-        If the optptr argument is not NULL, a copy of the  options  with  which
+        If  the  optptr  argument is not NULL, a copy of the options with which
-        the  pattern  was  compiled  is placed in the integer it points to (see
+        the pattern was compiled is placed in the integer  it  points  to  (see
         PCRE_INFO_OPTIONS above).
-        If the pattern is not anchored and the  firstcharptr  argument  is  not
+        If  the  pattern  is  not anchored and the firstcharptr argument is not
-        NULL,  it is used to pass back information about the first character of
+        NULL, it is used to pass back information about the first character  of
         any matched string (see PCRE_INFO_FIRSTBYTE above).
-Line 1887 
 REFERENCE COUNTS
+Line 1896 
 REFERENCE COUNTS
         int pcre_refcount(pcre *code, int adjust);
-        The pcre_refcount() function is used to maintain a reference  count  in
+        The  pcre_refcount()  function is used to maintain a reference count in
         the data block that contains a compiled pattern. It is provided for the
-        benefit of applications that  operate  in  an  object-oriented  manner,
+        benefit  of  applications  that  operate  in an object-oriented manner,
         where different parts of the application may be using the same compiled
         pattern, but you want to free the block when they are all done.
         When a pattern is compiled, the reference count field is initialized to
-        zero.   It is changed only by calling this function, whose action is to
+        zero.  It is changed only by calling this function, whose action is  to
-        add the adjust value (which may be positive or  negative)  to  it.  The
+        add  the  adjust  value  (which may be positive or negative) to it. The
         yield of the function is the new value. However, the value of the count
-        is constrained to lie between 0 and 65535, inclusive. If the new  value
+        is  constrained to lie between 0 and 65535, inclusive. If the new value
         is outside these limits, it is forced to the appropriate limit value.
-        Except  when it is zero, the reference count is not correctly preserved
+        Except when it is zero, the reference count is not correctly  preserved
-        if a pattern is compiled on one host and then  transferred  to  a  host
+        if  a  pattern  is  compiled on one host and then transferred to a host
         whose byte-order is different. (This seems a highly unlikely scenario.)
-Line 1911 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1920 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
              const char *subject, int length, int startoffset,
              int options, int *ovector, int ovecsize);
-        The  function pcre_exec() is called to match a subject string against a
+        The function pcre_exec() is called to match a subject string against  a
-        compiled pattern, which is passed in the code argument. If the  pattern
+        compiled  pattern, which is passed in the code argument. If the pattern
-        was  studied,  the  result  of  the study should be passed in the extra
+        was studied, the result of the study should  be  passed  in  the  extra
-        argument. This function is the main matching facility of  the  library,
+        argument.  This  function is the main matching facility of the library,
         and it operates in a Perl-like manner. For specialist use there is also
-        an alternative matching function, which is described below in the  sec-
+        an  alternative matching function, which is described below in the sec-
         tion about the pcre_dfa_exec() function.
-        In  most applications, the pattern will have been compiled (and option-
+        In most applications, the pattern will have been compiled (and  option-
-        ally studied) in the same process that calls pcre_exec().  However,  it
+        ally  studied)  in the same process that calls pcre_exec(). However, it
         is possible to save compiled patterns and study data, and then use them
-        later in different processes, possibly even on different hosts.  For  a
+        later  in  different processes, possibly even on different hosts. For a
         discussion about this, see the pcreprecompile documentation.
         Here is an example of a simple call to pcre_exec():
-Line 1941 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1950 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
     Extra data for pcre_exec()
-        If  the  extra argument is not NULL, it must point to a pcre_extra data
+        If the extra argument is not NULL, it must point to a  pcre_extra  data
-        block. The pcre_study() function returns such a block (when it  doesn't
+        block.  The pcre_study() function returns such a block (when it doesn't
-        return  NULL), but you can also create one for yourself, and pass addi-
+        return NULL), but you can also create one for yourself, and pass  addi-
-        tional information in it. The pcre_extra block contains  the  following
+        tional  information  in it. The pcre_extra block contains the following
         fields (not necessarily in this order):
           unsigned long int flags;
-Line 1955 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1964 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           const unsigned char *tables;
           unsigned char **mark;
-        The  flags  field  is a bitmap that specifies which of the other fields
+        The flags field is a bitmap that specifies which of  the  other  fields
         are set. The flag bits are:
           PCRE_EXTRA_STUDY_DATA
-Line 1965 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1974 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_EXTRA_TABLES
           PCRE_EXTRA_MARK
-        Other flag bits should be set to zero. The study_data field is  set  in
+        Other  flag  bits should be set to zero. The study_data field is set in
-        the  pcre_extra  block  that is returned by pcre_study(), together with
+        the pcre_extra block that is returned by  pcre_study(),  together  with
         the appropriate flag bit. You should not set this yourself, but you may
-        add  to  the  block by setting the other fields and their corresponding
+        add to the block by setting the other fields  and  their  corresponding
         flag bits.
         The match_limit field provides a means of preventing PCRE from using up
-        a  vast amount of resources when running patterns that are not going to
+        a vast amount of resources when running patterns that are not going  to
-        match, but which have a very large number  of  possibilities  in  their
+        match,  but  which  have  a very large number of possibilities in their
-        search  trees. The classic example is a pattern that uses nested unlim-
+        search trees. The classic example is a pattern that uses nested  unlim-
         ited repeats.
-        Internally, PCRE uses a function called match() which it calls  repeat-
+        Internally,  PCRE uses a function called match() which it calls repeat-
-        edly  (sometimes  recursively). The limit set by match_limit is imposed
+        edly (sometimes recursively). The limit set by match_limit  is  imposed
-        on the number of times this function is called during  a  match,  which
+        on  the  number  of times this function is called during a match, which
-        has  the  effect  of  limiting the amount of backtracking that can take
+        has the effect of limiting the amount of  backtracking  that  can  take
         place. For patterns that are not anchored, the count restarts from zero
         for each position in the subject string.
-        The  default  value  for  the  limit can be set when PCRE is built; the
+        The default value for the limit can be set  when  PCRE  is  built;  the
-        default default is 10 million, which handles all but the  most  extreme
+        default  default  is 10 million, which handles all but the most extreme
-        cases.  You  can  override  the  default by suppling pcre_exec() with a
+        cases. You can override the default  by  suppling  pcre_exec()  with  a
-        pcre_extra    block    in    which    match_limit    is    set,     and
+        pcre_extra     block    in    which    match_limit    is    set,    and
-        PCRE_EXTRA_MATCH_LIMIT  is  set  in  the  flags  field. If the limit is
+        PCRE_EXTRA_MATCH_LIMIT is set in the  flags  field.  If  the  limit  is
         exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
-        The match_limit_recursion field is similar to match_limit, but  instead
+        The  match_limit_recursion field is similar to match_limit, but instead
         of limiting the total number of times that match() is called, it limits
-        the depth of recursion. The recursion depth is a  smaller  number  than
+        the  depth  of  recursion. The recursion depth is a smaller number than
-        the  total number of calls, because not all calls to match() are recur-
+        the total number of calls, because not all calls to match() are  recur-
         sive.  This limit is of use only if it is set smaller than match_limit.
-        Limiting the recursion depth limits the amount of  stack  that  can  be
+        Limiting  the  recursion  depth  limits the amount of stack that can be
         used, or, when PCRE has been compiled to use memory on the heap instead
         of the stack, the amount of heap memory that can be used.
-        The default value for match_limit_recursion can be  set  when  PCRE  is
+        The  default  value  for  match_limit_recursion can be set when PCRE is
-        built;  the  default  default  is  the  same  value  as the default for
+        built; the default default  is  the  same  value  as  the  default  for
-        match_limit. You can override the default by suppling pcre_exec()  with
+        match_limit.  You can override the default by suppling pcre_exec() with
-        a   pcre_extra   block  in  which  match_limit_recursion  is  set,  and
+        a  pcre_extra  block  in  which  match_limit_recursion  is   set,   and
-        PCRE_EXTRA_MATCH_LIMIT_RECURSION is set in  the  flags  field.  If  the
+        PCRE_EXTRA_MATCH_LIMIT_RECURSION  is  set  in  the  flags field. If the
         limit is exceeded, pcre_exec() returns PCRE_ERROR_RECURSIONLIMIT.
-        The  callout_data  field is used in conjunction with the "callout" fea-
+        The callout_data field is used in conjunction with the  "callout"  fea-
         ture, and is described in the pcrecallout documentation.
-        The tables field  is  used  to  pass  a  character  tables  pointer  to
+        The  tables  field  is  used  to  pass  a  character  tables pointer to
-        pcre_exec();  this overrides the value that is stored with the compiled
+        pcre_exec(); this overrides the value that is stored with the  compiled
-        pattern. A non-NULL value is stored with the compiled pattern  only  if
+        pattern.  A  non-NULL value is stored with the compiled pattern only if
-        custom  tables  were  supplied to pcre_compile() via its tableptr argu-
+        custom tables were supplied to pcre_compile() via  its  tableptr  argu-
         ment.  If NULL is passed to pcre_exec() using this mechanism, it forces
-        PCRE's  internal  tables  to be used. This facility is helpful when re-
+        PCRE's internal tables to be used. This facility is  helpful  when  re-
-        using patterns that have been saved after compiling  with  an  external
+        using  patterns  that  have been saved after compiling with an external
-        set  of  tables,  because  the  external tables might be at a different
+        set of tables, because the external tables  might  be  at  a  different
-        address when pcre_exec() is called. See the  pcreprecompile  documenta-
+        address  when  pcre_exec() is called. See the pcreprecompile documenta-
         tion for a discussion of saving compiled patterns for later use.
-        If  PCRE_EXTRA_MARK  is  set in the flags field, the mark field must be
+        If PCRE_EXTRA_MARK is set in the flags field, the mark  field  must  be
-        set to point to a char * variable. If the pattern  contains  any  back-
+        set  to  point  to a char * variable. If the pattern contains any back-
-        tracking  control verbs such as (*MARK:NAME), and the execution ends up
+        tracking control verbs such as (*MARK:NAME), and the execution ends  up
-        with a name to pass back, a pointer to the  name  string  (zero  termi-
+        with  a  name  to  pass back, a pointer to the name string (zero termi-
-        nated)  is  placed  in  the  variable pointed to by the mark field. The
+        nated) is placed in the variable pointed to  by  the  mark  field.  The
-        names are within the compiled pattern; if you wish  to  retain  such  a
+        names  are  within  the  compiled pattern; if you wish to retain such a
-        name  you must copy it before freeing the memory of a compiled pattern.
+        name you must copy it before freeing the memory of a compiled  pattern.
-        If there is no name to pass back, the variable pointed to by  the  mark
+        If  there  is no name to pass back, the variable pointed to by the mark
-        field  set  to NULL. For details of the backtracking control verbs, see
+        field set to NULL. For details of the backtracking control  verbs,  see
         the section entitled "Backtracking control" in the pcrepattern documen-
         tation.
     Option bits for pcre_exec()
-        The  unused  bits of the options argument for pcre_exec() must be zero.
+        The unused bits of the options argument for pcre_exec() must  be  zero.
-        The only bits that may  be  set  are  PCRE_ANCHORED,  PCRE_NEWLINE_xxx,
+        The  only  bits  that  may  be set are PCRE_ANCHORED, PCRE_NEWLINE_xxx,
-        PCRE_NOTBOL,    PCRE_NOTEOL,    PCRE_NOTEMPTY,   PCRE_NOTEMPTY_ATSTART,
+        PCRE_NOTBOL,   PCRE_NOTEOL,    PCRE_NOTEMPTY,    PCRE_NOTEMPTY_ATSTART,
-        PCRE_NO_START_OPTIMIZE,  PCRE_NO_UTF8_CHECK,   PCRE_PARTIAL_SOFT,   and
+        PCRE_NO_START_OPTIMIZE,   PCRE_NO_UTF8_CHECK,   PCRE_PARTIAL_SOFT,  and
         PCRE_PARTIAL_HARD.
           PCRE_ANCHORED
-        The  PCRE_ANCHORED  option  limits pcre_exec() to matching at the first
+        The PCRE_ANCHORED option limits pcre_exec() to matching  at  the  first
-        matching position. If a pattern was  compiled  with  PCRE_ANCHORED,  or
+        matching  position.  If  a  pattern was compiled with PCRE_ANCHORED, or
-        turned  out to be anchored by virtue of its contents, it cannot be made
+        turned out to be anchored by virtue of its contents, it cannot be  made
         unachored at matching time.
           PCRE_BSR_ANYCRLF
           PCRE_BSR_UNICODE
         These options (which are mutually exclusive) control what the \R escape
-        sequence  matches.  The choice is either to match only CR, LF, or CRLF,
+        sequence matches. The choice is either to match only CR, LF,  or  CRLF,
-        or to match any Unicode newline sequence. These  options  override  the
+        or  to  match  any Unicode newline sequence. These options override the
         choice that was made or defaulted when the pattern was compiled.
           PCRE_NEWLINE_CR
-Line 2063 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2072 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_NEWLINE_ANYCRLF
           PCRE_NEWLINE_ANY
-        These  options  override  the  newline  definition  that  was chosen or
+        These options override  the  newline  definition  that  was  chosen  or
-        defaulted when the pattern was compiled. For details, see the  descrip-
+        defaulted  when the pattern was compiled. For details, see the descrip-
-        tion  of  pcre_compile()  above.  During  matching,  the newline choice
+        tion of pcre_compile()  above.  During  matching,  the  newline  choice
-        affects the behaviour of the dot, circumflex,  and  dollar  metacharac-
+        affects  the  behaviour  of the dot, circumflex, and dollar metacharac-
-        ters.  It may also alter the way the match position is advanced after a
+        ters. It may also alter the way the match position is advanced after  a
         match failure for an unanchored pattern.
-        When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF,  or  PCRE_NEWLINE_ANY  is
+        When  PCRE_NEWLINE_CRLF,  PCRE_NEWLINE_ANYCRLF,  or PCRE_NEWLINE_ANY is
-        set,  and a match attempt for an unanchored pattern fails when the cur-
+        set, and a match attempt for an unanchored pattern fails when the  cur-
-        rent position is at a  CRLF  sequence,  and  the  pattern  contains  no
+        rent  position  is  at  a  CRLF  sequence,  and the pattern contains no
-        explicit  matches  for  CR  or  LF  characters,  the  match position is
+        explicit matches for  CR  or  LF  characters,  the  match  position  is
         advanced by two characters instead of one, in other words, to after the
         CRLF.
         The above rule is a compromise that makes the most common cases work as
-        expected. For example, if the  pattern  is  .+A  (and  the  PCRE_DOTALL
+        expected.  For  example,  if  the  pattern  is .+A (and the PCRE_DOTALL
         option is not set), it does not match the string "\r\nA" because, after
-        failing at the start, it skips both the CR and the LF before  retrying.
+        failing  at the start, it skips both the CR and the LF before retrying.
-        However,  the  pattern  [\r\n]A does match that string, because it con-
+        However, the pattern [\r\n]A does match that string,  because  it  con-
         tains an explicit CR or LF reference, and so advances only by one char-
         acter after the first failure.
         An explicit match for CR of LF is either a literal appearance of one of
-        those characters, or one of the \r or  \n  escape  sequences.  Implicit
+        those  characters,  or  one  of the \r or \n escape sequences. Implicit
-        matches  such  as [^X] do not count, nor does \s (which includes CR and
+        matches such as [^X] do not count, nor does \s (which includes  CR  and
         LF in the characters that it matches).
-        Notwithstanding the above, anomalous effects may still occur when  CRLF
+        Notwithstanding  the above, anomalous effects may still occur when CRLF
         is a valid newline sequence and explicit \r or \n escapes appear in the
         pattern.
           PCRE_NOTBOL
         This option specifies that first character of the subject string is not
-        the  beginning  of  a  line, so the circumflex metacharacter should not
+        the beginning of a line, so the  circumflex  metacharacter  should  not
-        match before it. Setting this without PCRE_MULTILINE (at compile  time)
+        match  before it. Setting this without PCRE_MULTILINE (at compile time)
-        causes  circumflex  never to match. This option affects only the behav-
+        causes circumflex never to match. This option affects only  the  behav-
         iour of the circumflex metacharacter. It does not affect \A.
           PCRE_NOTEOL
         This option specifies that the end of the subject string is not the end
-        of  a line, so the dollar metacharacter should not match it nor (except
+        of a line, so the dollar metacharacter should not match it nor  (except
-        in multiline mode) a newline immediately before it. Setting this  with-
+        in  multiline mode) a newline immediately before it. Setting this with-
         out PCRE_MULTILINE (at compile time) causes dollar never to match. This
-        option affects only the behaviour of the dollar metacharacter. It  does
+        option  affects only the behaviour of the dollar metacharacter. It does
         not affect \Z or \z.
           PCRE_NOTEMPTY
         An empty string is not considered to be a valid match if this option is
-        set. If there are alternatives in the pattern, they are tried.  If  all
+        set.  If  there are alternatives in the pattern, they are tried. If all
-        the  alternatives  match  the empty string, the entire match fails. For
+        the alternatives match the empty string, the entire  match  fails.  For
         example, if the pattern
           a?b?
-        is applied to a string not beginning with "a" or  "b",  it  matches  an
+        is  applied  to  a  string not beginning with "a" or "b", it matches an
-        empty  string at the start of the subject. With PCRE_NOTEMPTY set, this
+        empty string at the start of the subject. With PCRE_NOTEMPTY set,  this
         match is not valid, so PCRE searches further into the string for occur-
         rences of "a" or "b".
           PCRE_NOTEMPTY_ATSTART
-        This  is  like PCRE_NOTEMPTY, except that an empty string match that is
+        This is like PCRE_NOTEMPTY, except that an empty string match  that  is
-        not at the start of  the  subject  is  permitted.  If  the  pattern  is
+        not  at  the  start  of  the  subject  is  permitted. If the pattern is
         anchored, such a match can occur only if the pattern contains \K.
