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

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-revision 185 by ph10,
Tue Jun 19 13:39:46 2007 UTC
+revision 289 by ph10,
Sun Dec 23 12:17:20 2007 UTC
 Line 45 
 INTRODUCTION
         Details of exactly which Perl regular expression features are  and  are
         not supported by PCRE are given in separate documents. See the pcrepat-
-        tern and pcrecompat pages.
+        tern and pcrecompat pages. There is a syntax summary in the  pcresyntax
+        page.
-        Some features of PCRE can be included, excluded, or  changed  when  the
+        Some  features  of  PCRE can be included, excluded, or changed when the
-        library  is  built.  The pcre_config() function makes it possible for a
+        library is built. The pcre_config() function makes it  possible  for  a
-        client to discover which features are  available.  The  features  them-
+        client  to  discover  which  features are available. The features them-
-        selves  are described in the pcrebuild page. Documentation about build-
+        selves are described in the pcrebuild page. Documentation about  build-
-        ing PCRE for various operating systems can be found in the README  file
+        ing  PCRE for various operating systems can be found in the README file
         in the source distribution.
-        The  library  contains  a number of undocumented internal functions and
+        The library contains a number of undocumented  internal  functions  and
-        data tables that are used by more than one  of  the  exported  external
+        data  tables  that  are  used by more than one of the exported external
-        functions,  but  which  are  not  intended for use by external callers.
+        functions, but which are not intended  for  use  by  external  callers.
-        Their names all begin with "_pcre_", which hopefully will  not  provoke
+        Their  names  all begin with "_pcre_", which hopefully will not provoke
         any name clashes. In some environments, it is possible to control which
-        external symbols are exported when a shared library is  built,  and  in
+        external  symbols  are  exported when a shared library is built, and in
         these cases the undocumented symbols are not exported.
  USER DOCUMENTATION
-        The  user  documentation  for PCRE comprises a number of different sec-
+        The user documentation for PCRE comprises a number  of  different  sec-
-        tions. In the "man" format, each of these is a separate "man page".  In
+        tions.  In the "man" format, each of these is a separate "man page". In
-        the  HTML  format, each is a separate page, linked from the index page.
+        the HTML format, each is a separate page, linked from the  index  page.
-        In the plain text format, all the sections are concatenated,  for  ease
+        In  the  plain text format, all the sections are concatenated, for ease
         of searching. The sections are as follows:
           pcre              this document
-Line 83 
 USER DOCUMENTATION
+Line 84 
 USER DOCUMENTATION
           pcrepartial       details of the partial matching facility
           pcrepattern       syntax and semantics of supported
                               regular expressions
+          pcresyntax        quick syntax reference
           pcreperform       discussion of performance issues
           pcreposix         the POSIX-compatible C API
           pcreprecompile    details of saving and re-using precompiled patterns
-Line 90 
 USER DOCUMENTATION
+Line 92 
 USER DOCUMENTATION
           pcrestack         discussion of stack usage
           pcretest          description of the pcretest testing command
-        In addition, in the "man" and HTML formats, there is a short  page  for
+        In  addition,  in the "man" and HTML formats, there is a short page for
         each C library function, listing its arguments and results.
  LIMITATIONS
-        There  are some size limitations in PCRE but it is hoped that they will
+        There are some size limitations in PCRE but it is hoped that they  will
         never in practice be relevant.
-        The maximum length of a compiled pattern is 65539 (sic) bytes  if  PCRE
+        The  maximum  length of a compiled pattern is 65539 (sic) bytes if PCRE
         is compiled with the default internal linkage size of 2. If you want to
-        process regular expressions that are truly enormous,  you  can  compile
+        process  regular  expressions  that are truly enormous, you can compile
-        PCRE  with  an  internal linkage size of 3 or 4 (see the README file in
+        PCRE with an internal linkage size of 3 or 4 (see the  README  file  in
-        the source distribution and the pcrebuild documentation  for  details).
+        the  source  distribution and the pcrebuild documentation for details).
-        In  these  cases the limit is substantially larger.  However, the speed
+        In these cases the limit is substantially larger.  However,  the  speed
         of execution is slower.
-        All values in repeating quantifiers must be less than 65536. The  maxi-
+        All values in repeating quantifiers must be less than 65536.
-        mum  compiled  length  of  subpattern  with an explicit repeat count is
-bytes. The maximum number of capturing subpatterns is 65535.
         There is no limit to the number of parenthesized subpatterns, but there
         can be no more than 65535 capturing subpatterns.
 Line 117 
 LIMITATIONS
         The maximum length of name for a named subpattern is 32 characters, and
         the maximum number of named subpatterns is 10000.
-        The maximum length of a subject string is the largest  positive  number
+        The  maximum  length of a subject string is the largest positive number
-        that  an integer variable can hold. However, when using the traditional
+        that an integer variable can hold. However, when using the  traditional
         matching function, PCRE uses recursion to handle subpatterns and indef-
-        inite  repetition.  This means that the available stack space may limit
+        inite repetition.  This means that the available stack space may  limit
         the size of a subject string that can be processed by certain patterns.
         For a discussion of stack issues, see the pcrestack documentation.
  UTF-8 AND UNICODE PROPERTY SUPPORT
-        From  release  3.3,  PCRE  has  had  some support for character strings
+        From release 3.3, PCRE has  had  some  support  for  character  strings
-        encoded in the UTF-8 format. For release 4.0 this was greatly  extended
+        encoded  in the UTF-8 format. For release 4.0 this was greatly extended
-        to  cover  most common requirements, and in release 5.0 additional sup-
+        to cover most common requirements, and in release 5.0  additional  sup-
         port for Unicode general category properties was added.
-        In order process UTF-8 strings, you must build PCRE  to  include  UTF-8
+        In  order  process  UTF-8 strings, you must build PCRE to include UTF-8
-        support  in  the  code,  and, in addition, you must call pcre_compile()
+        support in the code, and, in addition,  you  must  call  pcre_compile()
-        with the PCRE_UTF8 option flag. When you do this, both the pattern  and
+        with  the PCRE_UTF8 option flag. When you do this, both the pattern and
-        any  subject  strings  that are matched against it are treated as UTF-8
+        any subject strings that are matched against it are  treated  as  UTF-8
         strings instead of just strings of bytes.
-        If you compile PCRE with UTF-8 support, but do not use it at run  time,
+        If  you compile PCRE with UTF-8 support, but do not use it at run time,
-        the  library will be a bit bigger, but the additional run time overhead
+        the library will be a bit bigger, but the additional run time  overhead
         is limited to testing the PCRE_UTF8 flag occasionally, so should not be
         very big.
         If PCRE is built with Unicode character property support (which implies
-        UTF-8 support), the escape sequences \p{..}, \P{..}, and  \X  are  sup-
+        UTF-8  support),  the  escape sequences \p{..}, \P{..}, and \X are sup-
         ported.  The available properties that can be tested are limited to the
-        general category properties such as Lu for an upper case letter  or  Nd
+        general  category  properties such as Lu for an upper case letter or Nd
-        for  a  decimal number, the Unicode script names such as Arabic or Han,
+        for a decimal number, the Unicode script names such as Arabic  or  Han,
-        and the derived properties Any and L&. A full  list  is  given  in  the
+        and  the  derived  properties  Any  and L&. A full list is given in the
         pcrepattern documentation. Only the short names for properties are sup-
-        ported. For example, \p{L} matches a letter. Its Perl synonym,  \p{Let-
+        ported.  For example, \p{L} matches a letter. Its Perl synonym, \p{Let-
-        ter},  is  not  supported.   Furthermore,  in Perl, many properties may
+        ter}, is not supported.  Furthermore,  in  Perl,  many  properties  may
-        optionally be prefixed by "Is", for compatibility with Perl  5.6.  PCRE
+        optionally  be  prefixed by "Is", for compatibility with Perl 5.6. PCRE
         does not support this.
-        The following comments apply when PCRE is running in UTF-8 mode:
+    Validity of UTF-8 strings
+        When you set the PCRE_UTF8 flag, the strings  passed  as  patterns  and
+        subjects are (by default) checked for validity on entry to the relevant
+        functions. From release 7.3 of PCRE, the check is according  the  rules
+        of  RFC  3629, which are themselves derived from the Unicode specifica-
+        tion. Earlier releases of PCRE followed the rules of  RFC  2279,  which
+        allows  the  full range of 31-bit values (0 to 0x7FFFFFFF). The current
+        check allows only values in the range U+0 to U+10FFFF, excluding U+D800
+        to U+DFFF.
+        The  excluded  code  points are the "Low Surrogate Area" of Unicode, of
+        which the Unicode Standard says this: "The Low Surrogate Area does  not
+        contain  any  character  assignments,  consequently  no  character code
+        charts or namelists are provided for this area. Surrogates are reserved
+        for  use  with  UTF-16 and then must be used in pairs." The code points
+        that are encoded by UTF-16 pairs  are  available  as  independent  code
+        points  in  the  UTF-8  encoding.  (In other words, the whole surrogate
+        thing is a fudge for UTF-16 which unfortunately messes up UTF-8.)
+        If an  invalid  UTF-8  string  is  passed  to  PCRE,  an  error  return
+        (PCRE_ERROR_BADUTF8) is given. In some situations, you may already know
+        that your strings are valid, and therefore want to skip these checks in
+        order to improve performance. If you set the PCRE_NO_UTF8_CHECK flag at
+        compile time or at run time, PCRE assumes that the pattern  or  subject
+        it  is  given  (respectively)  contains only valid UTF-8 codes. In this
+        case, it does not diagnose an invalid UTF-8 string.
+        If you pass an invalid UTF-8 string  when  PCRE_NO_UTF8_CHECK  is  set,
+        what  happens  depends on why the string is invalid. If the string con-
+        forms to the "old" definition of UTF-8 (RFC 2279), it is processed as a
+        string  of  characters  in  the  range 0 to 0x7FFFFFFF. In other words,
+        apart from the initial validity test, PCRE (when in UTF-8 mode) handles
+        strings  according  to  the more liberal rules of RFC 2279. However, if
+        the string does not even conform to RFC 2279, the result is  undefined.
+        Your program may crash.
+        If  you  want  to  process  strings  of  values  in the full range 0 to
+x7FFFFFFF, encoded in a UTF-8-like manner as per the old RFC, you  can
+        set PCRE_NO_UTF8_CHECK to bypass the more restrictive test. However, in
+        this situation, you will have to apply your own validity check.
-.  When you set the PCRE_UTF8 flag, the strings passed as patterns and
+    General comments about UTF-8 mode
-        subjects are checked for validity on entry to the  relevant  functions.
-        If an invalid UTF-8 string is passed, an error return is given. In some
-        situations, you may already know  that  your  strings  are  valid,  and
-        therefore want to skip these checks in order to improve performance. If
-        you set the PCRE_NO_UTF8_CHECK flag at compile time  or  at  run  time,
-        PCRE  assumes  that  the  pattern or subject it is given (respectively)
-        contains only valid UTF-8 codes. In this case, it does not diagnose  an
-        invalid  UTF-8 string. If you pass an invalid UTF-8 string to PCRE when
-        PCRE_NO_UTF8_CHECK is set, the results are undefined. Your program  may
-        crash.
-.  An  unbraced  hexadecimal  escape sequence (such as \xb3) matches a
+. An unbraced hexadecimal escape sequence (such  as  \xb3)  matches  a
         two-byte UTF-8 character if the value is greater than 127.
-. Octal numbers up to \777 are recognized, and  match  two-byte  UTF-8
+.  Octal  numbers  up to \777 are recognized, and match two-byte UTF-8
         characters for values greater than \177.
-.  Repeat quantifiers apply to complete UTF-8 characters, not to indi-
+. Repeat quantifiers apply to complete UTF-8 characters, not to  indi-
         vidual bytes, for example: \x{100}{3}.
-. The dot metacharacter matches one UTF-8 character instead of a  sin-
+.  The dot metacharacter matches one UTF-8 character instead of a sin-
         gle byte.
-.  The  escape sequence \C can be used to match a single byte in UTF-8
+. The escape sequence \C can be used to match a single byte  in  UTF-8
-        mode, but its use can lead to some strange effects.  This  facility  is
+        mode,  but  its  use can lead to some strange effects. This facility is
         not available in the alternative matching function, pcre_dfa_exec().
-.  The  character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly
+. The character escapes \b, \B, \d, \D, \s, \S, \w, and  \W  correctly
-        test characters of any code value, but the characters that PCRE  recog-
+        test  characters of any code value, but the characters that PCRE recog-
-        nizes  as  digits,  spaces,  or  word characters remain the same set as
+        nizes as digits, spaces, or word characters  remain  the  same  set  as
         before, all with values less than 256. This remains true even when PCRE
-        includes  Unicode  property support, because to do otherwise would slow
+        includes Unicode property support, because to do otherwise  would  slow
-        down PCRE in many common cases. If you really want to test for a  wider
+        down  PCRE in many common cases. If you really want to test for a wider
-        sense  of,  say,  "digit",  you must use Unicode property tests such as
+        sense of, say, "digit", you must use Unicode  property  tests  such  as
         \p{Nd}.
-. Similarly, characters that match the POSIX named  character  classes
+.  Similarly,  characters that match the POSIX named character classes
         are all low-valued characters.
-.  However,  the Perl 5.10 horizontal and vertical whitespace matching
+. However, the Perl 5.10 horizontal and vertical  whitespace  matching
         escapes (\h, \H, \v, and \V) do match all the appropriate Unicode char-
         acters.
-.  Case-insensitive  matching applies only to characters whose values
+. Case-insensitive matching applies only to  characters  whose  values
-        are less than 128, unless PCRE is built with Unicode property  support.
+        are  less than 128, unless PCRE is built with Unicode property support.
-        Even  when  Unicode  property support is available, PCRE still uses its
+        Even when Unicode property support is available, PCRE  still  uses  its
-        own character tables when checking the case of  low-valued  characters,
+        own  character  tables when checking the case of low-valued characters,
-        so  as not to degrade performance.  The Unicode property information is
+        so as not to degrade performance.  The Unicode property information  is
         used only for characters with higher values. Even when Unicode property
         support is available, PCRE supports case-insensitive matching only when
-        there is a one-to-one mapping between a letter's  cases.  There  are  a
+        there  is  a  one-to-one  mapping between a letter's cases. There are a
-        small  number  of  many-to-one  mappings in Unicode; these are not sup-
+        small number of many-to-one mappings in Unicode;  these  are  not  sup-
         ported by PCRE.
-Line 219 
 AUTHOR
+Line 249 
 AUTHOR
         University Computing Service
         Cambridge CB2 3QH, England.
-        Putting an actual email address here seems to have been a spam  magnet,
+        Putting  an actual email address here seems to have been a spam magnet,
-        so  I've  taken  it away. If you want to email me, use my two initials,
+        so I've taken it away. If you want to email me, use  my  two  initials,
         followed by the two digits 10, at the domain cam.ac.uk.
  REVISION
-        Last updated: 13 June 2007
+        Last updated: 09 August 2007
         Copyright (c) 1997-2007 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 241 
 NAME
+Line 271 
 NAME
  PCRE BUILD-TIME OPTIONS
         This  document  describes  the  optional  features  of PCRE that can be
-        selected when the library is compiled. They are all selected, or  dese-
+        selected when the library is compiled. It assumes use of the  configure
-        lected, by providing options to the configure script that is run before
+        script,  where the optional features are selected or deselected by pro-
-        the make command. The complete list of  options  for  configure  (which
+        viding options to configure before running the make  command.  However,
-        includes  the  standard  ones such as the selection of the installation
+        the  same  options  can be selected in both Unix-like and non-Unix-like
-        directory) can be obtained by running
+        environments using the GUI facility of  CMakeSetup  if  you  are  using
+        CMake instead of configure to build PCRE.
+        The complete list of options for configure (which includes the standard
+        ones such as the  selection  of  the  installation  directory)  can  be
+        obtained by running
           ./configure --help
-        The following sections include  descriptions  of  options  whose  names
+        The  following  sections  include  descriptions  of options whose names
         begin with --enable or --disable. These settings specify changes to the
-        defaults for the configure command. Because of the way  that  configure
+        defaults  for  the configure command. Because of the way that configure
-        works,  --enable  and --disable always come in pairs, so the complemen-
+        works, --enable and --disable always come in pairs, so  the  complemen-
-        tary option always exists as well, but as it specifies the default,  it
+        tary  option always exists as well, but as it specifies the default, it
         is not described.
-Line 274 
 UTF-8 SUPPORT
+Line 309 
 UTF-8 SUPPORT
           --enable-utf8
-        to  the  configure  command.  Of  itself, this does not make PCRE treat
+        to the configure command. Of itself, this  does  not  make  PCRE  treat
-        strings as UTF-8. As well as compiling PCRE with this option, you  also
+        strings  as UTF-8. As well as compiling PCRE with this option, you also
-        have  have to set the PCRE_UTF8 option when you call the pcre_compile()
+        have have to set the PCRE_UTF8 option when you call the  pcre_compile()
         function.
