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-revision 77 by nigel,
Sat Feb 24 21:40:45 2007 UTC
+revision 589 by ph10,
Sat Jan 15 11:31:39 2011 UTC
 Line 2
  This file contains a concatenation of the PCRE man pages, converted to plain
  text format for ease of searching with a text editor, or for use on systems
  that do not have a man page processor. The small individual files that give
- synopses of each function in the library have not been included. There are
+ synopses of each function in the library have not been included. Neither has
- separate text files for the pcregrep and pcretest commands.
+ the pcredemo program. There are separate text files for the pcregrep and
+ pcretest commands.
  -----------------------------------------------------------------------------
+ PCRE(3)                                                                PCRE(3)
  NAME
         PCRE - Perl-compatible regular expressions
-Line 16 
 INTRODUCTION
+Line 19 
 INTRODUCTION
         The  PCRE  library is a set of functions that implement regular expres-
         sion pattern matching using the same syntax and semantics as Perl, with
-        just  a  few  differences.  The current implementation of PCRE (release
+        just  a few differences. Some features that appeared in Python and PCRE
-.x) corresponds approximately with Perl  5.8,  including  support  for
+        before they appeared in Perl are also available using the  Python  syn-
-        UTF-8 encoded strings and Unicode general category properties. However,
+        tax,  there  is  some  support for one or two .NET and Oniguruma syntax
-        this support has to be explicitly enabled; it is not the default.
+        items, and there is an option for requesting some  minor  changes  that
+        give better JavaScript compatibility.
-        In addition to the Perl-compatible matching function,  PCRE  also  con-
-        tains  an  alternative matching function that matches the same compiled
+        The  current implementation of PCRE corresponds approximately with Perl
-        patterns in a different way. In certain circumstances, the  alternative
+.12, including support for UTF-8 encoded strings and  Unicode  general
-        function  has  some  advantages.  For  a discussion of the two matching
+        category  properties.  However,  UTF-8  and  Unicode  support has to be
-        algorithms, see the pcrematching page.
+        explicitly enabled; it is not the default. The  Unicode  tables  corre-
+        spond to Unicode release 5.2.0.
-        PCRE is written in C and released as a C library. A  number  of  people
-        have  written  wrappers and interfaces of various kinds. In particular,
+        In  addition to the Perl-compatible matching function, PCRE contains an
-        Google Inc.  have provided a comprehensive C++  wrapper.  This  is  now
+        alternative function that matches the same compiled patterns in a  dif-
+        ferent way. In certain circumstances, the alternative function has some
+        advantages.  For a discussion of the two matching algorithms,  see  the
+        pcrematching page.
+        PCRE  is  written  in C and released as a C library. A number of people
+        have written wrappers and interfaces of various kinds.  In  particular,
+        Google  Inc.   have  provided  a comprehensive C++ wrapper. This is now
         included as part of the PCRE distribution. The pcrecpp page has details
-        of this interface. Other people's contributions can  be  found  in  the
+        of  this  interface.  Other  people's contributions can be found in the
         Contrib directory at the primary FTP site, which is:
         ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre
-        Details  of  exactly which Perl regular expression features are and are
+        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
         library is built. The pcre_config() function makes it  possible  for  a
         client  to  discover  which  features are available. The features them-
         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 and
-        in the source distribution.
+        NON-UNIX-USE files in the source distribution.
         The library contains a number of undocumented  internal  functions  and
         data  tables  that  are  used by more than one of the exported external
         functions, but which are not intended  for  use  by  external  callers.
         Their  names  all begin with "_pcre_", which hopefully will not provoke
-        any name clashes.
+        any name clashes. In some environments, it is possible to control which
+        external  symbols  are  exported when a shared library is built, and in
+        these cases the undocumented symbols are not exported.
  USER DOCUMENTATION
-Line 59 
 USER DOCUMENTATION
+Line 72 
 USER DOCUMENTATION
         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
         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, except the pcredemo sec-
-        of searching. The sections are as follows:
+        tion, are concatenated, for ease of searching. The sections are as fol-
+        lows:
           pcre              this document
+          pcre-config       show PCRE installation configuration information
           pcreapi           details of PCRE's native C API
           pcrebuild         options for building PCRE
           pcrecallout       details of the callout feature
           pcrecompat        discussion of Perl compatibility
           pcrecpp           details of the C++ wrapper
+          pcredemo          a demonstration C program that uses PCRE
           pcregrep          description of the pcregrep command
           pcrematching      discussion of the two matching algorithms
           pcrepartial       details of the partial matching facility
-Line 76 
 USER DOCUMENTATION
+Line 92 
 USER DOCUMENTATION
           pcreperform       discussion of performance issues
           pcreposix         the POSIX-compatible C API
           pcreprecompile    details of saving and re-using precompiled patterns
-          pcresample        discussion of the sample program
+          pcresample        discussion of the pcredemo program
+          pcrestack         discussion of stack usage
+          pcresyntax        quick syntax reference
           pcretest          description of the pcretest testing command
         In  addition,  in the "man" and HTML formats, there is a short page for
-Line 94 
 LIMITATIONS
+Line 112 
 LIMITATIONS
         PCRE with an internal linkage size of 3 or 4 (see the  README  file  in
         the  source  distribution and the pcrebuild documentation for details).
         In these cases the limit is substantially larger.  However,  the  speed
-        of execution will be slower.
+        of execution is slower.
+        All values in repeating quantifiers must be less than 65536.
-        All values in repeating quantifiers must be less than 65536.  The maxi-
+        There is no limit to the number of parenthesized subpatterns, but there
-        mum number of capturing subpatterns is 65535.
+        can be no more than 65535 capturing subpatterns.
-        There is no limit to the number of non-capturing subpatterns,  but  the
+        The maximum length of name for a named subpattern is 32 characters, and
-        maximum  depth  of  nesting  of  all kinds of parenthesized subpattern,
+        the maximum number of named subpatterns is 10000.
-        including capturing subpatterns, assertions, and other types of subpat-
-        tern, is 200.
         The  maximum  length of a subject string is the largest positive number
         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
         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
-Line 120 
 UTF-8 AND UNICODE PROPERTY SUPPORT
+Line 139 
 UTF-8 AND UNICODE PROPERTY SUPPORT
         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()
-        with  the PCRE_UTF8 option flag. When you do this, both the pattern and
+        with  the  PCRE_UTF8  option  flag,  or the pattern must start with the
-        any subject strings that are matched against it are  treated  as  UTF-8
+        sequence (*UTF8). When either of these is the case,  both  the  pattern
-        strings instead of just strings of bytes.
+        and  any  subject  strings  that  are matched against it are treated as
+        UTF-8 strings instead of strings of 1-byte characters.
-        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
+        If you compile PCRE with UTF-8 support, but do not use it at run  time,
-        is  limited  to testing the PCRE_UTF8 flag in several places, so should
+        the  library will be a bit bigger, but the additional run time overhead
-        not be very large.
+        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. A full list is given in the pcrepattern  documen-
+        for  a  decimal number, the Unicode script names such as Arabic or Han,
-        tation. The PCRE library is increased in size by about 90K when Unicode
+        and the derived properties Any and L&. A full  list  is  given  in  the
-        property support is included.
+        pcrepattern documentation. Only the short names for properties are sup-
+        ported. For example, \p{L} matches a letter. Its Perl synonym,  \p{Let-
-        The following comments apply when PCRE is running in UTF-8 mode:
+        ter},  is  not  supported.   Furthermore,  in Perl, many properties may
+        optionally be prefixed by "Is", for compatibility with Perl  5.6.  PCRE
-. When you set the PCRE_UTF8 flag, the strings passed as patterns  and
+        does not support this.
-        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
+    Validity of UTF-8 strings
-        situations,  you  may  already  know  that  your strings are valid, and
-        therefore want to skip these checks in order to improve performance. If
+        When  you  set  the  PCRE_UTF8 flag, the strings passed as patterns and
-        you  set  the  PCRE_NO_UTF8_CHECK  flag at compile time or at run time,
+        subjects are (by default) checked for validity on entry to the relevant
-        PCRE assumes that the pattern or subject  it  is  given  (respectively)
+        functions.  From  release 7.3 of PCRE, the check is according the rules
-        contains  only valid UTF-8 codes. In this case, it does not diagnose an
+        of RFC 3629, which are themselves derived from the  Unicode  specifica-
-        invalid UTF-8 string. If you pass an invalid UTF-8 string to PCRE  when
+        tion.  Earlier  releases  of PCRE followed the rules of RFC 2279, which
-        PCRE_NO_UTF8_CHECK  is set, the results are undefined. Your program may
+        allows the full range of 31-bit values (0 to 0x7FFFFFFF).  The  current
-        crash.
+        check allows only values in the range U+0 to U+10FFFF, excluding U+D800
+        to U+DFFF.
-. In a pattern, the escape sequence \x{...}, where the contents of the
-        braces  is  a  string  of hexadecimal digits, is interpreted as a UTF-8
+        The excluded code points are the "Low Surrogate Area"  of  Unicode,  of
-        character whose code number is the given hexadecimal number, for  exam-
+        which  the Unicode Standard says this: "The Low Surrogate Area does not
-        ple:  \x{1234}.  If a non-hexadecimal digit appears between the braces,
+        contain any  character  assignments,  consequently  no  character  code
-        the item is not recognized.  This escape sequence can be used either as
+        charts or namelists are provided for this area. Surrogates are reserved
-        a literal, or within a character class.
+        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.
+    General comments about UTF-8 mode
-.  The  original hexadecimal escape sequence, \xhh, matches a two-byte
+.  An  unbraced  hexadecimal  escape sequence (such as \xb3) matches a
-        UTF-8 character if the value is greater than 127.
+        two-byte UTF-8 character if the value is greater than 127.
-. Repeat quantifiers apply to complete UTF-8 characters, not to  indi-
+. 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-
         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, by default, the characters that
-        nizes as digits, spaces, or word characters  remain  the  same  set  as
+        PCRE  recognizes  as digits, spaces, or word characters remain the same
-        before, all with values less than 256. This remains true even when PCRE
+        set as before, all with values less than 256. This  remains  true  even
-        includes Unicode property support, because to do otherwise  would  slow
+        when  PCRE  is built to include Unicode property support, because to do
-        down  PCRE in many common cases. If you really want to test for a wider
+        otherwise would slow down PCRE in many common cases. Note in particular
-        sense of, say, "digit", you must use Unicode  property  tests  such  as
+        that this applies to \b and \B, because they are defined in terms of \w
-        \p{Nd}.
+        and \W. If you really want to test for a wider sense of, say,  "digit",
+        you  can  use  explicit Unicode property tests such as \p{Nd}. Alterna-
-.  Similarly,  characters that match the POSIX named character classes
+        tively, if you set the PCRE_UCP option,  the  way  that  the  character
-        are all low-valued characters.
+        escapes  work  is changed so that Unicode properties are used to deter-
+        mine which characters match. There are more details in the  section  on
+        generic character types in the pcrepattern documentation.
+.  Similarly,  characters that match the POSIX named character classes
+        are all low-valued characters, unless the PCRE_UCP option is set.
+. However, the horizontal and  vertical  whitespace  matching  escapes
+        (\h,  \H,  \v, and \V) do match all the appropriate Unicode characters,
+        whether or not PCRE_UCP is set.
 . Case-insensitive matching applies only to  characters  whose  values
         are  less than 128, unless PCRE is built with Unicode property support.
         Even when Unicode property support is available, PCRE  still  uses  its
         own  character  tables when checking the case of low-valued characters,
         so as not to degrade performance.  The Unicode property information  is
-        used only for characters with higher values.