-        Perl     has    no    direct    equivalent    of    PCRE_NOTEMPTY    or
+        Perl    has    no    direct    equivalent    of    PCRE_NOTEMPTY     or
-        PCRE_NOTEMPTY_ATSTART, but it does make a special  case  of  a  pattern
+        PCRE_NOTEMPTY_ATSTART,  but  it  does  make a special case of a pattern
-        match  of  the empty string within its split() function, and when using
+        match of the empty string within its split() function, and  when  using
-        the /g modifier. It is  possible  to  emulate  Perl's  behaviour  after
+        the  /g  modifier.  It  is  possible  to emulate Perl's behaviour after
         matching a null string by first trying the match again at the same off-
-        set with PCRE_NOTEMPTY_ATSTART and  PCRE_ANCHORED,  and  then  if  that
+        set  with  PCRE_NOTEMPTY_ATSTART  and  PCRE_ANCHORED,  and then if that
         fails, by advancing the starting offset (see below) and trying an ordi-
-        nary match again. There is some code that demonstrates how to  do  this
+        nary  match  again. There is some code that demonstrates how to do this
-        in  the  pcredemo sample program. In the most general case, you have to
+        in the pcredemo sample program. In the most general case, you  have  to
-        check to see if the newline convention recognizes CRLF  as  a  newline,
+        check  to  see  if the newline convention recognizes CRLF as a newline,
-        and  if so, and the current character is CR followed by LF, advance the
+        and if so, and the current character is CR followed by LF, advance  the
         starting offset by two characters instead of one.
           PCRE_NO_START_OPTIMIZE
-        There are a number of optimizations that pcre_exec() uses at the  start
+        There  are a number of optimizations that pcre_exec() uses at the start
-        of  a  match,  in  order to speed up the process. For example, if it is
+        of a match, in order to speed up the process. For  example,  if  it  is
         known that an unanchored match must start with a specific character, it
-        searches  the  subject  for that character, and fails immediately if it
+        searches the subject for that character, and fails  immediately  if  it
-        cannot find it, without actually running the  main  matching  function.
+        cannot  find  it,  without actually running the main matching function.
         This means that a special item such as (*COMMIT) at the start of a pat-
-        tern is not considered until after a suitable starting  point  for  the
+        tern  is  not  considered until after a suitable starting point for the
-        match  has been found. When callouts or (*MARK) items are in use, these
+        match has been found. When callouts or (*MARK) items are in use,  these
         "start-up" optimizations can cause them to be skipped if the pattern is
-        never  actually  used.  The start-up optimizations are in effect a pre-
+        never actually used. The start-up optimizations are in  effect  a  pre-
         scan of the subject that takes place before the pattern is run.
-        The PCRE_NO_START_OPTIMIZE option disables the start-up  optimizations,
+        The  PCRE_NO_START_OPTIMIZE option disables the start-up optimizations,
-        possibly  causing  performance  to  suffer,  but ensuring that in cases
+        possibly causing performance to suffer,  but  ensuring  that  in  cases
-        where the result is "no match", the callouts do occur, and  that  items
+        where  the  result is "no match", the callouts do occur, and that items
         such as (*COMMIT) and (*MARK) are considered at every possible starting
-        position in the subject  string.   Setting  PCRE_NO_START_OPTIMIZE  can
+        position  in  the  subject  string. If PCRE_NO_START_OPTIMIZE is set at
-        change the outcome of a matching operation.  Consider the pattern
+        compile time, it cannot be unset at matching time.
+        Setting PCRE_NO_START_OPTIMIZE can change the  outcome  of  a  matching
+        operation.  Consider the pattern
           (*COMMIT)ABC
-Line 2862 
 AUTHOR
+Line 2874 
 AUTHOR
  REVISION
-        Last updated: 13 November 2010
+        Last updated: 21 November 2010
         Copyright (c) 1997-2010 University of Cambridge.
  ------------------------------------------------------------------------------
  PCRECALLOUT(3)                                                  PCRECALLOUT(3)
-Line 2930 
 MISSING CALLOUTS
+Line 2942 
 MISSING CALLOUTS
         patterns, if it has been scanned far enough.
         You  can disable these optimizations by passing the PCRE_NO_START_OPTI-
-        MIZE option to pcre_exec() or  pcre_dfa_exec().  This  slows  down  the
+        MIZE option to pcre_compile(), pcre_exec(), or pcre_dfa_exec(),  or  by
-        matching  process,  but  does  ensure that callouts such as the example
+        starting the pattern with (*NO_START_OPT). This slows down the matching
-        above are obeyed.
+        process, but does ensure that callouts such as the  example  above  are
+        obeyed.
  THE CALLOUT INTERFACE
-        During matching, when PCRE reaches a callout point, the external  func-
+        During  matching, when PCRE reaches a callout point, the external func-
-        tion  defined by pcre_callout is called (if it is set). This applies to
+        tion defined by pcre_callout is called (if it is set). This applies  to
-        both the pcre_exec() and the pcre_dfa_exec()  matching  functions.  The
+        both  the  pcre_exec()  and the pcre_dfa_exec() matching functions. The
-        only  argument  to  the callout function is a pointer to a pcre_callout
+        only argument to the callout function is a pointer  to  a  pcre_callout
         block. This structure contains the following fields:
           int          version;
-Line 2956 
 THE CALLOUT INTERFACE
+Line 2969 
 THE CALLOUT INTERFACE
           int          pattern_position;
           int          next_item_length;
-        The version field is an integer containing the version  number  of  the
+        The  version  field  is an integer containing the version number of the
-        block  format. The initial version was 0; the current version is 1. The
+        block format. The initial version was 0; the current version is 1.  The
-        version number will change again in future  if  additional  fields  are
+        version  number  will  change  again in future if additional fields are
         added, but the intention is never to remove any of the existing fields.
-        The  callout_number  field  contains the number of the callout, as com-
+        The callout_number field contains the number of the  callout,  as  com-
-        piled into the pattern (that is, the number after ?C for  manual  call-
+        piled  into  the pattern (that is, the number after ?C for manual call-
         outs, and 255 for automatically generated callouts).
-        The  offset_vector field is a pointer to the vector of offsets that was
+        The offset_vector field is a pointer to the vector of offsets that  was
-        passed  by  the  caller  to  pcre_exec()   or   pcre_dfa_exec().   When
+        passed   by   the   caller  to  pcre_exec()  or  pcre_dfa_exec().  When
-        pcre_exec()  is used, the contents can be inspected in order to extract
+        pcre_exec() is used, the contents can be inspected in order to  extract
-        substrings that have been matched so  far,  in  the  same  way  as  for
+        substrings  that  have  been  matched  so  far,  in the same way as for
-        extracting  substrings after a match has completed. For pcre_dfa_exec()
+        extracting substrings after a match has completed. For  pcre_dfa_exec()
         this field is not useful.
         The subject and subject_length fields contain copies of the values that
         were passed to pcre_exec().
-        The  start_match  field normally contains the offset within the subject
+        The start_match field normally contains the offset within  the  subject
-        at which the current match attempt  started.  However,  if  the  escape
+        at  which  the  current  match  attempt started. However, if the escape
-        sequence  \K has been encountered, this value is changed to reflect the
+        sequence \K has been encountered, this value is changed to reflect  the
-        modified starting point. If the pattern is not  anchored,  the  callout
+        modified  starting  point.  If the pattern is not anchored, the callout
         function may be called several times from the same point in the pattern
         for different starting points in the subject.
-        The current_position field contains the offset within  the  subject  of
+        The  current_position  field  contains the offset within the subject of
         the current match pointer.
-        When  the  pcre_exec() function is used, the capture_top field contains
+        When the pcre_exec() function is used, the capture_top  field  contains
-        one more than the number of the highest numbered captured substring  so
+        one  more than the number of the highest numbered captured substring so
-        far.  If  no substrings have been captured, the value of capture_top is
+        far. If no substrings have been captured, the value of  capture_top  is
-        one. This is always the case when pcre_dfa_exec() is used,  because  it
+        one.  This  is always the case when pcre_dfa_exec() is used, because it
         does not support captured substrings.
-        The  capture_last  field  contains the number of the most recently cap-
+        The capture_last field contains the number of the  most  recently  cap-
-        tured substring. If no substrings have been captured, its value is  -1.
+        tured  substring. If no substrings have been captured, its value is -1.
         This is always the case when pcre_dfa_exec() is used.
-        The  callout_data  field contains a value that is passed to pcre_exec()
+        The callout_data field contains a value that is passed  to  pcre_exec()
-        or pcre_dfa_exec() specifically so that it can be passed back in  call-
+        or  pcre_dfa_exec() specifically so that it can be passed back in call-
-        outs.  It  is  passed  in the pcre_callout field of the pcre_extra data
+        outs. It is passed in the pcre_callout field  of  the  pcre_extra  data
-        structure. If no such data was passed, the value of callout_data  in  a
+        structure.  If  no such data was passed, the value of callout_data in a
-        pcre_callout  block  is  NULL. There is a description of the pcre_extra
+        pcre_callout block is NULL. There is a description  of  the  pcre_extra
         structure in the pcreapi documentation.
-        The pattern_position field is present from version 1 of the  pcre_call-
+        The  pattern_position field is present from version 1 of the pcre_call-
         out structure. It contains the offset to the next item to be matched in
         the pattern string.
-        The next_item_length field is present from version 1 of the  pcre_call-
+        The  next_item_length field is present from version 1 of the pcre_call-
         out structure. It contains the length of the next item to be matched in
-        the pattern string. When the callout immediately precedes  an  alterna-
+        the  pattern  string. When the callout immediately precedes an alterna-
-        tion  bar, a closing parenthesis, or the end of the pattern, the length
+        tion bar, a closing parenthesis, or the end of the pattern, the  length
-        is zero. When the callout precedes an opening parenthesis,  the  length
+        is  zero.  When the callout precedes an opening parenthesis, the length
         is that of the entire subpattern.
-        The  pattern_position  and next_item_length fields are intended to help
+        The pattern_position and next_item_length fields are intended  to  help
-        in distinguishing between different automatic callouts, which all  have
+        in  distinguishing between different automatic callouts, which all have
         the same callout number. However, they are set for all callouts.
  RETURN VALUES
-        The  external callout function returns an integer to PCRE. If the value
+        The external callout function returns an integer to PCRE. If the  value
-        is zero, matching proceeds as normal. If  the  value  is  greater  than
+        is  zero,  matching  proceeds  as  normal. If the value is greater than
-        zero,  matching  fails  at  the current point, but the testing of other
+        zero, matching fails at the current point, but  the  testing  of  other
         matching possibilities goes ahead, just as if a lookahead assertion had
-        failed.  If  the  value  is less than zero, the match is abandoned, and
+        failed. If the value is less than zero, the  match  is  abandoned,  and
         pcre_exec() or pcre_dfa_exec() returns the negative value.
-        Negative  values  should  normally  be   chosen   from   the   set   of
+        Negative   values   should   normally   be   chosen  from  the  set  of
         PCRE_ERROR_xxx values. In particular, PCRE_ERROR_NOMATCH forces a stan-
-        dard "no  match"  failure.   The  error  number  PCRE_ERROR_CALLOUT  is
+        dard  "no  match"  failure.   The  error  number  PCRE_ERROR_CALLOUT is
-        reserved  for  use  by callout functions; it will never be used by PCRE
+        reserved for use by callout functions; it will never be  used  by  PCRE
         itself.
-Line 3043 
 AUTHOR
+Line 3056 
 AUTHOR
  REVISION
-        Last updated: 29 September 2009
+        Last updated: 21 November 2010
-        Copyright (c) 1997-2009 University of Cambridge.
+        Copyright (c) 1997-2010 University of Cambridge.
  ------------------------------------------------------------------------------
  PCRECOMPAT(3)                                                    PCRECOMPAT(3)
-Line 3202 
 REVISION
+Line 3215 
 REVISION
         Last updated: 31 October 2010
         Copyright (c) 1997-2010 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREPATTERN(3)                                                  PCREPATTERN(3)
-Line 3252 
 PCRE REGULAR EXPRESSION DETAILS
+Line 3265 
 PCRE REGULAR EXPRESSION DETAILS
         character types, instead of recognizing only characters with codes less
         than 128 via a lookup table.
-        The remainder of this document discusses the  patterns  that  are  sup-
+        If a pattern starts with (*NO_START_OPT), it has  the  same  effect  as
-        ported  by  PCRE when its main matching function, pcre_exec(), is used.
+        setting the PCRE_NO_START_OPTIMIZE option either at compile or matching
-        From  release  6.0,   PCRE   offers   a   second   matching   function,
+        time. There are also some more of these special sequences that are con-
-        pcre_dfa_exec(),  which matches using a different algorithm that is not
+        cerned with the handling of newlines; they are described below.
+        The  remainder  of  this  document discusses the patterns that are sup-
+        ported by PCRE when its main matching function, pcre_exec(),  is  used.
+        From   release   6.0,   PCRE   offers   a   second  matching  function,
+        pcre_dfa_exec(), which matches using a different algorithm that is  not
         Perl-compatible. Some of the features discussed below are not available
-        when  pcre_dfa_exec()  is used. The advantages and disadvantages of the
+        when pcre_dfa_exec() is used. The advantages and disadvantages  of  the
-        alternative function, and how it differs from the normal function,  are
+        alternative  function, and how it differs from the normal function, are
         discussed in the pcrematching page.
  NEWLINE CONVENTIONS
-        PCRE  supports five different conventions for indicating line breaks in
+        PCRE supports five different conventions for indicating line breaks  in
-        strings: a single CR (carriage return) character, a  single  LF  (line-
+        strings:  a  single  CR (carriage return) character, a single LF (line-
         feed) character, the two-character sequence CRLF, any of the three pre-
-        ceding, or any Unicode newline sequence. The pcreapi page  has  further
+        ceding,  or  any Unicode newline sequence. The pcreapi page has further
-        discussion  about newlines, and shows how to set the newline convention
+        discussion about newlines, and shows how to set the newline  convention
         in the options arguments for the compiling and matching functions.
-        It is also possible to specify a newline convention by starting a  pat-
+        It  is also possible to specify a newline convention by starting a pat-
         tern string with one of the following five sequences:
           (*CR)        carriage return
-Line 3280 
 NEWLINE CONVENTIONS
+Line 3298 
 NEWLINE CONVENTIONS
           (*ANYCRLF)   any of the three above
           (*ANY)       all Unicode newline sequences
-        These  override  the default and the options given to pcre_compile() or
+        These override the default and the options given to  pcre_compile()  or
-        pcre_compile2(). For example, on a Unix system where LF is the  default
+        pcre_compile2().  For example, on a Unix system where LF is the default
         newline sequence, the pattern
           (*CR)a.b
         changes the convention to CR. That pattern matches "a\nb" because LF is
-        no longer a newline. Note that these special settings,  which  are  not
+        no  longer  a  newline. Note that these special settings, which are not
-        Perl-compatible,  are  recognized  only at the very start of a pattern,
+        Perl-compatible, are recognized only at the very start  of  a  pattern,
-        and that they must be in upper case.  If  more  than  one  of  them  is
+        and  that  they  must  be  in  upper  case. If more than one of them is
         present, the last one is used.
-        The  newline convention affects the interpretation of the dot metachar-
+        The newline convention affects the interpretation of the dot  metachar-
-        acter when PCRE_DOTALL is not set, and also the behaviour of  \N.  How-
+        acter  when  PCRE_DOTALL is not set, and also the behaviour of \N. How-
-        ever,  it  does  not  affect  what  the  \R escape sequence matches. By
+        ever, it does not affect  what  the  \R  escape  sequence  matches.  By
-        default, this is any Unicode newline sequence, for Perl  compatibility.
+        default,  this is any Unicode newline sequence, for Perl compatibility.
-        However,  this can be changed; see the description of \R in the section
+        However, this can be changed; see the description of \R in the  section
-        entitled "Newline sequences" below. A change of \R setting can be  com-
+        entitled  "Newline sequences" below. A change of \R setting can be com-
         bined with a change of newline convention.
  CHARACTERS AND METACHARACTERS
-        A  regular  expression  is  a pattern that is matched against a subject
+        A regular expression is a pattern that is  matched  against  a  subject
-        string from left to right. Most characters stand for  themselves  in  a
+        string  from  left  to right. Most characters stand for themselves in a
-        pattern,  and  match  the corresponding characters in the subject. As a
+        pattern, and match the corresponding characters in the  subject.  As  a
         trivial example, the pattern
           The quick brown fox
         matches a portion of a subject string that is identical to itself. When
-        caseless  matching is specified (the PCRE_CASELESS option), letters are
+        caseless matching is specified (the PCRE_CASELESS option), letters  are
-        matched independently of case. In UTF-8 mode, PCRE  always  understands
+        matched  independently  of case. In UTF-8 mode, PCRE always understands
-        the  concept  of case for characters whose values are less than 128, so
+        the concept of case for characters whose values are less than  128,  so
-        caseless matching is always possible. For characters with  higher  val-
+        caseless  matching  is always possible. For characters with higher val-
-        ues,  the concept of case is supported if PCRE is compiled with Unicode
+        ues, the concept of case is supported if PCRE is compiled with  Unicode
-        property support, but not otherwise.   If  you  want  to  use  caseless
+        property  support,  but  not  otherwise.   If  you want to use caseless
-        matching  for  characters  128  and above, you must ensure that PCRE is
+        matching for characters 128 and above, you must  ensure  that  PCRE  is
         compiled with Unicode property support as well as with UTF-8 support.
-        The power of regular expressions comes  from  the  ability  to  include
+        The  power  of  regular  expressions  comes from the ability to include
-        alternatives  and  repetitions in the pattern. These are encoded in the
+        alternatives and repetitions in the pattern. These are encoded  in  the
         pattern by the use of metacharacters, which do not stand for themselves
         but instead are interpreted in some special way.