  UNICODE CHARACTER PROPERTY SUPPORT
-        UTF-8 support allows PCRE to process character values greater than  255
+        UTF-8  support allows PCRE to process character values greater than 255
-        in  the  strings that it handles. On its own, however, it does not pro-
+        in the strings that it handles. On its own, however, it does  not  pro-
         vide any facilities for accessing the properties of such characters. If
-        you  want  to  be able to use the pattern escapes \P, \p, and \X, which
+        you want to be able to use the pattern escapes \P, \p,  and  \X,  which
         refer to Unicode character properties, you must add
           --enable-unicode-properties
-        to the configure command. This implies UTF-8 support, even if you  have
+        to  the configure command. This implies UTF-8 support, even if you have
         not explicitly requested it.
-        Including  Unicode  property  support  adds around 30K of tables to the
+        Including Unicode property support adds around 30K  of  tables  to  the
-        PCRE library. Only the general category properties such as  Lu  and  Nd
+        PCRE  library.  Only  the general category properties such as Lu and Nd
         are supported. Details are given in the pcrepattern documentation.
  CODE VALUE OF NEWLINE
-        By  default,  PCRE interprets character 10 (linefeed, LF) as indicating
+        By default, PCRE interprets character 10 (linefeed, LF)  as  indicating
-        the end of a line. This is the normal newline  character  on  Unix-like
+        the  end  of  a line. This is the normal newline character on Unix-like
         systems. You can compile PCRE to use character 13 (carriage return, CR)
         instead, by adding
           --enable-newline-is-cr
-        to the  configure  command.  There  is  also  a  --enable-newline-is-lf
+        to  the  configure  command.  There  is  also  a --enable-newline-is-lf
         option, which explicitly specifies linefeed as the newline character.
         Alternatively, you can specify that line endings are to be indicated by
-Line 319 
 CODE VALUE OF NEWLINE
+Line 354 
 CODE VALUE OF NEWLINE
           --enable-newline-is-anycrlf
-        which causes PCRE to recognize any of the three sequences  CR,  LF,  or
+        which  causes  PCRE  to recognize any of the three sequences CR, LF, or
         CRLF as indicating a line ending. Finally, a fifth option, specified by
           --enable-newline-is-any
         causes PCRE to recognize any Unicode newline sequence.
-        Whatever line ending convention is selected when PCRE is built  can  be
+        Whatever  line  ending convention is selected when PCRE is built can be
-        overridden  when  the library functions are called. At build time it is
+        overridden when the library functions are called. At build time  it  is
         conventional to use the standard for your operating system.
+ WHAT \R MATCHES
+        By  default,  the  sequence \R in a pattern matches any Unicode newline
+        sequence, whatever has been selected as the line  ending  sequence.  If
+        you specify
+          --enable-bsr-anycrlf
+        the  default  is changed so that \R matches only CR, LF, or CRLF. What-
+        ever is selected when PCRE is built can be overridden when the  library
+        functions are called.
  BUILDING SHARED AND STATIC LIBRARIES
-        The PCRE building process uses libtool to build both shared and  static
+        The  PCRE building process uses libtool to build both shared and static
-        Unix  libraries by default. You can suppress one of these by adding one
+        Unix libraries by default. You can suppress one of these by adding  one
         of
           --disable-shared
-Line 346 
 BUILDING SHARED AND STATIC LIBRARIES
+Line 394 
 BUILDING SHARED AND STATIC LIBRARIES
  POSIX MALLOC USAGE
         When PCRE is called through the POSIX interface (see the pcreposix doc-
-        umentation),  additional  working  storage  is required for holding the
+        umentation), additional working storage is  required  for  holding  the
-        pointers to capturing substrings, because PCRE requires three  integers
+        pointers  to capturing substrings, because PCRE requires three integers
-        per  substring,  whereas  the POSIX interface provides only two. If the
+        per substring, whereas the POSIX interface provides only  two.  If  the
         number of expected substrings is small, the wrapper function uses space
         on the stack, because this is faster than using malloc() for each call.
         The default threshold above which the stack is no longer used is 10; it
-Line 361 
 POSIX MALLOC USAGE
+Line 409 
 POSIX MALLOC USAGE
  HANDLING VERY LARGE PATTERNS
-        Within  a  compiled  pattern,  offset values are used to point from one
+        Within a compiled pattern, offset values are used  to  point  from  one
-        part to another (for example, from an opening parenthesis to an  alter-
+        part  to another (for example, from an opening parenthesis to an alter-
-        nation  metacharacter).  By default, two-byte values are used for these
+        nation metacharacter). By default, two-byte values are used  for  these
-        offsets, leading to a maximum size for a  compiled  pattern  of  around
+        offsets,  leading  to  a  maximum size for a compiled pattern of around
-K.  This  is sufficient to handle all but the most gigantic patterns.
+K. This is sufficient to handle all but the most  gigantic  patterns.
-        Nevertheless, some people do want to process enormous patterns,  so  it
+        Nevertheless,  some  people do want to process enormous patterns, so it
-        is  possible  to compile PCRE to use three-byte or four-byte offsets by
+        is possible to compile PCRE to use three-byte or four-byte  offsets  by
         adding a setting such as
           --with-link-size=3
-        to the configure command. The value given must be 2,  3,  or  4.  Using
+        to  the  configure  command.  The value given must be 2, 3, or 4. Using
-        longer  offsets slows down the operation of PCRE because it has to load
+        longer offsets slows down the operation of PCRE because it has to  load
         additional bytes when handling them.
  AVOIDING EXCESSIVE STACK USAGE
         When matching with the pcre_exec() function, PCRE implements backtrack-
-        ing  by  making recursive calls to an internal function called match().
+        ing by making recursive calls to an internal function  called  match().
-        In environments where the size of the stack is limited,  this  can  se-
+        In  environments  where  the size of the stack is limited, this can se-
-        verely  limit  PCRE's operation. (The Unix environment does not usually
+        verely limit PCRE's operation. (The Unix environment does  not  usually
         suffer from this problem, but it may sometimes be necessary to increase
-        the  maximum  stack size.  There is a discussion in the pcrestack docu-
+        the maximum stack size.  There is a discussion in the  pcrestack  docu-
-        mentation.) An alternative approach to recursion that uses memory  from
+        mentation.)  An alternative approach to recursion that uses memory from
-        the  heap  to remember data, instead of using recursive function calls,
+        the heap to remember data, instead of using recursive  function  calls,
-        has been implemented to work round the problem of limited  stack  size.
+        has  been  implemented to work round the problem of limited stack size.
         If you want to build a version of PCRE that works this way, add
           --disable-stack-for-recursion
-        to  the  configure  command. With this configuration, PCRE will use the
+        to the configure command. With this configuration, PCRE  will  use  the
-        pcre_stack_malloc and pcre_stack_free variables to call memory  manage-
+        pcre_stack_malloc  and pcre_stack_free variables to call memory manage-
-        ment  functions. By default these point to malloc() and free(), but you
+        ment functions. By default these point to malloc() and free(), but  you
         can replace the pointers so that your own functions are used.
-        Separate functions are  provided  rather  than  using  pcre_malloc  and
+        Separate  functions  are  provided  rather  than  using pcre_malloc and
-        pcre_free  because  the  usage  is  very  predictable:  the block sizes
+        pcre_free because the  usage  is  very  predictable:  the  block  sizes
-        requested are always the same, and  the  blocks  are  always  freed  in
+        requested  are  always  the  same,  and  the blocks are always freed in
-        reverse  order.  A calling program might be able to implement optimized
+        reverse order. A calling program might be able to  implement  optimized
-        functions that perform better  than  malloc()  and  free().  PCRE  runs
+        functions  that  perform  better  than  malloc()  and free(). PCRE runs
         noticeably more slowly when built in this way. This option affects only
-        the  pcre_exec()  function;  it   is   not   relevant   for   the   the
+        the   pcre_exec()   function;   it   is   not   relevant  for  the  the
         pcre_dfa_exec() function.
  LIMITING PCRE RESOURCE USAGE
-        Internally,  PCRE has a function called match(), which it calls repeat-
+        Internally, PCRE has a function called match(), which it calls  repeat-
-        edly  (sometimes  recursively)  when  matching  a  pattern   with   the
+        edly   (sometimes   recursively)  when  matching  a  pattern  with  the
-        pcre_exec()  function.  By controlling the maximum number of times this
+        pcre_exec() function. By controlling the maximum number of  times  this
-        function may be called during a single matching operation, a limit  can
+        function  may be called during a single matching operation, a limit can
-        be  placed  on  the resources used by a single call to pcre_exec(). The
+        be placed on the resources used by a single call  to  pcre_exec().  The
-        limit can be changed at run time, as described in the pcreapi  documen-
+        limit  can be changed at run time, as described in the pcreapi documen-
-        tation.  The default is 10 million, but this can be changed by adding a
+        tation. The default is 10 million, but this can be changed by adding  a
         setting such as
           --with-match-limit=500000
-        to  the  configure  command.  This  setting  has  no  effect   on   the
+        to   the   configure  command.  This  setting  has  no  effect  on  the
         pcre_dfa_exec() matching function.
-        In  some  environments  it is desirable to limit the depth of recursive
+        In some environments it is desirable to limit the  depth  of  recursive
         calls of match() more strictly than the total number of calls, in order
-        to  restrict  the maximum amount of stack (or heap, if --disable-stack-
+        to restrict the maximum amount of stack (or heap,  if  --disable-stack-
         for-recursion is specified) that is used. A second limit controls this;
-        it  defaults  to  the  value  that is set for --with-match-limit, which
+        it defaults to the value that  is  set  for  --with-match-limit,  which
-        imposes no additional constraints. However, you can set a  lower  limit
+        imposes  no  additional constraints. However, you can set a lower limit
         by adding, for example,
           --with-match-limit-recursion=10000
-        to  the  configure  command.  This  value can also be overridden at run
+        to the configure command. This value can  also  be  overridden  at  run
         time.
  CREATING CHARACTER TABLES AT BUILD TIME
-        PCRE uses fixed tables for processing characters whose code values  are
+        PCRE  uses fixed tables for processing characters whose code values are
-        less  than 256. By default, PCRE is built with a set of tables that are
+        less than 256. By default, PCRE is built with a set of tables that  are
-        distributed in the file pcre_chartables.c.dist. These  tables  are  for
+        distributed  in  the  file pcre_chartables.c.dist. These tables are for
         ASCII codes only. If you add
           --enable-rebuild-chartables
-        to  the  configure  command, the distributed tables are no longer used.
+        to the configure command, the distributed tables are  no  longer  used.
-        Instead, a program called dftables is compiled and  run.  This  outputs
+        Instead,  a  program  called dftables is compiled and run. This outputs
         the source for new set of tables, created in the default locale of your
         C runtime system. (This method of replacing the tables does not work if
-        you  are cross compiling, because dftables is run on the local host. If
+        you are cross compiling, because dftables is run on the local host.  If
-        you need to create alternative tables when cross  compiling,  you  will
+        you  need  to  create alternative tables when cross compiling, you will
         have to do so "by hand".)
  USING EBCDIC CODE
-        PCRE  assumes  by  default that it will run in an environment where the
+        PCRE assumes by default that it will run in an  environment  where  the
-        character code is ASCII (or Unicode, which is  a  superset  of  ASCII).
+        character  code  is  ASCII  (or Unicode, which is a superset of ASCII).
-        PCRE  can,  however,  be  compiled  to  run in an EBCDIC environment by
+        This is the case for most computer operating systems.  PCRE  can,  how-
-        adding
+        ever, be compiled to run in an EBCDIC environment by adding
           --enable-ebcdic
         to the configure command. This setting implies --enable-rebuild-charta-
-        bles.
+        bles. You should only use it if you know that  you  are  in  an  EBCDIC
+        environment (for example, an IBM mainframe operating system).
+ PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT
+        By default, pcregrep reads all files as plain text. You can build it so
+        that it recognizes files whose names end in .gz or .bz2, and reads them
+        with libz or libbz2, respectively, by adding one or both of
+          --enable-pcregrep-libz
+          --enable-pcregrep-libbz2
+        to the configure command. These options naturally require that the rel-
+        evant libraries are installed on your system. Configuration  will  fail
+        if they are not.
+ PCRETEST OPTION FOR LIBREADLINE SUPPORT
+        If you add
+          --enable-pcretest-libreadline
+        to  the  configure  command,  pcretest  is  linked with the libreadline
+        library, and when its input is from a terminal, it reads it  using  the
+        readline() function. This provides line-editing and history facilities.
+        Note that libreadline is GPL-licenced, so if you distribute a binary of
+        pcretest linked in this way, there may be licensing issues.
  SEE ALSO
-Line 482 
 AUTHOR
+Line 558 
 AUTHOR
  REVISION
-        Last updated: 05 June 2007
+        Last updated: 18 December 2007
         Copyright (c) 1997-2007 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 626 
 THE ALTERNATIVE MATCHING ALGORITHM
+Line 702 
 THE ALTERNATIVE MATCHING ALGORITHM
 .  Callouts  are  supported, but the value of the capture_top field is
         always 1, and the value of the capture_last field is always -1.
-.  The \C escape sequence, which (in the standard algorithm) matches a
+. The \C escape sequence, which (in the standard algorithm) matches  a
         single  byte, even in UTF-8 mode, is not supported because the alterna-
         tive algorithm moves through the subject  string  one  character  at  a
         time, for all active paths through the tree.
+.  None  of  the  backtracking control verbs such as (*PRUNE) are sup-
+        ported.
  ADVANTAGES OF THE ALTERNATIVE ALGORITHM
-        Using  the alternative matching algorithm provides the following advan-
+        Using the alternative matching algorithm provides the following  advan-
         tages:
 . All possible matches (at a single point in the subject) are automat-
-        ically  found,  and  in particular, the longest match is found. To find
+        ically found, and in particular, the longest match is  found.  To  find
         more than one match using the standard algorithm, you have to do kludgy
         things with callouts.
-.  There is much better support for partial matching. The restrictions
+. There is much better support for partial matching. The  restrictions
-        on the content of the pattern that apply when using the standard  algo-
+        on  the content of the pattern that apply when using the standard algo-
-        rithm  for  partial matching do not apply to the alternative algorithm.
+        rithm for partial matching do not apply to the  alternative  algorithm.
-        For non-anchored patterns, the starting position of a partial match  is
+        For  non-anchored patterns, the starting position of a partial match is
         available.
-.  Because  the  alternative  algorithm  scans the subject string just
+. Because the alternative algorithm  scans  the  subject  string  just
-        once, and never needs to backtrack, it is possible to  pass  very  long
+        once,  and  never  needs to backtrack, it is possible to pass very long
-        subject  strings  to  the matching function in several pieces, checking
+        subject strings to the matching function in  several  pieces,  checking
         for partial matching each time.
-Line 658 
 DISADVANTAGES OF THE ALTERNATIVE ALGORIT
+Line 737 
 DISADVANTAGES OF THE ALTERNATIVE ALGORIT
         The alternative algorithm suffers from a number of disadvantages:
-. It is substantially slower than  the  standard  algorithm.  This  is
+.  It  is  substantially  slower  than the standard algorithm. This is
-        partly  because  it has to search for all possible matches, but is also
+        partly because it has to search for all possible matches, but  is  also
         because it is less susceptible to optimization.
 . Capturing parentheses and back references are not supported.
-Line 677 
 AUTHOR
+Line 756 
 AUTHOR
  REVISION
-        Last updated: 29 May 2007
+        Last updated: 08 August 2007
         Copyright (c) 1997-2007 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 874 
 NEWLINES
+Line 953 
 NEWLINES
         dard. When PCRE is run, the default can be overridden,  either  when  a
         pattern is compiled, or when it is matched.
+        At compile time, the newline convention can be specified by the options
+        argument of pcre_compile(), or it can be specified by special  text  at
+        the start of the pattern itself; this overrides any other settings. See
+        the pcrepattern page for details of the special character sequences.
         In the PCRE documentation the word "newline" is used to mean "the char-
-        acter or pair of characters that indicate a line break". The choice  of
+        acter  or pair of characters that indicate a line break". The choice of
-        newline  convention  affects  the  handling of the dot, circumflex, and
+        newline convention affects the handling of  the  dot,  circumflex,  and
         dollar metacharacters, the handling of #-comments in /x mode, and, when
-        CRLF  is a recognized line ending sequence, the match position advance-
+        CRLF is a recognized line ending sequence, the match position  advance-
-        ment for a non-anchored pattern. The choice of newline convention  does
+        ment for a non-anchored pattern. There is more detail about this in the
-        not affect the interpretation of the \n or \r escape sequences.
+        section on pcre_exec() options below.
+        The choice of newline convention does not affect the interpretation  of
+        the  \n  or  \r  escape  sequences, nor does it affect what \R matches,
+        which is controlled in a similar way, but by separate options.
  MULTITHREADING
-        The  PCRE  functions  can be used in multi-threading applications, with
+        The PCRE functions can be used in  multi-threading  applications,  with
         the  proviso  that  the  memory  management  functions  pointed  to  by
         pcre_malloc, pcre_free, pcre_stack_malloc, and pcre_stack_free, and the
         callout function pointed to by pcre_callout, are shared by all threads.