+        used only for characters with higher values. Furthermore, PCRE supports
+        case-insensitive matching only  when  there  is  a  one-to-one  mapping
+        between  a letter's cases. There are a small number of many-to-one map-
+        pings in Unicode; these are not supported by PCRE.
  AUTHOR
         Philip Hazel
-        University Computing Service,
+        University Computing Service
-        Cambridge CB2 3QG, England.
+        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 initial and sur-
+        so  I've  taken  it away. If you want to email me, use my two initials,
-        name, separated by a dot, at the domain ucs.cam.ac.uk.
+        followed by the two digits 10, at the domain cam.ac.uk.
- Last updated: 07 March 2005
- Copyright (c) 1997-2005 University of Cambridge.
- -----------------------------------------------------------------------------
+ REVISION
+        Last updated: 13 November 2010
+        Copyright (c) 1997-2010 University of Cambridge.
+ ------------------------------------------------------------------------------
+ PCREBUILD(3)                                                      PCREBUILD(3)
  NAME
-Line 214 
 NAME
+Line 281 
 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 cmake-gui if you are using CMake
+        instead of configure to build PCRE.
+        There  is  a  lot more information about building PCRE in non-Unix-like
+        environments in the file called NON_UNIX_USE, which is part of the PCRE
+        distribution.  You  should consult this file as well as the README file
+        if you are building in a non-Unix-like environment.
+        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 describe certain options whose names begin  with
+        The following sections include  descriptions  of  options  whose  names
-        --enable  or  --disable. These settings specify changes to the defaults
+        begin with --enable or --disable. These settings specify changes to the
-        for the configure command. Because of the  way  that  configure  works,
+        defaults for the configure command. Because of the way  that  configure
-        --enable  and  --disable  always  come  in  pairs, so the complementary
+        works,  --enable  and --disable always come in pairs, so the complemen-
-        option always exists as well, but as it specifies the  default,  it  is
+        tary option always exists as well, but as it specifies the default,  it
-        not described.
+        is not described.
+ C++ SUPPORT
+        By default, the configure script will search for a C++ compiler and C++
+        header files. If it finds them, it automatically builds the C++ wrapper
+        library for PCRE. You can disable this by adding
+          --disable-cpp
+        to the configure command.
  UTF-8 SUPPORT
-        To build PCRE with support for UTF-8 character strings, add
+        To build PCRE with support for UTF-8 Unicode character strings, add
           --enable-utf8
         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
         have  have to set the PCRE_UTF8 option when you call the pcre_compile()
-        function.
+        or pcre_compile2() functions.
+        If you set --enable-utf8 when compiling in an EBCDIC environment,  PCRE
+        expects its input to be either ASCII or UTF-8 (depending on the runtime
+        option). It is not possible to support both EBCDIC and UTF-8  codes  in
+        the  same  version  of  the  library.  Consequently,  --enable-utf8 and
+        --enable-ebcdic are mutually exclusive.
  UNICODE CHARACTER PROPERTY SUPPORT
-Line 255 
 UNICODE CHARACTER PROPERTY SUPPORT
+Line 349 
 UNICODE CHARACTER PROPERTY SUPPORT
         to the configure command. This implies UTF-8 support, even if you  have
         not explicitly requested it.
-        Including  Unicode  property  support  adds around 90K of tables to the
+        Including  Unicode  property  support  adds around 30K of tables to the
-        PCRE library, approximately doubling its size. Only the  general  cate-
+        PCRE library. Only the general category properties such as  Lu  and  Nd
-        gory  properties  such as Lu and Nd are supported. Details are given in
+        are supported. Details are given in the pcrepattern documentation.
-        the pcrepattern documentation.
  CODE VALUE OF NEWLINE
-        By default, PCRE treats character 10 (linefeed) as the newline  charac-
+        By  default,  PCRE interprets the linefeed (LF) character as indicating
-        ter. This is the normal newline character on Unix-like systems. You can
+        the end of a line. This is the normal newline  character  on  Unix-like
-        compile PCRE to use character 13 (carriage return) instead by adding
+        systems.  You  can compile PCRE to use carriage return (CR) instead, by
+        adding
           --enable-newline-is-cr
-        to the configure command. For completeness there is  also  a  --enable-
+        to the  configure  command.  There  is  also  a  --enable-newline-is-lf
-        newline-is-lf  option,  which explicitly specifies linefeed as the new-
+        option, which explicitly specifies linefeed as the newline character.
-        line character.
+        Alternatively, you can specify that line endings are to be indicated by
+        the two character sequence CRLF. If you want this, add
+          --enable-newline-is-crlf
+        to the configure command. There is a fourth option, specified by
+          --enable-newline-is-anycrlf
+        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
+        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 289 
 BUILDING SHARED AND STATIC LIBRARIES
+Line 415 
 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 302 
 POSIX MALLOC USAGE
+Line 428 
 POSIX MALLOC USAGE
         to the configure command.
+ HANDLING VERY LARGE PATTERNS
+        Within a compiled pattern, offset values are used  to  point  from  one
+        part  to another (for example, from an opening parenthesis to an alter-
+        nation metacharacter). By default, two-byte values are used  for  these
+        offsets,  leading  to  a  maximum size for a compiled pattern of around
+K. This is sufficient to handle all but the most  gigantic  patterns.
+        Nevertheless,  some  people do want to process truyl enormous patterns,
+        so it is possible to compile PCRE to use three-byte or  four-byte  off-
+        sets by adding a setting such as
+          --with-link-size=3
+        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
+        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().
+        In  environments  where  the size of the stack is limited, this can se-
+        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-
+        mentation.)  An alternative approach to recursion that uses memory from
+        the heap to remember data, instead of using recursive  function  calls,
+        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
+        pcre_stack_malloc  and pcre_stack_free variables to call memory manage-
+        ment functions. By default these point to malloc() and free(), but  you
+        can replace the pointers so that your own functions are used instead.
+        Separate  functions  are  provided  rather  than  using pcre_malloc and
+        pcre_free because the  usage  is  very  predictable:  the  block  sizes
+        requested  are  always  the  same,  and  the blocks are always freed in
+        reverse order. A calling program might be able to  implement  optimized
+        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 pcre_dfa_exec().
  LIMITING PCRE RESOURCE USAGE
         Internally,  PCRE has a function called match(), which it calls repeat-
-        edly  (possibly  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
         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
-Line 318 
 LIMITING PCRE RESOURCE USAGE
+Line 491 
 LIMITING PCRE RESOURCE USAGE
         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
+        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-
+        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
+        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
+        time.
+ CREATING CHARACTER TABLES AT BUILD TIME
+        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
+        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.
+        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 need to create alternative tables when cross  compiling,  you  will
+        have to do so "by hand".)
- HANDLING VERY LARGE PATTERNS
-        Within  a  compiled  pattern,  offset values are used to point from one
+ USING EBCDIC CODE
-        part to another (for example, from an opening parenthesis to an  alter-
-        nation  metacharacter).  By default, two-byte values are used for these
-        offsets, leading to a maximum size for a  compiled  pattern  of  around
-K.  This  is sufficient to handle all but the most gigantic patterns.
-        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
-        adding a setting such as
-          --with-link-size=3
+        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).
+        This  is  the  case for most computer operating systems. PCRE can, how-
+        ever, be compiled to run in an EBCDIC environment by adding
-        to the configure command. The value given must be 2,  3,  or  4.  Using
+          --enable-ebcdic
-        longer  offsets slows down the operation of PCRE because it has to load
-        additional bytes when handling them.
-        If you build PCRE with an increased link size, test 2 (and  test  5  if
+        to the configure command. This setting implies --enable-rebuild-charta-
-        you  are using UTF-8) will fail. Part of the output of these tests is a
+        bles.  You  should  only  use  it if you know that you are in an EBCDIC
-        representation of the compiled pattern, and this changes with the  link
+        environment (for example,  an  IBM  mainframe  operating  system).  The
-        size.
+        --enable-ebcdic option is incompatible with --enable-utf8.
- AVOIDING EXCESSIVE STACK USAGE
+ PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT
-        When matching with the pcre_exec() function, PCRE implements backtrack-
+        By default, pcregrep reads all files as plain text. You can build it so
-        ing by making recursive calls to an internal function  called  match().
+        that it recognizes files whose names end in .gz or .bz2, and reads them
-        In  environments  where  the size of the stack is limited, this can se-
+        with libz or libbz2, respectively, by adding one or both of
-        verely limit PCRE's operation. (The Unix environment does  not  usually
-        suffer  from  this  problem.)  An alternative approach that uses memory
-        from the heap to remember data, instead  of  using  recursive  function
-        calls,  has been implemented to work round this problem. If you want to
-        build a version of PCRE that works this way, add
-          --disable-stack-for-recursion
+          --enable-pcregrep-libz
+          --enable-pcregrep-libbz2
-        to the configure command. With this configuration, PCRE  will  use  the
+        to the configure command. These options naturally require that the rel-
-        pcre_stack_malloc  and pcre_stack_free variables to call memory manage-
+        evant libraries are installed on your system. Configuration  will  fail
-        ment functions. Separate functions are provided because  the  usage  is
+        if they are not.
-        very  predictable:  the  block sizes requested are always the same, and
-        the blocks are always freed in reverse order. A calling  program  might
-        be  able  to implement optimized functions that perform better than the
-        standard malloc() and  free()  functions.  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 pcre_dfa_exec() function.
- USING EBCDIC CODE
+ PCRETEST OPTION FOR LIBREADLINE SUPPORT
-        PCRE assumes by default that it will run in an  environment  where  the
+        If you add
-        character  code  is  ASCII  (or Unicode, which is a superset of ASCII).
-        PCRE can, however, be compiled to  run  in  an  EBCDIC  environment  by
-        adding
-          --enable-ebcdic
+          --enable-pcretest-libreadline
-        to the configure command.
+        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-licensed, so if you distribute a binary of
+        pcretest linked in this way, there may be licensing issues.
- Last updated: 28 February 2005
+        Setting  this  option  causes  the -lreadline option to be added to the
- Copyright (c) 1997-2005 University of Cambridge.
+        pcretest build. In many operating environments with  a  sytem-installed
- -----------------------------------------------------------------------------
+        libreadline this is sufficient. However, in some environments (e.g.  if
+        an unmodified distribution version of readline is in use),  some  extra
+        configuration  may  be necessary. The INSTALL file for libreadline says
+        this:
+          "Readline uses the termcap functions, but does not link with the
+          termcap or curses library itself, allowing applications which link
+          with readline the to choose an appropriate library."
+        If your environment has not been set up so that an appropriate  library
+        is automatically included, you may need to add something like
+          LIBS="-ncurses"
+        immediately before the configure command.
+ SEE ALSO
+        pcreapi(3), pcre_config(3).
+ AUTHOR
+        Philip Hazel
+        University Computing Service
+        Cambridge CB2 3QH, England.
+ REVISION
+        Last updated: 29 September 2009
+        Copyright (c) 1997-2009 University of Cambridge.
+ ------------------------------------------------------------------------------
+ PCREMATCHING(3)                                                PCREMATCHING(3)
  NAME
         PCRE - Perl-compatible regular expressions
-Line 412 
 PCRE MATCHING ALGORITHMS
+Line 634 
 PCRE MATCHING ALGORITHMS
           <something> <something else> <something further>
         there are three possible answers. The standard algorithm finds only one
-        of them, whereas the DFA algorithm finds all three.
+        of them, whereas the alternative algorithm finds all three.