-        There  are  two different sets of metacharacters: those that are recog-
+        There are two different sets of metacharacters: those that  are  recog-
-        nized anywhere in the pattern except within square brackets, and  those
+        nized  anywhere in the pattern except within square brackets, and those
-        that  are  recognized  within square brackets. Outside square brackets,
+        that are recognized within square brackets.  Outside  square  brackets,
         the metacharacters are as follows:
           \      general escape character with several uses
-Line 3346 
 CHARACTERS AND METACHARACTERS
+Line 3364 
 CHARACTERS AND METACHARACTERS
                  also "possessive quantifier"
           {      start min/max quantifier
-        Part of a pattern that is in square brackets  is  called  a  "character
+        Part  of  a  pattern  that is in square brackets is called a "character
         class". In a character class the only metacharacters are:
           \      general escape character
-Line 3362 
 CHARACTERS AND METACHARACTERS
+Line 3380 
 CHARACTERS AND METACHARACTERS
  BACKSLASH
         The backslash character has several uses. Firstly, if it is followed by
-        a non-alphanumeric character, it takes away any  special  meaning  that
+        a character that is not a number or a letter, it takes away any special
-        character  may  have.  This  use  of  backslash  as an escape character
+        meaning that character may have. This use of  backslash  as  an  escape
-        applies both inside and outside character classes.
+        character applies both inside and outside character classes.
-        For example, if you want to match a * character, you write  \*  in  the
+        For  example,  if  you want to match a * character, you write \* in the
-        pattern.   This  escaping  action  applies whether or not the following
+        pattern.  This escaping action applies whether  or  not  the  following
-        character would otherwise be interpreted as a metacharacter, so  it  is
+        character  would  otherwise be interpreted as a metacharacter, so it is
-        always  safe  to  precede  a non-alphanumeric with backslash to specify
+        always safe to precede a non-alphanumeric  with  backslash  to  specify
-        that it stands for itself. In particular, if you want to match a  back-
+        that  it stands for itself. In particular, if you want to match a back-
         slash, you write \\.
-        If  a  pattern is compiled with the PCRE_EXTENDED option, whitespace in
+        In UTF-8 mode, only ASCII numbers and letters have any special  meaning
-        the pattern (other than in a character class) and characters between  a
+        after  a  backslash.  All  other characters (in particular, those whose
+        codepoints are greater than 127) are treated as literals.
+        If a pattern is compiled with the PCRE_EXTENDED option,  whitespace  in
+        the  pattern (other than in a character class) and characters between a
         # outside a character class and the next newline are ignored. An escap-
-        ing backslash can be used to include a whitespace  or  #  character  as
+        ing  backslash  can  be  used to include a whitespace or # character as
         part of the pattern.
-        If  you  want  to remove the special meaning from a sequence of charac-
+        If you want to remove the special meaning from a  sequence  of  charac-
-        ters, you can do so by putting them between \Q and \E. This is  differ-
+        ters,  you can do so by putting them between \Q and \E. This is differ-
-        ent  from  Perl  in  that  $  and  @ are handled as literals in \Q...\E
+        ent from Perl in that $ and  @  are  handled  as  literals  in  \Q...\E
-        sequences in PCRE, whereas in Perl, $ and @ cause  variable  interpola-
+        sequences  in  PCRE, whereas in Perl, $ and @ cause variable interpola-
         tion. Note the following examples:
           Pattern            PCRE matches   Perl matches
-Line 3392 
 BACKSLASH
+Line 3414 
 BACKSLASH
           \Qabc\$xyz\E       abc\$xyz       abc\$xyz
           \Qabc\E\$\Qxyz\E   abc$xyz        abc$xyz
-        The  \Q...\E  sequence  is recognized both inside and outside character
+        The \Q...\E sequence is recognized both inside  and  outside  character
         classes.  An isolated \E that is not preceded by \Q is ignored.
     Non-printing characters
         A second use of backslash provides a way of encoding non-printing char-
-        acters  in patterns in a visible manner. There is no restriction on the
+        acters in patterns in a visible manner. There is no restriction on  the
-        appearance of non-printing characters, apart from the binary zero  that
+        appearance  of non-printing characters, apart from the binary zero that
-        terminates  a  pattern,  but  when  a pattern is being prepared by text
+        terminates a pattern, but when a pattern  is  being  prepared  by  text
-        editing, it is  often  easier  to  use  one  of  the  following  escape
+        editing,  it  is  often  easier  to  use  one  of  the following escape
         sequences than the binary character it represents:
           \a        alarm, that is, the BEL character (hex 07)
-          \cx       "control-x", where x is any character
+          \cx       "control-x", where x is any ASCII character
           \e        escape (hex 1B)
           \f        formfeed (hex 0C)
           \n        linefeed (hex 0A)
-Line 3415 
 BACKSLASH
+Line 3437 
 BACKSLASH
           \xhh      character with hex code hh
           \x{hhh..} character with hex code hhh..
-        The  precise  effect of \cx is as follows: if x is a lower case letter,
+        The precise effect of \cx is as follows: if x is a lower  case  letter,
-        it is converted to upper case. Then bit 6 of the character (hex 40)  is
+        it  is converted to upper case. Then bit 6 of the character (hex 40) is
-        inverted.   Thus  \cz becomes hex 1A, but \c{ becomes hex 3B, while \c;
+        inverted.  Thus \cz becomes hex 1A (z is 7A), but \c{ becomes hex 3B ({
-        becomes hex 7B.
+        is  7B),  while  \c; becomes hex 7B (; is 3B). If the byte following \c
+        has a value greater than 127, a compile-time error occurs.  This  locks
-        After \x, from zero to two hexadecimal digits are read (letters can  be
+        out  non-ASCII  characters in both byte mode and UTF-8 mode. (When PCRE
-        in  upper  or  lower case). Any number of hexadecimal digits may appear
+        is compiled in EBCDIC mode, all byte values are  valid.  A  lower  case
-        between \x{ and }, but the value of the character  code  must  be  less
+        letter is converted to upper case, and then the 0xc0 bits are flipped.)
+        After  \x, from zero to two hexadecimal digits are read (letters can be
+        in upper or lower case). Any number of hexadecimal  digits  may  appear
+        between  \x{  and  },  but the value of the character code must be less
         than 256 in non-UTF-8 mode, and less than 2**31 in UTF-8 mode. That is,
-        the maximum value in hexadecimal is 7FFFFFFF. Note that this is  bigger
+        the  maximum value in hexadecimal is 7FFFFFFF. Note that this is bigger
         than the largest Unicode code point, which is 10FFFF.
-        If  characters  other than hexadecimal digits appear between \x{ and },
+        If characters other than hexadecimal digits appear between \x{  and  },
         or if there is no terminating }, this form of escape is not recognized.
-        Instead,  the  initial  \x  will  be interpreted as a basic hexadecimal
+        Instead, the initial \x will be  interpreted  as  a  basic  hexadecimal
-        escape, with no following digits, giving a  character  whose  value  is
+        escape,  with  no  following  digits, giving a character whose value is
         zero.
         Characters whose value is less than 256 can be defined by either of the
-        two syntaxes for \x. There is no difference in the way  they  are  han-
+        two  syntaxes  for  \x. There is no difference in the way they are han-
         dled. For example, \xdc is exactly the same as \x{dc}.
-        After  \0  up  to two further octal digits are read. If there are fewer
+        After \0 up to two further octal digits are read. If  there  are  fewer
-        than two digits, just  those  that  are  present  are  used.  Thus  the
+        than  two  digits,  just  those  that  are  present  are used. Thus the
         sequence \0\x\07 specifies two binary zeros followed by a BEL character
-        (code value 7). Make sure you supply two digits after the initial  zero
+        (code  value 7). Make sure you supply two digits after the initial zero
         if the pattern character that follows is itself an octal digit.
         The handling of a backslash followed by a digit other than 0 is compli-
         cated.  Outside a character class, PCRE reads it and any following dig-
-        its  as  a  decimal  number. If the number is less than 10, or if there
+        its as a decimal number. If the number is less than  10,  or  if  there
         have been at least that many previous capturing left parentheses in the
-        expression,  the  entire  sequence  is  taken  as  a  back reference. A
+        expression, the entire  sequence  is  taken  as  a  back  reference.  A
-        description of how this works is given later, following the  discussion
+        description  of how this works is given later, following the discussion
         of parenthesized subpatterns.
-        Inside  a  character  class, or if the decimal number is greater than 9
+        Inside a character class, or if the decimal number is  greater  than  9
-        and there have not been that many capturing subpatterns, PCRE  re-reads
+        and  there have not been that many capturing subpatterns, PCRE re-reads
         up to three octal digits following the backslash, and uses them to gen-
-        erate a data character. Any subsequent digits stand for themselves.  In
+        erate  a data character. Any subsequent digits stand for themselves. In
-        non-UTF-8  mode,  the  value  of a character specified in octal must be
+        non-UTF-8 mode, the value of a character specified  in  octal  must  be
-        less than \400. In UTF-8 mode, values up to  \777  are  permitted.  For
+        less  than  \400.  In  UTF-8 mode, values up to \777 are permitted. For
         example:
           \040   is another way of writing a space
-Line 3474 
 BACKSLASH
+Line 3500 
 BACKSLASH
           \81    is either a back reference, or a binary zero
                     followed by the two characters "8" and "1"
-        Note  that  octal  values of 100 or greater must not be introduced by a
+        Note that octal values of 100 or greater must not be  introduced  by  a
         leading zero, because no more than three octal digits are ever read.
         All the sequences that define a single character value can be used both
-        inside  and  outside character classes. In addition, inside a character
+        inside and outside character classes. In addition, inside  a  character
-        class, the sequence \b is interpreted as the backspace  character  (hex
+        class,  the  sequence \b is interpreted as the backspace character (hex
-).  The sequences \B, \N, \R, and \X are not special inside a charac-
+). The sequences \B, \N, \R, and \X are not special inside a  charac-
-        ter class. Like any  other  unrecognized  escape  sequences,  they  are
+        ter  class.  Like  any  other  unrecognized  escape sequences, they are
-        treated  as  the  literal characters "B", "N", "R", and "X" by default,
+        treated as the literal characters "B", "N", "R", and  "X"  by  default,
         but cause an error if the PCRE_EXTRA option is set. Outside a character
         class, these sequences have different meanings.
     Absolute and relative back references
-        The  sequence  \g followed by an unsigned or a negative number, option-
+        The sequence \g followed by an unsigned or a negative  number,  option-
-        ally enclosed in braces, is an absolute or relative back  reference.  A
+        ally  enclosed  in braces, is an absolute or relative back reference. A
         named back reference can be coded as \g{name}. Back references are dis-
         cussed later, following the discussion of parenthesized subpatterns.
     Absolute and relative subroutine calls
-        For compatibility with Oniguruma, the non-Perl syntax \g followed by  a
+        For  compatibility with Oniguruma, the non-Perl syntax \g followed by a
         name or a number enclosed either in angle brackets or single quotes, is
-        an alternative syntax for referencing a subpattern as  a  "subroutine".
+        an  alternative  syntax for referencing a subpattern as a "subroutine".
-        Details  are  discussed  later.   Note  that  \g{...} (Perl syntax) and
+        Details are discussed later.   Note  that  \g{...}  (Perl  syntax)  and
-        \g<...> (Oniguruma syntax) are not synonymous. The  former  is  a  back
+        \g<...>  (Oniguruma  syntax)  are  not synonymous. The former is a back
         reference; the latter is a subroutine call.
     Generic character types
-Line 3518 
 BACKSLASH
+Line 3544 
 BACKSLASH
           \W     any "non-word" character
         There is also the single sequence \N, which matches a non-newline char-
-        acter.  This is the same as the "." metacharacter when  PCRE_DOTALL  is
+        acter.   This  is the same as the "." metacharacter when PCRE_DOTALL is
         not set.
-        Each  pair of lower and upper case escape sequences partitions the com-
+        Each pair of lower and upper case escape sequences partitions the  com-
-        plete set of characters into two disjoint  sets.  Any  given  character
+        plete  set  of  characters  into two disjoint sets. Any given character
-        matches  one, and only one, of each pair. The sequences can appear both
+        matches one, and only one, of each pair. The sequences can appear  both
-        inside and outside character classes. They each match one character  of
+        inside  and outside character classes. They each match one character of
-        the  appropriate  type.  If the current matching point is at the end of
+        the appropriate type. If the current matching point is at  the  end  of
-        the subject string, all of them fail, because there is no character  to
+        the  subject string, all of them fail, because there is no character to
         match.
-        For  compatibility  with Perl, \s does not match the VT character (code
+        For compatibility with Perl, \s does not match the VT  character  (code
-).  This makes it different from the the POSIX "space" class. The  \s
+).   This makes it different from the the POSIX "space" class. The \s
-        characters  are  HT  (9), LF (10), FF (12), CR (13), and space (32). If
+        characters are HT (9), LF (10), FF (12), CR (13), and  space  (32).  If
         "use locale;" is included in a Perl script, \s may match the VT charac-
         ter. In PCRE, it never does.
-        A  "word"  character is an underscore or any character that is a letter
+        A "word" character is an underscore or any character that is  a  letter
-        or digit.  By default, the definition of letters  and  digits  is  con-
+        or  digit.   By  default,  the definition of letters and digits is con-
-        trolled  by PCRE's low-valued character tables, and may vary if locale-
+        trolled by PCRE's low-valued character tables, and may vary if  locale-
-        specific matching is taking place (see "Locale support" in the  pcreapi
+        specific  matching is taking place (see "Locale support" in the pcreapi
-        page).  For  example,  in  a French locale such as "fr_FR" in Unix-like
+        page). For example, in a French locale such  as  "fr_FR"  in  Unix-like
-        systems, or "french" in Windows, some character codes greater than  128
+        systems,  or "french" in Windows, some character codes greater than 128
-        are  used  for  accented letters, and these are then matched by \w. The
+        are used for accented letters, and these are then matched  by  \w.  The
         use of locales with Unicode is discouraged.
-        By default, in UTF-8 mode, characters  with  values  greater  than  128
+        By  default,  in  UTF-8  mode,  characters with values greater than 128
-        never  match  \d,  \s,  or  \w,  and always match \D, \S, and \W. These
+        never match \d, \s, or \w, and always  match  \D,  \S,  and  \W.  These
-        sequences retain their original meanings from before UTF-8 support  was
+        sequences  retain their original meanings from before UTF-8 support was
-        available,  mainly for efficiency reasons. However, if PCRE is compiled
+        available, mainly for efficiency reasons. However, if PCRE is  compiled
-        with Unicode property support, and the PCRE_UCP option is set, the  be-
+        with  Unicode property support, and the PCRE_UCP option is set, the be-
-        haviour  is  changed  so  that Unicode properties are used to determine
+        haviour is changed so that Unicode properties  are  used  to  determine
         character types, as follows:
           \d  any character that \p{Nd} matches (decimal digit)
           \s  any character that \p{Z} matches, plus HT, LF, FF, CR
           \w  any character that \p{L} or \p{N} matches, plus underscore
-        The upper case escapes match the inverse sets of characters. Note  that
+        The  upper case escapes match the inverse sets of characters. Note that
-        \d  matches  only decimal digits, whereas \w matches any Unicode digit,
+        \d matches only decimal digits, whereas \w matches any  Unicode  digit,
-        as well as any Unicode letter, and underscore. Note also that  PCRE_UCP
+        as  well as any Unicode letter, and underscore. Note also that PCRE_UCP
-        affects  \b,  and  \B  because  they are defined in terms of \w and \W.
+        affects \b, and \B because they are defined in  terms  of  \w  and  \W.
         Matching these sequences is noticeably slower when PCRE_UCP is set.
-        The sequences \h, \H, \v, and \V are features that were added  to  Perl
+        The  sequences  \h, \H, \v, and \V are features that were added to Perl
-        at  release  5.10. In contrast to the other sequences, which match only
+        at release 5.10. In contrast to the other sequences, which  match  only
-        ASCII characters by default, these  always  match  certain  high-valued
+        ASCII  characters  by  default,  these always match certain high-valued
-        codepoints  in UTF-8 mode, whether or not PCRE_UCP is set. The horizon-
+        codepoints in UTF-8 mode, whether or not PCRE_UCP is set. The  horizon-
         tal space characters are:
           U+0009     Horizontal tab
-Line 3600 
 BACKSLASH
+Line 3626 
 BACKSLASH
     Newline sequences
-        Outside a character class, by default, the escape sequence  \R  matches
+        Outside  a  character class, by default, the escape sequence \R matches
         any Unicode newline sequence. In non-UTF-8 mode \R is equivalent to the
         following:
           (?>\r\n|\n|\x0b|\f|\r|\x85)
-        This is an example of an "atomic group", details  of  which  are  given
+        This  is  an  example  of an "atomic group", details of which are given
         below.  This particular group matches either the two-character sequence
-        CR followed by LF, or  one  of  the  single  characters  LF  (linefeed,
+        CR  followed  by  LF,  or  one  of  the single characters LF (linefeed,
         U+000A), VT (vertical tab, U+000B), FF (formfeed, U+000C), CR (carriage
         return, U+000D), or NEL (next line, U+0085). The two-character sequence
         is treated as a single unit that cannot be split.
-        In  UTF-8  mode, two additional characters whose codepoints are greater
+        In UTF-8 mode, two additional characters whose codepoints  are  greater
         than 255 are added: LS (line separator, U+2028) and PS (paragraph sepa-
-        rator,  U+2029).   Unicode character property support is not needed for
+        rator, U+2029).  Unicode character property support is not  needed  for
         these characters to be recognized.
         It is possible to restrict \R to match only CR, LF, or CRLF (instead of
-        the  complete  set  of  Unicode  line  endings)  by  setting the option
+        the complete set  of  Unicode  line  endings)  by  setting  the  option
         PCRE_BSR_ANYCRLF either at compile time or when the pattern is matched.