-        The  compiled form of a regular expression is not altered during match-
+        The compiled form of a regular expression is not altered during  match-
         ing, so the same compiled pattern can safely be used by several threads
         at once.
-Line 898 
 MULTITHREADING
+Line 986 
 MULTITHREADING
  SAVING PRECOMPILED PATTERNS FOR LATER USE
         The compiled form of a regular expression can be saved and re-used at a
-        later time, possibly by a different program, and even on a  host  other
+        later  time,  possibly by a different program, and even on a host other
-        than  the  one  on  which  it  was  compiled.  Details are given in the
+        than the one on which  it  was  compiled.  Details  are  given  in  the
-        pcreprecompile documentation. However, compiling a  regular  expression
+        pcreprecompile  documentation.  However, compiling a regular expression
-        with  one version of PCRE for use with a different version is not guar-
+        with one version of PCRE for use with a different version is not  guar-
         anteed to work and may cause crashes.
-Line 909 
 CHECKING BUILD-TIME OPTIONS
+Line 997 
 CHECKING BUILD-TIME OPTIONS
         int pcre_config(int what, void *where);
-        The function pcre_config() makes it possible for a PCRE client to  dis-
+        The  function pcre_config() makes it possible for a PCRE client to dis-
         cover which optional features have been compiled into the PCRE library.
-        The pcrebuild documentation has more details about these optional  fea-
+        The  pcrebuild documentation has more details about these optional fea-
         tures.
-        The  first  argument  for pcre_config() is an integer, specifying which
+        The first argument for pcre_config() is an  integer,  specifying  which
         information is required; the second argument is a pointer to a variable
-        into  which  the  information  is  placed. The following information is
+        into which the information is  placed.  The  following  information  is
         available:
           PCRE_CONFIG_UTF8
-        The output is an integer that is set to one if UTF-8 support is  avail-
+        The  output is an integer that is set to one if UTF-8 support is avail-
         able; otherwise it is set to zero.
           PCRE_CONFIG_UNICODE_PROPERTIES
-        The  output  is  an  integer  that is set to one if support for Unicode
+        The output is an integer that is set to  one  if  support  for  Unicode
         character properties is available; otherwise it is set to zero.
           PCRE_CONFIG_NEWLINE
-        The output is an integer whose value specifies  the  default  character
+        The  output  is  an integer whose value specifies the default character
-        sequence  that is recognized as meaning "newline". The four values that
+        sequence that is recognized as meaning "newline". The four values  that
         are supported are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF,
-        and  -1  for  ANY. The default should normally be the standard sequence
+        and -1 for ANY. The default should normally be  the  standard  sequence
         for your operating system.
+          PCRE_CONFIG_BSR
+        The output is an integer whose value indicates what character sequences
+        the \R escape sequence matches by default. A value of 0 means  that  \R
+        matches  any  Unicode  line ending sequence; a value of 1 means that \R
+        matches only CR, LF, or CRLF. The default can be overridden when a pat-
+        tern is compiled or matched.
           PCRE_CONFIG_LINK_SIZE
-        The output is an integer that contains the number  of  bytes  used  for
+        The  output  is  an  integer that contains the number of bytes used for
         internal linkage in compiled regular expressions. The value is 2, 3, or
-. Larger values allow larger regular expressions to  be  compiled,  at
+.  Larger  values  allow larger regular expressions to be compiled, at
-        the  expense  of  slower matching. The default value of 2 is sufficient
+        the expense of slower matching. The default value of  2  is  sufficient
-        for all but the most massive patterns, since  it  allows  the  compiled
+        for  all  but  the  most massive patterns, since it allows the compiled
         pattern to be up to 64K in size.
           PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
-        The  output  is  an integer that contains the threshold above which the
+        The output is an integer that contains the threshold  above  which  the
-        POSIX interface uses malloc() for output vectors. Further  details  are
+        POSIX  interface  uses malloc() for output vectors. Further details are
         given in the pcreposix documentation.
           PCRE_CONFIG_MATCH_LIMIT
         The output is an integer that gives the default limit for the number of
-        internal matching function calls in a  pcre_exec()  execution.  Further
+        internal  matching  function  calls in a pcre_exec() execution. Further
         details are given with pcre_exec() below.
           PCRE_CONFIG_MATCH_LIMIT_RECURSION
-        The  output is an integer that gives the default limit for the depth of
+        The output is an integer that gives the default limit for the depth  of
-        recursion when calling the internal matching function in a  pcre_exec()
+        recursion  when calling the internal matching function in a pcre_exec()
         execution. Further details are given with pcre_exec() below.
           PCRE_CONFIG_STACKRECURSE
-        The  output is an integer that is set to one if internal recursion when
+        The output is an integer that is set to one if internal recursion  when
         running pcre_exec() is implemented by recursive function calls that use
-        the  stack  to remember their state. This is the usual way that PCRE is
+        the stack to remember their state. This is the usual way that  PCRE  is
         compiled. The output is zero if PCRE was compiled to use blocks of data
-        on  the  heap  instead  of  recursive  function  calls.  In  this case,
+        on the  heap  instead  of  recursive  function  calls.  In  this  case,
-        pcre_stack_malloc and  pcre_stack_free  are  called  to  manage  memory
+        pcre_stack_malloc  and  pcre_stack_free  are  called  to  manage memory
         blocks on the heap, thus avoiding the use of the stack.
-Line 988 
 COMPILING A PATTERN
+Line 1084 
 COMPILING A PATTERN
         Either of the functions pcre_compile() or pcre_compile2() can be called
         to compile a pattern into an internal form. The only difference between
-        the  two interfaces is that pcre_compile2() has an additional argument,
+        the two interfaces is that pcre_compile2() has an additional  argument,
         errorcodeptr, via which a numerical error code can be returned.
         The pattern is a C string terminated by a binary zero, and is passed in
-        the  pattern  argument.  A  pointer to a single block of memory that is
+        the pattern argument. A pointer to a single block  of  memory  that  is
-        obtained via pcre_malloc is returned. This contains the  compiled  code
+        obtained  via  pcre_malloc is returned. This contains the compiled code
         and related data. The pcre type is defined for the returned block; this
         is a typedef for a structure whose contents are not externally defined.
         It is up to the caller to free the memory (via pcre_free) when it is no
         longer required.
-        Although the compiled code of a PCRE regex is relocatable, that is,  it
+        Although  the compiled code of a PCRE regex is relocatable, that is, it
         does not depend on memory location, the complete pcre data block is not
-        fully relocatable, because it may contain a copy of the tableptr  argu-
+        fully  relocatable, because it may contain a copy of the tableptr argu-
         ment, which is an address (see below).
         The options argument contains various bit settings that affect the com-
-        pilation. It should be zero if no options are required.  The  available
+        pilation.  It  should be zero if no options are required. The available
-        options  are  described  below. Some of them, in particular, those that
+        options are described below. Some of them, in  particular,  those  that
-        are compatible with Perl, can also be set and  unset  from  within  the
+        are  compatible  with  Perl,  can also be set and unset from within the
-        pattern  (see  the  detailed  description in the pcrepattern documenta-
+        pattern (see the detailed description  in  the  pcrepattern  documenta-
-        tion). For these options, the contents of the options  argument  speci-
+        tion).  For  these options, the contents of the options argument speci-
-        fies  their initial settings at the start of compilation and execution.
+        fies their initial settings at the start of compilation and  execution.
-        The PCRE_ANCHORED and PCRE_NEWLINE_xxx options can be set at  the  time
+        The  PCRE_ANCHORED  and PCRE_NEWLINE_xxx 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 charac-
         ter where the error was discovered is placed in the variable pointed to
-        by  erroffset,  which must not be NULL. If it is, an immediate error is
+        by erroffset, which must not be NULL. If it is, an immediate  error  is
         given.
-        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 1049 
 COMPILING A PATTERN
+Line 1145 
 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,
+        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 metacharater in the pattern matches all char-
-        acters, including those that indicate newline. Without it, a  dot  does
+        acters,  including  those that indicate newline. Without it, a dot does
-        not  match  when  the  current position is at a newline. This option is
+        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
+        equivalent  to Perl's /s option, and it can be changed within a pattern
-        by  a (?s) option setting. A negative class such as [^a] always matches
+        by a (?s) option setting. A negative class such as [^a] always  matches
         newline characters, independent of the setting 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.
-        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 (?( which
+        sequences in a pattern, for  example  within  the  sequence  (?(  which
         introduces 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 a warning for  this.)
+        literal.  (Perl can, however, be persuaded to give a warning for this.)
-        There  are  at  present no other features controlled by this option. It
+        There are at present no other features 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_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 1162 
 COMPILING A PATTERN
+Line 1267 
 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 is specially recognized when  compiling
+        The  only time that a line break is specially recognized when compiling
-        a  pattern  is  if  PCRE_EXTENDED  is set, and an unescaped # outside a
+        a pattern is if PCRE_EXTENDED is set, and  an  unescaped  #  outside  a
-        character class is encountered. This indicates  a  comment  that  lasts
+        character  class  is  encountered.  This indicates a comment that lasts
-        until  after the next line break sequence. In other circumstances, line
+        until after the next line break sequence. In other circumstances,  line
-        break  sequences  are  treated  as  literal  data,   except   that   in
+        break   sequences   are   treated  as  literal  data,  except  that  in
         PCRE_EXTENDED mode, both CR and LF are treated as whitespace characters
         and are therefore ignored.
         The newline option that is set at compile time becomes the default that
-        is  used for pcre_exec() and pcre_dfa_exec(), but it can be overridden.
+        is used for pcre_exec() and pcre_dfa_exec(), but it can be  overridden.
           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.
           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. If an invalid UTF-8 sequence of bytes is found,
+        automatically checked. There is a  discussion  about  the  validity  of
-        pcre_compile() returns an error. If you already know that your  pattern
+        UTF-8  strings  in  the main pcre page. If an invalid UTF-8 sequence of
-        is  valid, and you want to skip this check for performance reasons, you
+        bytes is found, pcre_compile() returns an error. If  you  already  know
-        can set the PCRE_NO_UTF8_CHECK option. When it is set,  the  effect  of
+        that your pattern is valid, and you want to skip this check for perfor-
-        passing an invalid UTF-8 string as a pattern is undefined. It may cause
+        mance reasons, you can set the PCRE_NO_UTF8_CHECK option.  When  it  is
-        your program to crash.  Note that this option can  also  be  passed  to
+        set,  the  effect  of  passing  an invalid UTF-8 string as a pattern is
-        pcre_exec()  and pcre_dfa_exec(), to suppress the UTF-8 validity check-
+        undefined. It may cause your program to crash. Note  that  this  option
-        ing of subject strings.
+        can  also be passed to pcre_exec() and pcre_dfa_exec(), to suppress the
+        UTF-8 validity checking of subject strings.
  COMPILATION ERROR CODES
-Line 1288 
 COMPILATION ERROR CODES
+Line 1394 
 COMPILATION ERROR CODES
  unknown property name after \P or \p
  subpattern name is too long (maximum 32 characters)
  too many named subpatterns (maximum 10,000)
- repeated subpattern is too long
+ [this code is not in use]
  octal value is greater than \377 (not in UTF-8 mode)
  internal error: overran compiling workspace
   internal  error:  previously-checked  referenced  subpattern not
         found
  DEFINE group contains more than one branch
  repeating a DEFINE group is not allowed
- inconsistent NEWLINE options"
+ inconsistent NEWLINE options
  \g is not followed by a braced name or an optionally braced
                 non-zero number
  (?+ or (?- or (?(+ or (?(- must be followed by a non-zero number
-Line 1487 
 INFORMATION ABOUT A PATTERN
+Line 1593 
 INFORMATION ABOUT A PATTERN
         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
+        characters, otherwise 0. The fourth argument should  point  to  an  int
+        variable.  An explicit match is either a literal CR or LF character, or
+        \r or \n.
           PCRE_INFO_JCHANGED
-        Return  1  if the (?J) option setting is used in the pattern, otherwise
+        Return 1 if the (?J) or (?-J) option setting is used  in  the  pattern,
-. The fourth argument should point to an int variable. The (?J) inter-
+        otherwise  0. The fourth argument should point to an int variable. (?J)
-        nal option setting changes the local PCRE_DUPNAMES option.
+        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.
-Line 1507 
 INFORMATION ABOUT A PATTERN
+Line 1620 
 INFORMATION ABOUT A PATTERN
           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.
+        sponding  name,  zero  terminated. The names are in alphabetical order.
         When PCRE_DUPNAMES is set, duplicate names are in order of their paren-
-        theses numbers. For example, consider  the  following  pattern  (assume
+        theses  numbers.  For  example,  consider the following pattern (assume
-        PCRE_EXTENDED  is  set,  so  white  space  -  including  newlines  - is
+        PCRE_EXTENDED is  set,  so  white  space  -  including  newlines  -  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 1543 
 INFORMATION ABOUT A PATTERN
+Line 1656 
 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, otherwise 0.
+        Return 1 if the pattern can be used for partial matching, otherwise  0.
-        The fourth argument should point to an int  variable.  The  pcrepartial
+        The  fourth  argument  should point to an int variable. The pcrepartial
-        documentation  lists  the restrictions that apply to patterns when par-
+        documentation lists the restrictions that apply to patterns  when  par-
         tial matching is used.
           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 within the pattern itself.
+        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
+        starts. For example, if the pattern /(?im)abc(?-i)d/ is  compiled  with
+        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 1575 
 INFORMATION ABOUT A PATTERN
+Line 1692 
 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 1583 
 INFORMATION ABOUT A PATTERN
+Line 1700 
 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(). The fourth argument should point to a size_t
+        created by pcre_study(). The fourth argument should point to  a  size_t
         variable.
-Line 1593 
 OBSOLETE INFO FUNCTION
+Line 1710 
 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 1615 
 REFERENCE COUNTS
+Line 1732 
 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 1639 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1756 
 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
         has been 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 1669 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1786 
 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 1682 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1799 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           void *callout_data;
           const unsigned char *tables;
-        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 1691 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1808 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_EXTRA_CALLOUT_DATA
           PCRE_EXTRA_TABLES
-        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  the  use  of  nested  unlimited
+        search  trees.  The  classic  example  is  the  use of nested unlimited
         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  pcre_callout  field is used in conjunction with the "callout" fea-
+        The pcre_callout field is used in conjunction with the  "callout"  fea-
         ture, which 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.
     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_NO_UTF8_CHECK   and
         PCRE_PARTIAL.
           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,
+        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
           PCRE_NEWLINE_LF
           PCRE_NEWLINE_CRLF
-Line 1773 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1898 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         tion  of  pcre_compile()  above.  During  matching,  the newline choice
         affects the behaviour of the dot, circumflex,  and  dollar  metacharac-
         ters.  It may also alter the way the match position is advanced after a
-        match  failure  for  an  unanchored  pattern.  When  PCRE_NEWLINE_CRLF,
+        match failure for an unanchored pattern.
-        PCRE_NEWLINE_ANYCRLF,  or  PCRE_NEWLINE_ANY is set, and a match attempt
-        fails when the current position is at a CRLF sequence, the match  posi-
+        When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF,  or  PCRE_NEWLINE_ANY  is
-        tion  is  advanced by two characters instead of one, in other words, to
+        set,  and a match attempt for an unanchored pattern fails when the cur-
-        after the CRLF.
+        rent position is at a  CRLF  sequence,  and  the  pattern  contains  no
+        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
+        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.
+        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
+        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
+        is a valid newline sequence and explicit \r or \n escapes appear in the
+        pattern.
           PCRE_NOTBOL
-Line 1824 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1969 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         When PCRE_UTF8 is set at compile time, the validity of the subject as a
         UTF-8  string is automatically checked when pcre_exec() is subsequently
         called.  The value of startoffset is also checked  to  ensure  that  it
-        points  to the start of a UTF-8 character. If an invalid UTF-8 sequence
+        points  to  the start of a UTF-8 character. There is a discussion about
-        of bytes is found, pcre_exec() returns the error PCRE_ERROR_BADUTF8. If
+        the validity of UTF-8 strings in the section on UTF-8  support  in  the
-        startoffset  contains  an  invalid  value, PCRE_ERROR_BADUTF8_OFFSET is
+        main  pcre  page.  If  an  invalid  UTF-8  sequence  of bytes is found,
-        returned.
+        pcre_exec() returns the error PCRE_ERROR_BADUTF8. If  startoffset  con-
+        tains an invalid value, PCRE_ERROR_BADUTF8_OFFSET is returned.