  REGULAR EXPRESSIONS AS TREES
-Line 421 
 REGULAR EXPRESSIONS AS TREES
+Line 643 
 REGULAR EXPRESSIONS AS TREES
         resented  as  a  tree structure. An unlimited repetition in the pattern
         makes the tree of infinite size, but it is still a tree.  Matching  the
         pattern  to a given subject string (from a given starting point) can be
-        thought of as a search of the tree.  There are  two  standard  ways  to
+        thought of as a search of the tree.  There are two  ways  to  search  a
-        search  a  tree: depth-first and breadth-first, and these correspond to
+        tree:  depth-first  and  breadth-first, and these correspond to the two
-        the two matching algorithms provided by PCRE.
+        matching algorithms provided by PCRE.
  THE STANDARD MATCHING ALGORITHM
-        In the terminology of Jeffrey Friedl's book Mastering  Regular  Expres-
+        In the terminology of Jeffrey Friedl's book "Mastering Regular  Expres-
-        sions,  the  standard  algorithm  is  an "NFA algorithm". It conducts a
+        sions",  the  standard  algorithm  is an "NFA algorithm". It conducts a
         depth-first search of the pattern tree. That is, it  proceeds  along  a
         single path through the tree, checking that the subject matches what is
         required. When there is a mismatch, the algorithm  tries  any  alterna-
-Line 453 
 THE STANDARD MATCHING ALGORITHM
+Line 675 
 THE STANDARD MATCHING ALGORITHM
         This provides support for capturing parentheses and back references.
- THE DFA MATCHING ALGORITHM
+ THE ALTERNATIVE MATCHING ALGORITHM
-        DFA stands for "deterministic finite automaton", but you do not need to
+        This algorithm conducts a breadth-first search of  the  tree.  Starting
-        understand the origins of that name. This algorithm conducts a breadth-
+        from  the  first  matching  point  in the subject, it scans the subject
-        first search of the tree. Starting from the first matching point in the
+        string from left to right, once, character by character, and as it does
-        subject,  it scans the subject string from left to right, once, charac-
+        this,  it remembers all the paths through the tree that represent valid
-        ter by character, and as it does  this,  it  remembers  all  the  paths
+        matches. In Friedl's terminology, this is a kind  of  "DFA  algorithm",
-        through the tree that represent valid matches.
+        though  it is not implemented as a traditional finite state machine (it
+        keeps multiple states active simultaneously).
-        The  scan  continues until either the end of the subject is reached, or
-        there are no more unterminated paths. At this point,  terminated  paths
+        Although the general principle of this matching algorithm  is  that  it
-        represent  the different matching possibilities (if there are none, the
+        scans  the subject string only once, without backtracking, there is one
-        match has failed).  Thus, if there is more  than  one  possible  match,
+        exception: when a lookaround assertion is encountered,  the  characters
+        following  or  preceding  the  current  point  have to be independently
+        inspected.
+        The scan continues until either the end of the subject is  reached,  or
+        there  are  no more unterminated paths. At this point, terminated paths
+        represent the different matching possibilities (if there are none,  the
+        match  has  failed).   Thus,  if there is more than one possible match,
         this algorithm finds all of them, and in particular, it finds the long-
-        est. In PCRE, there is an option to stop the algorithm after the  first
+        est.  The  matches are returned in decreasing order of length. There is
-        match (which is necessarily the shortest) has been found.
+        an option to stop the algorithm after the first match (which is  neces-
+        sarily the shortest) is found.
         Note that all the matches that are found start at the same point in the
         subject. If the pattern
-          cat(er(pillar)?)
+          cat(er(pillar)?)?
         is matched against the string "the caterpillar catchment",  the  result
-        will  be the three strings "cat", "cater", and "caterpillar" that start
+        will  be the three strings "caterpillar", "cater", and "cat" that start
-        at the fourth character of the subject. The algorithm does not automat-
+        at the fifth character of the subject. The algorithm does not automati-
-        ically move on to find matches that start at later positions.
+        cally move on to find matches that start at later positions.
         There are a number of features of PCRE regular expressions that are not
-        supported by the DFA matching algorithm. They are as follows:
+        supported by the alternative matching algorithm. They are as follows:
 . Because the algorithm finds all  possible  matches,  the  greedy  or
         ungreedy  nature  of repetition quantifiers is not relevant. Greedy and
-        ungreedy quantifiers are treated in exactly the same way.
+        ungreedy quantifiers are treated in exactly the same way. However, pos-
+        sessive  quantifiers can make a difference when what follows could also
+        match what is quantified, for example in a pattern like this:
+          ^a++\w!
+        This pattern matches "aaab!" but not "aaa!", which would be matched  by
+        a  non-possessive quantifier. Similarly, if an atomic group is present,
+        it is matched as if it were a standalone pattern at the current  point,
+        and  the  longest match is then "locked in" for the rest of the overall
+        pattern.
 . When dealing with multiple paths through the tree simultaneously, it
         is  not  straightforward  to  keep track of captured substrings for the
-Line 497 
 THE DFA MATCHING ALGORITHM
+Line 737 
 THE DFA MATCHING ALGORITHM
         tern are not supported, and cause errors if encountered.
 .  For  the same reason, conditional expressions that use a backrefer-
-        ence as the condition are not supported.
+        ence as the condition or test for a specific group  recursion  are  not
+        supported.
+.  Because  many  paths  through the tree may be active, the \K escape
+        sequence, which resets the start of the match when encountered (but may
+        be  on  some  paths  and not on others), is not supported. It causes an
+        error if encountered.
 . 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
-        single byte, even in UTF-8 mode, is not supported because the DFA algo-
+        single byte, even in UTF-8 mode, is not supported because the  alterna-
-        rithm moves through the subject string one character at a time, for all
+        tive  algorithm  moves  through  the  subject string one character at a
-        active paths through the tree.
+        time, for all active paths through the tree.
+. Except for (*FAIL), the backtracking control verbs such as  (*PRUNE)
+        are  not  supported.  (*FAIL)  is supported, and behaves like a failing
+        negative assertion.
- ADVANTAGES OF THE DFA ALGORITHM
-        Using the DFA matching algorithm provides the following advantages:
+ ADVANTAGES OF THE ALTERNATIVE ALGORITHM
+        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
+. Because the alternative algorithm  scans  the  subject  string  just
-        on the content of the pattern that apply when using the standard  algo-
+        once,  and  never  needs to backtrack, it is possible to pass very long
-        rithm  for partial matching do not apply to the DFA algorithm. For non-
+        subject strings to the matching function in  several  pieces,  checking
-        anchored patterns, the starting position of a partial match  is  avail-
+        for  partial  matching  each time. Although it is possible to do multi-
-        able.
+        segment matching using the standard algorithm (pcre_exec()), by retain-
+        ing  partially matched substrings, it is more complicated. The pcrepar-
-.  Because  the  DFA algorithm scans the subject string just once, and
+        tial documentation gives details  of  partial  matching  and  discusses
-        never needs to backtrack, it is possible  to  pass  very  long  subject
+        multi-segment matching.
-        strings  to  the matching function in several pieces, checking for par-
-        tial matching each time.
- DISADVANTAGES OF THE DFA ALGORITHM
+ DISADVANTAGES OF THE ALTERNATIVE ALGORITHM
-        The DFA algorithm suffers from a number of disadvantages:
+        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.
-. The "atomic group" feature of PCRE regular expressions is supported,
+. Although atomic groups are supported, their use does not provide the
-        but  does not provide the advantage that it does for the standard algo-
+        performance advantage that it does for the standard algorithm.
-        rithm.
- Last updated: 28 February 2005
- Copyright (c) 1997-2005 University of Cambridge.
+ AUTHOR
- -----------------------------------------------------------------------------
+        Philip Hazel
+        University Computing Service
+        Cambridge CB2 3QH, England.
+ REVISION
+        Last updated: 17 November 2010
+        Copyright (c) 1997-2010 University of Cambridge.
+ ------------------------------------------------------------------------------
+ PCREAPI(3)                                                          PCREAPI(3)
  NAME
         PCRE - Perl-compatible regular expressions
-Line 595 
 PCRE NATIVE API
+Line 855 
 PCRE NATIVE API
         int pcre_get_stringnumber(const pcre *code,
              const char *name);
+        int pcre_get_stringtable_entries(const pcre *code,
+             const char *name, char **first, char **last);
         int pcre_get_substring(const char *subject, int *ovector,
              int stringcount, int stringnumber,
              const char **stringptr);
-Line 633 
 PCRE NATIVE API
+Line 896 
 PCRE NATIVE API
  PCRE API OVERVIEW
         PCRE has its own native API, which is described in this document. There
-        is also a set of wrapper functions that correspond to the POSIX regular
+        are also some wrapper functions that correspond to  the  POSIX  regular
         expression  API.  These  are  described in the pcreposix documentation.
         Both of these APIs define a set of C function calls. A C++  wrapper  is
         distributed with PCRE. It is documented in the pcrecpp page.
-Line 646 
 PCRE API OVERVIEW
+Line 909 
 PCRE API OVERVIEW
         bers for the library.  Applications can use these  to  include  support
         for different releases of PCRE.
+        In a Windows environment, if you want to statically link an application
+        program against a non-dll pcre.a  file,  you  must  define  PCRE_STATIC
+        before  including  pcre.h or pcrecpp.h, because otherwise the pcre_mal-
+        loc()   and   pcre_free()   exported   functions   will   be   declared
+        __declspec(dllimport), with unwanted results.
         The   functions   pcre_compile(),  pcre_compile2(),  pcre_study(),  and
         pcre_exec() are used for compiling and matching regular expressions  in
         a  Perl-compatible  manner. A sample program that demonstrates the sim-
         plest way of using them is provided in the file  called  pcredemo.c  in
-        the  source distribution. The pcresample documentation describes how to
+        the PCRE source distribution. A listing of this program is given in the
-        run it.
+        pcredemo documentation, and the pcresample documentation describes  how
+        to compile and run it.
         A second matching function, pcre_dfa_exec(), which is not Perl-compati-
-        ble,  is  also provided. This uses a different algorithm for the match-
+        ble, is also provided. This uses a different algorithm for  the  match-
-        ing. This allows it to find all possible matches (at a given  point  in
+        ing.  The  alternative algorithm finds all possible matches (at a given
-        the  subject),  not  just  one. However, this algorithm does not return
+        point in the subject), and scans the subject just  once  (unless  there
+        are  lookbehind  assertions).  However,  this algorithm does not return
         captured substrings. A description of the two matching  algorithms  and
         their  advantages  and disadvantages is given in the pcrematching docu-
         mentation.
-Line 671 
 PCRE API OVERVIEW
+Line 942 
 PCRE API OVERVIEW
           pcre_get_named_substring()
           pcre_get_substring_list()
           pcre_get_stringnumber()
+          pcre_get_stringtable_entries()
         pcre_free_substring() and pcre_free_substring_list() are also provided,
         to free the memory used for extracted strings.
-Line 702 
 PCRE API OVERVIEW
+Line 974 
 PCRE API OVERVIEW
         indirections  to  memory  management functions. These special functions
         are used only when PCRE is compiled to use  the  heap  for  remembering
         data, instead of recursive function calls, when running the pcre_exec()
-        function. This is a non-standard way of building PCRE, for use in envi-
+        function. See the pcrebuild documentation for  details  of  how  to  do
-        ronments that have limited stacks. Because of the greater use of memory
+        this.  It  is  a non-standard way of building PCRE, for use in environ-
-        management, it runs more slowly.  Separate functions  are  provided  so
+        ments that have limited stacks. Because of the greater  use  of  memory
-        that  special-purpose  external  code  can  be used for this case. When
+        management,  it  runs  more  slowly. Separate functions are provided so
-        used, these functions are always called in a  stack-like  manner  (last
+        that special-purpose external code can be  used  for  this  case.  When
-        obtained,  first freed), and always for memory blocks of the same size.