         (BSR is an abbrevation for "backslash R".) This can be made the default
-        when PCRE is built; if this is the case, the  other  behaviour  can  be
+        when  PCRE  is  built;  if this is the case, the other behaviour can be
-        requested  via  the  PCRE_BSR_UNICODE  option.   It is also possible to
+        requested via the PCRE_BSR_UNICODE option.   It  is  also  possible  to
-        specify these settings by starting a pattern string  with  one  of  the
+        specify  these  settings  by  starting a pattern string with one of the
         following sequences:
           (*BSR_ANYCRLF)   CR, LF, or CRLF only
           (*BSR_UNICODE)   any Unicode newline sequence
-        These  override  the default and the options given to pcre_compile() or
+        These override the default and the options given to  pcre_compile()  or
-        pcre_compile2(), but  they  can  be  overridden  by  options  given  to
+        pcre_compile2(),  but  they  can  be  overridden  by  options  given to
         pcre_exec() or pcre_dfa_exec(). Note that these special settings, which
-        are not Perl-compatible, are recognized only at the  very  start  of  a
+        are  not  Perl-compatible,  are  recognized only at the very start of a
-        pattern,  and that they must be in upper case. If more than one of them
+        pattern, and that they must be in upper case. If more than one of  them
         is present, the last one is used. They can be combined with a change of
         newline convention; for example, a pattern can start with:
           (*ANY)(*BSR_ANYCRLF)
         They can also be combined with the (*UTF8) or (*UCP) special sequences.
-        Inside a character class, \R  is  treated  as  an  unrecognized  escape
+        Inside  a  character  class,  \R  is  treated as an unrecognized escape
         sequence, and so matches the letter "R" by default, but causes an error
         if PCRE_EXTRA is set.
     Unicode character properties
         When PCRE is built with Unicode character property support, three addi-
-        tional  escape sequences that match characters with specific properties
+        tional escape sequences that match characters with specific  properties
-        are available.  When not in UTF-8 mode, these sequences are  of  course
+        are  available.   When not in UTF-8 mode, these sequences are of course
-        limited  to  testing characters whose codepoints are less than 256, but
+        limited to testing characters whose codepoints are less than  256,  but
         they do work in this mode.  The extra escape sequences are:
           \p{xx}   a character with the xx property
           \P{xx}   a character without the xx property
           \X       an extended Unicode sequence
-        The property names represented by xx above are limited to  the  Unicode
+        The  property  names represented by xx above are limited to the Unicode
         script names, the general category properties, "Any", which matches any
-        character  (including  newline),  and  some  special  PCRE   properties
+        character   (including  newline),  and  some  special  PCRE  properties
-        (described  in the next section).  Other Perl properties such as "InMu-
+        (described in the next section).  Other Perl properties such as  "InMu-
-        sicalSymbols" are not currently supported by PCRE.  Note  that  \P{Any}
+        sicalSymbols"  are  not  currently supported by PCRE. Note that \P{Any}
         does not match any characters, so always causes a match failure.
         Sets of Unicode characters are defined as belonging to certain scripts.
-        A character from one of these sets can be matched using a script  name.
+        A  character from one of these sets can be matched using a script name.
         For example:
           \p{Greek}
           \P{Han}
-        Those  that are not part of an identified script are lumped together as
+        Those that are not part of an identified script are lumped together  as
         "Common". The current list of scripts is:
         Arabic, Armenian, Avestan, Balinese, Bamum, Bengali, Bopomofo, Braille,
-        Buginese,  Buhid,  Canadian_Aboriginal, Carian, Cham, Cherokee, Common,
+        Buginese, Buhid, Canadian_Aboriginal, Carian, Cham,  Cherokee,  Common,
-        Coptic,  Cuneiform,  Cypriot,  Cyrillic,  Deseret,  Devanagari,   Egyp-
+        Coptic,   Cuneiform,  Cypriot,  Cyrillic,  Deseret,  Devanagari,  Egyp-
-        tian_Hieroglyphs,   Ethiopic,   Georgian,  Glagolitic,  Gothic,  Greek,
+        tian_Hieroglyphs,  Ethiopic,  Georgian,  Glagolitic,   Gothic,   Greek,
-        Gujarati, Gurmukhi,  Han,  Hangul,  Hanunoo,  Hebrew,  Hiragana,  Impe-
+        Gujarati,  Gurmukhi,  Han,  Hangul,  Hanunoo,  Hebrew,  Hiragana, Impe-
         rial_Aramaic, Inherited, Inscriptional_Pahlavi, Inscriptional_Parthian,
-        Javanese, Kaithi, Kannada, Katakana, Kayah_Li, Kharoshthi, Khmer,  Lao,
+        Javanese,  Kaithi, Kannada, Katakana, Kayah_Li, Kharoshthi, Khmer, Lao,
         Latin,  Lepcha,  Limbu,  Linear_B,  Lisu,  Lycian,  Lydian,  Malayalam,
-        Meetei_Mayek, Mongolian, Myanmar, New_Tai_Lue, Nko, Ogham,  Old_Italic,
+        Meetei_Mayek,  Mongolian, Myanmar, New_Tai_Lue, Nko, Ogham, Old_Italic,
-        Old_Persian,  Old_South_Arabian,  Old_Turkic, Ol_Chiki, Oriya, Osmanya,
+        Old_Persian, Old_South_Arabian, Old_Turkic, Ol_Chiki,  Oriya,  Osmanya,
-        Phags_Pa, Phoenician, Rejang, Runic,  Samaritan,  Saurashtra,  Shavian,
+        Phags_Pa,  Phoenician,  Rejang,  Runic, Samaritan, Saurashtra, Shavian,
-        Sinhala,  Sundanese,  Syloti_Nagri,  Syriac, Tagalog, Tagbanwa, Tai_Le,
+        Sinhala, Sundanese, Syloti_Nagri, Syriac,  Tagalog,  Tagbanwa,  Tai_Le,
-        Tai_Tham, Tai_Viet, Tamil, Telugu,  Thaana,  Thai,  Tibetan,  Tifinagh,
+        Tai_Tham,  Tai_Viet,  Tamil,  Telugu,  Thaana, Thai, Tibetan, Tifinagh,
         Ugaritic, Vai, Yi.
         Each character has exactly one Unicode general category property, spec-
-        ified by a two-letter abbreviation. For compatibility with Perl,  nega-
+        ified  by a two-letter abbreviation. For compatibility with Perl, nega-
-        tion  can  be  specified  by including a circumflex between the opening
+        tion can be specified by including a  circumflex  between  the  opening
-        brace and the property name.  For  example,  \p{^Lu}  is  the  same  as
+        brace  and  the  property  name.  For  example,  \p{^Lu} is the same as
         \P{Lu}.
         If only one letter is specified with \p or \P, it includes all the gen-
-        eral category properties that start with that letter. In this case,  in
+        eral  category properties that start with that letter. In this case, in
-        the  absence of negation, the curly brackets in the escape sequence are
+        the absence of negation, the curly brackets in the escape sequence  are
         optional; these two examples have the same effect:
           \p{L}
-Line 3749 
 BACKSLASH
+Line 3775 
 BACKSLASH
           Zp    Paragraph separator
           Zs    Space separator
-        The special property L& is also supported: it matches a character  that
+        The  special property L& is also supported: it matches a character that
-        has  the  Lu,  Ll, or Lt property, in other words, a letter that is not
+        has the Lu, Ll, or Lt property, in other words, a letter  that  is  not
         classified as a modifier or "other".
-        The Cs (Surrogate) property applies only to  characters  in  the  range
+        The  Cs  (Surrogate)  property  applies only to characters in the range
-        U+D800  to  U+DFFF. Such characters are not valid in UTF-8 strings (see
+        U+D800 to U+DFFF. Such characters are not valid in UTF-8  strings  (see
         RFC 3629) and so cannot be tested by PCRE, unless UTF-8 validity check-
-        ing  has  been  turned off (see the discussion of PCRE_NO_UTF8_CHECK in
+        ing has been turned off (see the discussion  of  PCRE_NO_UTF8_CHECK  in
         the pcreapi page). Perl does not support the Cs property.
-        The long synonyms for  property  names  that  Perl  supports  (such  as
+        The  long  synonyms  for  property  names  that  Perl supports (such as
-        \p{Letter})  are  not  supported by PCRE, nor is it permitted to prefix
+        \p{Letter}) are not supported by PCRE, nor is it  permitted  to  prefix
         any of these properties with "Is".
         No character that is in the Unicode table has the Cn (unassigned) prop-
         erty.  Instead, this property is assumed for any code point that is not
         in the Unicode table.
-        Specifying caseless matching does not affect  these  escape  sequences.
+        Specifying  caseless  matching  does not affect these escape sequences.
         For example, \p{Lu} always matches only upper case letters.
-        The  \X  escape  matches  any number of Unicode characters that form an
+        The \X escape matches any number of Unicode  characters  that  form  an
         extended Unicode sequence. \X is equivalent to
           (?>\PM\pM*)
-        That is, it matches a character without the "mark"  property,  followed
+        That  is,  it matches a character without the "mark" property, followed
-        by  zero  or  more  characters with the "mark" property, and treats the
+        by zero or more characters with the "mark"  property,  and  treats  the
-        sequence as an atomic group (see below).  Characters  with  the  "mark"
+        sequence  as  an  atomic group (see below).  Characters with the "mark"
-        property  are  typically  accents  that affect the preceding character.
+        property are typically accents that  affect  the  preceding  character.
-        None of them have codepoints less than 256, so  in  non-UTF-8  mode  \X
+        None  of  them  have  codepoints less than 256, so in non-UTF-8 mode \X
         matches any one character.
-        Matching  characters  by Unicode property is not fast, because PCRE has
+        Matching characters by Unicode property is not fast, because  PCRE  has
-        to search a structure that contains  data  for  over  fifteen  thousand
+        to  search  a  structure  that  contains data for over fifteen thousand
         characters. That is why the traditional escape sequences such as \d and
-        \w do not use Unicode properties in PCRE by  default,  though  you  can
+        \w  do  not  use  Unicode properties in PCRE by default, though you can
         make them do so by setting the PCRE_UCP option for pcre_compile() or by
         starting the pattern with (*UCP).
     PCRE's additional properties
-        As well as the standard Unicode properties described  in  the  previous
+        As  well  as  the standard Unicode properties described in the previous
-        section,  PCRE supports four more that make it possible to convert tra-
+        section, PCRE supports four more that make it possible to convert  tra-
         ditional escape sequences such as \w and \s and POSIX character classes
         to use Unicode properties. PCRE uses these non-standard, non-Perl prop-
         erties internally when PCRE_UCP is set. They are:
-Line 3802 
 BACKSLASH
+Line 3828 
 BACKSLASH
           Xsp   Any Perl space character
           Xwd   Any Perl "word" character
-        Xan matches characters that have either the L (letter) or the  N  (num-
+        Xan  matches  characters that have either the L (letter) or the N (num-
-        ber)  property. Xps matches the characters tab, linefeed, vertical tab,
+        ber) property. Xps matches the characters tab, linefeed, vertical  tab,
-        formfeed, or carriage return, and any other character that  has  the  Z
+        formfeed,  or  carriage  return, and any other character that has the Z
         (separator) property.  Xsp is the same as Xps, except that vertical tab
         is excluded. Xwd matches the same characters as Xan, plus underscore.
     Resetting the match start
-        The escape sequence \K causes any previously matched characters not  to
+        The  escape sequence \K causes any previously matched characters not to
         be included in the final matched sequence. For example, the pattern:
           foo\Kbar
-        matches  "foobar",  but reports that it has matched "bar". This feature
+        matches "foobar", but reports that it has matched "bar".  This  feature
-        is similar to a lookbehind assertion (described  below).   However,  in
+        is  similar  to  a lookbehind assertion (described below).  However, in
-        this  case, the part of the subject before the real match does not have
+        this case, the part of the subject before the real match does not  have
-        to be of fixed length, as lookbehind assertions do. The use of \K  does
+        to  be of fixed length, as lookbehind assertions do. The use of \K does
-        not  interfere  with  the setting of captured substrings.  For example,
+        not interfere with the setting of captured  substrings.   For  example,
         when the pattern
           (foo)\Kbar
         matches "foobar", the first substring is still set to "foo".
-        Perl documents that the use  of  \K  within  assertions  is  "not  well
+        Perl  documents  that  the  use  of  \K  within assertions is "not well
-        defined".  In  PCRE,  \K  is  acted upon when it occurs inside positive
+        defined". In PCRE, \K is acted upon  when  it  occurs  inside  positive
         assertions, but is ignored in negative assertions.
     Simple assertions
-        The final use of backslash is for certain simple assertions. An  asser-
+        The  final use of backslash is for certain simple assertions. An asser-
-        tion  specifies a condition that has to be met at a particular point in
+        tion specifies a condition that has to be met at a particular point  in
-        a match, without consuming any characters from the subject string.  The
+        a  match, without consuming any characters from the subject string. The
-        use  of subpatterns for more complicated assertions is described below.
+        use of subpatterns for more complicated assertions is described  below.
         The backslashed assertions are:
           \b     matches at a word boundary
-Line 3846 
 BACKSLASH
+Line 3872 
 BACKSLASH
           \z     matches only at the end of the subject
           \G     matches at the first matching position in the subject
-        Inside a character class, \b has a different meaning;  it  matches  the
+        Inside  a  character  class, \b has a different meaning; it matches the
-        backspace  character.  If  any  other  of these assertions appears in a
+        backspace character. If any other of  these  assertions  appears  in  a
-        character class, by default it matches the corresponding literal  char-
+        character  class, by default it matches the corresponding literal char-
         acter  (for  example,  \B  matches  the  letter  B).  However,  if  the
-        PCRE_EXTRA option is set, an "invalid escape sequence" error is  gener-
+        PCRE_EXTRA  option is set, an "invalid escape sequence" error is gener-
         ated instead.
-        A  word  boundary is a position in the subject string where the current
+        A word boundary is a position in the subject string where  the  current
-        character and the previous character do not both match \w or  \W  (i.e.
+        character  and  the previous character do not both match \w or \W (i.e.
-        one  matches  \w  and the other matches \W), or the start or end of the
+        one matches \w and the other matches \W), or the start or  end  of  the
-        string if the first or last  character  matches  \w,  respectively.  In
+        string  if  the  first  or  last character matches \w, respectively. In
-        UTF-8  mode,  the  meanings  of \w and \W can be changed by setting the
+        UTF-8 mode, the meanings of \w and \W can be  changed  by  setting  the
-        PCRE_UCP option. When this is done, it also affects \b and \B.  Neither
+        PCRE_UCP  option. When this is done, it also affects \b and \B. Neither
-        PCRE  nor  Perl has a separate "start of word" or "end of word" metase-
+        PCRE nor Perl has a separate "start of word" or "end of  word"  metase-
-        quence. However, whatever follows \b normally determines which  it  is.
+        quence.  However,  whatever follows \b normally determines which it is.
         For example, the fragment \ba matches "a" at the start of a word.
-        The  \A,  \Z,  and \z assertions differ from the traditional circumflex
+        The \A, \Z, and \z assertions differ from  the  traditional  circumflex
         and dollar (described in the next section) in that they only ever match
-        at  the  very start and end of the subject string, whatever options are
+        at the very start and end of the subject string, whatever  options  are
-        set. Thus, they are independent of multiline mode. These  three  asser-
+        set.  Thus,  they are independent of multiline mode. These three asser-
         tions are not affected by the PCRE_NOTBOL or PCRE_NOTEOL options, which
-        affect only the behaviour of the circumflex and dollar  metacharacters.
+        affect  only the behaviour of the circumflex and dollar metacharacters.
-        However,  if the startoffset argument of pcre_exec() is non-zero, indi-
+        However, if the startoffset argument of pcre_exec() is non-zero,  indi-
         cating that matching is to start at a point other than the beginning of
-        the  subject,  \A  can never match. The difference between \Z and \z is
+        the subject, \A can never match. The difference between \Z  and  \z  is
         that \Z matches before a newline at the end of the string as well as at
         the very end, whereas \z matches only at the end.
-        The  \G assertion is true only when the current matching position is at
+        The \G assertion is true only when the current matching position is  at
-        the start point of the match, as specified by the startoffset  argument
+        the  start point of the match, as specified by the startoffset argument
-        of  pcre_exec().  It  differs  from \A when the value of startoffset is
+        of pcre_exec(). It differs from \A when the  value  of  startoffset  is
-        non-zero. By calling pcre_exec() multiple times with appropriate  argu-
+        non-zero.  By calling pcre_exec() multiple times with appropriate argu-
         ments, you can mimic Perl's /g option, and it is in this kind of imple-
         mentation where \G can be useful.
-        Note, however, that PCRE's interpretation of \G, as the  start  of  the
+        Note,  however,  that  PCRE's interpretation of \G, as the start of the
         current match, is subtly different from Perl's, which defines it as the
-        end of the previous match. In Perl, these can  be  different  when  the
+        end  of  the  previous  match. In Perl, these can be different when the
-        previously  matched  string was empty. Because PCRE does just one match
+        previously matched string was empty. Because PCRE does just  one  match
         at a time, it cannot reproduce this behaviour.
-        If all the alternatives of a pattern begin with \G, the  expression  is
+        If  all  the alternatives of a pattern begin with \G, the expression is
         anchored to the starting match position, and the "anchored" flag is set
         in the compiled regular expression.
-Line 3896 
 BACKSLASH
+Line 3922 
 BACKSLASH
  CIRCUMFLEX AND DOLLAR
         Outside a character class, in the default matching mode, the circumflex
-        character  is  an  assertion  that is true only if the current matching
+        character is an assertion that is true only  if  the  current  matching
-        point is at the start of the subject string. If the  startoffset  argu-
+        point  is  at the start of the subject string. If the startoffset argu-
-        ment  of  pcre_exec()  is  non-zero,  circumflex can never match if the
+        ment of pcre_exec() is non-zero, circumflex  can  never  match  if  the
-        PCRE_MULTILINE option is unset. Inside a  character  class,  circumflex
+        PCRE_MULTILINE  option  is  unset. Inside a character class, circumflex
         has an entirely different meaning (see below).