-        If you already know that your subject is valid, and you  want  to  skip
-        these    checks    for   performance   reasons,   you   can   set   the
+        If  you  already  know that your subject is valid, and you want to skip
-        PCRE_NO_UTF8_CHECK option when calling pcre_exec(). You might  want  to
+        these   checks   for   performance   reasons,   you   can    set    the
-        do  this  for the second and subsequent calls to pcre_exec() if you are
+        PCRE_NO_UTF8_CHECK  option  when calling pcre_exec(). You might want to
-        making repeated calls to find all  the  matches  in  a  single  subject
+        do this for the second and subsequent calls to pcre_exec() if  you  are
-        string.  However,  you  should  be  sure  that the value of startoffset
+        making  repeated  calls  to  find  all  the matches in a single subject
-        points to the start of a UTF-8 character.  When  PCRE_NO_UTF8_CHECK  is
+        string. However, you should be  sure  that  the  value  of  startoffset
-        set,  the  effect of passing an invalid UTF-8 string as a subject, or a
+        points  to  the  start of a UTF-8 character. When PCRE_NO_UTF8_CHECK is
-        value of startoffset that does not point to the start of a UTF-8  char-
+        set, the effect of passing an invalid UTF-8 string as a subject,  or  a
+        value  of startoffset that does not point to the start of a UTF-8 char-
         acter, is undefined. Your program may crash.
           PCRE_PARTIAL
-        This  option  turns  on  the  partial  matching feature. If the subject
+        This option turns on the  partial  matching  feature.  If  the  subject
-        string fails to match the pattern, but at some point during the  match-
+        string  fails to match the pattern, but at some point during the match-
-        ing  process  the  end of the subject was reached (that is, the subject
+        ing process the end of the subject was reached (that  is,  the  subject
-        partially matches the pattern and the failure to  match  occurred  only
+        partially  matches  the  pattern and the failure to match occurred only
-        because  there were not enough subject characters), pcre_exec() returns
+        because there were not enough subject characters), pcre_exec()  returns
-        PCRE_ERROR_PARTIAL instead of PCRE_ERROR_NOMATCH. When PCRE_PARTIAL  is
+        PCRE_ERROR_PARTIAL  instead of PCRE_ERROR_NOMATCH. When PCRE_PARTIAL is
-        used,  there  are restrictions on what may appear in the pattern. These
+        used, there are restrictions on what may appear in the  pattern.  These
         are discussed in the pcrepartial documentation.
     The string to be matched by pcre_exec()
-        The subject string is passed to pcre_exec() as a pointer in subject,  a
+        The  subject string is passed to pcre_exec() as a pointer in subject, a
-        length  in  length, and a starting byte offset in startoffset. In UTF-8
+        length in length, and a starting byte offset in startoffset.  In  UTF-8
-        mode, the byte offset must point to the start  of  a  UTF-8  character.
+        mode,  the  byte  offset  must point to the start of a UTF-8 character.
-        Unlike  the  pattern string, the subject may contain binary zero bytes.
+        Unlike the pattern string, the subject may contain binary  zero  bytes.
-        When the starting offset is zero, the search for a match starts at  the
+        When  the starting offset is zero, the search for a match starts at the
         beginning of the subject, and this is by far the most common case.
-        A  non-zero  starting offset is useful when searching for another match
+        A non-zero starting offset is useful when searching for  another  match
-        in the same subject by calling pcre_exec() again after a previous  suc-
+        in  the same subject by calling pcre_exec() again after a previous suc-
-        cess.   Setting  startoffset differs from just passing over a shortened
+        cess.  Setting startoffset differs from just passing over  a  shortened
-        string and setting PCRE_NOTBOL in the case of  a  pattern  that  begins
+        string  and  setting  PCRE_NOTBOL  in the case of a pattern that begins
         with any kind of lookbehind. For example, consider the pattern
           \Biss\B
-        which  finds  occurrences  of "iss" in the middle of words. (\B matches
+        which finds occurrences of "iss" in the middle of  words.  (\B  matches
-        only if the current position in the subject is not  a  word  boundary.)
+        only  if  the  current position in the subject is not a word boundary.)
-        When  applied  to the string "Mississipi" the first call to pcre_exec()
+        When applied to the string "Mississipi" the first call  to  pcre_exec()
-        finds the first occurrence. If pcre_exec() is called  again  with  just
+        finds  the  first  occurrence. If pcre_exec() is called again with just
-        the  remainder  of  the  subject,  namely  "issipi", it does not match,
+        the remainder of the subject,  namely  "issipi",  it  does  not  match,
         because \B is always false at the start of the subject, which is deemed
-        to  be  a  word  boundary. However, if pcre_exec() is passed the entire
+        to be a word boundary. However, if pcre_exec()  is  passed  the  entire
         string again, but with startoffset set to 4, it finds the second occur-
-        rence  of "iss" because it is able to look behind the starting point to
+        rence of "iss" because it is able to look behind the starting point  to
         discover that it is preceded by a letter.
-        If a non-zero starting offset is passed when the pattern  is  anchored,
+        If  a  non-zero starting offset is passed when the pattern is anchored,
         one attempt to match at the given offset is made. This can only succeed
-        if the pattern does not require the match to be at  the  start  of  the
+        if  the  pattern  does  not require the match to be at the start of the
         subject.
     How pcre_exec() returns captured substrings
-        In  general, a pattern matches a certain portion of the subject, and in
+        In general, a pattern matches a certain portion of the subject, and  in
-        addition, further substrings from the subject  may  be  picked  out  by
+        addition,  further  substrings  from  the  subject may be picked out by
-        parts  of  the  pattern.  Following the usage in Jeffrey Friedl's book,
+        parts of the pattern. Following the usage  in  Jeffrey  Friedl's  book,
-        this is called "capturing" in what follows, and the  phrase  "capturing
+        this  is  called "capturing" in what follows, and the phrase "capturing
-        subpattern"  is  used for a fragment of a pattern that picks out a sub-
+        subpattern" is used for a fragment of a pattern that picks out  a  sub-
-        string. PCRE supports several other kinds of  parenthesized  subpattern
+        string.  PCRE  supports several other kinds of parenthesized subpattern
         that do not cause substrings to be captured.
-        Captured  substrings are returned to the caller via a vector of integer
+        Captured substrings are returned to the caller via a vector of  integer
-        offsets whose address is passed in ovector. The number of  elements  in
+        offsets  whose  address is passed in ovector. The number of elements in
-        the  vector is passed in ovecsize, which must be a non-negative number.
+        the vector is passed in ovecsize, which must be a non-negative  number.
         Note: this argument is NOT the size of ovector in bytes.
-        The first two-thirds of the vector is used to pass back  captured  sub-
+        The  first  two-thirds of the vector is used to pass back captured sub-
-        strings,  each  substring using a pair of integers. The remaining third
+        strings, each substring using a pair of integers. The  remaining  third
-        of the vector is used as workspace by pcre_exec() while  matching  cap-
+        of  the  vector is used as workspace by pcre_exec() while matching cap-
-        turing  subpatterns, and is not available for passing back information.
+        turing subpatterns, and is not available for passing back  information.
-        The length passed in ovecsize should always be a multiple of three.  If
+        The  length passed in ovecsize should always be a multiple of three. If
         it is not, it is rounded down.
-        When  a  match  is successful, information about captured substrings is
+        When a match is successful, information about  captured  substrings  is
-        returned in pairs of integers, starting at the  beginning  of  ovector,
+        returned  in  pairs  of integers, starting at the beginning of ovector,
-        and  continuing  up  to two-thirds of its length at the most. The first
+        and continuing up to two-thirds of its length at the  most.  The  first
         element of a pair is set to the offset of the first character in a sub-
-        string,  and  the  second  is  set to the offset of the first character
+        string, and the second is set to the  offset  of  the  first  character
-        after the end of a substring. The  first  pair,  ovector[0]  and  ovec-
+        after  the  end  of  a  substring. The first pair, ovector[0] and ovec-
-        tor[1],  identify  the  portion  of  the  subject string matched by the
+        tor[1], identify the portion of  the  subject  string  matched  by  the
-        entire pattern. The next pair is used for the first  capturing  subpat-
+        entire  pattern.  The next pair is used for the first capturing subpat-
         tern, and so on. The value returned by pcre_exec() is one more than the
         highest numbered pair that has been set. For example, if two substrings
-        have  been captured, the returned value is 3. If there are no capturing
+        have been captured, the returned value is 3. If there are no  capturing
-        subpatterns, the return value from a successful match is 1,  indicating
+        subpatterns,  the return value from a successful match is 1, indicating
         that just the first pair of offsets has been set.
         If a capturing subpattern is matched repeatedly, it is the last portion
         of the string that it matched that is returned.
-        If the vector is too small to hold all the captured substring  offsets,
+        If  the vector is too small to hold all the captured substring offsets,
         it is used as far as possible (up to two-thirds of its length), and the
-        function returns a value of zero. In particular, if the substring  off-
+        function  returns a value of zero. In particular, if the substring off-
         sets are not of interest, pcre_exec() may be called with ovector passed
-        as NULL and ovecsize as zero. However, if  the  pattern  contains  back
+        as  NULL  and  ovecsize  as zero. However, if the pattern contains back
-        references  and  the  ovector is not big enough to remember the related
+        references and the ovector is not big enough to  remember  the  related
-        substrings, PCRE has to get additional memory for use during  matching.
+        substrings,  PCRE has to get additional memory for use during matching.
         Thus it is usually advisable to supply an ovector.
-        The  pcre_info()  function  can  be used to find out how many capturing
+        The pcre_info() function can be used to find  out  how  many  capturing
-        subpatterns there are in a compiled  pattern.  The  smallest  size  for
+        subpatterns  there  are  in  a  compiled pattern. The smallest size for
-        ovector  that  will allow for n captured substrings, in addition to the
+        ovector that will allow for n captured substrings, in addition  to  the
         offsets of the substring matched by the whole pattern, is (n+1)*3.
-        It is possible for capturing subpattern number n+1 to match  some  part
+        It  is  possible for capturing subpattern number n+1 to match some part
         of the subject when subpattern n has not been used at all. For example,
-        if the string "abc" is matched  against  the  pattern  (a|(z))(bc)  the
+        if  the  string  "abc"  is  matched against the pattern (a|(z))(bc) the
         return from the function is 4, and subpatterns 1 and 3 are matched, but
-is not. When this happens, both values in  the  offset  pairs  corre-
+ is  not.  When  this happens, both values in the offset pairs corre-
         sponding to unused subpatterns are set to -1.
-        Offset  values  that correspond to unused subpatterns at the end of the
+        Offset values that correspond to unused subpatterns at the end  of  the
-        expression are also set to -1. For example,  if  the  string  "abc"  is
+        expression  are  also  set  to  -1. For example, if the string "abc" is
-        matched  against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not
+        matched against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are  not
-        matched. The return from the function is 2, because  the  highest  used
+        matched.  The  return  from the function is 2, because the highest used
         capturing subpattern number is 1. However, you can refer to the offsets
-        for the second and third capturing subpatterns if  you  wish  (assuming
+        for  the  second  and third capturing subpatterns if you wish (assuming
         the vector is large enough, of course).
-        Some  convenience  functions  are  provided for extracting the captured
+        Some convenience functions are provided  for  extracting  the  captured
         substrings as separate strings. These are described below.
     Error return values from pcre_exec()
-        If pcre_exec() fails, it returns a negative number. The  following  are
+        If  pcre_exec()  fails, it returns a negative number. The following are
         defined in the header file:
           PCRE_ERROR_NOMATCH        (-1)
-Line 1966 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2112 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_ERROR_NULL           (-2)
-        Either  code  or  subject  was  passed as NULL, or ovector was NULL and
+        Either code or subject was passed as NULL,  or  ovector  was  NULL  and
         ovecsize was not zero.
           PCRE_ERROR_BADOPTION      (-3)
-Line 1975 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2121 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_ERROR_BADMAGIC       (-4)
-        PCRE stores a 4-byte "magic number" at the start of the compiled  code,
+        PCRE  stores a 4-byte "magic number" at the start of the compiled code,
         to catch the case when it is passed a junk pointer and to detect when a
         pattern that was compiled in an environment of one endianness is run in
-        an  environment  with the other endianness. This is the error that PCRE
+        an environment with the other endianness. This is the error  that  PCRE
         gives when the magic number is not present.
           PCRE_ERROR_UNKNOWN_OPCODE (-5)
         While running the pattern match, an unknown item was encountered in the
-        compiled  pattern.  This  error  could be caused by a bug in PCRE or by
+        compiled pattern. This error could be caused by a bug  in  PCRE  or  by
         overwriting of the compiled pattern.
           PCRE_ERROR_NOMEMORY       (-6)
-        If a pattern contains back references, but the ovector that  is  passed
+        If  a  pattern contains back references, but the ovector that is passed
         to pcre_exec() is not big enough to remember the referenced substrings,
-        PCRE gets a block of memory at the start of matching to  use  for  this
+        PCRE  gets  a  block of memory at the start of matching to use for this
-        purpose.  If the call via pcre_malloc() fails, this error is given. The
+        purpose. If the call via pcre_malloc() fails, this error is given.  The
         memory is automatically freed at the end of matching.
           PCRE_ERROR_NOSUBSTRING    (-7)
-        This error is used by the pcre_copy_substring(),  pcre_get_substring(),
+        This  error is used by the pcre_copy_substring(), pcre_get_substring(),
         and  pcre_get_substring_list()  functions  (see  below).  It  is  never
         returned by pcre_exec().
           PCRE_ERROR_MATCHLIMIT     (-8)
-        The backtracking limit, as specified by  the  match_limit  field  in  a
+        The  backtracking  limit,  as  specified  by the match_limit field in a
-        pcre_extra  structure  (or  defaulted) was reached. See the description
+        pcre_extra structure (or defaulted) was reached.  See  the  description
         above.
           PCRE_ERROR_CALLOUT        (-9)
         This error is never generated by pcre_exec() itself. It is provided for
-        use  by  callout functions that want to yield a distinctive error code.
+        use by callout functions that want to yield a distinctive  error  code.
         See the pcrecallout documentation for details.
           PCRE_ERROR_BADUTF8        (-10)
-        A string that contains an invalid UTF-8 byte sequence was passed  as  a
+        A  string  that contains an invalid UTF-8 byte sequence was passed as a
         subject.
           PCRE_ERROR_BADUTF8_OFFSET (-11)
         The UTF-8 byte sequence that was passed as a subject was valid, but the
-        value of startoffset did not point to the beginning of a UTF-8  charac-
+        value  of startoffset did not point to the beginning of a UTF-8 charac-
         ter.
           PCRE_ERROR_PARTIAL        (-12)
-        The  subject  string did not match, but it did match partially. See the
+        The subject string did not match, but it did match partially.  See  the
         pcrepartial documentation for details of partial matching.
           PCRE_ERROR_BADPARTIAL     (-13)
-        The PCRE_PARTIAL option was used with  a  compiled  pattern  containing
+        The  PCRE_PARTIAL  option  was  used with a compiled pattern containing
-        items  that are not supported for partial matching. See the pcrepartial
+        items that are not supported for partial matching. See the  pcrepartial
         documentation for details of partial matching.
           PCRE_ERROR_INTERNAL       (-14)
-        An unexpected internal error has occurred. This error could  be  caused
+        An  unexpected  internal error has occurred. This error could be caused
         by a bug in PCRE or by overwriting of the compiled pattern.
           PCRE_ERROR_BADCOUNT       (-15)
-        This  error is given if the value of the ovecsize argument is negative.
+        This error is given if the value of the ovecsize argument is  negative.
           PCRE_ERROR_RECURSIONLIMIT (-21)
         The internal recursion limit, as specified by the match_limit_recursion
-        field  in  a  pcre_extra  structure (or defaulted) was reached. See the
+        field in a pcre_extra structure (or defaulted)  was  reached.  See  the
         description above.
-          PCRE_ERROR_NULLWSLIMIT    (-22)
-        When a group that can match an empty  substring  is  repeated  with  an
-        unbounded  upper  limit, the subject position at the start of the group
-        must be remembered, so that a test for an empty string can be made when
-        the  end  of the group is reached. Some workspace is required for this;
-        if it runs out, this error is given.
           PCRE_ERROR_BADNEWLINE     (-23)
         An invalid combination of PCRE_NEWLINE_xxx options was given.
-        Error numbers -16 to -20 are not used by pcre_exec().
+        Error numbers -16 to -20 and -22 are not used by pcre_exec().
  EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
-Line 2078 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
+Line 2216 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
         int pcre_get_substring_list(const char *subject,
              int *ovector, int stringcount, const char ***listptr);
-        Captured substrings can be  accessed  directly  by  using  the  offsets
+        Captured  substrings  can  be  accessed  directly  by using the offsets
-        returned  by  pcre_exec()  in  ovector.  For convenience, the functions
+        returned by pcre_exec() in  ovector.  For  convenience,  the  functions
         pcre_copy_substring(),    pcre_get_substring(),    and    pcre_get_sub-
-        string_list()  are  provided for extracting captured substrings as new,
+        string_list() are provided for extracting captured substrings  as  new,
-        separate, zero-terminated strings. These functions identify  substrings
+        separate,  zero-terminated strings. These functions identify substrings
-        by  number.  The  next section describes functions for extracting named
+        by number. The next section describes functions  for  extracting  named
         substrings.
-        A substring that contains a binary zero is correctly extracted and  has
+        A  substring that contains a binary zero is correctly extracted and has
-        a  further zero added on the end, but the result is not, of course, a C
+        a further zero added on the end, but the result is not, of course, a  C
-        string.  However, you can process such a string  by  referring  to  the
+        string.   However,  you  can  process such a string by referring to the
-        length  that  is  returned  by  pcre_copy_substring() and pcre_get_sub-
+        length that is  returned  by  pcre_copy_substring()  and  pcre_get_sub-
         string().  Unfortunately, the interface to pcre_get_substring_list() is
-        not  adequate for handling strings containing binary zeros, because the
+        not adequate for handling strings containing binary zeros, because  the
         end of the final string is not independently indicated.