+        used,  these  functions  are always called in a stack-like manner (last
+        obtained, first freed), and always for memory blocks of the same  size.
+        There  is  a discussion about PCRE's stack usage in the pcrestack docu-
+        mentation.
         The global variable pcre_callout initially contains NULL. It can be set
         by  the  caller  to  a "callout" function, which PCRE will then call at
-Line 715 
 PCRE API OVERVIEW
+Line 990 
 PCRE API OVERVIEW
         pcrecallout documentation.
+ NEWLINES
+        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 Unicode newline  sequences
+        are  the  three just mentioned, 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 (paragraph separator, U+2029).
+        Each  of  the first three conventions is used by at least one operating
+        system as its standard newline sequence. When PCRE is built, a  default
+        can  be  specified.  The default default is LF, which is the Unix stan-
+        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
+        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-
+        ment for a non-anchored pattern. There is more detail about this in the
+        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.
-Line 732 
 SAVING PRECOMPILED PATTERNS FOR LATER US
+Line 1041 
 SAVING PRECOMPILED PATTERNS FOR LATER US
         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
         than  the  one  on  which  it  was  compiled.  Details are given in the
-        pcreprecompile documentation.
+        pcreprecompile documentation. However, compiling a  regular  expression
+        with  one version of PCRE for use with a different version is not guar-
+        anteed to work and may cause crashes.
  CHECKING BUILD-TIME OPTIONS
-Line 761 
 CHECKING BUILD-TIME OPTIONS
+Line 1072 
 CHECKING BUILD-TIME OPTIONS
           PCRE_CONFIG_NEWLINE
-        The output is an integer that is set to the value of the code  that  is
+        The output is an integer whose value specifies  the  default  character
-        used  for the newline character. It is either linefeed (10) or carriage
+        sequence  that is recognized as meaning "newline". The four values that
-        return (13), and should normally be the  standard  character  for  your
+        are supported are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF,
-        operating system.
+        and  -1  for  ANY.  Though they are derived from ASCII, the same values
+        are returned in EBCDIC environments. The default should normally corre-
+        spond to 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
-Line 783 
 CHECKING BUILD-TIME OPTIONS
+Line 1104 
 CHECKING BUILD-TIME OPTIONS
           PCRE_CONFIG_MATCH_LIMIT
-        The output is an integer that gives the default limit for the number of
+        The output is a long integer that gives the default limit for the  num-
-        internal  matching  function  calls in a pcre_exec() execution. Further
+        ber  of  internal  matching  function calls in a pcre_exec() execution.
-        details are given with pcre_exec() below.
+        Further details are given with pcre_exec() below.
+          PCRE_CONFIG_MATCH_LIMIT_RECURSION
+        The output is a long integer that gives the default limit for the depth
+        of   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 811 
 COMPILING A PATTERN
+Line 1139 
 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.
+        errorcodeptr, via which a numerical error  code  can  be  returned.  To
+        avoid  too  much repetition, we refer just to pcre_compile() below, but
+        the information applies equally to pcre_compile2().
         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  when  it  is  no  longer
+        It is up to the caller to free the memory (via pcre_free) when it is no
-        required.
+        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 independent bits that affect the compila-
+        The options argument contains various bit settings that affect the com-
-        tion.  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, but some others as well) can also be set  and
-        pattern (see the detailed description  in  the  pcrepattern  documenta-
+        unset  from  within  the  pattern  (see the detailed description in the
-        tion).  For  these options, the contents of the options argument speci-
+        pcrepattern documentation). For those options that can be different  in
-        fies their initial settings at the start of compilation and  execution.
+        different  parts  of  the pattern, the contents of the options argument
-        The  PCRE_ANCHORED option can be set at the time of matching as well as
+        specifies their settings at the start of compilation and execution. The
+        PCRE_ANCHORED,  PCRE_BSR_xxx, PCRE_NEWLINE_xxx, PCRE_NO_UTF8_CHECK, and
+        PCRE_NO_START_OPT options can be set at the time of matching as well as
         at compile time.
         If errptr is NULL, pcre_compile() returns NULL immediately.  Otherwise,
-        if  compilation  of  a  pattern fails, pcre_compile() returns NULL, and
+        if compilation of a pattern fails,  pcre_compile()  returns  NULL,  and
         sets the variable pointed to by errptr to point to a textual error mes-
-        sage.  The  offset from the start of the pattern to the character where
+        sage. This is a static string that is part of the library. You must not
-        the error was discovered is  placed  in  the  variable  pointed  to  by
+        try  to  free  it. The offset from the start of the pattern to the byte
-        erroffset,  which  must  not  be  NULL. If it is, an immediate error is
+        that was being processed when the error was discovered is placed in the
-        given.
+        variable  pointed to by erroffset, which must not be NULL. If it is, an
+        immediate error is given. Some errors are not detected until checks are
+        carried  out  when the whole pattern has been scanned; in this case the
+        offset is set to the end of the pattern.
+        Note that the offset is in bytes, not characters, even in  UTF-8  mode.
+        It  may  point  into the middle of a UTF-8 character (for example, when
+        PCRE_ERROR_BADUTF8 is returned for an invalid UTF-8 string).
         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
-Line 888 
 COMPILING A PATTERN
+Line 1227 
 COMPILING A PATTERN
         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
-Line 905 
 COMPILING A PATTERN
+Line 1253 
 COMPILING A PATTERN
         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
-        matches immediately before the final character if it is a newline  (but
+        matches immediately before a newline at the end of the string (but  not
-        not  before  any  other  newlines).  The  PCRE_DOLLAR_ENDONLY option is
+        before  any  other newlines). The PCRE_DOLLAR_ENDONLY option is ignored
-        ignored if PCRE_MULTILINE is set. There is no equivalent to this option
+        if PCRE_MULTILINE is set.  There is no equivalent  to  this  option  in
-        in Perl, and no way to set it within a pattern.
+        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-
+        If  this bit is set, a dot metacharacter in the pattern matches a char-
-        acters, including newlines. Without it,  newlines  are  excluded.  This
+        acter of any value, including one that indicates a newline. However, it
-        option  is equivalent to Perl's /s option, and it can be changed within
+        only  ever  matches  one character, even if newlines are coded as CRLF.
-        a pattern by a (?s) option setting.  A  negative  class  such  as  [^a]
+        Without this option, a dot does not match when the current position  is
-        always  matches a newline character, independent of the setting of this
+        at a newline. This option is equivalent to Perl's /s option, and it can
-        option.
+        be changed within a pattern by a (?s) option setting. A negative  class
+        such as [^a] always matches newline characters, independent of the set-
+        ting of this option.
+          PCRE_DUPNAMES
+        If this bit is set, names used to identify capturing  subpatterns  need
+        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
+        matched.  There  are  more details of named subpatterns below; see also
+        the pcrepattern documentation.
           PCRE_EXTENDED
-Line 925 
 COMPILING A PATTERN
+Line 1283 
 COMPILING A PATTERN
         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 character, inclusive, are also  ignored.  This  is  equivalent  to
+        line, inclusive, are also ignored. This  is  equivalent  to  Perl's  /x
-        Perl's  /x  option,  and  it  can be changed within a pattern by a (?x)
+        option,  and  it  can be changed within a pattern by a (?x) option set-
-        option setting.
+        ting.
-        This option makes it possible to include  comments  inside  complicated
+        Which characters are interpreted  as  newlines  is  controlled  by  the
-        patterns.   Note,  however,  that this applies only to data characters.
+        options  passed to pcre_compile() or by a special sequence at the start
-        Whitespace  characters  may  never  appear  within  special   character
+        of the pattern, as described in the section entitled  "Newline  conven-
-        sequences  in  a  pattern,  for  example  within the sequence (?( which
+        tions" in the pcrepattern documentation. Note that the end of this type
-        introduces a conditional subpattern.
+        of comment is  a  literal  newline  sequence  in  the  pattern;  escape
+        sequences that happen to represent a newline do not count.
+        This  option  makes  it possible to include comments inside complicated
+        patterns.  Note, however, that this applies only  to  data  characters.
+        Whitespace   characters  may  never  appear  within  special  character
+        sequences in a pattern, for example within the sequence (?( that intro-
+        duces a conditional subpattern.
           PCRE_EXTRA
-        This option was invented in order to turn on  additional  functionality
+        This  option  was invented in order to turn on additional functionality
-        of  PCRE  that  is  incompatible with Perl, but it is currently of very
+        of PCRE that is incompatible with Perl, but it  is  currently  of  very
-        little use. When set, any backslash in a pattern that is followed by  a
+        little  use. When set, any backslash in a pattern that is followed by a
-        letter  that  has  no  special  meaning causes an error, thus reserving
+        letter that has no special meaning  causes  an  error,  thus  reserving
-        these combinations for future expansion. By  default,  as  in  Perl,  a
+        these  combinations  for  future  expansion.  By default, as in Perl, a
-        backslash  followed by a letter with no special meaning is treated as a
+        backslash followed by a letter with no special meaning is treated as  a
-        literal. There are at present no  other  features  controlled  by  this
+        literal. (Perl can, however, be persuaded to give an error for this, by
-        option. It can also be set by a (?X) option setting within a pattern.
+        running it with the -w option.) There are at present no other  features
+        controlled  by this option. It can also be set by a (?X) option setting
+        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 character in the subject string,  though
+        before  or  at  the  first  newline  in  the subject string, though the
-        the matched text may continue over the newline.
+        matched text may continue over the newline.
+          PCRE_JAVASCRIPT_COMPAT
+        If this option is set, PCRE's behaviour is changed in some ways so that
+        it  is  compatible with JavaScript rather than Perl. The changes are as
+        follows:
+        (1) A lone closing square bracket in a pattern  causes  a  compile-time
+        error,  because this is illegal in JavaScript (by default it is treated
+        as a data character). Thus, the pattern AB]CD becomes illegal when this
+        option is set.
+        (2)  At run time, a back reference to an unset subpattern group matches
+        an empty string (by default this causes the current  matching  alterna-
+        tive  to  fail). A pattern such as (\1)(a) succeeds when this option is
+        set (assuming it can find an "a" in the subject), whereas it  fails  by
+        default, for Perl compatibility.
           PCRE_MULTILINE
-Line 962 
 COMPILING A PATTERN
+Line 1346 
 COMPILING A PATTERN
         is set). This is the same as Perl.
         When PCRE_MULTILINE it is set, the "start of line" and  "end  of  line"
-        constructs  match  immediately following or immediately before any new-
+        constructs  match  immediately following or immediately before internal
-        line in the subject string, respectively, as well as at the very  start
+        newlines in the subject string, respectively, as well as  at  the  very
-        and  end. This is equivalent to Perl's /m option, and it can be changed
+        start  and  end.  This is equivalent to Perl's /m option, and it can be
-        within a pattern by a (?m) option setting. If there are no "\n" charac-
+        changed within a pattern by a (?m) option setting. If there are no new-
-        ters  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
+          PCRE_NEWLINE_LF
+          PCRE_NEWLINE_CRLF
+          PCRE_NEWLINE_ANYCRLF
+          PCRE_NEWLINE_ANY
+        These options override the default newline definition that  was  chosen
+        when  PCRE  was built. Setting the first or the second specifies that a
+        newline is indicated by a single character (CR  or  LF,  respectively).
+        Setting  PCRE_NEWLINE_CRLF specifies that a newline is indicated by the
+        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
+        recognized. The Unicode newline sequences are the three just mentioned,
+        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
+        (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
+        treated as a number, giving eight possibilities. Currently only six are
+        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-
+        ble. For example, PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to
+        PCRE_NEWLINE_CRLF, but other combinations may yield unused numbers  and
+        cause an error.