-        Circumflex  need  not be the first character of the pattern if a number
+        Circumflex need not be the first character of the pattern if  a  number
-        of alternatives are involved, but it should be the first thing in  each
+        of  alternatives are involved, but it should be the first thing in each
-        alternative  in  which  it appears if the pattern is ever to match that
+        alternative in which it appears if the pattern is ever  to  match  that
-        branch. If all possible alternatives start with a circumflex, that  is,
+        branch.  If all possible alternatives start with a circumflex, that is,
-        if  the  pattern  is constrained to match only at the start of the sub-
+        if the pattern is constrained to match only at the start  of  the  sub-
-        ject, it is said to be an "anchored" pattern.  (There  are  also  other
+        ject,  it  is  said  to be an "anchored" pattern. (There are also other
         constructs that can cause a pattern to be anchored.)
-        A  dollar  character  is  an assertion that is true only if the current
+        A dollar character is an assertion that is true  only  if  the  current
-        matching point is at the end of  the  subject  string,  or  immediately
+        matching  point  is  at  the  end of the subject string, or immediately
         before a newline at the end of the string (by default). Dollar need not
-        be the last character of the pattern if a number  of  alternatives  are
+        be  the  last  character of the pattern if a number of alternatives are
-        involved,  but  it  should  be  the last item in any branch in which it
+        involved, but it should be the last item in  any  branch  in  which  it
         appears. Dollar has no special meaning in a character class.
-        The meaning of dollar can be changed so that it  matches  only  at  the
+        The  meaning  of  dollar  can be changed so that it matches only at the
-        very  end  of  the string, by setting the PCRE_DOLLAR_ENDONLY option at
+        very end of the string, by setting the  PCRE_DOLLAR_ENDONLY  option  at
         compile time. This does not affect the \Z assertion.
         The meanings of the circumflex and dollar characters are changed if the
-        PCRE_MULTILINE  option  is  set.  When  this  is the case, a circumflex
+        PCRE_MULTILINE option is set. When  this  is  the  case,  a  circumflex
-        matches immediately after internal newlines as well as at the start  of
+        matches  immediately after internal newlines as well as at the start of
-        the  subject  string.  It  does not match after a newline that ends the
+        the subject string. It does not match after a  newline  that  ends  the
-        string. A dollar matches before any newlines in the string, as well  as
+        string.  A dollar matches before any newlines in the string, as well as
-        at  the very end, when PCRE_MULTILINE is set. When newline is specified
+        at the very end, when PCRE_MULTILINE is set. When newline is  specified
-        as the two-character sequence CRLF, isolated CR and  LF  characters  do
+        as  the  two-character  sequence CRLF, isolated CR and LF characters do
         not indicate newlines.
-        For  example, the pattern /^abc$/ matches the subject string "def\nabc"
+        For example, the pattern /^abc$/ matches the subject string  "def\nabc"
-        (where \n represents a newline) in multiline mode, but  not  otherwise.
+        (where  \n  represents a newline) in multiline mode, but not otherwise.
-        Consequently,  patterns  that  are anchored in single line mode because
+        Consequently, patterns that are anchored in single  line  mode  because
-        all branches start with ^ are not anchored in  multiline  mode,  and  a
+        all  branches  start  with  ^ are not anchored in multiline mode, and a
-        match  for  circumflex  is  possible  when  the startoffset argument of
+        match for circumflex is  possible  when  the  startoffset  argument  of
-        pcre_exec() is non-zero. The PCRE_DOLLAR_ENDONLY option is  ignored  if
+        pcre_exec()  is  non-zero. The PCRE_DOLLAR_ENDONLY option is ignored if
         PCRE_MULTILINE is set.
-        Note  that  the sequences \A, \Z, and \z can be used to match the start
+        Note that the sequences \A, \Z, and \z can be used to match  the  start
-        and end of the subject in both modes, and if all branches of a  pattern
+        and  end of the subject in both modes, and if all branches of a pattern
-        start  with  \A it is always anchored, whether or not PCRE_MULTILINE is
+        start with \A it is always anchored, whether or not  PCRE_MULTILINE  is
         set.
  FULL STOP (PERIOD, DOT) AND \N
         Outside a character class, a dot in the pattern matches any one charac-
-        ter  in  the subject string except (by default) a character that signi-
+        ter in the subject string except (by default) a character  that  signi-
-        fies the end of a line. In UTF-8 mode, the  matched  character  may  be
+        fies  the  end  of  a line. In UTF-8 mode, the matched character may be
         more than one byte long.
-        When  a line ending is defined as a single character, dot never matches
+        When a line ending is defined as a single character, dot never  matches
-        that character; when the two-character sequence CRLF is used, dot  does
+        that  character; when the two-character sequence CRLF is used, dot does
-        not  match  CR  if  it  is immediately followed by LF, but otherwise it
+        not match CR if it is immediately followed  by  LF,  but  otherwise  it
-        matches all characters (including isolated CRs and LFs). When any  Uni-
+        matches  all characters (including isolated CRs and LFs). When any Uni-
-        code  line endings are being recognized, dot does not match CR or LF or
+        code line endings are being recognized, dot does not match CR or LF  or
         any of the other line ending characters.
-        The behaviour of dot with regard to newlines can  be  changed.  If  the
+        The  behaviour  of  dot  with regard to newlines can be changed. If the
-        PCRE_DOTALL  option  is  set,  a dot matches any one character, without
+        PCRE_DOTALL option is set, a dot matches  any  one  character,  without
         exception. If the two-character sequence CRLF is present in the subject
         string, it takes two dots to match it.
-        The  handling of dot is entirely independent of the handling of circum-
+        The handling of dot is entirely independent of the handling of  circum-
-        flex and dollar, the only relationship being  that  they  both  involve
+        flex  and  dollar,  the  only relationship being that they both involve
         newlines. Dot has no special meaning in a character class.
-        The  escape  sequence  \N  behaves  like  a  dot, except that it is not
+        The escape sequence \N behaves like  a  dot,  except  that  it  is  not
-        affected by the PCRE_DOTALL option. In  other  words,  it  matches  any
+        affected  by  the  PCRE_DOTALL  option.  In other words, it matches any
         character except one that signifies the end of a line.
  MATCHING A SINGLE BYTE
         Outside a character class, the escape sequence \C matches any one byte,
-        both in and out of UTF-8 mode. Unlike a  dot,  it  always  matches  any
+        both  in  and  out  of  UTF-8 mode. Unlike a dot, it always matches any
-        line-ending  characters.  The  feature  is provided in Perl in order to
+        line-ending characters. The feature is provided in  Perl  in  order  to
-        match individual bytes in UTF-8 mode. Because it breaks up UTF-8  char-
+        match  individual bytes in UTF-8 mode. Because it breaks up UTF-8 char-
-        acters  into  individual bytes, the rest of the string may start with a
+        acters into individual bytes, the rest of the string may start  with  a
-        malformed UTF-8 character. For this reason, the \C escape  sequence  is
+        malformed  UTF-8  character. For this reason, the \C escape sequence is
         best avoided.
-        PCRE  does  not  allow \C to appear in lookbehind assertions (described
+        PCRE does not allow \C to appear in  lookbehind  assertions  (described
-        below), because in UTF-8 mode this would make it impossible  to  calcu-
+        below),  because  in UTF-8 mode this would make it impossible to calcu-
         late the length of the lookbehind.
-Line 3993 
 SQUARE BRACKETS AND CHARACTER CLASSES
+Line 4019 
 SQUARE BRACKETS AND CHARACTER CLASSES
         closing square bracket. A closing square bracket on its own is not spe-
         cial by default.  However, if the PCRE_JAVASCRIPT_COMPAT option is set,
         a lone closing square bracket causes a compile-time error. If a closing
-        square  bracket  is required as a member of the class, it should be the
+        square bracket is required as a member of the class, it should  be  the
-        first data character in the class  (after  an  initial  circumflex,  if
+        first  data  character  in  the  class (after an initial circumflex, if
         present) or escaped with a backslash.
-        A  character  class matches a single character in the subject. In UTF-8
+        A character class matches a single character in the subject.  In  UTF-8
         mode, the character may be more than one byte long. A matched character
         must be in the set of characters defined by the class, unless the first
-        character in the class definition is a circumflex, in  which  case  the
+        character  in  the  class definition is a circumflex, in which case the
-        subject  character  must  not  be in the set defined by the class. If a
+        subject character must not be in the set defined by  the  class.  If  a
-        circumflex is actually required as a member of the class, ensure it  is
+        circumflex  is actually required as a member of the class, ensure it is
         not the first character, or escape it with a backslash.
-        For  example, the character class [aeiou] matches any lower case vowel,
+        For example, the character class [aeiou] matches any lower case  vowel,
-        while [^aeiou] matches any character that is not a  lower  case  vowel.
+        while  [^aeiou]  matches  any character that is not a lower case vowel.
         Note that a circumflex is just a convenient notation for specifying the
-        characters that are in the class by enumerating those that are  not.  A
+        characters  that  are in the class by enumerating those that are not. A
-        class  that starts with a circumflex is not an assertion; it still con-
+        class that starts with a circumflex is not an assertion; it still  con-
-        sumes a character from the subject string, and therefore  it  fails  if
+        sumes  a  character  from the subject string, and therefore it fails if
         the current pointer is at the end of the string.
-        In  UTF-8 mode, characters with values greater than 255 can be included
+        In UTF-8 mode, characters with values greater than 255 can be  included
-        in a class as a literal string of bytes, or by using the  \x{  escaping
+        in  a  class as a literal string of bytes, or by using the \x{ escaping
         mechanism.
-        When  caseless  matching  is set, any letters in a class represent both
+        When caseless matching is set, any letters in a  class  represent  both
-        their upper case and lower case versions, so for  example,  a  caseless
+        their  upper  case  and lower case versions, so for example, a caseless
-        [aeiou]  matches  "A"  as well as "a", and a caseless [^aeiou] does not
+        [aeiou] matches "A" as well as "a", and a caseless  [^aeiou]  does  not
-        match "A", whereas a caseful version would. In UTF-8 mode, PCRE  always
+        match  "A", whereas a caseful version would. In UTF-8 mode, PCRE always
-        understands  the  concept  of case for characters whose values are less
+        understands the concept of case for characters whose  values  are  less
-        than 128, so caseless matching is always possible. For characters  with
+        than  128, so caseless matching is always possible. For characters with
-        higher  values,  the  concept  of case is supported if PCRE is compiled
+        higher values, the concept of case is supported  if  PCRE  is  compiled
-        with Unicode property support, but not otherwise.  If you want  to  use
+        with  Unicode  property support, but not otherwise.  If you want to use
-        caseless  matching  in UTF8-mode for characters 128 and above, you must
+        caseless matching in UTF8-mode for characters 128 and above,  you  must
-        ensure that PCRE is compiled with Unicode property support as  well  as
+        ensure  that  PCRE is compiled with Unicode property support as well as
         with UTF-8 support.
-        Characters  that  might  indicate  line breaks are never treated in any
+        Characters that might indicate line breaks are  never  treated  in  any
-        special way  when  matching  character  classes,  whatever  line-ending
+        special  way  when  matching  character  classes,  whatever line-ending
-        sequence  is  in  use,  and  whatever  setting  of  the PCRE_DOTALL and
+        sequence is in  use,  and  whatever  setting  of  the  PCRE_DOTALL  and
         PCRE_MULTILINE options is used. A class such as [^a] always matches one
         of these characters.
-        The  minus (hyphen) character can be used to specify a range of charac-
+        The minus (hyphen) character can be used to specify a range of  charac-
-        ters in a character  class.  For  example,  [d-m]  matches  any  letter
+        ters  in  a  character  class.  For  example,  [d-m] matches any letter
-        between  d  and  m,  inclusive.  If  a minus character is required in a
+        between d and m, inclusive. If a  minus  character  is  required  in  a
-        class, it must be escaped with a backslash  or  appear  in  a  position
+        class,  it  must  be  escaped  with a backslash or appear in a position
-        where  it cannot be interpreted as indicating a range, typically as the
+        where it cannot be interpreted as indicating a range, typically as  the
         first or last character in the class.
         It is not possible to have the literal character "]" as the end charac-
-        ter  of a range. A pattern such as [W-]46] is interpreted as a class of
+        ter of a range. A pattern such as [W-]46] is interpreted as a class  of
-        two characters ("W" and "-") followed by a literal string "46]", so  it
+        two  characters ("W" and "-") followed by a literal string "46]", so it
-        would  match  "W46]"  or  "-46]". However, if the "]" is escaped with a
+        would match "W46]" or "-46]". However, if the "]"  is  escaped  with  a
-        backslash it is interpreted as the end of range, so [W-\]46] is  inter-
+        backslash  it is interpreted as the end of range, so [W-\]46] is inter-
-        preted  as a class containing a range followed by two other characters.
+        preted as a class containing a range followed by two other  characters.
-        The octal or hexadecimal representation of "]" can also be used to  end
+        The  octal or hexadecimal representation of "]" can also be used to end
         a range.
-        Ranges  operate in the collating sequence of character values. They can
+        Ranges operate in the collating sequence of character values. They  can
-        also  be  used  for  characters  specified  numerically,  for   example
+        also   be  used  for  characters  specified  numerically,  for  example
-        [\000-\037].  In UTF-8 mode, ranges can include characters whose values
+        [\000-\037]. In UTF-8 mode, ranges can include characters whose  values
         are greater than 255, for example [\x{100}-\x{2ff}].
         If a range that includes letters is used when caseless matching is set,
         it matches the letters in either case. For example, [W-c] is equivalent
-        to [][\\^_`wxyzabc], matched caselessly,  and  in  non-UTF-8  mode,  if
+        to  [][\\^_`wxyzabc],  matched  caselessly,  and  in non-UTF-8 mode, if
-        character  tables  for  a French locale are in use, [\xc8-\xcb] matches
+        character tables for a French locale are in  use,  [\xc8-\xcb]  matches
-        accented E characters in both cases. In UTF-8 mode, PCRE  supports  the
+        accented  E  characters in both cases. In UTF-8 mode, PCRE supports the
-        concept  of  case for characters with values greater than 128 only when
+        concept of case for characters with values greater than 128  only  when
         it is compiled with Unicode property support.
-        The character types \d, \D, \h, \H, \p, \P, \s, \S, \v, \V, \w, and  \W
+        The  character escape sequences \d, \D, \h, \H, \p, \P, \s, \S, \v, \V,
-        may  also appear in a character class, and add the characters that they
+        \w, and \W may appear in a character class, and add the characters that
-        match to the class. For example,  [\dABCDEF]  matches  any  hexadecimal
+        they  match to the class. For example, [\dABCDEF] matches any hexadeci-
-        digit.  A circumflex can conveniently be used with the upper case char-
+        mal digit. In UTF-8 mode, the PCRE_UCP option affects the  meanings  of
-        acter types to specify a more restricted set  of  characters  than  the
+        \d,  \s,  \w  and  their upper case partners, just as it does when they
-        matching  lower  case  type.  For example, the class [^\W_] matches any
+        appear outside a character class, as described in the section  entitled
-        letter or digit, but not underscore.
+        "Generic character types" above. The escape sequence \b has a different
+        meaning inside a character class; it matches the  backspace  character.
-        The only metacharacters that are recognized in  character  classes  are
+        The  sequences  \B,  \N,  \R, and \X are not special inside a character
-        backslash,  hyphen  (only  where  it can be interpreted as specifying a
+        class. Like any other unrecognized escape sequences, they  are  treated
-        range), circumflex (only at the start), opening  square  bracket  (only
+        as  the literal characters "B", "N", "R", and "X" by default, but cause
-        when  it can be interpreted as introducing a POSIX class name - see the
+        an error if the PCRE_EXTRA option is set.
-        next section), and the terminating  closing  square  bracket.  However,
+        A circumflex can conveniently be used with  the  upper  case  character
+        types  to specify a more restricted set of characters than the matching
+        lower case type.  For example, the class [^\W_] matches any  letter  or
+        digit, but not underscore, whereas [\w] includes underscore. A positive
+        character class should be read as "something OR something OR ..." and a
+        negative class as "NOT something AND NOT something AND NOT ...".
+        The  only  metacharacters  that are recognized in character classes are
+        backslash, hyphen (only where it can be  interpreted  as  specifying  a
+        range),  circumflex  (only  at the start), opening square bracket (only
+        when it can be interpreted as introducing a POSIX class name - see  the
+        next  section),  and  the  terminating closing square bracket. However,
         escaping other non-alphanumeric characters does no harm.
  POSIX CHARACTER CLASSES
         Perl supports the POSIX notation for character classes. This uses names
-        enclosed by [: and :] within the enclosing square brackets.  PCRE  also
+        enclosed  by  [: and :] within the enclosing square brackets. PCRE also
         supports this notation. For example,
           [01[:alpha:]%]
-Line 4106 
 POSIX CHARACTER CLASSES
+Line 4144 
 POSIX CHARACTER CLASSES
           word     "word" characters (same as \w)
           xdigit   hexadecimal digits
-        The "space" characters are HT (9), LF (10), VT (11), FF (12), CR  (13),
+        The  "space" characters are HT (9), LF (10), VT (11), FF (12), CR (13),
-        and  space  (32). Notice that this list includes the VT character (code
+        and space (32). Notice that this list includes the VT  character  (code
 ). This makes "space" different to \s, which does not include VT (for
         Perl compatibility).