-        The first three arguments are the same for all  three  of  these  func-
+        The  first  three  arguments  are the same for all three of these func-
-        tions:  subject  is  the subject string that has just been successfully
+        tions: subject is the subject string that has  just  been  successfully
         matched, ovector is a pointer to the vector of integer offsets that was
         passed to pcre_exec(), and stringcount is the number of substrings that
-        were captured by the match, including the substring  that  matched  the
+        were  captured  by  the match, including the substring that matched the
         entire regular expression. This is the value returned by pcre_exec() if
-        it is greater than zero. If pcre_exec() returned zero, indicating  that
+        it  is greater than zero. If pcre_exec() returned zero, indicating that
-        it  ran out of space in ovector, the value passed as stringcount should
+        it ran out of space in ovector, the value passed as stringcount  should
         be the number of elements in the vector divided by three.
-        The functions pcre_copy_substring() and pcre_get_substring() extract  a
+        The  functions pcre_copy_substring() and pcre_get_substring() extract a
-        single  substring,  whose  number  is given as stringnumber. A value of
+        single substring, whose number is given as  stringnumber.  A  value  of
-        zero extracts the substring that matched the  entire  pattern,  whereas
+        zero  extracts  the  substring that matched the entire pattern, whereas
-        higher  values  extract  the  captured  substrings.  For pcre_copy_sub-
+        higher values  extract  the  captured  substrings.  For  pcre_copy_sub-
-        string(), the string is placed in buffer,  whose  length  is  given  by
+        string(),  the  string  is  placed  in buffer, whose length is given by
-        buffersize,  while  for  pcre_get_substring()  a new block of memory is
+        buffersize, while for pcre_get_substring() a new  block  of  memory  is
-        obtained via pcre_malloc, and its address is  returned  via  stringptr.
+        obtained  via  pcre_malloc,  and its address is returned via stringptr.
-        The  yield  of  the function is the length of the string, not including
+        The yield of the function is the length of the  string,  not  including
         the terminating zero, or one of these error codes:
           PCRE_ERROR_NOMEMORY       (-6)
-        The buffer was too small for pcre_copy_substring(), or the  attempt  to
+        The  buffer  was too small for pcre_copy_substring(), or the attempt to
         get memory failed for pcre_get_substring().
           PCRE_ERROR_NOSUBSTRING    (-7)
         There is no substring whose number is stringnumber.
-        The  pcre_get_substring_list()  function  extracts  all  available sub-
+        The pcre_get_substring_list()  function  extracts  all  available  sub-
-        strings and builds a list of pointers to them. All this is  done  in  a
+        strings  and  builds  a list of pointers to them. All this is done in a
         single block of memory that is obtained via pcre_malloc. The address of
-        the memory block is returned via listptr, which is also  the  start  of
+        the  memory  block  is returned via listptr, which is also the start of
-        the  list  of  string pointers. The end of the list is marked by a NULL
+        the list of string pointers. The end of the list is marked  by  a  NULL
-        pointer. The yield of the function is zero if all  went  well,  or  the
+        pointer.  The  yield  of  the function is zero if all went well, or the
         error code
           PCRE_ERROR_NOMEMORY       (-6)
         if the attempt to get the memory block failed.
-        When  any of these functions encounter a substring that is unset, which
+        When any of these functions encounter a substring that is unset,  which
-        can happen when capturing subpattern number n+1 matches  some  part  of
+        can  happen  when  capturing subpattern number n+1 matches some part of
-        the  subject, but subpattern n has not been used at all, they return an
+        the subject, but subpattern n has not been used at all, they return  an
         empty string. This can be distinguished from a genuine zero-length sub-
-        string  by inspecting the appropriate offset in ovector, which is nega-
+        string by inspecting the appropriate offset in ovector, which is  nega-
         tive for unset substrings.
-        The two convenience functions pcre_free_substring() and  pcre_free_sub-
+        The  two convenience functions pcre_free_substring() and pcre_free_sub-
-        string_list()  can  be  used  to free the memory returned by a previous
+        string_list() can be used to free the memory  returned  by  a  previous
         call  of  pcre_get_substring()  or  pcre_get_substring_list(),  respec-
-        tively.  They  do  nothing  more  than  call the function pointed to by
+        tively. They do nothing more than  call  the  function  pointed  to  by
-        pcre_free, which of course could be called directly from a  C  program.
+        pcre_free,  which  of course could be called directly from a C program.
-        However,  PCRE is used in some situations where it is linked via a spe-
+        However, PCRE is used in some situations where it is linked via a  spe-
-        cial  interface  to  another  programming  language  that  cannot   use
+        cial   interface  to  another  programming  language  that  cannot  use
-        pcre_free  directly;  it is for these cases that the functions are pro-
+        pcre_free directly; it is for these cases that the functions  are  pro-
         vided.
-Line 2168 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
+Line 2306 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
              int stringcount, const char *stringname,
              const char **stringptr);
-        To extract a substring by name, you first have to find associated  num-
+        To  extract a substring by name, you first have to find associated num-
         ber.  For example, for this pattern
           (a+)b(?<xxx>\d+)...
-Line 2177 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
+Line 2315 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
         be unique (PCRE_DUPNAMES was not set), you can find the number from the
         name by calling pcre_get_stringnumber(). The first argument is the com-
         piled pattern, and the second is the name. The yield of the function is
-        the  subpattern  number,  or PCRE_ERROR_NOSUBSTRING (-7) if there is no
+        the subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if  there  is  no
         subpattern of that name.
         Given the number, you can extract the substring directly, or use one of
         the functions described in the previous section. For convenience, there
         are also two functions that do the whole job.
-        Most   of   the   arguments    of    pcre_copy_named_substring()    and
+        Most    of    the    arguments   of   pcre_copy_named_substring()   and
-        pcre_get_named_substring()  are  the  same  as  those for the similarly
+        pcre_get_named_substring() are the same  as  those  for  the  similarly
-        named functions that extract by number. As these are described  in  the
+        named  functions  that extract by number. As these are described in the
-        previous  section,  they  are not re-described here. There are just two
+        previous section, they are not re-described here. There  are  just  two
         differences:
-        First, instead of a substring number, a substring name is  given.  Sec-
+        First,  instead  of a substring number, a substring name is given. Sec-
         ond, there is an extra argument, given at the start, which is a pointer
-        to the compiled pattern. This is needed in order to gain access to  the
+        to  the compiled pattern. This is needed in order to gain access to the
         name-to-number translation table.
-        These  functions call pcre_get_stringnumber(), and if it succeeds, they
+        These functions call pcre_get_stringnumber(), and if it succeeds,  they
-        then call pcre_copy_substring() or pcre_get_substring(),  as  appropri-
+        then  call  pcre_copy_substring() or pcre_get_substring(), as appropri-
-        ate.  NOTE:  If PCRE_DUPNAMES is set and there are duplicate names, the
+        ate. NOTE: If PCRE_DUPNAMES is set and there are duplicate  names,  the
         behaviour may not be what you want (see the next section).
-Line 2206 
 DUPLICATE SUBPATTERN NAMES
+Line 2344 
 DUPLICATE SUBPATTERN NAMES
         int pcre_get_stringtable_entries(const pcre *code,
              const char *name, char **first, char **last);
-        When a pattern is compiled with the  PCRE_DUPNAMES  option,  names  for
+        When  a  pattern  is  compiled with the PCRE_DUPNAMES option, names for
-        subpatterns  are  not  required  to  be unique. Normally, patterns with
+        subpatterns are not required to  be  unique.  Normally,  patterns  with
-        duplicate names are such that in any one match, only one of  the  named
+        duplicate  names  are such that in any one match, only one of the named
-        subpatterns  participates. An example is shown in the pcrepattern docu-
+        subpatterns participates. An example is shown in the pcrepattern  docu-
-        mentation. When duplicates are present, pcre_copy_named_substring() and
+        mentation.
-        pcre_get_named_substring()  return the first substring corresponding to
-        the given name that is set.  If  none  are  set,  an  empty  string  is
+        When    duplicates   are   present,   pcre_copy_named_substring()   and
-        returned.  The pcre_get_stringnumber() function returns one of the num-
+        pcre_get_named_substring() return the first substring corresponding  to
-        bers that are associated with the name, but it is not defined which  it
+        the  given  name  that  is set. If none are set, PCRE_ERROR_NOSUBSTRING
-        is.
+        (-7) is returned; no  data  is  returned.  The  pcre_get_stringnumber()
+        function  returns one of the numbers that are associated with the name,
+        but it is not defined which it is.
-        If  you want to get full details of all captured substrings for a given
+        If you want to get full details of all captured substrings for a  given
-        name, you must use  the  pcre_get_stringtable_entries()  function.  The
+        name,  you  must  use  the pcre_get_stringtable_entries() function. The
         first argument is the compiled pattern, and the second is the name. The
-        third and fourth are pointers to variables which  are  updated  by  the
+        third  and  fourth  are  pointers to variables which are updated by the
         function. After it has run, they point to the first and last entries in
-        the name-to-number table  for  the  given  name.  The  function  itself
+        the  name-to-number  table  for  the  given  name.  The function itself
-        returns  the  length  of  each entry, or PCRE_ERROR_NOSUBSTRING (-7) if
+        returns the length of each entry,  or  PCRE_ERROR_NOSUBSTRING  (-7)  if
-        there are none. The format of the table is described above in the  sec-
+        there  are none. The format of the table is described above in the sec-
-        tion  entitled  Information  about  a  pattern.  Given all the relevant
+        tion entitled Information about a  pattern.   Given  all  the  relevant
-        entries for the name, you can extract each of their numbers, and  hence
+        entries  for the name, you can extract each of their numbers, and hence
         the captured data, if any.
  FINDING ALL POSSIBLE MATCHES
-        The  traditional  matching  function  uses a similar algorithm to Perl,
+        The traditional matching function uses a  similar  algorithm  to  Perl,
         which stops when it finds the first match, starting at a given point in
-        the  subject.  If you want to find all possible matches, or the longest
+        the subject. If you want to find all possible matches, or  the  longest
-        possible match, consider using the alternative matching  function  (see
+        possible  match,  consider using the alternative matching function (see
-        below)  instead.  If you cannot use the alternative function, but still
+        below) instead. If you cannot use the alternative function,  but  still
-        need to find all possible matches, you can kludge it up by  making  use
+        need  to  find all possible matches, you can kludge it up by making use
         of the callout facility, which is described in the pcrecallout documen-
         tation.
         What you have to do is to insert a callout right at the end of the pat-
-        tern.   When your callout function is called, extract and save the cur-
+        tern.  When your callout function is called, extract and save the  cur-
-        rent matched substring. Then return  1,  which  forces  pcre_exec()  to
+        rent  matched  substring.  Then  return  1, which forces pcre_exec() to
-        backtrack  and  try other alternatives. Ultimately, when it runs out of
+        backtrack and try other alternatives. Ultimately, when it runs  out  of
         matches, pcre_exec() will yield PCRE_ERROR_NOMATCH.
-Line 2255 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2395 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
              int options, int *ovector, int ovecsize,
              int *workspace, int wscount);
-        The function pcre_dfa_exec()  is  called  to  match  a  subject  string
+        The  function  pcre_dfa_exec()  is  called  to  match  a subject string
-        against  a  compiled pattern, using a matching algorithm that scans the
+        against a compiled pattern, using a matching algorithm that  scans  the
-        subject string just once, and does not backtrack.  This  has  different
+        subject  string  just  once, and does not backtrack. This has different
-        characteristics  to  the  normal  algorithm, and is not compatible with
+        characteristics to the normal algorithm, and  is  not  compatible  with
-        Perl. Some of the features of PCRE patterns are not  supported.  Never-
+        Perl.  Some  of the features of PCRE patterns are not supported. Never-
-        theless,  there are times when this kind of matching can be useful. For
+        theless, there are times when this kind of matching can be useful.  For
         a discussion of the two matching algorithms, see the pcrematching docu-
         mentation.
-        The  arguments  for  the  pcre_dfa_exec()  function are the same as for
+        The arguments for the pcre_dfa_exec() function  are  the  same  as  for
         pcre_exec(), plus two extras. The ovector argument is used in a differ-
-        ent  way,  and  this is described below. The other common arguments are
+        ent way, and this is described below. The other  common  arguments  are
-        used in the same way as for pcre_exec(), so their  description  is  not
+        used  in  the  same way as for pcre_exec(), so their description is not
         repeated here.
-        The  two  additional  arguments provide workspace for the function. The
+        The two additional arguments provide workspace for  the  function.  The
-        workspace vector should contain at least 20 elements. It  is  used  for
+        workspace  vector  should  contain at least 20 elements. It is used for
         keeping  track  of  multiple  paths  through  the  pattern  tree.  More
-        workspace will be needed for patterns and subjects where  there  are  a
+        workspace  will  be  needed for patterns and subjects where there are a
         lot of potential matches.
         Here is an example of a simple call to pcre_dfa_exec():
-Line 2295 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2435 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
     Option bits for pcre_dfa_exec()
-        The  unused  bits  of  the options argument for pcre_dfa_exec() must be
+        The unused bits of the options argument  for  pcre_dfa_exec()  must  be
-        zero. The only bits  that  may  be  set  are  PCRE_ANCHORED,  PCRE_NEW-
+        zero.  The  only  bits  that  may  be  set are PCRE_ANCHORED, PCRE_NEW-
-        LINE_xxx,  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK,
+        LINE_xxx, PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY,  PCRE_NO_UTF8_CHECK,
         PCRE_PARTIAL, PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All but the last
         three of these are the same as for pcre_exec(), so their description is
         not repeated here.
           PCRE_PARTIAL
-        This has the same general effect as it does for  pcre_exec(),  but  the
+        This  has  the  same general effect as it does for pcre_exec(), but the
-        details   are   slightly   different.  When  PCRE_PARTIAL  is  set  for
+        details  are  slightly  different.  When  PCRE_PARTIAL   is   set   for
-        pcre_dfa_exec(), the return code PCRE_ERROR_NOMATCH is  converted  into
+        pcre_dfa_exec(),  the  return code PCRE_ERROR_NOMATCH is converted into
-        PCRE_ERROR_PARTIAL  if  the  end  of the subject is reached, there have
+        PCRE_ERROR_PARTIAL if the end of the subject  is  reached,  there  have
         been no complete matches, but there is still at least one matching pos-
-        sibility.  The portion of the string that provided the partial match is
+        sibility. The portion of the string that provided the partial match  is
         set as the first matching string.
           PCRE_DFA_SHORTEST
-        Setting the PCRE_DFA_SHORTEST option causes the matching  algorithm  to
+        Setting  the  PCRE_DFA_SHORTEST option causes the matching algorithm to
         stop as soon as it has found one match. Because of the way the alterna-
-        tive algorithm works, this is necessarily the shortest  possible  match
+        tive  algorithm  works, this is necessarily the shortest possible match
         at the first possible matching point in the subject string.
           PCRE_DFA_RESTART
-        When  pcre_dfa_exec()  is  called  with  the  PCRE_PARTIAL  option, and
+        When pcre_dfa_exec()  is  called  with  the  PCRE_PARTIAL  option,  and
-        returns a partial match, it is possible to call it  again,  with  addi-
+        returns  a  partial  match, it is possible to call it again, with addi-
-        tional  subject  characters,  and have it continue with the same match.
+        tional subject characters, and have it continue with  the  same  match.
-        The PCRE_DFA_RESTART option requests this action; when it is  set,  the
+        The  PCRE_DFA_RESTART  option requests this action; when it is set, the
-        workspace  and wscount options must reference the same vector as before
+        workspace and wscount options must reference the same vector as  before
-        because data about the match so far is left in  them  after  a  partial
+        because  data  about  the  match so far is left in them after a partial
-        match.  There  is  more  discussion of this facility in the pcrepartial
+        match. There is more discussion of this  facility  in  the  pcrepartial
         documentation.
     Successful returns from pcre_dfa_exec()
-        When pcre_dfa_exec() succeeds, it may have matched more than  one  sub-
+        When  pcre_dfa_exec()  succeeds, it may have matched more than one sub-
         string in the subject. Note, however, that all the matches from one run
-        of the function start at the same point in  the  subject.  The  shorter
+        of  the  function  start  at the same point in the subject. The shorter
-        matches  are all initial substrings of the longer matches. For example,
+        matches are all initial substrings of the longer matches. For  example,
         if the pattern
           <.*>
-Line 2350 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2490 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
           <something> <something else>
           <something> <something else> <something further>
-        On success, the yield of the function is a number  greater  than  zero,
+        On  success,  the  yield of the function is a number greater than zero,
-        which  is  the  number of matched substrings. The substrings themselves
+        which is the number of matched substrings.  The  substrings  themselves
-        are returned in ovector. Each string uses two elements;  the  first  is
+        are  returned  in  ovector. Each string uses two elements; the first is
-        the  offset  to  the start, and the second is the offset to the end. In
+        the offset to the start, and the second is the offset to  the  end.  In
-        fact, all the strings have the same start  offset.  (Space  could  have
+        fact,  all  the  strings  have the same start offset. (Space could have
-        been  saved by giving this only once, but it was decided to retain some
+        been saved by giving this only once, but it was decided to retain  some
-        compatibility with the way pcre_exec() returns data,  even  though  the
+        compatibility  with  the  way pcre_exec() returns data, even though the
         meaning of the strings is different.)