+        The  only  time  that a line break in a pattern is specially recognized
+        when compiling is when PCRE_EXTENDED is set. CR and LF  are  whitespace
+        characters,  and so are ignored in this mode. Also, an unescaped # out-
+        side a character class indicates a comment that lasts until  after  the
+        next  line break sequence. In other circumstances, line break sequences
+        in patterns are treated as literal data.
+        The newline option that is set at compile time becomes the default that
+        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.
+          NO_START_OPTIMIZE
+        This  is an option that acts at matching time; that is, it is really an
+        option for pcre_exec() or pcre_dfa_exec(). If  it  is  set  at  compile
+        time,  it is remembered with the compiled pattern and assumed at match-
+        ing time. For details  see  the  discussion  of  PCRE_NO_START_OPTIMIZE
+        below.
+          PCRE_UCP
+        This  option changes the way PCRE processes \B, \b, \D, \d, \S, \s, \W,
+        \w, and some of the POSIX character classes.  By  default,  only  ASCII
+        characters  are  recognized, but if PCRE_UCP is set, Unicode properties
+        are used instead to classify characters. More details are given in  the
+        section  on generic character types in the pcrepattern page. If you set
+        PCRE_UCP, matching one of the items it affects takes much  longer.  The
+        option  is  available only if PCRE has been compiled with Unicode prop-
+        erty support.
           PCRE_UNGREEDY
         This option inverts the "greediness" of the quantifiers  so  that  they
-Line 996 
 COMPILING A PATTERN
+Line 1436 
 COMPILING A PATTERN
           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
-        The following table lists the error  codes  than  may  be  returned  by
+        The  following  table  lists  the  error  codes than may be returned by
-        pcre_compile2(),  along with the error messages that may be returned by
+        pcre_compile2(), along with the error messages that may be returned  by
-        both compiling functions.
+        both  compiling functions. As PCRE has developed, some error codes have
+        fallen out of use. To avoid confusion, they have not been re-used.
  no error
  \ at end of pattern
-Line 1022 
 COMPILATION ERROR CODES
+Line 1464 
 COMPILATION ERROR CODES
  invalid escape sequence in character class
  range out of order in character class
  nothing to repeat
- operand of unlimited repeat could match the empty string
+ [this code is not in use]
  internal error: unexpected repeat
- unrecognized character after (?
+ unrecognized character after (? or (?-
  POSIX named classes are supported only within a class
  missing )
  reference to non-existent subpattern
  erroffset passed as NULL
  unknown option bit(s) set
  missing ) after comment
- parentheses nested too deeply
+ [this code is not in use]
- regular expression too large
+ regular expression is too large
  failed to get memory
  unmatched parentheses
  internal error: code overflow
  unrecognized character after (?<
  lookbehind assertion is not fixed length
- malformed number after (?(
+ malformed number or name after (?(
  conditional group contains more than two branches
  assertion expected after (?(
- (?R or (?digits must be followed by )
+ (?R or (?[+-]digits must be followed by )
  unknown POSIX class name
  POSIX collating elements are not supported
  this version of PCRE is not compiled with PCRE_UTF8 support
- spare error
+ [this code is not in use]
  character value in \x{...} sequence is too large
  invalid condition (?(0)
  \C not allowed in lookbehind assertion
-Line 1054 
 COMPILATION ERROR CODES
+Line 1496 
 COMPILATION ERROR CODES
  closing ) for (?C expected
  recursive call could loop indefinitely
  unrecognized character after (?P
- syntax error after (?P
+ syntax error in subpattern name (missing terminator)
- two named groups have the same name
+ two named subpatterns have the same name
  invalid UTF-8 string
  support for \P, \p, and \X has not been compiled
  malformed \P or \p sequence
  unknown property name after \P or \p
+ subpattern name is too long (maximum 32 characters)
+ too many named subpatterns (maximum 10000)
+ [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
+ \g is not followed by a braced, angle-bracketed, or quoted
+                name/number or by a plain number
+ a numbered reference must not be zero
+ an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT)
+ (*VERB) not recognized
+ number is too big
+ subpattern name expected
+ digit expected after (?+
+ ] is an invalid data character in JavaScript compatibility mode
+ different names for subpatterns of the same number are
+                not allowed
+ (*MARK) must have an argument
+ this version of PCRE is not compiled with PCRE_UCP support
+        The numbers 32 and 10000 in errors 48 and 49  are  defaults;  different
+        values may be used if the limits were changed when PCRE was built.
  STUDYING A PATTERN
-Line 1067 
 STUDYING A PATTERN
+Line 1535 
 STUDYING A PATTERN
         pcre_extra *pcre_study(const pcre *code, int options
              const char **errptr);
-        If a compiled pattern is going to be used several times,  it  is  worth
+        If  a  compiled  pattern is going to be used several times, it is worth
         spending more time analyzing it in order to speed up the time taken for
-        matching. The function pcre_study() takes a pointer to a compiled  pat-
+        matching.  The function pcre_study() takes a pointer to a compiled pat-
         tern as its first argument. If studying the pattern produces additional
-        information that will help speed up matching,  pcre_study()  returns  a
+        information  that  will  help speed up matching, pcre_study() returns a
-        pointer  to a pcre_extra block, in which the study_data field points to
+        pointer to a pcre_extra block, in which the study_data field points  to
         the results of the study.
         The  returned  value  from  pcre_study()  can  be  passed  directly  to
-        pcre_exec().  However,  a  pcre_extra  block also contains other fields
+        pcre_exec() or pcre_dfa_exec(). However, a pcre_extra block  also  con-
-        that can be set by the caller before the block  is  passed;  these  are
+        tains  other  fields  that can be set by the caller before the block is
-        described below in the section on matching a pattern.
+        passed; these are described below in the section on matching a pattern.
-        If  studying  the  pattern  does not produce any additional information
+        If studying the  pattern  does  not  produce  any  useful  information,
         pcre_study() returns NULL. In that circumstance, if the calling program
-        wants  to  pass  any of the other fields to pcre_exec(), it must set up
+        wants  to  pass  any  of   the   other   fields   to   pcre_exec()   or
-        its own pcre_extra block.
+        pcre_dfa_exec(), it must set up its own pcre_extra block.
-        The second argument of pcre_study() contains option bits.  At  present,
+        The  second  argument of pcre_study() contains option bits. At present,
         no options are defined, and this argument should always be zero.
-        The  third argument for pcre_study() is a pointer for an error message.
+        The third argument for pcre_study() is a pointer for an error  message.
-        If studying succeeds (even if no data is  returned),  the  variable  it
+        If  studying  succeeds  (even  if no data is returned), the variable it
-        points  to  is set to NULL. Otherwise it points to a textual error mes-
+        points to is set to NULL. Otherwise it is set to  point  to  a  textual
-        sage. You should therefore test the error pointer for NULL after  call-
+        error message. This is a static string that is part of the library. You
-        ing pcre_study(), to be sure that it has run successfully.
+        must not try to free it. You should test the  error  pointer  for  NULL
+        after calling pcre_study(), to be sure that it has run successfully.
         This is a typical call to pcre_study():
-Line 1102 
 STUDYING A PATTERN
+Line 1571 
 STUDYING A PATTERN
 ,              /* no options exist */
             &error);        /* set to NULL or points to a message */
-        At present, studying a pattern is useful only for non-anchored patterns
+        Studying a pattern does two things: first, a lower bound for the length
-        that do not have a single fixed starting character. A bitmap of  possi-
+        of subject string that is needed to match the pattern is computed. This
-        ble starting bytes is created.
+        does not mean that there are any strings of that length that match, but
+        it does guarantee that no shorter strings match. The value is  used  by
+        pcre_exec()  and  pcre_dfa_exec()  to  avoid  wasting time by trying to
+        match strings that are shorter than the lower bound. You can  find  out
+        the value in a calling program via the pcre_fullinfo() function.
+        Studying a pattern is also useful for non-anchored patterns that do not
+        have a single fixed starting character. A bitmap of  possible  starting
+        bytes  is  created. This speeds up finding a position in the subject at
+        which to start matching.
+        The two optimizations just described can be  disabled  by  setting  the
+        PCRE_NO_START_OPTIMIZE    option    when    calling    pcre_exec()   or
+        pcre_dfa_exec(). You might want to do this  if  your  pattern  contains
+        callouts  or  (*MARK),  and you want to make use of these facilities in
+        cases where matching fails. See the discussion  of  PCRE_NO_START_OPTI-
+        MIZE below.
  LOCALE SUPPORT
         PCRE  handles  caseless matching, and determines whether characters are
-        letters digits, or whatever, by reference to a set of  tables,  indexed
+        letters, digits, or whatever, by reference to a set of tables,  indexed
         by  character  value.  When running in UTF-8 mode, this applies only to
-        characters with codes less than 128. Higher-valued  codes  never  match
+        characters with codes less than 128. By  default,  higher-valued  codes
-        escapes  such  as  \w or \d, but can be tested with \p if PCRE is built
+        never match escapes such as \w or \d, but they can be tested with \p if
-        with Unicode character property support.
+        PCRE is built with Unicode character property  support.  Alternatively,
+        the  PCRE_UCP  option  can  be  set at compile time; this causes \w and
-        An internal set of tables is created in the default C locale when  PCRE
+        friends to use Unicode property support instead of built-in tables. The
-        is  built.  This  is  used when the final argument of pcre_compile() is
+        use of locales with Unicode is discouraged. If you are handling charac-
-        NULL, and is sufficient for many applications. An  alternative  set  of
+        ters with codes greater than 128, you should either use UTF-8 and  Uni-
-        tables  can,  however, be supplied. These may be created in a different
+        code, or use locales, but not try to mix the two.
-        locale from the default. As more and more applications change to  using
-        Unicode, the need for this locale support is expected to die away.
+        PCRE  contains  an  internal set of tables that are used when the final
+        argument of pcre_compile() is  NULL.  These  are  sufficient  for  many
+        applications.  Normally, the internal tables recognize only ASCII char-
+        acters. However, when PCRE is built, it is possible to cause the inter-
+        nal tables to be rebuilt in the default "C" locale of the local system,
+        which may cause them to be different.
+        The internal tables can always be overridden by tables supplied by  the
+        application that calls PCRE. These may be created in a different locale
+        from the default. As more and more applications change  to  using  Uni-
+        code, the need for this locale support is expected to die away.
         External  tables  are  built by calling the pcre_maketables() function,
         which has no arguments, in the relevant locale. The result can then  be
-Line 1134 
 LOCALE SUPPORT
+Line 1629 
 LOCALE SUPPORT
           tables = pcre_maketables();
           re = pcre_compile(..., tables);
-        When pcre_maketables() runs, the tables are built  in  memory  that  is
+        The locale name "fr_FR" is used on Linux and other  Unix-like  systems;
-        obtained  via  pcre_malloc. It is the caller's responsibility to ensure
+        if you are using Windows, the name for the French locale is "french".
-        that the memory containing the tables remains available for as long  as
+        When  pcre_maketables()  runs,  the  tables are built in memory that is
+        obtained via pcre_malloc. It is the caller's responsibility  to  ensure
+        that  the memory containing the tables remains available for as long as
         it is needed.
         The pointer that is passed to pcre_compile() is saved with the compiled
-        pattern, and the same tables are used via this pointer by  pcre_study()
+        pattern,  and the same tables are used via this pointer by pcre_study()
         and normally also by pcre_exec(). Thus, by default, for any single pat-
         tern, compilation, studying and matching all happen in the same locale,
         but different patterns can be compiled in different locales.