-        The  name  "word"  is  a Perl extension, and "blank" is a GNU extension
+        The name "word" is a Perl extension, and "blank"  is  a  GNU  extension
-        from Perl 5.8. Another Perl extension is negation, which  is  indicated
+        from  Perl  5.8. Another Perl extension is negation, which is indicated
         by a ^ character after the colon. For example,
           [12[:^digit:]]
-        matches  "1", "2", or any non-digit. PCRE (and Perl) also recognize the
+        matches "1", "2", or any non-digit. PCRE (and Perl) also recognize  the
         POSIX syntax [.ch.] and [=ch=] where "ch" is a "collating element", but
         these are not supported, and an error is given if they are encountered.
-        By  default,  in UTF-8 mode, characters with values greater than 128 do
+        By default, in UTF-8 mode, characters with values greater than  128  do
-        not match any of the POSIX character classes. However, if the  PCRE_UCP
+        not  match any of the POSIX character classes. However, if the PCRE_UCP
-        option  is passed to pcre_compile(), some of the classes are changed so
+        option is passed to pcre_compile(), some of the classes are changed  so
         that Unicode character properties are used. This is achieved by replac-
         ing the POSIX classes by other sequences, as follows:
-Line 4136 
 POSIX CHARACTER CLASSES
+Line 4174 
 POSIX CHARACTER CLASSES
           [:upper:]  becomes  \p{Lu}
           [:word:]   becomes  \p{Xwd}
-        Negated  versions,  such  as [:^alpha:] use \P instead of \p. The other
+        Negated versions, such as [:^alpha:] use \P instead of  \p.  The  other
         POSIX classes are unchanged, and match only characters with code points
         less than 128.
  VERTICAL BAR
-        Vertical  bar characters are used to separate alternative patterns. For
+        Vertical bar characters are used to separate alternative patterns.  For
         example, the pattern
           gilbert|sullivan
-        matches either "gilbert" or "sullivan". Any number of alternatives  may
+        matches  either "gilbert" or "sullivan". Any number of alternatives may
-        appear,  and  an  empty  alternative  is  permitted (matching the empty
+        appear, and an empty  alternative  is  permitted  (matching  the  empty
         string). The matching process tries each alternative in turn, from left
-        to  right, and the first one that succeeds is used. If the alternatives
+        to right, and the first one that succeeds is used. If the  alternatives
-        are within a subpattern (defined below), "succeeds" means matching  the
+        are  within a subpattern (defined below), "succeeds" means matching the
         rest of the main pattern as well as the alternative in the subpattern.
  INTERNAL OPTION SETTING
-        The  settings  of  the  PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and
+        The settings of the  PCRE_CASELESS,  PCRE_MULTILINE,  PCRE_DOTALL,  and
-        PCRE_EXTENDED options (which are Perl-compatible) can be  changed  from
+        PCRE_EXTENDED  options  (which are Perl-compatible) can be changed from
-        within  the  pattern  by  a  sequence  of  Perl option letters enclosed
+        within the pattern by  a  sequence  of  Perl  option  letters  enclosed
         between "(?" and ")".  The option letters are
           i  for PCRE_CASELESS
-Line 4170 
 INTERNAL OPTION SETTING
+Line 4208 
 INTERNAL OPTION SETTING
         For example, (?im) sets caseless, multiline matching. It is also possi-
         ble to unset these options by preceding the letter with a hyphen, and a
-        combined setting and unsetting such as (?im-sx), which sets  PCRE_CASE-
+        combined  setting and unsetting such as (?im-sx), which sets PCRE_CASE-
-        LESS  and PCRE_MULTILINE while unsetting PCRE_DOTALL and PCRE_EXTENDED,
+        LESS and PCRE_MULTILINE while unsetting PCRE_DOTALL and  PCRE_EXTENDED,
-        is also permitted. If a  letter  appears  both  before  and  after  the
+        is  also  permitted.  If  a  letter  appears  both before and after the
         hyphen, the option is unset.
-        The  PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and PCRE_EXTRA
+        The PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and  PCRE_EXTRA
-        can be changed in the same way as the Perl-compatible options by  using
+        can  be changed in the same way as the Perl-compatible options by using
         the characters J, U and X respectively.
-        When  one  of  these  option  changes occurs at top level (that is, not
+        When one of these option changes occurs at  top  level  (that  is,  not
-        inside subpattern parentheses), the change applies to the remainder  of
+        inside  subpattern parentheses), the change applies to the remainder of
         the pattern that follows. If the change is placed right at the start of
         a pattern, PCRE extracts it into the global options (and it will there-
         fore show up in data extracted by the pcre_fullinfo() function).
-        An  option  change  within a subpattern (see below for a description of
+        An option change within a subpattern (see below for  a  description  of
-        subpatterns) affects only that part of the subpattern that follows  it,
+        subpatterns)  affects only that part of the subpattern that follows it,
         so
           (a(?i)b)c
         matches abc and aBc and no other strings (assuming PCRE_CASELESS is not
-        used).  By this means, options can be made to have  different  settings
+        used).   By  this means, options can be made to have different settings
-        in  different parts of the pattern. Any changes made in one alternative
+        in different parts of the pattern. Any changes made in one  alternative
-        do carry on into subsequent branches within the  same  subpattern.  For
+        do  carry  on  into subsequent branches within the same subpattern. For
         example,
           (a(?i)b|c)
-        matches  "ab",  "aB",  "c",  and "C", even though when matching "C" the
+        matches "ab", "aB", "c", and "C", even though  when  matching  "C"  the
-        first branch is abandoned before the option setting.  This  is  because
+        first  branch  is  abandoned before the option setting. This is because
-        the  effects  of option settings happen at compile time. There would be
+        the effects of option settings happen at compile time. There  would  be
         some very weird behaviour otherwise.
-        Note: There are other PCRE-specific options that  can  be  set  by  the
+        Note:  There  are  other  PCRE-specific  options that can be set by the
-        application  when  the  compile  or match functions are called. In some
+        application when the compile or match functions  are  called.  In  some
         cases the pattern can contain special leading sequences such as (*CRLF)
-        to  override  what  the application has set or what has been defaulted.
+        to override what the application has set or what  has  been  defaulted.
-        Details are given in the section entitled  "Newline  sequences"  above.
+        Details  are  given  in the section entitled "Newline sequences" above.
-        There  are  also  the  (*UTF8) and (*UCP) leading sequences that can be
+        There are also the (*UTF8) and (*UCP) leading  sequences  that  can  be
-        used to set UTF-8 and Unicode property modes; they  are  equivalent  to
+        used  to  set  UTF-8 and Unicode property modes; they are equivalent to
         setting the PCRE_UTF8 and the PCRE_UCP options, respectively.
-Line 4223 
 SUBPATTERNS
+Line 4261 
 SUBPATTERNS
           cat(aract|erpillar|)
-        matches "cataract", "caterpillar", or "cat". Without  the  parentheses,
+        matches  "cataract",  "caterpillar", or "cat". Without the parentheses,
         it would match "cataract", "erpillar" or an empty string.
-.  It  sets  up  the  subpattern as a capturing subpattern. This means
+. It sets up the subpattern as  a  capturing  subpattern.  This  means
-        that, when the whole pattern  matches,  that  portion  of  the  subject
+        that,  when  the  whole  pattern  matches,  that portion of the subject
         string that matched the subpattern is passed back to the caller via the
-        ovector argument of pcre_exec(). Opening parentheses are  counted  from
+        ovector  argument  of pcre_exec(). Opening parentheses are counted from
-        left  to  right  (starting  from 1) to obtain numbers for the capturing
+        left to right (starting from 1) to obtain  numbers  for  the  capturing
-        subpatterns. For example, if the  string  "the  red  king"  is  matched
+        subpatterns.  For  example,  if  the  string  "the red king" is matched
         against the pattern
           the ((red|white) (king|queen))
-Line 4239 
 SUBPATTERNS
+Line 4277 
 SUBPATTERNS
         the captured substrings are "red king", "red", and "king", and are num-
         bered 1, 2, and 3, respectively.
-        The fact that plain parentheses fulfil  two  functions  is  not  always
+        The  fact  that  plain  parentheses  fulfil two functions is not always
-        helpful.   There are often times when a grouping subpattern is required
+        helpful.  There are often times when a grouping subpattern is  required
-        without a capturing requirement. If an opening parenthesis is  followed
+        without  a capturing requirement. If an opening parenthesis is followed
-        by  a question mark and a colon, the subpattern does not do any captur-
+        by a question mark and a colon, the subpattern does not do any  captur-
-        ing, and is not counted when computing the  number  of  any  subsequent
+        ing,  and  is  not  counted when computing the number of any subsequent
-        capturing  subpatterns. For example, if the string "the white queen" is
+        capturing subpatterns. For example, if the string "the white queen"  is
         matched against the pattern
           the ((?:red|white) (king|queen))
-Line 4252 
 SUBPATTERNS
+Line 4290 
 SUBPATTERNS
         the captured substrings are "white queen" and "queen", and are numbered
 and 2. The maximum number of capturing subpatterns is 65535.
-        As  a  convenient shorthand, if any option settings are required at the
+        As a convenient shorthand, if any option settings are required  at  the
-        start of a non-capturing subpattern,  the  option  letters  may  appear
+        start  of  a  non-capturing  subpattern,  the option letters may appear
         between the "?" and the ":". Thus the two patterns
           (?i:saturday|sunday)
           (?:(?i)saturday|sunday)
         match exactly the same set of strings. Because alternative branches are
-        tried from left to right, and options are not reset until  the  end  of
+        tried  from  left  to right, and options are not reset until the end of
-        the  subpattern is reached, an option setting in one branch does affect
+        the subpattern is reached, an option setting in one branch does  affect
-        subsequent branches, so the above patterns match "SUNDAY"  as  well  as
+        subsequent  branches,  so  the above patterns match "SUNDAY" as well as
         "Saturday".
  DUPLICATE SUBPATTERN NUMBERS
         Perl 5.10 introduced a feature whereby each alternative in a subpattern
-        uses the same numbers for its capturing parentheses. Such a  subpattern
+        uses  the same numbers for its capturing parentheses. Such a subpattern
-        starts  with (?| and is itself a non-capturing subpattern. For example,
+        starts with (?| and is itself a non-capturing subpattern. For  example,
         consider this pattern:
           (?|(Sat)ur|(Sun))day
-        Because the two alternatives are inside a (?| group, both sets of  cap-
+        Because  the two alternatives are inside a (?| group, both sets of cap-
-        turing  parentheses  are  numbered one. Thus, when the pattern matches,
+        turing parentheses are numbered one. Thus, when  the  pattern  matches,
-        you can look at captured substring number  one,  whichever  alternative
+        you  can  look  at captured substring number one, whichever alternative
-        matched.  This  construct  is useful when you want to capture part, but
+        matched. This construct is useful when you want to  capture  part,  but
         not all, of one of a number of alternatives. Inside a (?| group, paren-
-        theses  are  numbered as usual, but the number is reset at the start of
+        theses are numbered as usual, but the number is reset at the  start  of
-        each branch. The numbers of any capturing parentheses that  follow  the
+        each  branch.  The numbers of any capturing parentheses that follow the
-        subpattern  start after the highest number used in any branch. The fol-
+        subpattern start after the highest number used in any branch. The  fol-
         lowing example is taken from the Perl documentation. The numbers under-
         neath show in which buffer the captured content will be stored.
-Line 4290 
 DUPLICATE SUBPATTERN NUMBERS
+Line 4328 
 DUPLICATE SUBPATTERN NUMBERS
           / ( a )  (?| x ( y ) z | (p (q) r) | (t) u (v) ) ( z ) /x
           # 1            2         2  3        2     3     4
-        A  back  reference  to a numbered subpattern uses the most recent value
+        A back reference to a numbered subpattern uses the  most  recent  value
-        that is set for that number by any subpattern.  The  following  pattern
+        that  is  set  for that number by any subpattern. The following pattern
         matches "abcabc" or "defdef":
           /(?|(abc)|(def))\1/
-        In  contrast, a recursive or "subroutine" call to a numbered subpattern
+        In contrast, a recursive or "subroutine" call to a numbered  subpattern
-        always refers to the first one in the pattern with  the  given  number.
+        always  refers  to  the first one in the pattern with the given number.
         The following pattern matches "abcabc" or "defabc":
           /(?|(abc)|(def))(?1)/
-        If  a condition test for a subpattern's having matched refers to a non-
+        If a condition test for a subpattern's having matched refers to a  non-
-        unique number, the test is true if any of the subpatterns of that  num-
+        unique  number, the test is true if any of the subpatterns of that num-
         ber have matched.
-        An  alternative approach to using this "branch reset" feature is to use
+        An alternative approach to using this "branch reset" feature is to  use
         duplicate named subpatterns, as described in the next section.
  NAMED SUBPATTERNS
-        Identifying capturing parentheses by number is simple, but  it  can  be
+        Identifying  capturing  parentheses  by number is simple, but it can be
-        very  hard  to keep track of the numbers in complicated regular expres-
+        very hard to keep track of the numbers in complicated  regular  expres-
-        sions. Furthermore, if an  expression  is  modified,  the  numbers  may
+        sions.  Furthermore,  if  an  expression  is  modified, the numbers may
-        change.  To help with this difficulty, PCRE supports the naming of sub-
+        change. To help with this difficulty, PCRE supports the naming of  sub-
         patterns. This feature was not added to Perl until release 5.10. Python
-        had  the  feature earlier, and PCRE introduced it at release 4.0, using
+        had the feature earlier, and PCRE introduced it at release  4.0,  using
-        the Python syntax. PCRE now supports both the Perl and the Python  syn-
+        the  Python syntax. PCRE now supports both the Perl and the Python syn-
-        tax.  Perl  allows  identically  numbered subpatterns to have different
+        tax. Perl allows identically numbered  subpatterns  to  have  different
         names, but PCRE does not.
-        In PCRE, a subpattern can be named in one of three  ways:  (?<name>...)
+        In  PCRE,  a subpattern can be named in one of three ways: (?<name>...)
-        or  (?'name'...)  as in Perl, or (?P<name>...) as in Python. References
+        or (?'name'...) as in Perl, or (?P<name>...) as in  Python.  References
-        to capturing parentheses from other parts of the pattern, such as  back
+        to  capturing parentheses from other parts of the pattern, such as back
-        references,  recursion,  and conditions, can be made by name as well as
+        references, recursion, and conditions, can be made by name as  well  as
         by number.
-        Names consist of up to  32  alphanumeric  characters  and  underscores.
+        Names  consist  of  up  to  32 alphanumeric characters and underscores.
-        Named  capturing  parentheses  are  still  allocated numbers as well as
+        Named capturing parentheses are still  allocated  numbers  as  well  as
-        names, exactly as if the names were not present. The PCRE API  provides
+        names,  exactly as if the names were not present. The PCRE API provides
         function calls for extracting the name-to-number translation table from
         a compiled pattern. There is also a convenience function for extracting
         a captured substring by name.
-        By  default, a name must be unique within a pattern, but it is possible
+        By default, a name must be unique within a pattern, but it is  possible
         to relax this constraint by setting the PCRE_DUPNAMES option at compile
-        time.  (Duplicate  names are also always permitted for subpatterns with
+        time. (Duplicate names are also always permitted for  subpatterns  with
-        the same number, set up as described in the previous  section.)  Dupli-
+        the  same  number, set up as described in the previous section.) Dupli-
-        cate  names  can  be useful for patterns where only one instance of the
+        cate names can be useful for patterns where only one  instance  of  the
-        named parentheses can match. Suppose you want to match the  name  of  a
+        named  parentheses  can  match. Suppose you want to match the name of a
-        weekday,  either as a 3-letter abbreviation or as the full name, and in
+        weekday, either as a 3-letter abbreviation or as the full name, and  in
         both cases you want to extract the abbreviation. This pattern (ignoring
         the line breaks) does the job:
-Line 4351 
 NAMED SUBPATTERNS
+Line 4389 
 NAMED SUBPATTERNS
           (?<DN>Thu)(?:rsday)?|
           (?<DN>Sat)(?:urday)?
-        There  are  five capturing substrings, but only one is ever set after a
+        There are five capturing substrings, but only one is ever set  after  a
         match.  (An alternative way of solving this problem is to use a "branch
         reset" subpattern, as described in the previous section.)
-        The  convenience  function  for extracting the data by name returns the
+        The convenience function for extracting the data by  name  returns  the
-        substring for the first (and in this example, the only)  subpattern  of
+        substring  for  the first (and in this example, the only) subpattern of
-        that  name  that  matched.  This saves searching to find which numbered
+        that name that matched. This saves searching  to  find  which  numbered
         subpattern it was.
-        If you make a back reference to  a  non-unique  named  subpattern  from
+        If  you  make  a  back  reference to a non-unique named subpattern from
-        elsewhere  in the pattern, the one that corresponds to the first occur-
+        elsewhere in the pattern, the one that corresponds to the first  occur-
         rence of the name is used. In the absence of duplicate numbers (see the
-        previous  section) this is the one with the lowest number. If you use a
+        previous section) this is the one with the lowest number. If you use  a
-        named reference in a condition test (see the section  about  conditions
+        named  reference  in a condition test (see the section about conditions
-        below),  either  to check whether a subpattern has matched, or to check
+        below), either to check whether a subpattern has matched, or  to  check
-        for recursion, all subpatterns with the same name are  tested.  If  the
+        for  recursion,  all  subpatterns with the same name are tested. If the
-        condition  is  true for any one of them, the overall condition is true.
+        condition is true for any one of them, the overall condition  is  true.
         This is the same behaviour as testing by number. For further details of
         the interfaces for handling named subpatterns, see the pcreapi documen-
         tation.
         Warning: You cannot use different names to distinguish between two sub-
-        patterns  with  the same number because PCRE uses only the numbers when
+        patterns with the same number because PCRE uses only the  numbers  when
         matching. For this reason, an error is given at compile time if differ-
-        ent  names  are given to subpatterns with the same number. However, you
+        ent names are given to subpatterns with the same number.  However,  you
-        can give the same name to subpatterns with the same number,  even  when
+        can  give  the same name to subpatterns with the same number, even when
         PCRE_DUPNAMES is not set.