         The strings are returned in reverse order of length; that is, the long-
-        est matching string is given first. If there were too many  matches  to
+        est  matching  string is given first. If there were too many matches to
-        fit  into ovector, the yield of the function is zero, and the vector is
+        fit into ovector, the yield of the function is zero, and the vector  is
         filled with the longest matches.
     Error returns from pcre_dfa_exec()
-        The pcre_dfa_exec() function returns a negative number when  it  fails.
+        The  pcre_dfa_exec()  function returns a negative number when it fails.
-        Many  of  the  errors  are  the  same as for pcre_exec(), and these are
+        Many of the errors are the same  as  for  pcre_exec(),  and  these  are
-        described above.  There are in addition the following errors  that  are
+        described  above.   There are in addition the following errors that are
         specific to pcre_dfa_exec():
           PCRE_ERROR_DFA_UITEM      (-16)
-        This  return is given if pcre_dfa_exec() encounters an item in the pat-
+        This return is given if pcre_dfa_exec() encounters an item in the  pat-
-        tern that it does not support, for instance, the use of \C  or  a  back
+        tern  that  it  does not support, for instance, the use of \C or a back
         reference.
           PCRE_ERROR_DFA_UCOND      (-17)
-        This  return  is  given  if pcre_dfa_exec() encounters a condition item
+        This return is given if pcre_dfa_exec()  encounters  a  condition  item
-        that uses a back reference for the condition, or a test  for  recursion
+        that  uses  a back reference for the condition, or a test for recursion
         in a specific group. These are not supported.
           PCRE_ERROR_DFA_UMLIMIT    (-18)
-        This  return  is given if pcre_dfa_exec() is called with an extra block
+        This return is given if pcre_dfa_exec() is called with an  extra  block
         that contains a setting of the match_limit field. This is not supported
         (it is meaningless).
           PCRE_ERROR_DFA_WSSIZE     (-19)
-        This  return  is  given  if  pcre_dfa_exec()  runs  out of space in the
+        This return is given if  pcre_dfa_exec()  runs  out  of  space  in  the
         workspace vector.
           PCRE_ERROR_DFA_RECURSE    (-20)
-        When a recursive subpattern is processed, the matching  function  calls
+        When  a  recursive subpattern is processed, the matching function calls
-        itself  recursively,  using  private vectors for ovector and workspace.
+        itself recursively, using private vectors for  ovector  and  workspace.
-        This error is given if the output vector  is  not  large  enough.  This
+        This  error  is  given  if  the output vector is not large enough. This
         should be extremely rare, as a vector of size 1000 is used.
  SEE ALSO
-        pcrebuild(3),  pcrecallout(3), pcrecpp(3)(3), pcrematching(3), pcrepar-
+        pcrebuild(3), pcrecallout(3), pcrecpp(3)(3), pcrematching(3),  pcrepar-
-        tial(3), pcreposix(3), pcreprecompile(3), pcresample(3),  pcrestack(3).
+        tial(3),  pcreposix(3), pcreprecompile(3), pcresample(3), pcrestack(3).
  AUTHOR
-Line 2417 
 AUTHOR
+Line 2557 
 AUTHOR
  REVISION
-        Last updated: 13 June 2007
+        Last updated: 27 November 2007
         Copyright (c) 1997-2007 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 2670 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2810 
 DIFFERENCES BETWEEN PCRE AND PERL
         matching  "aba"  against  the  pattern  /^(a(b)?)+$/  in Perl leaves $2
         unset, but in PCRE it is set to "b".
-. PCRE provides some extensions to the Perl regular expression facil-
+.  PCRE  does  support  Perl  5.10's  backtracking  verbs  (*ACCEPT),
+        (*FAIL),  (*F),  (*COMMIT), (*PRUNE), (*SKIP), and (*THEN), but only in
+        the forms without an  argument.  PCRE  does  not  support  (*MARK).  If
+        (*ACCEPT)  is within capturing parentheses, PCRE does not set that cap-
+        ture group; this is different to Perl.
+. PCRE provides some extensions to the Perl regular expression facil-
         ities.   Perl  5.10  will  include new features that are not in earlier
         versions, some of which (such as named parentheses) have been  in  PCRE
         for some time. This list is with respect to Perl 5.10:
-Line 2696 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2842 
 DIFFERENCES BETWEEN PCRE AND PERL
         (f)  The PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NO_AUTO_CAP-
         TURE options for pcre_exec() have no Perl equivalents.
-        (g) The callout facility is PCRE-specific.
+        (g) The \R escape sequence can be restricted to match only CR,  LF,  or
+        CRLF by the PCRE_BSR_ANYCRLF option.
-        (h) The partial matching facility is PCRE-specific.
+        (h) The callout facility is PCRE-specific.
-        (i) Patterns compiled by PCRE can be saved and re-used at a later time,
+        (i) The partial matching facility is PCRE-specific.
+        (j) Patterns compiled by PCRE can be saved and re-used at a later time,
         even on different hosts that have the other endianness.
-        (j)  The  alternative  matching function (pcre_dfa_exec()) matches in a
+        (k) The alternative matching function (pcre_dfa_exec())  matches  in  a
         different way and is not Perl-compatible.
+        (l)  PCRE  recognizes some special sequences such as (*CR) at the start
+        of a pattern that set overall options that cannot be changed within the
+        pattern.
  AUTHOR
-Line 2716 
 AUTHOR
+Line 2869 
 AUTHOR
  REVISION
-        Last updated: 13 June 2007
+        Last updated: 11 September 2007
         Copyright (c) 1997-2007 University of Cambridge.
  ------------------------------------------------------------------------------
-Line 2730 
 NAME
+Line 2883 
 NAME
  PCRE REGULAR EXPRESSION DETAILS
-        The  syntax  and semantics of the regular expressions supported by PCRE
+        The  syntax and semantics of the regular expressions that are supported
-        are described below. Regular expressions are also described in the Perl
+        by PCRE are described in detail below. There is a quick-reference  syn-
-        documentation  and  in  a  number  of books, some of which have copious
+        tax  summary  in  the  pcresyntax  page. Perl's regular expressions are
-        examples.  Jeffrey Friedl's "Mastering Regular Expressions",  published
+        described in its own documentation, and regular expressions in  general
-        by  O'Reilly, covers regular expressions in great detail. This descrip-
+        are  covered in a number of books, some of which have copious examples.
-        tion of PCRE's regular expressions is intended as reference material.
+        Jeffrey  Friedl's  "Mastering  Regular   Expressions",   published   by
+        O'Reilly,  covers regular expressions in great detail. This description
+        of PCRE's regular expressions is intended as reference material.
         The original operation of PCRE was on strings of  one-byte  characters.
         However,  there is now also support for UTF-8 character strings. To use
-Line 2755 
 PCRE REGULAR EXPRESSION DETAILS
+Line 2910 
 PCRE REGULAR EXPRESSION DETAILS
         discussed in the pcrematching page.
+ NEWLINE CONVENTIONS
+        PCRE  supports five different conventions for indicating line breaks in
+        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
+        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-
+        tern string with one of the following five sequences:
+          (*CR)        carriage return
+          (*LF)        linefeed
+          (*CRLF)      carriage return, followed by linefeed
+          (*ANYCRLF)   any of the three above
+          (*ANY)       all Unicode newline sequences
+        These override the default and the options given to pcre_compile(). 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
+        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
+        present, the last one is used.
+        The  newline  convention  does  not  affect what the \R escape sequence
+        matches. By default, this is any Unicode  newline  sequence,  for  Perl
+        compatibility.  However, this can be changed; see the description of \R
+        in the section entitled "Newline sequences" below. A change of \R  set-
+        ting can be combined with a change of newline convention.
  CHARACTERS AND METACHARACTERS
         A  regular  expression  is  a pattern that is matched against a subject
-Line 2862 
 BACKSLASH
+Line 3054 
 BACKSLASH
           \cx       "control-x", where x is any character
           \e        escape (hex 1B)
           \f        formfeed (hex 0C)
-          \n        newline (hex 0A)
+          \n        linefeed (hex 0A)
           \r        carriage return (hex 0D)
           \t        tab (hex 09)
           \ddd      character with octal code ddd, or backreference
-Line 2877 
 BACKSLASH
+Line 3069 
 BACKSLASH
         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,
+        than 256 in non-UTF-8 mode, and less than 2**31 in UTF-8 mode. That is,
-        the  maximum  hexadecimal  value is 7FFFFFFF). If characters other than
+        the  maximum value in hexadecimal is 7FFFFFFF. Note that this is bigger
-        hexadecimal digits appear between \x{ and }, or if there is  no  termi-
+        than the largest Unicode code point, which is 10FFFF.
-        nating  }, this form of escape is not recognized.  Instead, the initial
-        \x will be interpreted as a basic hexadecimal escape, with no following
+        If characters other than hexadecimal digits appear between \x{  and  },
-        digits, giving a character whose value is zero.
+        or if there is no terminating }, this form of escape is not recognized.
+        Instead, the initial \x will be  interpreted  as  a  basic  hexadecimal
+        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 2925 
 BACKSLASH
+Line 3120 
 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
-),  and the sequences \R and \X are interpreted as the characters "R"
+), and the sequences \R and \X are interpreted as the characters  "R"
-        and "X", respectively. Outside a character class, these sequences  have
+        and  "X", respectively. Outside a character class, these sequences have
         different meanings (see below).
     Absolute and relative back references
-        The  sequence  \g followed by a positive or negative number, optionally
+        The sequence \g followed by an unsigned or a negative  number,  option-
-        enclosed in braces, is an absolute or relative back reference. A  named
+        ally  enclosed  in braces, is an absolute or relative back reference. A
-        back  reference can be coded as \g{name}. Back references are discussed
+        named back reference can be coded as \g{name}. Back references are dis-
-        later, following the discussion of parenthesized subpatterns.
+        cussed later, following the discussion of parenthesized subpatterns.
     Generic character types
-Line 2959 
 BACKSLASH
+Line 3154 
 BACKSLASH
           \W     any "non-word" character
         Each pair of escape sequences partitions the complete set of characters
-        into two disjoint sets. Any given character matches one, and only  one,
+        into  two disjoint sets. Any given character matches one, and only one,
         of each pair.
         These character type sequences can appear both inside and outside char-
-        acter classes. They each match one character of the  appropriate  type.
+        acter  classes.  They each match one character of the appropriate type.
-        If  the current matching point is at the end of the subject string, all
+        If the current matching point is at the end of the subject string,  all
         of them fail, since 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.
-        In UTF-8 mode, characters with values greater than 128 never match  \d,
+        In  UTF-8 mode, characters with values greater than 128 never match \d,
         \s, or \w, and always match \D, \S, and \W. This is true even when Uni-
-        code character property support is available.  These  sequences  retain
+        code  character  property  support is available. These sequences retain
         their original meanings from before UTF-8 support was available, mainly
         for efficiency reasons.
         The sequences \h, \H, \v, and \V are Perl 5.10 features. In contrast to
-        the  other  sequences, these do match certain high-valued codepoints in
+        the other sequences, these do match certain high-valued  codepoints  in
         UTF-8 mode.  The horizontal space characters are:
           U+0009     Horizontal tab
-Line 3014 
 BACKSLASH
+Line 3209 
 BACKSLASH
           U+2029     Paragraph separator
         A "word" character is an underscore or any character less than 256 that
-        is  a  letter  or  digit.  The definition of letters and digits is con-
+        is a letter or digit. 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 matched by \w. The use  of
+        are  used for accented letters, and these are matched by \w. The use of
         locales with Unicode is discouraged.
     Newline sequences
-        Outside  a  character class, the escape sequence \R matches any Unicode
+        Outside a character class, by default, the escape sequence  \R  matches
-        newline sequence. This is a Perl 5.10 feature. In non-UTF-8 mode \R  is
+        any Unicode newline sequence. This is a Perl 5.10 feature. In non-UTF-8
-        equivalent to the following:
+        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
+        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
+        requested  via  the  PCRE_BSR_UNICODE  option.   It is also possible to
+        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(), but
+        they can be overridden by options given to pcre_exec(). Note that these
+        special settings, which 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 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)
         Inside a character class, \R matches the letter "R".
     Unicode character properties
-Line 3145 
 BACKSLASH
+Line 3362 
 BACKSLASH
         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
+        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
+        the pcreapi page).
         The long synonyms for these properties  that  Perl  supports  (such  as
         \p{Letter})  are  not  supported by PCRE, nor is it permitted to prefix
         any of these properties with "Is".
-Line 3491 
 VERTICAL BAR
+Line 3714 
 VERTICAL BAR
  INTERNAL OPTION SETTING
         The  settings  of  the  PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and
-        PCRE_EXTENDED options can be changed  from  within  the  pattern  by  a
+        PCRE_EXTENDED options (which are Perl-compatible) can be  changed  from
-        sequence  of  Perl  option  letters  enclosed between "(?" and ")". The
+        within  the  pattern  by  a  sequence  of  Perl option letters enclosed
-        option letters are
+        between "(?" and ")".  The option letters are
           i  for PCRE_CASELESS
           m  for PCRE_MULTILINE
-Line 3507 
 INTERNAL OPTION SETTING
+Line 3730 
 INTERNAL OPTION SETTING
         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
+        can be changed in the same way as the Perl-compatible options by  using
+        the characters J, U and X respectively.
         When  an option change occurs at top level (that is, not inside subpat-
         tern parentheses), the change applies to the remainder of  the  pattern
         that follows.  If the change is placed right at the start of a pattern,
-Line 3532 
 INTERNAL OPTION SETTING
+Line 3759 
 INTERNAL OPTION SETTING
         the  effects  of option settings happen at compile time. There would be
         some very weird behaviour otherwise.
-        The PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and  PCRE_EXTRA
+        Note: There are other PCRE-specific options that  can  be  set  by  the
-        can  be changed in the same way as the Perl-compatible options by using
+        application  when  the  compile  or match functions are called. In some
-        the characters J, U and X respectively.
+        cases the pattern can contain special  leading  sequences  to  override
+        what  the  application  has set or what has been defaulted. Details are
+        given in the section entitled "Newline sequences" above.
  SUBPATTERNS
-Line 3876 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
+Line 4105 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
           \d++foo
-        Possessive  quantifiers  are  always  greedy;  the   setting   of   the
+        Note that a possessive quantifier can be used with an entire group, for
+        example:
+          (abc|xyz){2,3}+
+        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+>)*[!?]
-        sequences  of non-digits cannot be broken, and failure happens quickly.
+        sequences of non-digits cannot be broken, and failure happens  quickly.
  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, which is a fea-
-        ture introduced in Perl 5.10. This escape must be followed by  a  posi-
+        ture  introduced  in  Perl  5.10.  This  escape  must be followed by an
-        tive  or  a negative number, optionally enclosed in braces. These exam-
+        unsigned number or a negative number, optionally  enclosed  in  braces.
-        ples are all identical:
+        These examples are all identical:
           (ring), \1
           (ring), \g1
           (ring), \g{1}
-        A positive number specifies an absolute reference without the ambiguity
+        An  unsigned number specifies an absolute reference without the ambigu-
-        that  is  present  in  the older syntax. It is also useful when literal
+        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:
           (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. Similarly,
         \g{-2} would be equivalent to \1. The use of relative references can be
-        helpful in long patterns, and also in  patterns  that  are  created  by
+        helpful  in  long  patterns,  and  also in patterns that are created by
         joining together fragments that contain references within themselves.
-        A  back  reference matches whatever actually matched the capturing sub-
+        A back reference matches whatever actually matched the  capturing  sub-
-        pattern in the current subject string, rather  than  anything  matching
+        pattern  in  the  current subject string, rather than anything matching
         the subpattern itself (see "Subpatterns as subroutines" below for a way
         of doing that). So the pattern
           (sens|respons)e and \1ibility
-        matches "sense and sensibility" and "response and responsibility",  but
+        matches  "sense and sensibility" and "response and responsibility", but
-        not  "sense and responsibility". If caseful matching is in force at the
+        not "sense and responsibility". If caseful matching is in force at  the
-        time of the back reference, the case of letters is relevant. For  exam-
+        time  of the back reference, the case of letters is relevant. For exam-
         ple,
           ((?i)rah)\s+\1
-        matches  "rah  rah"  and  "RAH RAH", but not "RAH rah", even though the
+        matches "rah rah" and "RAH RAH", but not "RAH  rah",  even  though  the
         original capturing subpattern is matched caselessly.