-        It  is  possible to pass a table pointer or NULL (indicating the use of
+        It is possible to pass a table pointer or NULL (indicating the  use  of
-        the internal tables) to pcre_exec(). Although  not  intended  for  this
+        the  internal  tables)  to  pcre_exec(). Although not intended for this
-        purpose,  this facility could be used to match a pattern in a different
+        purpose, this facility could be used to match a pattern in a  different
         locale from the one in which it was compiled. Passing table pointers at
         run time is discussed below in the section on matching a pattern.
-Line 1157 
 INFORMATION ABOUT A PATTERN
+Line 1655 
 INFORMATION ABOUT A PATTERN
         int pcre_fullinfo(const pcre *code, const pcre_extra *extra,
              int what, void *where);
-        The  pcre_fullinfo() function returns information about a compiled pat-
+        The pcre_fullinfo() function returns information about a compiled  pat-
         tern. It replaces the obsolete pcre_info() function, which is neverthe-
         less retained for backwards compability (and is documented below).
-        The  first  argument  for  pcre_fullinfo() is a pointer to the compiled
+        The first argument for pcre_fullinfo() is a  pointer  to  the  compiled
-        pattern. The second argument is the result of pcre_study(), or NULL  if
+        pattern.  The second argument is the result of pcre_study(), or NULL if
-        the  pattern  was not studied. The third argument specifies which piece
+        the pattern was not studied. The third argument specifies  which  piece
-        of information is required, and the fourth argument is a pointer  to  a
+        of  information  is required, and the fourth argument is a pointer to a
-        variable  to  receive  the  data. The yield of the function is zero for
+        variable to receive the data. The yield of the  function  is  zero  for
         success, or one of the following negative numbers:
           PCRE_ERROR_NULL       the argument code was NULL
-Line 1173 
 INFORMATION ABOUT A PATTERN
+Line 1671 
 INFORMATION ABOUT A PATTERN
           PCRE_ERROR_BADMAGIC   the "magic number" was not found
           PCRE_ERROR_BADOPTION  the value of what was invalid
-        The "magic number" is placed at the start of each compiled  pattern  as
+        The  "magic  number" is placed at the start of each compiled pattern as
-        an  simple check against passing an arbitrary memory pointer. Here is a
+        an simple check against passing an arbitrary memory pointer. Here is  a
-        typical call of pcre_fullinfo(), to obtain the length of  the  compiled
+        typical  call  of pcre_fullinfo(), to obtain the length of the compiled
         pattern:
           int rc;
-          unsigned long int length;
+          size_t length;
           rc = pcre_fullinfo(
             re,               /* result of pcre_compile() */
             pe,               /* result of pcre_study(), or NULL */
             PCRE_INFO_SIZE,   /* what is required */
             &length);         /* where to put the data */
-        The  possible  values for the third argument are defined in pcre.h, and
+        The possible values for the third argument are defined in  pcre.h,  and
         are as follows:
           PCRE_INFO_BACKREFMAX
-        Return the number of the highest back reference  in  the  pattern.  The
+        Return  the  number  of  the highest back reference in the pattern. The
-        fourth  argument  should  point to an int variable. Zero is returned if
+        fourth argument should point to an int variable. Zero  is  returned  if
         there are no back references.
           PCRE_INFO_CAPTURECOUNT
-        Return the number of capturing subpatterns in the pattern.  The  fourth
+        Return  the  number of capturing subpatterns in the pattern. The fourth
         argument should point to an int variable.
           PCRE_INFO_DEFAULT_TABLES
-        Return  a pointer to the internal default character tables within PCRE.
+        Return a pointer to the internal default character tables within  PCRE.
-        The fourth argument should point to an unsigned char *  variable.  This
+        The  fourth  argument should point to an unsigned char * variable. This
         information call is provided for internal use by the pcre_study() func-
-        tion. External callers can cause PCRE to use  its  internal  tables  by
+        tion.  External  callers  can  cause PCRE to use its internal tables by
         passing a NULL table pointer.
           PCRE_INFO_FIRSTBYTE
-        Return  information  about  the first byte of any matched string, for a
+        Return information about the first byte of any matched  string,  for  a
-        non-anchored   pattern.   (This    option    used    to    be    called
+        non-anchored  pattern. The fourth argument should point to an int vari-
-        PCRE_INFO_FIRSTCHAR;  the  old  name  is still recognized for backwards
+        able. (This option used to be called PCRE_INFO_FIRSTCHAR; the old  name
-        compatibility.)
+        is still recognized for backwards compatibility.)
-        If there is a fixed first byte, for example, from  a  pattern  such  as
+        If  there  is  a  fixed first byte, for example, from a pattern such as
-        (cat|cow|coyote),  it  is  returned in the integer pointed to by where.
+        (cat|cow|coyote), its value is returned. Otherwise, if either
-        Otherwise, if either
         (a) the pattern was compiled with the PCRE_MULTILINE option, and  every
         branch starts with "^", or
-Line 1237 
 INFORMATION ABOUT A PATTERN
+Line 1734 
 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) or (?-J) option setting is used in the pattern,
+        otherwise 0. The fourth argument should point to an int variable.  (?J)
+        and (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
           PCRE_INFO_LASTLITERAL
-        Return the value of the rightmost literal byte that must exist  in  any
+        Return  the  value of the rightmost literal byte that must exist in any
-        matched  string,  other  than  at  its  start,  if such a byte has been
+        matched string, other than at its  start,  if  such  a  byte  has  been
         recorded. The fourth argument should point to an int variable. If there
-        is  no such byte, -1 is returned. For anchored patterns, a last literal
+        is no such byte, -1 is returned. For anchored patterns, a last  literal
-        byte is recorded only if it follows something of variable  length.  For
+        byte  is  recorded only if it follows something of variable length. For
         example, for the pattern /^a\d+z\d+/ the returned value is "z", but for
         /^a\dz\d/ the returned value is -1.
+          PCRE_INFO_MINLENGTH
+        If  the  pattern  was studied and a minimum length for matching subject
+        strings was computed, its value is  returned.  Otherwise  the  returned
+        value  is  -1. The value is a number of characters, not bytes (this may
+        be relevant in UTF-8 mode). The fourth argument should point to an  int
+        variable.  A  non-negative  value is a lower bound to the length of any
+        matching string. There may not be any strings of that  length  that  do
+        actually match, but every string that does match is at least that long.
           PCRE_INFO_NAMECOUNT
           PCRE_INFO_NAMEENTRYSIZE
           PCRE_INFO_NAMETABLE
-        PCRE supports the use of named as well as numbered capturing  parenthe-
+        PCRE  supports the use of named as well as numbered capturing parenthe-
-        ses.  The names are just an additional way of identifying the parenthe-
+        ses. The names are just an additional way of identifying the  parenthe-
-        ses,  which  still  acquire  numbers.  A  convenience  function  called
+        ses, which still acquire numbers. Several convenience functions such as
-        pcre_get_named_substring()  is  provided  for  extracting an individual
+        pcre_get_named_substring() are provided for  extracting  captured  sub-
-        captured substring by name. It is also possible  to  extract  the  data
+        strings  by  name. It is also possible to extract the data directly, by
-        directly,  by  first converting the name to a number in order to access
+        first converting the name to a number in order to  access  the  correct
-        the correct pointers in the output vector (described  with  pcre_exec()
+        pointers in the output vector (described with pcre_exec() below). To do
-        below).  To  do the conversion, you need to use the name-to-number map,
+        the conversion, you need  to  use  the  name-to-number  map,  which  is
-        which is described by these three values.
+        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.
-        For example, consider the following pattern  (assume  PCRE_EXTENDED  is
-        set, so white space - including newlines - is ignored):
-          (?P<date> (?P<year>(\d\d)?\d\d) -
+        The names are in alphabetical order. Duplicate names may appear if  (?|
-          (?P<month>\d\d) - (?P<day>\d\d) )
+        is used to create multiple groups with the same number, as described in
+        the section on duplicate subpattern numbers in  the  pcrepattern  page.
+        Duplicate  names  for  subpatterns with different numbers are permitted
+        only if PCRE_DUPNAMES is set. In all cases  of  duplicate  names,  they
+        appear  in  the table in the order in which they were found in the pat-
+        tern. In the absence of (?| this is the  order  of  increasing  number;
+        when (?| is used this is not necessarily the case because later subpat-
+        terns may have lower numbers.
+        As a simple example of the name/number table,  consider  the  following
+        pattern  (assume  PCRE_EXTENDED is set, so white space - including new-
+        lines - is ignored):
-        There  are  four  named subpatterns, so the table has four entries, and
+          (?<date> (?<year>(\d\d)?\d\d) -
-        each entry in the table is eight bytes long. The table is  as  follows,
+          (?<month>\d\d) - (?<day>\d\d) )
+        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,
         with non-printing bytes shows in hexadecimal, and undefined bytes shown
         as ??:
-Line 1285 
 INFORMATION ABOUT A PATTERN
+Line 1817 
 INFORMATION ABOUT A PATTERN
 04 m  o  n  t  h  00
 02 y  e  a  r  00 ??
-        When writing code to extract data  from  named  subpatterns  using  the
+        When  writing  code  to  extract  data from named subpatterns using the
-        name-to-number map, remember that the length of each entry is likely to
+        name-to-number map, remember that the length of the entries  is  likely
-        be different for each compiled pattern.
+        to be different for each compiled pattern.
+          PCRE_INFO_OKPARTIAL
+        Return  1  if  the  pattern  can  be  used  for  partial  matching with
+        pcre_exec(), otherwise 0. The fourth argument should point  to  an  int
+        variable.  From  release  8.00,  this  always  returns  1,  because the
+        restrictions that previously applied  to  partial  matching  have  been
+        lifted.  The  pcrepartial documentation gives details of partial match-
+        ing.
           PCRE_INFO_OPTIONS
         Return a copy of the options with which the pattern was  compiled.  The
         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
         alternatives begin with one of the following:
-Line 1320 
 INFORMATION ABOUT A PATTERN
+Line 1865 
 INFORMATION ABOUT A PATTERN
         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
         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().  If pcre_extra is NULL, or there is no study
+        data, zero is returned. The fourth argument should point  to  a  size_t
         variable.
-Line 1328 
 OBSOLETE INFO FUNCTION
+Line 1874 
 OBSOLETE INFO FUNCTION
         int pcre_info(const pcre *code, int *optptr, int *firstcharptr);
-        The pcre_info() function is now obsolete because its interface  is  too
+        The  pcre_info()  function is now obsolete because its interface is too
-        restrictive  to return all the available data about a compiled pattern.
+        restrictive to return all the available data about a compiled  pattern.
-        New  programs  should  use  pcre_fullinfo()  instead.  The   yield   of
+        New   programs   should  use  pcre_fullinfo()  instead.  The  yield  of
-        pcre_info()  is the number of capturing subpatterns, or one of the fol-
+        pcre_info() is the number of capturing subpatterns, or one of the  fol-
         lowing negative numbers:
           PCRE_ERROR_NULL       the argument code was NULL
           PCRE_ERROR_BADMAGIC   the "magic number" was not found
-        If the optptr argument is not NULL, a copy of the  options  with  which
+        If  the  optptr  argument is not NULL, a copy of the options with which
-        the  pattern  was  compiled  is placed in the integer it points to (see
+        the pattern was compiled is placed in the integer  it  points  to  (see
         PCRE_INFO_OPTIONS above).
-        If the pattern is not anchored and the  firstcharptr  argument  is  not
+        If  the  pattern  is  not anchored and the firstcharptr argument is not
-        NULL,  it is used to pass back information about the first character of
+        NULL, it is used to pass back information about the first character  of
         any matched string (see PCRE_INFO_FIRSTBYTE above).