  REPETITION
-        Repetition  is  specified  by  quantifiers, which can follow any of the
+        Repetition is specified by quantifiers, which can  follow  any  of  the
         following items:
           a literal data character
-Line 4396 
 REPETITION
+Line 4434 
 REPETITION
           a parenthesized subpattern (unless it is an assertion)
           a recursive or "subroutine" call to a subpattern
-        The general repetition quantifier specifies a minimum and maximum  num-
+        The  general repetition quantifier specifies a minimum and maximum num-
-        ber  of  permitted matches, by giving the two numbers in curly brackets
+        ber of permitted matches, by giving the two numbers in  curly  brackets
-        (braces), separated by a comma. The numbers must be  less  than  65536,
+        (braces),  separated  by  a comma. The numbers must be less than 65536,
         and the first must be less than or equal to the second. For example:
           z{2,4}
-        matches  "zz",  "zzz",  or  "zzzz". A closing brace on its own is not a
+        matches "zz", "zzz", or "zzzz". A closing brace on its  own  is  not  a
-        special character. If the second number is omitted, but  the  comma  is
+        special  character.  If  the second number is omitted, but the comma is
-        present,  there  is  no upper limit; if the second number and the comma
+        present, there is no upper limit; if the second number  and  the  comma
-        are both omitted, the quantifier specifies an exact number of  required
+        are  both omitted, the quantifier specifies an exact number of required
         matches. Thus
           [aeiou]{3,}
-Line 4415 
 REPETITION
+Line 4453 
 REPETITION
           \d{8}
-        matches  exactly  8  digits. An opening curly bracket that appears in a
+        matches exactly 8 digits. An opening curly bracket that  appears  in  a
-        position where a quantifier is not allowed, or one that does not  match
+        position  where a quantifier is not allowed, or one that does not match
-        the  syntax of a quantifier, is taken as a literal character. For exam-
+        the syntax of a quantifier, is taken as a literal character. For  exam-
         ple, {,6} is not a quantifier, but a literal string of four characters.
-        In UTF-8 mode, quantifiers apply to UTF-8  characters  rather  than  to
+        In  UTF-8  mode,  quantifiers  apply to UTF-8 characters rather than to
         individual bytes. Thus, for example, \x{100}{2} matches two UTF-8 char-
         acters, each of which is represented by a two-byte sequence. Similarly,
         when Unicode property support is available, \X{3} matches three Unicode
-        extended sequences, each of which may be several bytes long  (and  they
+        extended  sequences,  each of which may be several bytes long (and they
         may be of different lengths).
         The quantifier {0} is permitted, causing the expression to behave as if
         the previous item and the quantifier were not present. This may be use-
-        ful  for  subpatterns that are referenced as subroutines from elsewhere
+        ful for subpatterns that are referenced as subroutines  from  elsewhere
         in the pattern (but see also the section entitled "Defining subpatterns
-        for  use  by  reference only" below). Items other than subpatterns that
+        for use by reference only" below). Items other  than  subpatterns  that
         have a {0} quantifier are omitted from the compiled pattern.
-        For convenience, the three most common quantifiers have  single-charac-
+        For  convenience, the three most common quantifiers have single-charac-
         ter abbreviations:
           *    is equivalent to {0,}
           +    is equivalent to {1,}
           ?    is equivalent to {0,1}
-        It  is  possible  to construct infinite loops by following a subpattern
+        It is possible to construct infinite loops by  following  a  subpattern
         that can match no characters with a quantifier that has no upper limit,
         for example:
           (a?)*
         Earlier versions of Perl and PCRE used to give an error at compile time
-        for such patterns. However, because there are cases where this  can  be
+        for  such  patterns. However, because there are cases where this can be
-        useful,  such  patterns  are now accepted, but if any repetition of the
+        useful, such patterns are now accepted, but if any  repetition  of  the
-        subpattern does in fact match no characters, the loop is forcibly  bro-
+        subpattern  does in fact match no characters, the loop is forcibly bro-
         ken.
-        By  default,  the quantifiers are "greedy", that is, they match as much
+        By default, the quantifiers are "greedy", that is, they match  as  much
-        as possible (up to the maximum  number  of  permitted  times),  without
+        as  possible  (up  to  the  maximum number of permitted times), without
-        causing  the  rest of the pattern to fail. The classic example of where
+        causing the rest of the pattern to fail. The classic example  of  where
         this gives problems is in trying to match comments in C programs. These
-        appear  between  /*  and  */ and within the comment, individual * and /
+        appear between /* and */ and within the comment,  individual  *  and  /
-        characters may appear. An attempt to match C comments by  applying  the
+        characters  may  appear. An attempt to match C comments by applying the
         pattern
           /\*.*\*/
-Line 4467 
 REPETITION
+Line 4505 
 REPETITION
           /* first comment */  not comment  /* second comment */
-        fails,  because it matches the entire string owing to the greediness of
+        fails, because it matches the entire string owing to the greediness  of
         the .*  item.
-        However, if a quantifier is followed by a question mark, it  ceases  to
+        However,  if  a quantifier is followed by a question mark, it ceases to
         be greedy, and instead matches the minimum number of times possible, so
         the pattern
           /\*.*?\*/
-        does the right thing with the C comments. The meaning  of  the  various
+        does  the  right  thing with the C comments. The meaning of the various
-        quantifiers  is  not  otherwise  changed,  just the preferred number of
+        quantifiers is not otherwise changed,  just  the  preferred  number  of
-        matches.  Do not confuse this use of question mark with its  use  as  a
+        matches.   Do  not  confuse this use of question mark with its use as a
-        quantifier  in its own right. Because it has two uses, it can sometimes
+        quantifier in its own right. Because it has two uses, it can  sometimes
         appear doubled, as in
           \d??\d
-Line 4487 
 REPETITION
+Line 4525 
 REPETITION
         which matches one digit by preference, but can match two if that is the
         only way the rest of the pattern matches.
-        If  the PCRE_UNGREEDY option is set (an option that is not available in
+        If the PCRE_UNGREEDY option is set (an option that is not available  in
-        Perl), the quantifiers are not greedy by default, but  individual  ones
+        Perl),  the  quantifiers are not greedy by default, but individual ones
-        can  be  made  greedy  by following them with a question mark. In other
+        can be made greedy by following them with a  question  mark.  In  other
         words, it inverts the default behaviour.
-        When a parenthesized subpattern is quantified  with  a  minimum  repeat
+        When  a  parenthesized  subpattern  is quantified with a minimum repeat
-        count  that is greater than 1 or with a limited maximum, more memory is
+        count that is greater than 1 or with a limited maximum, more memory  is
-        required for the compiled pattern, in proportion to  the  size  of  the
+        required  for  the  compiled  pattern, in proportion to the size of the
         minimum or maximum.
         If a pattern starts with .* or .{0,} and the PCRE_DOTALL option (equiv-
-        alent to Perl's /s) is set, thus allowing the dot  to  match  newlines,
+        alent  to  Perl's  /s) is set, thus allowing the dot to match newlines,
-        the  pattern  is  implicitly anchored, because whatever follows will be
+        the pattern is implicitly anchored, because whatever  follows  will  be
-        tried against every character position in the subject string, so  there
+        tried  against every character position in the subject string, so there
-        is  no  point  in  retrying the overall match at any position after the
+        is no point in retrying the overall match at  any  position  after  the
-        first. PCRE normally treats such a pattern as though it  were  preceded
+        first.  PCRE  normally treats such a pattern as though it were preceded
         by \A.
-        In  cases  where  it  is known that the subject string contains no new-
+        In cases where it is known that the subject  string  contains  no  new-
-        lines, it is worth setting PCRE_DOTALL in order to  obtain  this  opti-
+        lines,  it  is  worth setting PCRE_DOTALL in order to obtain this opti-
         mization, or alternatively using ^ to indicate anchoring explicitly.
-        However,  there is one situation where the optimization cannot be used.
+        However, there is one situation where the optimization cannot be  used.
         When .*  is inside capturing parentheses that are the subject of a back
         reference elsewhere in the pattern, a match at the start may fail where
         a later one succeeds. Consider, for example:
           (.*)abc\1
-        If the subject is "xyz123abc123" the match point is the fourth  charac-
+        If  the subject is "xyz123abc123" the match point is the fourth charac-
         ter. For this reason, such a pattern is not implicitly anchored.
         When a capturing subpattern is repeated, the value captured is the sub-
-Line 4525 
 REPETITION
+Line 4563 
 REPETITION
           (tweedle[dume]{3}\s*)+
         has matched "tweedledum tweedledee" the value of the captured substring
-        is  "tweedledee".  However,  if there are nested capturing subpatterns,
+        is "tweedledee". However, if there are  nested  capturing  subpatterns,
-        the corresponding captured values may have been set in previous  itera-
+        the  corresponding captured values may have been set in previous itera-
         tions. For example, after
           /(a|(b))+/
-Line 4536 
 REPETITION
+Line 4574 
 REPETITION
  ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS
-        With  both  maximizing ("greedy") and minimizing ("ungreedy" or "lazy")
+        With both maximizing ("greedy") and minimizing ("ungreedy"  or  "lazy")
-        repetition, failure of what follows normally causes the  repeated  item
+        repetition,  failure  of what follows normally causes the repeated item
-        to  be  re-evaluated to see if a different number of repeats allows the
+        to be re-evaluated to see if a different number of repeats  allows  the
-        rest of the pattern to match. Sometimes it is useful to  prevent  this,
+        rest  of  the pattern to match. Sometimes it is useful to prevent this,
-        either  to  change the nature of the match, or to cause it fail earlier
+        either to change the nature of the match, or to cause it  fail  earlier
-        than it otherwise might, when the author of the pattern knows there  is
+        than  it otherwise might, when the author of the pattern knows there is
         no point in carrying on.
-        Consider,  for  example, the pattern \d+foo when applied to the subject
+        Consider, for example, the pattern \d+foo when applied to  the  subject
         line
 bar
         After matching all 6 digits and then failing to match "foo", the normal
-        action  of  the matcher is to try again with only 5 digits matching the
+        action of the matcher is to try again with only 5 digits  matching  the
-        \d+ item, and then with  4,  and  so  on,  before  ultimately  failing.
+        \d+  item,  and  then  with  4,  and  so on, before ultimately failing.
-        "Atomic  grouping"  (a  term taken from Jeffrey Friedl's book) provides
+        "Atomic grouping" (a term taken from Jeffrey  Friedl's  book)  provides
-        the means for specifying that once a subpattern has matched, it is  not
+        the  means for specifying that once a subpattern has matched, it is not
         to be re-evaluated in this way.
-        If  we  use atomic grouping for the previous example, the matcher gives
+        If we use atomic grouping for the previous example, the  matcher  gives
-        up immediately on failing to match "foo" the first time.  The  notation
+        up  immediately  on failing to match "foo" the first time. The notation
         is a kind of special parenthesis, starting with (?> as in this example:
           (?>\d+)foo
-        This  kind  of  parenthesis "locks up" the  part of the pattern it con-
+        This kind of parenthesis "locks up" the  part of the  pattern  it  con-
-        tains once it has matched, and a failure further into  the  pattern  is
+        tains  once  it  has matched, and a failure further into the pattern is
-        prevented  from  backtracking into it. Backtracking past it to previous
+        prevented from backtracking into it. Backtracking past it  to  previous
         items, however, works as normal.
-        An alternative description is that a subpattern of  this  type  matches
+        An  alternative  description  is that a subpattern of this type matches
-        the  string  of  characters  that an identical standalone pattern would
+        the string of characters that an  identical  standalone  pattern  would
         match, if anchored at the current point in the subject string.
         Atomic grouping subpatterns are not capturing subpatterns. Simple cases
         such as the above example can be thought of as a maximizing repeat that
-        must swallow everything it can. So, while both \d+ and  \d+?  are  pre-
+        must  swallow  everything  it can. So, while both \d+ and \d+? are pre-
-        pared  to  adjust  the number of digits they match in order to make the
+        pared to adjust the number of digits they match in order  to  make  the
         rest of the pattern match, (?>\d+) can only match an entire sequence of
         digits.
-        Atomic  groups in general can of course contain arbitrarily complicated
+        Atomic groups in general can of course contain arbitrarily  complicated
-        subpatterns, and can be nested. However, when  the  subpattern  for  an
+        subpatterns,  and  can  be  nested. However, when the subpattern for an
         atomic group is just a single repeated item, as in the example above, a
-        simpler notation, called a "possessive quantifier" can  be  used.  This
+        simpler  notation,  called  a "possessive quantifier" can be used. This
-        consists  of  an  additional  + character following a quantifier. Using
+        consists of an additional + character  following  a  quantifier.  Using
         this notation, the previous example can be rewritten as
           \d++foo
-Line 4592 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
+Line 4630 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
           (abc|xyz){2,3}+
-        Possessive   quantifiers   are   always  greedy;  the  setting  of  the
+        Possessive  quantifiers  are  always  greedy;  the   setting   of   the
         PCRE_UNGREEDY option is ignored. They are a convenient notation for the
-        simpler  forms  of atomic group. However, there is no difference in the
+        simpler forms of atomic group. However, there is no difference  in  the
-        meaning of a possessive quantifier and  the  equivalent  atomic  group,
+        meaning  of  a  possessive  quantifier and the equivalent atomic group,
-        though  there  may  be a performance difference; possessive quantifiers
+        though there may be a performance  difference;  possessive  quantifiers
         should be slightly faster.
-        The possessive quantifier syntax is an extension to the Perl  5.8  syn-
+        The  possessive  quantifier syntax is an extension to the Perl 5.8 syn-
-        tax.   Jeffrey  Friedl  originated the idea (and the name) in the first
+        tax.  Jeffrey Friedl originated the idea (and the name)  in  the  first
         edition of his book. Mike McCloskey liked it, so implemented it when he
-        built  Sun's Java package, and PCRE copied it from there. It ultimately
+        built Sun's Java package, and PCRE copied it from there. It  ultimately
         found its way into Perl at release 5.10.
         PCRE has an optimization that automatically "possessifies" certain sim-
-        ple  pattern  constructs.  For  example, the sequence A+B is treated as
+        ple pattern constructs. For example, the sequence  A+B  is  treated  as
-        A++B because there is no point in backtracking into a sequence  of  A's
+        A++B  because  there is no point in backtracking into a sequence of A's
         when B must follow.
-        When  a  pattern  contains an unlimited repeat inside a subpattern that
+        When a pattern contains an unlimited repeat inside  a  subpattern  that
-        can itself be repeated an unlimited number of  times,  the  use  of  an
+        can  itself  be  repeated  an  unlimited number of times, the use of an
-        atomic  group  is  the  only way to avoid some failing matches taking a
+        atomic group is the only way to avoid some  failing  matches  taking  a
         very long time indeed. The pattern
           (\D+|<\d+>)*[!?]
-        matches an unlimited number of substrings that either consist  of  non-
+        matches  an  unlimited number of substrings that either consist of non-
-        digits,  or  digits  enclosed in <>, followed by either ! or ?. When it
+        digits, or digits enclosed in <>, followed by either ! or  ?.  When  it
         matches, it runs quickly. However, if it is applied to
           aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
-        it takes a long time before reporting  failure.  This  is  because  the
+        it  takes  a  long  time  before reporting failure. This is because the
-        string  can be divided between the internal \D+ repeat and the external
+        string can be divided between the internal \D+ repeat and the  external
-        * repeat in a large number of ways, and all  have  to  be  tried.  (The
+        *  repeat  in  a  large  number of ways, and all have to be tried. (The
-        example  uses  [!?]  rather than a single character at the end, because
+        example uses [!?] rather than a single character at  the  end,  because
-        both PCRE and Perl have an optimization that allows  for  fast  failure
+        both  PCRE  and  Perl have an optimization that allows for fast failure
-        when  a single character is used. They remember the last single charac-
+        when a single character is used. They remember the last single  charac-
-        ter that is required for a match, and fail early if it is  not  present
+        ter  that  is required for a match, and fail early if it is not present
-        in  the  string.)  If  the pattern is changed so that it uses an atomic
+        in the string.) If the pattern is changed so that  it  uses  an  atomic
         group, like this:
           ((?>\D+)|<\d+>)*[!?]
-Line 4642 
 BACK REFERENCES
+Line 4680 
 BACK REFERENCES
         Outside a character class, a backslash followed by a digit greater than
 (and possibly further digits) is a back reference to a capturing sub-
-        pattern earlier (that is, to its left) in the pattern,  provided  there
+        pattern  earlier  (that is, to its left) in the pattern, provided there
         have been that many previous capturing left parentheses.
         However, if the decimal number following the backslash is less than 10,
-        it is always taken as a back reference, and causes  an  error  only  if
+        it  is  always  taken  as a back reference, and causes an error only if
-        there  are  not that many capturing left parentheses in the entire pat-
+        there are not that many capturing left parentheses in the  entire  pat-
-        tern. In other words, the parentheses that are referenced need  not  be
+        tern.  In  other words, the parentheses that are referenced need not be
-        to  the left of the reference for numbers less than 10. A "forward back
+        to the left of the reference for numbers less than 10. A "forward  back
-        reference" of this type can make sense when a  repetition  is  involved
+        reference"  of  this  type can make sense when a repetition is involved
-        and  the  subpattern to the right has participated in an earlier itera-
+        and the subpattern to the right has participated in an  earlier  itera-
         tion.
-        It is not possible to have a numerical "forward back  reference"  to  a
+        It  is  not  possible to have a numerical "forward back reference" to a
-        subpattern  whose  number  is  10  or  more using this syntax because a
+        subpattern whose number is 10 or  more  using  this  syntax  because  a
-        sequence such as \50 is interpreted as a character  defined  in  octal.
+        sequence  such  as  \50 is interpreted as a character defined in octal.