-        There are several different ways of writing back  references  to  named
+        There  are  several  different ways of writing back references to named
-        subpatterns.  The  .NET syntax \k{name} and the Perl syntax \k<name> or
+        subpatterns. The .NET syntax \k{name} and the Perl syntax  \k<name>  or
-        \k'name' are supported, as is the Python syntax (?P=name). Perl  5.10's
+        \k'name'  are supported, as is the Python syntax (?P=name). Perl 5.10's
         unified back reference syntax, in which \g can be used for both numeric
-        and named references, is also supported. We  could  rewrite  the  above
+        and  named  references,  is  also supported. We could rewrite the above
         example in any of the following ways:
           (?<p1>(?i)rah)\s+\k<p1>
-Line 3998 
 BACK REFERENCES
+Line 4232 
 BACK REFERENCES
           (?P<p1>(?i)rah)\s+(?P=p1)
           (?<p1>(?i)rah)\s+\g{p1}
-        A  subpattern  that  is  referenced  by  name may appear in the pattern
+        A subpattern that is referenced by  name  may  appear  in  the  pattern
         before or after the reference.
-        There may be more than one back reference to the same subpattern. If  a
+        There  may be more than one back reference to the same subpattern. If a
-        subpattern  has  not actually been used in a particular match, any back
+        subpattern has not actually been used in a particular match,  any  back
         references to it always fail. For example, the pattern
           (a|(bc))\2
-        always fails if it starts to match "a" rather than "bc". Because  there
+        always  fails if it starts to match "a" rather than "bc". Because there
-        may  be  many  capturing parentheses in a pattern, all digits following
+        may be many capturing parentheses in a pattern,  all  digits  following
-        the backslash are taken as part of a potential back  reference  number.
+        the  backslash  are taken as part of a potential back reference number.
         If the pattern continues with a digit character, some delimiter must be
-        used to terminate the back reference. If the  PCRE_EXTENDED  option  is
+        used  to  terminate  the back reference. If the PCRE_EXTENDED option is
-        set,  this  can  be  whitespace.  Otherwise an empty comment (see "Com-
+        set, this can be whitespace.  Otherwise an  empty  comment  (see  "Com-
         ments" below) can be used.
-        A back reference that occurs inside the parentheses to which it  refers
+        A  back reference that occurs inside the parentheses to which it refers
-        fails  when  the subpattern is first used, so, for example, (a\1) never
+        fails when the subpattern is first used, so, for example,  (a\1)  never
-        matches.  However, such references can be useful inside  repeated  sub-
+        matches.   However,  such references can be useful inside repeated sub-
         patterns. For example, the pattern
           (a|b\1)+
         matches any number of "a"s and also "aba", "ababbaa" etc. At each iter-
-        ation of the subpattern,  the  back  reference  matches  the  character
+        ation  of  the  subpattern,  the  back  reference matches the character
-        string  corresponding  to  the previous iteration. In order for this to
+        string corresponding to the previous iteration. In order  for  this  to
-        work, the pattern must be such that the first iteration does  not  need
+        work,  the  pattern must be such that the first iteration does not need
-        to  match the back reference. This can be done using alternation, as in
+        to match the back reference. This can be done using alternation, as  in
         the example above, or by a quantifier with a minimum of zero.
  ASSERTIONS
-        An assertion is a test on the characters  following  or  preceding  the
+        An  assertion  is  a  test on the characters following or preceding the
-        current  matching  point that does not actually consume any characters.
+        current matching point that does not actually consume  any  characters.
-        The simple assertions coded as \b, \B, \A, \G, \Z,  \z,  ^  and  $  are
+        The  simple  assertions  coded  as  \b, \B, \A, \G, \Z, \z, ^ and $ are
         described above.
-        More  complicated  assertions  are  coded as subpatterns. There are two
+        More complicated assertions are coded as  subpatterns.  There  are  two
-        kinds: those that look ahead of the current  position  in  the  subject
+        kinds:  those  that  look  ahead of the current position in the subject
-        string,  and  those  that  look  behind  it. An assertion subpattern is
+        string, and those that look  behind  it.  An  assertion  subpattern  is
-        matched in the normal way, except that it does not  cause  the  current
+        matched  in  the  normal way, except that it does not cause the current
         matching position to be changed.
-        Assertion  subpatterns  are  not  capturing subpatterns, and may not be
+        Assertion subpatterns are not capturing subpatterns,  and  may  not  be
-        repeated, because it makes no sense to assert the  same  thing  several
+        repeated,  because  it  makes no sense to assert the same thing several
-        times.  If  any kind of assertion contains capturing subpatterns within
+        times. If any kind of assertion contains capturing  subpatterns  within
-        it, these are counted for the purposes of numbering the capturing  sub-
+        it,  these are counted for the purposes of numbering the capturing sub-
         patterns in the whole pattern.  However, substring capturing is carried
-        out only for positive assertions, because it does not  make  sense  for
+        out  only  for  positive assertions, because it does not make sense for
         negative assertions.
     Lookahead assertions
-Line 4058 
 ASSERTIONS
+Line 4292 
 ASSERTIONS
           \w+(?=;)
-        matches a word followed by a semicolon, but does not include the  semi-
+        matches  a word followed by a semicolon, but does not include the semi-
         colon in the match, and
           foo(?!bar)
-        matches  any  occurrence  of  "foo" that is not followed by "bar". Note
+        matches any occurrence of "foo" that is not  followed  by  "bar".  Note
         that the apparently similar pattern
           (?!foo)bar
-        does not find an occurrence of "bar"  that  is  preceded  by  something
+        does  not  find  an  occurrence  of "bar" that is preceded by something
-        other  than "foo"; it finds any occurrence of "bar" whatsoever, because
+        other than "foo"; it finds any occurrence of "bar" whatsoever,  because
         the assertion (?!foo) is always true when the next three characters are
         "bar". A lookbehind assertion is needed to achieve the other effect.
         If you want to force a matching failure at some point in a pattern, the
-        most convenient way to do it is  with  (?!)  because  an  empty  string
+        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
+        always matches, so an assertion that requires there not to be an  empty
         string must always fail.
     Lookbehind assertions
-        Lookbehind assertions start with (?<= for positive assertions and  (?<!
+        Lookbehind  assertions start with (?<= for positive assertions and (?<!
         for negative assertions. For example,
           (?<!foo)bar
-        does  find  an  occurrence  of "bar" that is not preceded by "foo". The
+        does find an occurrence of "bar" that is not  preceded  by  "foo".  The
-        contents of a lookbehind assertion are restricted  such  that  all  the
+        contents  of  a  lookbehind  assertion are restricted such that all the
         strings it matches must have a fixed length. However, if there are sev-
-        eral top-level alternatives, they do not all  have  to  have  the  same
+        eral  top-level  alternatives,  they  do  not all have to have the same
         fixed length. Thus
           (?<=bullock|donkey)
-Line 4097 
 ASSERTIONS
+Line 4331 
 ASSERTIONS
           (?<!dogs?|cats?)
-        causes  an  error at compile time. Branches that match different length
+        causes an error at compile time. Branches that match  different  length
-        strings are permitted only at the top level of a lookbehind  assertion.
+        strings  are permitted only at the top level of a lookbehind assertion.
-        This  is  an  extension  compared  with  Perl (at least for 5.8), which
+        This is an extension compared with  Perl  (at  least  for  5.8),  which
-        requires all branches to match the same length of string. An  assertion
+        requires  all branches to match the same length of string. An assertion
         such as
           (?<=ab(c|de))
-        is  not  permitted,  because  its single top-level branch can match two
+        is not permitted, because its single top-level  branch  can  match  two
-        different lengths, but it is acceptable if rewritten to  use  two  top-
+        different  lengths,  but  it is acceptable if rewritten to use two top-
         level branches:
           (?<=abc|abde)
         In some cases, the Perl 5.10 escape sequence \K (see above) can be used
-        instead of a lookbehind assertion; this is not restricted to  a  fixed-
+        instead  of  a lookbehind assertion; this is not restricted to a fixed-
         length.
-        The  implementation  of lookbehind assertions is, for each alternative,
+        The implementation of lookbehind assertions is, for  each  alternative,
-        to temporarily move the current position back by the fixed  length  and
+        to  temporarily  move the current position back by the fixed length and
         then try to match. If there are insufficient characters before the cur-
         rent position, the assertion fails.
         PCRE does not allow the \C escape (which matches a single byte in UTF-8
-        mode)  to appear in lookbehind assertions, because it makes it impossi-
+        mode) to appear in lookbehind assertions, because it makes it  impossi-
-        ble to calculate the length of the lookbehind. The \X and  \R  escapes,
+        ble  to  calculate the length of the lookbehind. The \X and \R escapes,
         which can match different numbers of bytes, are also not permitted.
-        Possessive  quantifiers  can  be  used  in  conjunction with lookbehind
+        Possessive quantifiers can  be  used  in  conjunction  with  lookbehind
-        assertions to specify efficient matching at  the  end  of  the  subject
+        assertions  to  specify  efficient  matching  at the end of the subject
         string. Consider a simple pattern such as
           abcd$
-        when  applied  to  a  long string that does not match. Because matching
+        when applied to a long string that does  not  match.  Because  matching
         proceeds from left to right, PCRE will look for each "a" in the subject
-        and  then  see  if what follows matches the rest of the pattern. If the
+        and then see if what follows matches the rest of the  pattern.  If  the
         pattern is specified as
           ^.*abcd$
-        the initial .* matches the entire string at first, but when this  fails
+        the  initial .* matches the entire string at first, but when this fails
         (because there is no following "a"), it backtracks to match all but the
-        last character, then all but the last two characters, and so  on.  Once
+        last  character,  then all but the last two characters, and so on. Once
-        again  the search for "a" covers the entire string, from right to left,
+        again the search for "a" covers the entire string, from right to  left,
         so we are no better off. However, if the pattern is written as
           ^.*+(?<=abcd)
-        there can be no backtracking for the .*+ item; it can  match  only  the
+        there  can  be  no backtracking for the .*+ item; it can match only the
-        entire  string.  The subsequent lookbehind assertion does a single test
+        entire string. The subsequent lookbehind assertion does a  single  test
-        on the last four characters. If it fails, the match fails  immediately.
+        on  the last four characters. If it fails, the match fails immediately.
-        For  long  strings, this approach makes a significant difference to the
+        For long strings, this approach makes a significant difference  to  the
         processing time.
     Using multiple assertions
-Line 4158 
 ASSERTIONS
+Line 4392 
 ASSERTIONS
           (?<=\d{3})(?<!999)foo
-        matches "foo" preceded by three digits that are not "999". Notice  that
+        matches  "foo" preceded by three digits that are not "999". Notice that
-        each  of  the  assertions is applied independently at the same point in
+        each of the assertions is applied independently at the  same  point  in
-        the subject string. First there is a  check  that  the  previous  three
+        the  subject  string.  First  there  is a check that the previous three
-        characters  are  all  digits,  and  then there is a check that the same
+        characters are all digits, and then there is  a  check  that  the  same
         three characters are not "999".  This pattern does not match "foo" pre-
-        ceded  by  six  characters,  the first of which are digits and the last
+        ceded by six characters, the first of which are  digits  and  the  last
-        three of which are not "999". For example, it  doesn't  match  "123abc-
+        three  of  which  are not "999". For example, it doesn't match "123abc-
         foo". A pattern to do that is
           (?<=\d{3}...)(?<!999)foo
-        This  time  the  first assertion looks at the preceding six characters,
+        This time the first assertion looks at the  preceding  six  characters,
         checking that the first three are digits, and then the second assertion
         checks that the preceding three characters are not "999".
-Line 4177 
 ASSERTIONS
+Line 4411 
 ASSERTIONS
           (?<=(?<!foo)bar)baz
-        matches  an occurrence of "baz" that is preceded by "bar" which in turn
+        matches an occurrence of "baz" that is preceded by "bar" which in  turn
         is not preceded by "foo", while
           (?<=\d{3}(?!999)...)foo
-        is another pattern that matches "foo" preceded by three digits and  any
+        is  another pattern that matches "foo" preceded by three digits and any
         three characters that are not "999".
  CONDITIONAL SUBPATTERNS
-        It  is possible to cause the matching process to obey a subpattern con-
+        It is possible to cause the matching process to obey a subpattern  con-
-        ditionally or to choose between two alternative subpatterns,  depending
+        ditionally  or to choose between two alternative subpatterns, depending
-        on  the result of an assertion, or whether a previous capturing subpat-
+        on the result of an assertion, or whether a previous capturing  subpat-
-        tern matched or not. The two possible forms of  conditional  subpattern
+        tern  matched  or not. The two possible forms of conditional subpattern
         are
           (?(condition)yes-pattern)
           (?(condition)yes-pattern|no-pattern)
-        If  the  condition is satisfied, the yes-pattern is used; otherwise the
+        If the condition is satisfied, the yes-pattern is used;  otherwise  the
-        no-pattern (if present) is used. If there are more  than  two  alterna-
+        no-pattern  (if  present)  is used. If there are more than two alterna-
         tives in the subpattern, a compile-time error occurs.
-        There  are  four  kinds of condition: references to subpatterns, refer-
+        There are four kinds of condition: references  to  subpatterns,  refer-
         ences to recursion, a pseudo-condition called DEFINE, and assertions.
     Checking for a used subpattern by number
-        If the text between the parentheses consists of a sequence  of  digits,
+        If  the  text between the parentheses consists of a sequence of digits,
-        the  condition  is  true if the capturing subpattern of that number has
+        the condition is true if the capturing subpattern of  that  number  has
-        previously matched. An alternative notation is to  precede  the  digits
+        previously  matched.  An  alternative notation is to precede the digits
         with a plus or minus sign. In this case, the subpattern number is rela-
         tive rather than absolute.  The most recently opened parentheses can be
-        referenced  by  (?(-1),  the  next most recent by (?(-2), and so on. In
+        referenced by (?(-1), the next most recent by (?(-2),  and  so  on.  In
         looping constructs it can also make sense to refer to subsequent groups
         with constructs such as (?(+2).
-        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
         of parentheses matched or not. If they did, that is, if subject started
         with an opening parenthesis, the condition is true, and so the yes-pat-
-        tern  is  executed  and  a  closing parenthesis is required. Otherwise,
+        tern is executed and a  closing  parenthesis  is  required.  Otherwise,
-        since no-pattern is not present, the  subpattern  matches  nothing.  In
+        since  no-pattern  is  not  present, the subpattern matches nothing. In
-        other  words,  this  pattern  matches  a  sequence  of non-parentheses,
+        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:
-Line 4260 
 CONDITIONAL SUBPATTERNS
+Line 4494 
 CONDITIONAL SUBPATTERNS
     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:
           (?(R3)...) or (?(R&name)...)
-        the  condition is true if the most recent recursion is into the subpat-
+        the condition is true if the most recent recursion is into the  subpat-
-        tern whose number or name is given. This condition does not  check  the
+        tern  whose  number or name is given. This condition does not check the
         entire recursion stack.
-        At  "top  level", all these recursion test conditions are false. Recur-
+        At "top level", all these recursion test conditions are  false.  Recur-
         sive patterns are 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 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
-        The  first part of the pattern is a DEFINE group inside which a another
+        The first part of the pattern is a DEFINE group inside which a  another
-        group named "byte" is defined. This matches an individual component  of
+        group  named "byte" is defined. This matches an individual component of
-        an  IPv4  address  (a number less than 256). When matching takes place,
+        an IPv4 address (a number less than 256). When  matching  takes  place,
-        this part of the pattern is skipped because DEFINE acts  like  a  false
+        this  part  of  the pattern is skipped because DEFINE acts like a false
         condition.
         The rest of the pattern uses references to the named group to match the
-        four dot-separated components of an IPv4 address, insisting on  a  word
+        four  dot-separated  components of an IPv4 address, insisting on a word
         boundary at each end.
     Assertion conditions
-        If  the  condition  is  not  in any of the above formats, it must be an
+        If the condition is not in any of the above  formats,  it  must  be  an
-        assertion.  This may be a positive or negative lookahead or  lookbehind
+        assertion.   This may be a positive or negative lookahead or lookbehind
-        assertion.  Consider  this  pattern,  again  containing non-significant
+        assertion. Consider  this  pattern,  again  containing  non-significant
         white space, and with the two alternatives on the second line:
           (?(?=[^a-z]*[a-z])
           \d{2}-[a-z]{3}-\d{2}  |  \d{2}-\d{2}-\d{2} )
-        The condition  is  a  positive  lookahead  assertion  that  matches  an
+        The  condition  is  a  positive  lookahead  assertion  that  matches an
-        optional  sequence of non-letters followed by a letter. In other words,
+        optional sequence of non-letters followed by a letter. In other  words,
-        it tests for the presence of at least one letter in the subject.  If  a
+        it  tests  for the presence of at least one letter in the subject. If a
-        letter  is found, the subject is matched against the first alternative;
+        letter is found, the subject is matched against the first  alternative;
-        otherwise it is  matched  against  the  second.  This  pattern  matches
+        otherwise  it  is  matched  against  the  second.  This pattern matches
-        strings  in  one  of the two forms dd-aaa-dd or dd-dd-dd, where aaa are
+        strings in one of the two forms dd-aaa-dd or dd-dd-dd,  where  aaa  are
         letters and dd are digits.