-Line 1350 
 REFERENCE COUNTS
+Line 1896 
 REFERENCE COUNTS
         int pcre_refcount(pcre *code, int adjust);
-        The pcre_refcount() function is used to maintain a reference  count  in
+        The  pcre_refcount()  function is used to maintain a reference count in
         the data block that contains a compiled pattern. It is provided for the
-        benefit of applications that  operate  in  an  object-oriented  manner,
+        benefit  of  applications  that  operate  in an object-oriented manner,
         where different parts of the application may be using the same compiled
         pattern, but you want to free the block when they are all done.
         When a pattern is compiled, the reference count field is initialized to
-        zero.   It is changed only by calling this function, whose action is to
+        zero.  It is changed only by calling this function, whose action is  to
-        add the adjust value (which may be positive or  negative)  to  it.  The
+        add  the  adjust  value  (which may be positive or negative) to it. The
         yield of the function is the new value. However, the value of the count
-        is constrained to lie between 0 and 65535, inclusive. If the new  value
+        is  constrained to lie between 0 and 65535, inclusive. If the new value
         is outside these limits, it is forced to the appropriate limit value.
-        Except  when it is zero, the reference count is not correctly preserved
+        Except when it is zero, the reference count is not correctly  preserved
-        if a pattern is compiled on one host and then  transferred  to  a  host
+        if  a  pattern  is  compiled on one host and then transferred to a host
         whose byte-order is different. (This seems a highly unlikely scenario.)
-Line 1376 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1922 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         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
-        has been studied, the result of the study should be passed in the extra
+        was studied, the result of the study should  be  passed  in  the  extra
         argument.  This  function is the main matching facility of the library,
         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-
-Line 1407 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1953 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         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
         return NULL), but you can also create one for yourself, and pass  addi-
-        tional  information in it. The fields in a pcre_extra block are as fol-
+        tional  information  in it. The pcre_extra block contains the following
-        lows:
+        fields (not necessarily in this order):
           unsigned long int flags;
           void *study_data;
           unsigned long int match_limit;
+          unsigned long int match_limit_recursion;
           void *callout_data;
           const unsigned char *tables;
+          unsigned char **mark;
         The flags field is a bitmap that specifies which of  the  other  fields
         are set. The flag bits are:
           PCRE_EXTRA_STUDY_DATA
           PCRE_EXTRA_MATCH_LIMIT
+          PCRE_EXTRA_MATCH_LIMIT_RECURSION
           PCRE_EXTRA_CALLOUT_DATA
           PCRE_EXTRA_TABLES
+          PCRE_EXTRA_MARK
         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
-Line 1433 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1983 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         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
         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 a pattern that uses nested  unlim-
-        repeats.
+        ited repeats.
         Internally,  PCRE uses a function called match() which it calls repeat-
-        edly (sometimes recursively). The limit is imposed  on  the  number  of
+        edly (sometimes recursively). The limit set by match_limit  is  imposed
-        times  this  function is called during a match, which has the effect of
+        on  the  number  of times this function is called during a match, which
-        limiting the amount of recursion and backtracking that can take  place.
+        has the effect of limiting the amount of  backtracking  that  can  take
-        For patterns that are not anchored, the count starts from zero for each
+        place. For patterns that are not anchored, the count restarts from zero
-        position in the subject string.
+        for each position in the subject string.
-        The default limit for the library 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
-        cases. You can reduce  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 to a smaller value, 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
         exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
-        The  pcre_callout  field is used in conjunction with the "callout" fea-
+        The  match_limit_recursion field is similar to match_limit, but instead
-        ture, which is described in the pcrecallout documentation.
+        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 tables field  is  used  to  pass  a  character  tables  pointer  to
+        the total number of calls, because not all calls to match() are  recur-
-        pcre_exec();  this overrides the value that is stored with the compiled
+        sive.  This limit is of use only if it is set smaller than match_limit.
-        pattern. A non-NULL value is stored with the compiled pattern  only  if
-        custom  tables  were  supplied to pcre_compile() via its tableptr argu-
+        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
+        built; the default default  is  the  same  value  as  the  default  for
+        match_limit.  You can override the default by suppling pcre_exec() with
+        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
+        limit is exceeded, pcre_exec() returns PCRE_ERROR_RECURSIONLIMIT.
+        The callout_data field is used in conjunction with the  "callout"  fea-
+        ture, and is described in the pcrecallout documentation.
+        The  tables  field  is  used  to  pass  a  character  tables pointer to
+        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
+        custom tables were supplied to pcre_compile() via  its  tableptr  argu-
         ment.  If NULL is passed to pcre_exec() using this mechanism, it forces
-        PCRE's  internal  tables  to be used. This facility is helpful when re-
+        PCRE's internal tables to be used. This facility is  helpful  when  re-
-        using patterns that have been saved after compiling  with  an  external
+        using  patterns  that  have been saved after compiling with an external
-        set  of  tables,  because  the  external tables might be at a different
+        set of tables, because the external tables  might  be  at  a  different
-        address when pcre_exec() is called. See the  pcreprecompile  documenta-
+        address  when  pcre_exec() is called. See the pcreprecompile documenta-
         tion for a discussion of saving compiled patterns for later use.
+        If PCRE_EXTRA_MARK is set in the flags field, the mark  field  must  be
+        set  to  point  to a char * variable. If the pattern contains any back-
+        tracking control verbs such as (*MARK:NAME), and the execution ends  up
+        with  a  name  to  pass back, a pointer to the name string (zero termi-
+        nated) is placed in the variable pointed to  by  the  mark  field.  The
+        names  are  within  the  compiled pattern; if you wish to retain such a
+        name you must copy it before freeing the memory of a compiled  pattern.
+        If  there  is no name to pass back, the variable pointed to by the mark
+        field set to NULL. For details of the backtracking control  verbs,  see
+        the section entitled "Backtracking control" in the pcrepattern documen-
+        tation.
     Option bits for pcre_exec()
-        The  unused  bits of the options argument for pcre_exec() must be zero.
+        The unused bits of the options argument for pcre_exec() must  be  zero.
-        The  only  bits  that  may  be  set  are  PCRE_ANCHORED,   PCRE_NOTBOL,
+        The  only  bits  that  may  be set are PCRE_ANCHORED, PCRE_NEWLINE_xxx,
-        PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.
+        PCRE_NOTBOL,   PCRE_NOTEOL,    PCRE_NOTEMPTY,    PCRE_NOTEMPTY_ATSTART,
+        PCRE_NO_START_OPTIMIZE,   PCRE_NO_UTF8_CHECK,   PCRE_PARTIAL_SOFT,  and
+        PCRE_PARTIAL_HARD.
           PCRE_ANCHORED
-        The  PCRE_ANCHORED  option  limits pcre_exec() to matching at the first
+        The PCRE_ANCHORED option limits pcre_exec() to matching  at  the  first
-        matching position. If a pattern was  compiled  with  PCRE_ANCHORED,  or
+        matching  position.  If  a  pattern was compiled with PCRE_ANCHORED, or
-        turned  out to be anchored by virtue of its contents, it cannot be made
+        turned out to be anchored by virtue of its contents, it cannot be  made
         unachored at matching time.
+          PCRE_BSR_ANYCRLF
+          PCRE_BSR_UNICODE
+        These options (which are mutually exclusive) control what the \R escape
+        sequence matches. The choice is either to match only CR, LF,  or  CRLF,
+        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
+          PCRE_NEWLINE_ANYCRLF
+          PCRE_NEWLINE_ANY
+        These options override  the  newline  definition  that  was  chosen  or
+        defaulted  when the pattern was compiled. For details, see the descrip-
+        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,  PCRE_NEWLINE_ANYCRLF,  or PCRE_NEWLINE_ANY is
+        set, and a match attempt for an unanchored pattern fails when the  cur-
+        rent  position  is  at  a  CRLF  sequence,  and the pattern contains no
+        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
         This option specifies that first character of the subject string is not
-        the  beginning  of  a  line, so the circumflex metacharacter should not
+        the beginning of a line, so the  circumflex  metacharacter  should  not
-        match before it. Setting this without PCRE_MULTILINE (at compile  time)
+        match  before it. Setting this without PCRE_MULTILINE (at compile time)
-        causes  circumflex  never to match. This option affects only the behav-
+        causes circumflex never to match. This option affects only  the  behav-
         iour of the circumflex metacharacter. It does not affect \A.
           PCRE_NOTEOL
         This option specifies that the end of the subject string is not the end
-        of  a line, so the dollar metacharacter should not match it nor (except
+        of a line, so the dollar metacharacter should not match it nor  (except
-        in multiline mode) a newline immediately before it. Setting this  with-
+        in  multiline mode) a newline immediately before it. Setting this with-
         out PCRE_MULTILINE (at compile time) causes dollar never to match. This
-        option affects only the behaviour of the dollar metacharacter. It  does
+        option  affects only the behaviour of the dollar metacharacter. It does
         not affect \Z or \z.
           PCRE_NOTEMPTY
         An empty string is not considered to be a valid match if this option is
-        set. If there are alternatives in the pattern, they are tried.  If  all
+        set.  If  there are alternatives in the pattern, they are tried. If all
-        the  alternatives  match  the empty string, the entire match fails. For
+        the alternatives match the empty string, the entire  match  fails.  For
         example, if the pattern
           a?b?
-        is applied to a string not beginning with "a" or "b",  it  matches  the
+        is  applied  to  a  string not beginning with "a" or "b", it matches an
-        empty  string at the start of the subject. With PCRE_NOTEMPTY set, this
+        empty string at the start of the subject. With PCRE_NOTEMPTY set,  this
         match is not valid, so PCRE searches further into the string for occur-
         rences of "a" or "b".
-        Perl has no direct equivalent of PCRE_NOTEMPTY, but it does make a spe-
+          PCRE_NOTEMPTY_ATSTART
-        cial case of a pattern match of the empty  string  within  its  split()
-        function,  and  when  using  the /g modifier. It is possible to emulate
+        This is like PCRE_NOTEMPTY, except that an empty string match  that  is
-        Perl's behaviour after matching a null string by first trying the match
+        not  at  the  start  of  the  subject  is  permitted. If the pattern is
-        again at the same offset with PCRE_NOTEMPTY and PCRE_ANCHORED, and then
+        anchored, such a match can occur only if the pattern contains \K.
-        if that fails by advancing the starting offset (see below)  and  trying
-        an ordinary match again. There is some code that demonstrates how to do
+        Perl    has    no    direct    equivalent    of    PCRE_NOTEMPTY     or
-        this in the pcredemo.c sample program.
+        PCRE_NOTEMPTY_ATSTART,  but  it  does  make a special case of a pattern
+        match of the empty string within its split() function, and  when  using
+        the  /g  modifier.  It  is  possible  to emulate Perl's behaviour after
+        matching a null string by first trying the match again at the same off-
+        set  with  PCRE_NOTEMPTY_ATSTART  and  PCRE_ANCHORED,  and then if that
+        fails, by advancing the starting offset (see below) and trying an ordi-
+        nary  match  again. There is some code that demonstrates how to do this
+        in the pcredemo sample program. In the most general case, you  have  to
+        check  to  see  if the newline convention recognizes CRLF as a newline,
+        and if so, and the current character is CR followed by LF, advance  the
+        starting offset by two characters instead of one.
+          PCRE_NO_START_OPTIMIZE
+        There  are a number of optimizations that pcre_exec() uses at the start
+        of a match, in order to speed up the process. For  example,  if  it  is
+        known that an unanchored match must start with a specific character, it
+        searches the subject for that character, and fails  immediately  if  it
+        cannot  find  it,  without actually running the main matching function.