         See the subsection entitled "Non-printing characters" above for further
-        details of the handling of digits following a backslash.  There  is  no
+        details  of  the  handling of digits following a backslash. There is no
-        such  problem  when named parentheses are used. A back reference to any
+        such problem when named parentheses are used. A back reference  to  any
         subpattern is possible using named parentheses (see below).
-        Another way of avoiding the ambiguity inherent in  the  use  of  digits
+        Another  way  of  avoiding  the ambiguity inherent in the use of digits
-        following  a  backslash  is  to use the \g escape sequence. This escape
+        following a backslash is to use the \g  escape  sequence.  This  escape
         must be followed by an unsigned number or a negative number, optionally
         enclosed in braces. These examples are all identical:
-Line 4671 
 BACK REFERENCES
+Line 4709 
 BACK REFERENCES
           (ring), \g1
           (ring), \g{1}
-        An  unsigned number specifies an absolute reference without the ambigu-
+        An unsigned number specifies an absolute reference without the  ambigu-
         ity that is present in the older syntax. It is also useful when literal
         digits follow the reference. A negative number is a relative reference.
         Consider this example:
-Line 4679 
 BACK REFERENCES
+Line 4717 
 BACK REFERENCES
           (abc(def)ghi)\g{-1}
         The sequence \g{-1} is a reference to the most recently started captur-
-        ing  subpattern  before \g, that is, is it equivalent to \2. Similarly,
+        ing subpattern before \g, that is, is it equivalent to \2 in this exam-
-        \g{-2} would be equivalent to \1. The use of relative references can be
+        ple.   Similarly, \g{-2} would be equivalent to \1. The use of relative
-        helpful  in  long  patterns,  and  also in patterns that are created by
+        references can be helpful in long patterns, and also in  patterns  that
-        joining together fragments that contain references within themselves.
+        are  created  by  joining  together  fragments  that contain references
+        within themselves.
         A back reference matches whatever actually matched the  capturing  sub-
         pattern  in  the  current subject string, rather than anything matching
-Line 4802 
 ASSERTIONS
+Line 4841 
 ASSERTIONS
         most  convenient  way  to  do  it  is with (?!) because an empty string
         always matches, so an assertion that requires there not to be an  empty
         string must always fail.  The backtracking control verb (*FAIL) or (*F)
-        is essentially a synonym for (?!).
+        is a synonym for (?!).
     Lookbehind assertions
-Line 4945 
 CONDITIONAL SUBPATTERNS
+Line 4984 
 CONDITIONAL SUBPATTERNS
         the condition is true if a capturing subpattern of that number has pre-
         viously matched. If there is more than one  capturing  subpattern  with
         the  same  number  (see  the earlier section about duplicate subpattern
-        numbers), the condition is true if any of them have been set. An alter-
+        numbers), the condition is true if any of them have matched. An  alter-
         native  notation is to precede the digits with a plus or minus sign. In
         this case, the subpattern number is relative rather than absolute.  The
         most  recently opened parentheses can be referenced by (?(-1), the next
-        most recent by (?(-2), and so on. In looping  constructs  it  can  also
+        most recent by (?(-2), and so on. Inside loops it can also  make  sense
-        make  sense  to  refer  to  subsequent  groups  with constructs such as
+        to refer to subsequent groups. The next parentheses to be opened can be
-        (?(+2).
+        referenced as (?(+1), and so on. (The value zero in any of these  forms
+        is not used; it provokes a compile-time error.)
-        Consider the following pattern, which  contains  non-significant  white
+        Consider  the  following  pattern, which contains non-significant white
         space to make it more readable (assume the PCRE_EXTENDED option) and to
         divide it into three parts for ease of discussion:
           ( \( )?    [^()]+    (?(1) \) )
-        The first part matches an optional opening  parenthesis,  and  if  that
+        The  first  part  matches  an optional opening parenthesis, and if that
         character is present, sets it as the first captured substring. The sec-
-        ond part matches one or more characters that are not  parentheses.  The
+        ond  part  matches one or more characters that are not parentheses. The
-        third part is a conditional subpattern that tests whether the first set
+        third part is a conditional subpattern that tests whether  or  not  the
-        of parentheses matched or not. If they did, that is, if subject started
+        first  set  of  parentheses  matched.  If they did, that is, if subject
-        with an opening parenthesis, the condition is true, and so the yes-pat-
+        started with an opening parenthesis, the condition is true, and so  the
-        tern is executed and a  closing  parenthesis  is  required.  Otherwise,
+        yes-pattern  is  executed and a closing parenthesis is required. Other-
-        since  no-pattern  is  not  present, the subpattern matches nothing. In
+        wise, since no-pattern is not present, the subpattern matches  nothing.
-        other words,  this  pattern  matches  a  sequence  of  non-parentheses,
+        In  other  words,  this  pattern matches a sequence of non-parentheses,
         optionally enclosed in parentheses.
-        If  you  were  embedding  this pattern in a larger one, you could use a
+        If you were embedding this pattern in a larger one,  you  could  use  a
         relative reference:
           ...other stuff... ( \( )?    [^()]+    (?(-1) \) ) ...
-        This makes the fragment independent of the parentheses  in  the  larger
+        This  makes  the  fragment independent of the parentheses in the larger
         pattern.
     Checking for a used subpattern by name
-        Perl  uses  the  syntax  (?(<name>)...) or (?('name')...) to test for a
+        Perl uses the syntax (?(<name>)...) or (?('name')...)  to  test  for  a
-        used subpattern by name. For compatibility  with  earlier  versions  of
+        used  subpattern  by  name.  For compatibility with earlier versions of
-        PCRE,  which  had this facility before Perl, the syntax (?(name)...) is
+        PCRE, which had this facility before Perl, the syntax  (?(name)...)  is
-        also recognized. However, there is a possible ambiguity with this  syn-
+        also  recognized. However, there is a possible ambiguity with this syn-
-        tax,  because  subpattern  names  may  consist entirely of digits. PCRE
+        tax, because subpattern names may  consist  entirely  of  digits.  PCRE
-        looks first for a named subpattern; if it cannot find one and the  name
+        looks  first for a named subpattern; if it cannot find one and the name
-        consists  entirely  of digits, PCRE looks for a subpattern of that num-
+        consists entirely of digits, PCRE looks for a subpattern of  that  num-
-        ber, which must be greater than zero. Using subpattern names that  con-
+        ber,  which must be greater than zero. Using subpattern names that con-
         sist entirely of digits is not recommended.
         Rewriting the above example to use a named subpattern gives this:
           (?<OPEN> \( )?    [^()]+    (?(<OPEN>) \) )
-        If  the  name used in a condition of this kind is a duplicate, the test
+        If the name used in a condition of this kind is a duplicate,  the  test
-        is applied to all subpatterns of the same name, and is true if any  one
+        is  applied to all subpatterns of the same name, and is true if any one
         of them has matched.
     Checking for pattern recursion
         If the condition is the string (R), and there is no subpattern with the
-        name R, the condition is true if a recursive call to the whole  pattern
+        name  R, the condition is true if a recursive call to the whole pattern
         or any subpattern has been made. If digits or a name preceded by amper-
         sand follow the letter R, for example:
-Line 5009 
 CONDITIONAL SUBPATTERNS
+Line 5049 
 CONDITIONAL SUBPATTERNS
         the condition is true if the most recent recursion is into a subpattern
         whose number or name is given. This condition does not check the entire
-        recursion stack. If the name used in a condition  of  this  kind  is  a
+        recursion  stack.  If  the  name  used in a condition of this kind is a
         duplicate, the test is applied to all subpatterns of the same name, and
         is true if any one of them is the most recent recursion.
-        At "top level", all these recursion test  conditions  are  false.   The
+        At  "top  level",  all  these recursion test conditions are false.  The
         syntax for recursive patterns is described below.
     Defining subpatterns for use by reference only
-        If  the  condition  is  the string (DEFINE), and there is no subpattern
+        If the condition is the string (DEFINE), and  there  is  no  subpattern
-        with the name DEFINE, the condition is  always  false.  In  this  case,
+        with  the  name  DEFINE,  the  condition is always false. In this case,
-        there  may  be  only  one  alternative  in the subpattern. It is always
+        there may be only one alternative  in  the  subpattern.  It  is  always
-        skipped if control reaches this point  in  the  pattern;  the  idea  of
+        skipped  if  control  reaches  this  point  in the pattern; the idea of
-        DEFINE  is that it can be used to define "subroutines" that can be ref-
+        DEFINE is that it can be used to define "subroutines" that can be  ref-
-        erenced from elsewhere. (The use of "subroutines" is described  below.)
+        erenced  from elsewhere. (The use of "subroutines" is described below.)
-        For  example,  a pattern to match an IPv4 address could be written like
+        For  example,  a  pattern  to   match   an   IPv4   address   such   as
-        this (ignore whitespace and line breaks):
+        "192.168.23.245" could be written like this (ignore whitespace and line
+        breaks):
           (?(DEFINE) (?<byte> 2[0-4]\d | 25[0-5] | 1\d\d | [1-9]?\d) )
           \b (?&byte) (\.(?&byte)){3} \b
-Line 5242 
 RECURSIVE PATTERNS
+Line 5283 
 RECURSIVE PATTERNS
         remaining alternative is at a deeper recursion level, which PCRE cannot
         use.
-        To change the pattern so that matches all palindromic strings, not just
+        To  change  the pattern so that it matches all palindromic strings, not
-        those with an odd number of characters, it is tempting  to  change  the
+        just those with an odd number of characters, it is tempting  to  change
-        pattern to this:
+        the pattern to this:
           ^((.)(?1)\2|.?)$
-Line 5411 
 BACKTRACKING CONTROL
+Line 5452 
 BACKTRACKING CONTROL
         character must be present. When one of these  optimizations  suppresses
         the  running  of  a match, any included backtracking verbs will not, of
         course, be processed. You can suppress the start-of-match optimizations
-        by setting the PCRE_NO_START_OPTIMIZE option when calling pcre_exec().
+        by  setting  the  PCRE_NO_START_OPTIMIZE  option when calling pcre_com-
+        pile() or pcre_exec(), or by starting the pattern with (*NO_START_OPT).
     Verbs that act immediately
-        The  following  verbs act as soon as they are encountered. They may not
+        The following verbs act as soon as they are encountered. They  may  not
         be followed by a name.
            (*ACCEPT)
-        This verb causes the match to end successfully, skipping the  remainder
+        This  verb causes the match to end successfully, skipping the remainder
-        of  the pattern. When inside a recursion, only the innermost pattern is
+        of the pattern. When inside a recursion, only the innermost pattern  is
-        ended immediately. If (*ACCEPT) is inside  capturing  parentheses,  the
+        ended  immediately.  If  (*ACCEPT) is inside capturing parentheses, the
-        data  so  far  is  captured. (This feature was added to PCRE at release
+        data so far is captured. (This feature was added  to  PCRE  at  release
 .00.) For example:
           A((?:A|B(*ACCEPT)|C)D)
-        This matches "AB", "AAD", or "ACD"; when it matches "AB", "B"  is  cap-
+        This  matches  "AB", "AAD", or "ACD"; when it matches "AB", "B" is cap-
         tured by the outer parentheses.
           (*FAIL) or (*F)
-        This  verb  causes the match to fail, forcing backtracking to occur. It
+        This verb causes the match to fail, forcing backtracking to  occur.  It
-        is equivalent to (?!) but easier to read. The Perl documentation  notes
+        is  equivalent to (?!) but easier to read. The Perl documentation notes
-        that  it  is  probably  useful only when combined with (?{}) or (??{}).
+        that it is probably useful only when combined  with  (?{})  or  (??{}).
-        Those are, of course, Perl features that are not present in  PCRE.  The
+        Those  are,  of course, Perl features that are not present in PCRE. The
-        nearest  equivalent is the callout feature, as for example in this pat-
+        nearest equivalent is the callout feature, as for example in this  pat-
         tern:
           a+(?C)(*FAIL)
-        A match with the string "aaaa" always fails, but the callout  is  taken
+        A  match  with the string "aaaa" always fails, but the callout is taken
         before each backtrack happens (in this example, 10 times).
     Recording which path was taken
-        There  is  one  verb  whose  main  purpose  is to track how a match was
+        There is one verb whose main purpose  is  to  track  how  a  match  was
-        arrived at, though it also has a  secondary  use  in  conjunction  with
+        arrived  at,  though  it  also  has a secondary use in conjunction with
         advancing the match starting point (see (*SKIP) below).
           (*MARK:NAME) or (*:NAME)
-        A  name  is  always  required  with  this  verb.  There  may be as many
+        A name is always  required  with  this  verb.  There  may  be  as  many
-        instances of (*MARK) as you like in a pattern, and their names  do  not
+        instances  of  (*MARK) as you like in a pattern, and their names do not
         have to be unique.
-        When  a  match  succeeds,  the  name of the last-encountered (*MARK) is
+        When a match succeeds, the name  of  the  last-encountered  (*MARK)  is
-        passed back to  the  caller  via  the  pcre_extra  data  structure,  as
+        passed  back  to  the  caller  via  the  pcre_extra  data structure, as
         described in the section on pcre_extra in the pcreapi documentation. No
-        data is returned for a partial match. Here is an  example  of  pcretest
+        data  is  returned  for a partial match. Here is an example of pcretest
-        output,  where the /K modifier requests the retrieval and outputting of
+        output, where the /K modifier requests the retrieval and outputting  of
         (*MARK) data:
           /X(*MARK:A)Y|X(*MARK:B)Z/K
-Line 5473 
 BACKTRACKING CONTROL
+Line 5515 
 BACKTRACKING CONTROL
           MK: B
         The (*MARK) name is tagged with "MK:" in this output, and in this exam-
-        ple  it indicates which of the two alternatives matched. This is a more
+        ple it indicates which of the two alternatives matched. This is a  more
-        efficient way of obtaining this information than putting each  alterna-
+        efficient  way of obtaining this information than putting each alterna-
         tive in its own capturing parentheses.
-        A  name  may  also  be  returned after a failed match if the final path
+        A name may also be returned after a failed  match  if  the  final  path
-        through the pattern involves (*MARK). However, unless (*MARK)  used  in
+        through  the  pattern involves (*MARK). However, unless (*MARK) used in
-        conjunction  with  (*COMMIT),  this  is unlikely to happen for an unan-
+        conjunction with (*COMMIT), this is unlikely to  happen  for  an  unan-
         chored pattern because, as the starting point for matching is advanced,
         the final check is often with an empty string, causing a failure before
         (*MARK) is reached. For example:
-Line 5489 
 BACKTRACKING CONTROL
+Line 5531 
 BACKTRACKING CONTROL
           No match
         There are three potential starting points for this match (starting with
-        X,  starting  with  P,  and  with  an  empty string). If the pattern is
+        X, starting with P, and with  an  empty  string).  If  the  pattern  is
         anchored, the result is different:
           /^X(*MARK:A)Y|^X(*MARK:B)Z/K
           XP
           No match, mark = B
-        PCRE's start-of-match optimizations can also interfere with  this.  For
+        PCRE's  start-of-match  optimizations can also interfere with this. For
-        example,  if, as a result of a call to pcre_study(), it knows the mini-
+        example, if, as a result of a call to pcre_study(), it knows the  mini-
-        mum subject length for a match, a shorter subject will not  be  scanned
+        mum  subject  length for a match, a shorter subject will not be scanned
         at all.
         Note that similar anomalies (though different in detail) exist in Perl,
-        no doubt for the same reasons. The use of (*MARK) data after  a  failed
+        no  doubt  for the same reasons. The use of (*MARK) data after a failed
-        match  of an unanchored pattern is not recommended, unless (*COMMIT) is
+        match of an unanchored pattern is not recommended, unless (*COMMIT)  is
         involved.
     Verbs that act after backtracking
         The following verbs do nothing when they are encountered. Matching con-
-        tinues  with what follows, but if there is no subsequent match, causing
+        tinues with what follows, but if there is no subsequent match,  causing
-        a backtrack to the verb, a failure is  forced.  That  is,  backtracking
+        a  backtrack  to  the  verb, a failure is forced. That is, backtracking
-        cannot  pass  to the left of the verb. However, when one of these verbs
+        cannot pass to the left of the verb. However, when one of  these  verbs
-        appears inside an atomic group, its effect is confined to  that  group,
+        appears  inside  an atomic group, its effect is confined to that group,
-        because  once the group has been matched, there is never any backtrack-
+        because once the group has been matched, there is never any  backtrack-
-        ing into it. In this situation, backtracking can  "jump  back"  to  the
+        ing  into  it.  In  this situation, backtracking can "jump back" to the
-        left  of the entire atomic group. (Remember also, as stated above, that
+        left of the entire atomic group. (Remember also, as stated above,  that
         this localization also applies in subroutine calls and assertions.)
-        These verbs differ in exactly what kind of failure  occurs  when  back-
+        These  verbs  differ  in exactly what kind of failure occurs when back-
         tracking reaches them.
           (*COMMIT)
-        This  verb, which may not be followed by a name, causes the whole match
+        This verb, which may not be followed by a name, causes the whole  match
         to fail outright if the rest of the pattern does not match. Even if the
         pattern is unanchored, no further attempts to find a match by advancing
         the  starting  point  take  place.  Once  (*COMMIT)  has  been  passed,
-        pcre_exec()  is  committed  to  finding a match at the current starting
+        pcre_exec() is committed to finding a match  at  the  current  starting
         point, or not at all. For example:
           a+(*COMMIT)b
-        This matches "xxaab" but not "aacaab". It can be thought of as  a  kind
+        This  matches  "xxaab" but not "aacaab". It can be thought of as a kind
         of dynamic anchor, or "I've started, so I must finish." The name of the
-        most recently passed (*MARK) in the path is passed back when  (*COMMIT)
+        most  recently passed (*MARK) in the path is passed back when (*COMMIT)
         forces a match failure.