  COMMENTS
-        The sequence (?# marks the start of a comment that continues up to  the
+        The  sequence (?# marks the start of a comment that continues up to the
-        next  closing  parenthesis.  Nested  parentheses are not permitted. The
+        next closing parenthesis. Nested parentheses  are  not  permitted.  The
-        characters that make up a comment play no part in the pattern  matching
+        characters  that make up a comment play no part in the pattern matching
         at all.
-        If  the PCRE_EXTENDED option is set, an unescaped # character outside a
+        If the PCRE_EXTENDED option is set, an unescaped # character outside  a
-        character class introduces a  comment  that  continues  to  immediately
+        character  class  introduces  a  comment  that continues to immediately
         after the next newline in the pattern.
  RECURSIVE PATTERNS
-        Consider  the problem of matching a string in parentheses, allowing for
+        Consider the problem of matching a string in parentheses, allowing  for
-        unlimited nested parentheses. Without the use of  recursion,  the  best
+        unlimited  nested  parentheses.  Without the use of recursion, the best
-        that  can  be  done  is  to use a pattern that matches up to some fixed
+        that can be done is to use a pattern that  matches  up  to  some  fixed
-        depth of nesting. It is not possible to  handle  an  arbitrary  nesting
+        depth  of  nesting.  It  is not possible to handle an arbitrary nesting
         depth.
         For some time, Perl has provided a facility that allows regular expres-
-        sions to recurse (amongst other things). It does this by  interpolating
+        sions  to recurse (amongst other things). It does this by interpolating
-        Perl  code in the expression at run time, and the code can refer to the
+        Perl code in the expression at run time, and the code can refer to  the
         expression itself. A Perl pattern using code interpolation to solve the
         parentheses problem can be created like this:
-Line 4348 
 RECURSIVE PATTERNS
+Line 4582 
 RECURSIVE PATTERNS
         refers recursively to the pattern in which it appears.
         Obviously, PCRE cannot support the interpolation of Perl code. Instead,
-        it  supports  special  syntax  for recursion of the entire pattern, and
+        it supports special syntax for recursion of  the  entire  pattern,  and
-        also for individual subpattern recursion.  After  its  introduction  in
+        also  for  individual  subpattern  recursion. After its introduction in
-        PCRE  and  Python,  this  kind of recursion was introduced into Perl at
+        PCRE and Python, this kind of recursion was  introduced  into  Perl  at
         release 5.10.
-        A special item that consists of (? followed by a  number  greater  than
+        A  special  item  that consists of (? followed by a number greater than
         zero and a closing parenthesis is a recursive call of the subpattern of
-        the given number, provided that it occurs inside that  subpattern.  (If
+        the  given  number, provided that it occurs inside that subpattern. (If
-        not,  it  is  a  "subroutine" call, which is described in the next sec-
+        not, it is a "subroutine" call, which is described  in  the  next  sec-
-        tion.) The special item (?R) or (?0) is a recursive call of the  entire
+        tion.)  The special item (?R) or (?0) is a recursive call of the entire
         regular expression.
-        In  PCRE (like Python, but unlike Perl), a recursive subpattern call is
+        In PCRE (like Python, but unlike Perl), a recursive subpattern call  is
         always treated as an atomic group. That is, once it has matched some of
         the subject string, it is never re-entered, even if it contains untried
         alternatives and there is a subsequent matching failure.
-        This PCRE pattern solves the nested  parentheses  problem  (assume  the
+        This  PCRE  pattern  solves  the nested parentheses problem (assume the
         PCRE_EXTENDED option is set so that white space is ignored):
           \( ( (?>[^()]+) | (?R) )* \)
-        First  it matches an opening parenthesis. Then it matches any number of
+        First it matches an opening parenthesis. Then it matches any number  of
-        substrings which can either be a  sequence  of  non-parentheses,  or  a
+        substrings  which  can  either  be  a sequence of non-parentheses, or a
-        recursive  match  of the pattern itself (that is, a correctly parenthe-
+        recursive match of the pattern itself (that is, a  correctly  parenthe-
         sized substring).  Finally there is a closing parenthesis.
-        If this were part of a larger pattern, you would not  want  to  recurse
+        If  this  were  part of a larger pattern, you would not want to recurse
         the entire pattern, so instead you could use this:
           ( \( ( (?>[^()]+) | (?1) )* \) )
-        We  have  put the pattern into parentheses, and caused the recursion to
+        We have put the pattern into parentheses, and caused the  recursion  to
         refer to them instead of the whole pattern.
-        In a larger pattern,  keeping  track  of  parenthesis  numbers  can  be
+        In  a  larger  pattern,  keeping  track  of  parenthesis numbers can be
-        tricky.  This is made easier by the use of relative references. (A Perl
+        tricky. This is made easier by the use of relative references. (A  Perl
-.10 feature.)  Instead of (?1) in the  pattern  above  you  can  write
+.10  feature.)   Instead  of  (?1)  in the pattern above you can write
         (?-2) to refer to the second most recently opened parentheses preceding
-        the recursion. In other  words,  a  negative  number  counts  capturing
+        the  recursion.  In  other  words,  a  negative number counts capturing
         parentheses leftwards from the point at which it is encountered.
-        It  is  also  possible  to refer to subsequently opened parentheses, by
+        It is also possible to refer to  subsequently  opened  parentheses,  by
-        writing references such as (?+2). However, these  cannot  be  recursive
+        writing  references  such  as (?+2). However, these cannot be recursive
-        because  the  reference  is  not inside the parentheses that are refer-
+        because the reference is not inside the  parentheses  that  are  refer-
-        enced. They are always "subroutine" calls, as  described  in  the  next
+        enced.  They  are  always  "subroutine" calls, as described in the next
         section.
-        An  alternative  approach is to use named parentheses instead. The Perl
+        An alternative approach is to use named parentheses instead.  The  Perl
-        syntax for this is (?&name); PCRE's earlier syntax  (?P>name)  is  also
+        syntax  for  this  is (?&name); PCRE's earlier syntax (?P>name) is also
         supported. We could rewrite the above example as follows:
           (?<pn> \( ( (?>[^()]+) | (?&pn) )* \) )
-        If  there  is more than one subpattern with the same name, the earliest
+        If there is more than one subpattern with the same name,  the  earliest
         one is used.
-        This particular example pattern that we have been looking  at  contains
+        This  particular  example pattern that we have been looking at contains
-        nested  unlimited repeats, and so the use of atomic grouping for match-
+        nested unlimited repeats, and so the use of atomic grouping for  match-
-        ing strings of non-parentheses is important when applying  the  pattern
+        ing  strings  of non-parentheses is important when applying the pattern
         to strings that do not match. For example, when this pattern is applied
         to
           (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa()
-        it yields "no match" quickly. However, if atomic grouping is not  used,
+        it  yields "no match" quickly. However, if atomic grouping is not used,
-        the  match  runs  for a very long time indeed because there are so many
+        the match runs for a very long time indeed because there  are  so  many
-        different ways the + and * repeats can carve up the  subject,  and  all
+        different  ways  the  + and * repeats can carve up the subject, and all
         have to be tested before failure can be reported.
         At the end of a match, the values set for any capturing subpatterns are
         those from the outermost level of the recursion at which the subpattern
-        value  is  set.   If  you want to obtain intermediate values, a callout
+        value is set.  If you want to obtain  intermediate  values,  a  callout
-        function can be used (see below and the pcrecallout documentation).  If
+        function  can be used (see below and the pcrecallout documentation). If
         the pattern above is matched against
           (ab(cd)ef)
-        the  value  for  the  capturing  parentheses is "ef", which is the last
+        the value for the capturing parentheses is  "ef",  which  is  the  last
-        value taken on at the top level. If additional parentheses  are  added,
+        value  taken  on at the top level. If additional parentheses are added,
         giving
           \( ( ( (?>[^()]+) | (?R) )* ) \)
              ^                        ^
              ^                        ^
-        the  string  they  capture is "ab(cd)ef", the contents of the top level
+        the string they capture is "ab(cd)ef", the contents of  the  top  level
-        parentheses. If there are more than 15 capturing parentheses in a  pat-
+        parentheses.  If there are more than 15 capturing parentheses in a pat-
         tern, PCRE has to obtain extra memory to store data during a recursion,
-        which it does by using pcre_malloc, freeing  it  via  pcre_free  after-
+        which  it  does  by  using pcre_malloc, freeing it via pcre_free after-
-        wards.  If  no  memory  can  be  obtained,  the  match  fails  with the
+        wards. If  no  memory  can  be  obtained,  the  match  fails  with  the
         PCRE_ERROR_NOMEMORY error.
-        Do not confuse the (?R) item with the condition (R),  which  tests  for
+        Do  not  confuse  the (?R) item with the condition (R), which tests for
-        recursion.   Consider  this pattern, which matches text in angle brack-
+        recursion.  Consider this pattern, which matches text in  angle  brack-
-        ets, allowing for arbitrary nesting. Only digits are allowed in  nested
+        ets,  allowing for arbitrary nesting. Only digits are allowed in nested
-        brackets  (that is, when recursing), whereas any characters are permit-
+        brackets (that is, when recursing), whereas any characters are  permit-
         ted at the outer level.
           < (?: (?(R) \d++  | [^<>]*+) | (?R)) * >
-        In this pattern, (?(R) is the start of a conditional  subpattern,  with
+        In  this  pattern, (?(R) is the start of a conditional subpattern, with
-        two  different  alternatives for the recursive and non-recursive cases.
+        two different alternatives for the recursive and  non-recursive  cases.
         The (?R) item is the actual recursive call.
  SUBPATTERNS AS SUBROUTINES
         If the syntax for a recursive subpattern reference (either by number or
-        by  name)  is used outside the parentheses to which it refers, it oper-
+        by name) is used outside the parentheses to which it refers,  it  oper-
-        ates like a subroutine in a programming language. The "called"  subpat-
+        ates  like a subroutine in a programming language. The "called" subpat-
         tern may be defined before or after the reference. A numbered reference
         can be absolute or relative, as in these examples:
-Line 4470 
 SUBPATTERNS AS SUBROUTINES
+Line 4704 
 SUBPATTERNS AS SUBROUTINES
           (sens|respons)e and \1ibility
-        matches "sense and sensibility" and "response and responsibility",  but
+        matches  "sense and sensibility" and "response and responsibility", but
         not "sense and responsibility". If instead the pattern
           (sens|respons)e and (?1)ibility
-        is  used, it does match "sense and responsibility" as well as the other
+        is used, it does match "sense and responsibility" as well as the  other
-        two strings. Another example is  given  in  the  discussion  of  DEFINE
+        two  strings.  Another  example  is  given  in the discussion of DEFINE
         above.
         Like recursive subpatterns, a "subroutine" call is always treated as an
-        atomic group. That is, once it has matched some of the subject  string,
+        atomic  group. That is, once it has matched some of the subject string,
-        it  is  never  re-entered, even if it contains untried alternatives and
+        it is never re-entered, even if it contains  untried  alternatives  and
         there is a subsequent matching failure.
-        When a subpattern is used as a subroutine, processing options  such  as
+        When  a  subpattern is used as a subroutine, processing options such as
         case-independence are fixed when the subpattern is defined. They cannot
         be changed for different calls. For example, consider this pattern:
           (abc)(?i:(?-1))
-        It matches "abcabc". It does not match "abcABC" because the  change  of
+        It  matches  "abcabc". It does not match "abcABC" because the change of
         processing option does not affect the called subpattern.
  CALLOUTS
         Perl has a feature whereby using the sequence (?{...}) causes arbitrary
-        Perl code to be obeyed in the middle of matching a regular  expression.
+        Perl  code to be obeyed in the middle of matching a regular expression.
         This makes it possible, amongst other things, to extract different sub-
         strings that match the same pair of parentheses when there is a repeti-
         tion.
         PCRE provides a similar feature, but of course it cannot obey arbitrary
         Perl code. The feature is called "callout". The caller of PCRE provides
-        an  external function by putting its entry point in the global variable
+        an external function by putting its entry point in the global  variable
-        pcre_callout.  By default, this variable contains NULL, which  disables
+        pcre_callout.   By default, this variable contains NULL, which disables
         all calling out.
-        Within  a  regular  expression,  (?C) indicates the points at which the
+        Within a regular expression, (?C) indicates the  points  at  which  the
-        external function is to be called. If you want  to  identify  different
+        external  function  is  to be called. If you want to identify different
-        callout  points, you can put a number less than 256 after the letter C.
+        callout points, you can put a number less than 256 after the letter  C.
-        The default value is zero.  For example, this pattern has  two  callout
+        The  default  value is zero.  For example, this pattern has two callout
         points:
           (?C1)abc(?C2)def
         If the PCRE_AUTO_CALLOUT flag is passed to pcre_compile(), callouts are
-        automatically installed before each item in the pattern. They  are  all
+        automatically  installed  before each item in the pattern. They are all
         numbered 255.
         During matching, when PCRE reaches a callout point (and pcre_callout is
-        set), the external function is called. It is provided with  the  number
+        set),  the  external function is called. It is provided with the number
-        of  the callout, the position in the pattern, and, optionally, one item
+        of the callout, the position in the pattern, and, optionally, one  item
-        of data originally supplied by the caller of pcre_exec().  The  callout
+        of  data  originally supplied by the caller of pcre_exec(). The callout
-        function  may cause matching to proceed, to backtrack, or to fail alto-
+        function may cause matching to proceed, to backtrack, or to fail  alto-
         gether. A complete description of the interface to the callout function
         is given in the pcrecallout documentation.
+ BACKTRACKING CONTROL
+        Perl 5.10 introduced a number of "Special Backtracking Control  Verbs",
+        which are described in the Perl documentation as "experimental and sub-
+        ject to change or removal in a future version of Perl". It goes  on  to
+        say:  "Their usage in production code should be noted to avoid problems
+        during upgrades." The same remarks apply to the PCRE features described
+        in this section.
+        Since these verbs are specifically related to backtracking, they can be
+        used only when the pattern is to be matched  using  pcre_exec(),  which
+        uses  a  backtracking  algorithm. They cause an error if encountered by
+        pcre_dfa_exec().
+        The new verbs make use of what was previously invalid syntax: an  open-
+        ing parenthesis followed by an asterisk. In Perl, they are generally of
+        the form (*VERB:ARG) but PCRE does not support the use of arguments, so
+        its  general  form is just (*VERB). Any number of these verbs may occur
+        in a pattern. There are two kinds:
+    Verbs that act immediately
+        The following verbs act as soon as they are encountered:
+           (*ACCEPT)
+        This verb causes the match to end successfully, skipping the  remainder
+        of  the pattern. When inside a recursion, only the innermost pattern is
+        ended immediately. PCRE differs  from  Perl  in  what  happens  if  the
+        (*ACCEPT)  is inside capturing parentheses. In Perl, the data so far is
+        captured: in PCRE no data is captured. For example:
+          A(A|B(*ACCEPT)|C)D
+        This matches "AB", "AAD", or "ACD", but when it matches "AB",  no  data
+        is captured.
+          (*FAIL) or (*F)
+        This  verb  causes the match to fail, forcing backtracking to occur. It
+        is equivalent to (?!) but easier to read. The Perl documentation  notes
+        that  it  is  probably  useful only when combined with (?{}) or (??{}).
+        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-
+        tern:
+          a+(?C)(*FAIL)
+        A match with the string "aaaa" always fails, but the callout  is  taken
+        before each backtrack happens (in this example, 10 times).
+    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, a  fail-
+        ure  is  forced.   The  verbs  differ  in  exactly what kind of failure
+        occurs.
+          (*COMMIT)
+        This verb 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 start point take place.  Once
+        (*COMMIT)  has been passed, 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
+        of dynamic anchor, or "I've started, so I must finish."
+          (*PRUNE)
+        This  verb causes the match to fail at the current position if the rest
+        of the pattern does not match. If the pattern is unanchored, the normal
+        "bumpalong"  advance to the next starting character then happens. Back-
+        tracking can occur as usual to the left of (*PRUNE), or  when  matching
+        to  the right of (*PRUNE), but if there is no match to the right, back-
+        tracking cannot cross (*PRUNE).  In simple cases, the use  of  (*PRUNE)
+        is just an alternative to an atomic group or possessive quantifier, but
+        there are some uses of (*PRUNE) that cannot be expressed in  any  other
+        way.
+          (*SKIP)
+        This  verb  is like (*PRUNE), except that if the pattern is unanchored,
+        the "bumpalong" advance is not to the next character, but to the  posi-
+        tion  in  the  subject where (*SKIP) was encountered. (*SKIP) signifies
+        that whatever text was matched leading up to it cannot  be  part  of  a
+        successful match. Consider:
+          a+(*SKIP)b
+        If  the  subject  is  "aaaac...",  after  the first match attempt fails
+        (starting at the first character in the  string),  the  starting  point
+        skips on to start the next attempt at "c". Note that a possessive quan-
+        tifer does not have the same effect in this example; although it  would
+        suppress  backtracking  during  the  first  match  attempt,  the second
+        attempt would start at the second character instead of skipping  on  to
+        "c".