+        This means that a special item such as (*COMMIT) at the start of a pat-
+        tern  is  not  considered until after a suitable starting point for the
+        match has been found. When callouts or (*MARK) items are in use,  these
+        "start-up" optimizations can cause them to be skipped if the pattern is
+        never actually used. The start-up optimizations are in  effect  a  pre-
+        scan of the subject that takes place before the pattern is run.
+        The  PCRE_NO_START_OPTIMIZE option disables the start-up optimizations,
+        possibly causing performance to suffer,  but  ensuring  that  in  cases
+        where  the  result is "no match", the callouts do occur, and that items
+        such as (*COMMIT) and (*MARK) are considered at every possible starting
+        position  in  the  subject  string. If PCRE_NO_START_OPTIMIZE is set at
+        compile time, it cannot be unset at matching time.
+        Setting PCRE_NO_START_OPTIMIZE can change the  outcome  of  a  matching
+        operation.  Consider the pattern
+          (*COMMIT)ABC
+        When  this  is  compiled, PCRE records the fact that a match must start
+        with the character "A". Suppose the subject  string  is  "DEFABC".  The
+        start-up  optimization  scans along the subject, finds "A" and runs the
+        first match attempt from there. The (*COMMIT) item means that the  pat-
+        tern  must  match the current starting position, which in this case, it
+        does. However, if the same match  is  run  with  PCRE_NO_START_OPTIMIZE
+        set,  the  initial  scan  along the subject string does not happen. The
+        first match attempt is run starting  from  "D"  and  when  this  fails,
+        (*COMMIT)  prevents  any  further  matches  being tried, so the overall
+        result is "no match". If the pattern is studied,  more  start-up  opti-
+        mizations  may  be  used. For example, a minimum length for the subject
+        may be recorded. Consider the pattern
+          (*MARK:A)(X|Y)
+        The minimum length for a match is one  character.  If  the  subject  is
+        "ABC",  there  will  be  attempts  to  match "ABC", "BC", "C", and then
+        finally an empty string.  If the pattern is studied, the final  attempt
+        does  not take place, because PCRE knows that the subject is too short,
+        and so the (*MARK) is never encountered.  In this  case,  studying  the
+        pattern  does  not  affect the overall match result, which is still "no
+        match", but it does affect the auxiliary information that is returned.
           PCRE_NO_UTF8_CHECK
         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  or,  if  PCRE_PAR-
+        TIAL_HARD  is set and the problem is a truncated UTF-8 character at the
+        end of the subject, PCRE_ERROR_SHORTUTF8.  If  startoffset  contains  a
+        value  that does not point to the start of a UTF-8 character (or to the
+        end of the subject), 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
-Line 1533 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2222 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         do  this  for the second and subsequent calls to pcre_exec() if you are
         making repeated calls to find all  the  matches  in  a  single  subject
         string.  However,  you  should  be  sure  that the value of startoffset
-        points to the start of a UTF-8 character.  When  PCRE_NO_UTF8_CHECK  is
+        points to the start of a UTF-8 character (or the end of  the  subject).
-        set,  the  effect of passing an invalid UTF-8 string as a subject, or a
+        When  PCRE_NO_UTF8_CHECK is set, the effect of passing an invalid UTF-8
-        value of startoffset that does not point to the start of a UTF-8  char-
+        string as a subject or an invalid value of  startoffset  is  undefined.
-        acter, is undefined. Your program may crash.
+        Your program may crash.
-          PCRE_PARTIAL
+          PCRE_PARTIAL_HARD
+          PCRE_PARTIAL_SOFT
-        This  option  turns  on  the  partial  matching feature. If the subject
-        string fails to match the pattern, but at some point during the  match-
+        These  options turn on the partial matching feature. For backwards com-
-        ing  process  the  end of the subject was reached (that is, the subject
+        patibility, PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A  partial
-        partially matches the pattern and the failure to  match  occurred  only
+        match  occurs if the end of the subject string is reached successfully,
-        because  there were not enough subject characters), pcre_exec() returns
+        but there are not enough subject characters to complete the  match.  If
-        PCRE_ERROR_PARTIAL instead of PCRE_ERROR_NOMATCH. When PCRE_PARTIAL  is
+        this happens when PCRE_PARTIAL_SOFT (but not PCRE_PARTIAL_HARD) is set,
-        used,  there  are restrictions on what may appear in the pattern. These
+        matching continues by testing any remaining alternatives.  Only  if  no
-        are discussed in the pcrepartial documentation.
+        complete  match  can be found is PCRE_ERROR_PARTIAL returned instead of
+        PCRE_ERROR_NOMATCH. In other words,  PCRE_PARTIAL_SOFT  says  that  the
+        caller  is  prepared to handle a partial match, but only if no complete
+        match can be found.
+        If PCRE_PARTIAL_HARD is set, it overrides  PCRE_PARTIAL_SOFT.  In  this
+        case,  if  a  partial  match  is found, pcre_exec() immediately returns
+        PCRE_ERROR_PARTIAL, without  considering  any  other  alternatives.  In
+        other  words, when PCRE_PARTIAL_HARD is set, a partial match is consid-
+        ered to be more important that an alternative complete match.
+        In both cases, the portion of the string that was  inspected  when  the
+        partial match was found is set as the first matching string. There is a
+        more detailed discussion of partial and  multi-segment  matching,  with
+        examples, 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 bytes) in length, and a starting byte offset in startoffset.
-        mode, the byte offset must point to the start  of  a  UTF-8  character.
+        If  this  is  negative  or  greater  than  the  length  of the subject,
-        Unlike  the  pattern string, the subject may contain binary zero bytes.
+        pcre_exec() returns PCRE_ERROR_BADOFFSET. When the starting  offset  is
-        When the starting offset is zero, the search for a match starts at  the
+        zero,  the  search  for a match starts at the beginning of the subject,
-        beginning of the subject, and this is by far the most common case.
+        and this is by far the most common case. In UTF-8 mode, the byte offset
+        must  point  to  the start of a UTF-8 character (or the end of the sub-
+        ject). Unlike the pattern string, the subject may contain  binary  zero
+        bytes.
         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-
-Line 1577 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2283 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         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,
+        Finding all the matches in a subject is tricky  when  the  pattern  can
+        match an empty string. It is possible to emulate Perl's /g behaviour by
+        first  trying  the  match  again  at  the   same   offset,   with   the
+        PCRE_NOTEMPTY_ATSTART  and  PCRE_ANCHORED  options,  and  then  if that
+        fails, advancing the starting  offset  and  trying  an  ordinary  match
+        again. There is some code that demonstrates how to do this in the pcre-
+        demo sample program. In the most general case, you have to check to see
+        if  the newline convention recognizes CRLF as a newline, and if so, and
+        the current character is CR followed by LF, advance the starting offset
+        by two characters instead of one.
+        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 integers
-        offsets whose address is passed in ovector. The number of  elements  in
+        whose  address is passed in ovector. The number of elements in the vec-
-        the  vector is passed in ovecsize, which must be a non-negative number.
+        tor is passed in ovecsize, which must be a non-negative  number.  Note:
-        Note: this argument is NOT the size of ovector in bytes.
+        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  number 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-
+        element  of  each pair is set to the byte offset of the first character
-        string,  and  the  second  is  set to the offset of the first character
+        in a substring, and the second is set to the byte offset of  the  first
-        after the end of a substring. The  first  pair,  ovector[0]  and  ovec-
+        character  after  the end of a substring. Note: these values are always
-        tor[1],  identify  the  portion  of  the  subject string matched by the
+        byte offsets, even in UTF-8 mode. They are not character counts.
-        entire pattern. The next pair is used for the first  capturing  subpat-
-        tern,  and  so  on.  The value returned by pcre_exec() is the number of
+        The first pair of integers, ovector[0]  and  ovector[1],  identify  the
-        pairs that have been set. If there are no  capturing  subpatterns,  the
+        portion  of  the subject string matched by the entire pattern. The next
-        return  value  from  a  successful match is 1, indicating that just the
+        pair is used for the first capturing subpattern, and so on.  The  value
-        first pair of offsets has been set.
+        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
-        Some convenience functions are provided  for  extracting  the  captured
+        returned  value is 3. If there are no capturing subpatterns, the return
-        substrings  as  separate  strings. These are described in the following
+        value from a successful match is 1, indicating that just the first pair
-        section.
+        of offsets has been set.
-        It is possible for an 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)
-        subpatterns  1 and 3 are matched, but 2 is not. When this happens, both
-        offset values corresponding to the unused subpattern are set to -1.
         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. If the substring offsets are  not  of
-        sets are not of interest, pcre_exec() may be called with ovector passed
+        interest,  pcre_exec()  may  be  called with ovector passed as NULL and
-        as  NULL  and  ovecsize  as zero. However, if the pattern contains back
+        ovecsize as zero. However, if the pattern contains back references  and
-        references and the ovector is not big enough to  remember  the  related
+        the  ovector is not big enough to remember the related substrings, PCRE
-        substrings,  PCRE has to get additional memory for use during matching.
+        has to get additional memory for use during matching. Thus it  is  usu-
-        Thus it is usually advisable to supply an ovector.
+        ally advisable to supply an ovector.
-        Note that pcre_info() can be used to find out how many  capturing  sub-
+        The pcre_fullinfo() function can be used to find out how many capturing
-        patterns there are in a compiled pattern. The smallest size for ovector
+        subpatterns there are in a compiled  pattern.  The  smallest  size  for
-        that will allow for n captured substrings, in addition to  the  offsets
+        ovector  that  will allow for n captured substrings, in addition to the
-        of the substring matched by the whole pattern, is (n+1)*3.
+        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
+        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
+        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-
+        sponding to unused subpatterns are set to -1.
+        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
+        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
+        capturing  subpattern  number  is 1, and the offsets for for the second
+        and third capturing subpatterns (assuming the vector is  large  enough,
+        of course) are set to -1.
+        Note: Elements of ovector that do not correspond to capturing parenthe-
+        ses in the pattern are never changed. That is, if a pattern contains  n
+        capturing parentheses, no more than ovector[0] to ovector[2n+1] are set
+        by pcre_exec(). The other elements retain whatever values  they  previ-
+        ously had.
-    Return values from pcre_exec()
+        Some  convenience  functions  are  provided for extracting the captured
+        substrings as separate strings. These are described below.
-        If  pcre_exec()  fails, it returns a negative number. The following are
+    Error return values from pcre_exec()
+        If pcre_exec() fails, it returns a negative number. The  following  are
         defined in the header file:
           PCRE_ERROR_NOMATCH        (-1)
-Line 1655 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2390 
 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 1664 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2399 
 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_NODE   (-5)
+          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.
+        This error is also given if pcre_stack_malloc() fails  in  pcre_exec().
+        This  can happen only when PCRE has been compiled with --disable-stack-
+        for-recursion.
           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  recursion  and backtracking limit, as specified by the match_limit
+        The backtracking limit, as specified by  the  match_limit  field  in  a
-        field in a pcre_extra structure (or defaulted)  was  reached.  See  the
+        pcre_extra  structure  (or  defaulted) was reached. See the description
-        description above.
+        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.
+        subject.   However,  if  PCRE_PARTIAL_HARD  is set and the problem is a
+        truncated UTF-8 character at the end of the subject,  PCRE_ERROR_SHORT-
+        UTF8 is used instead.
           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.
+        ter or the end of the subject.
           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
+        This code is no longer in  use.  It  was  formerly  returned  when  the
-        items that are not supported for partial matching. See the  pcrepartial
+        PCRE_PARTIAL  option  was used with a compiled pattern containing items
-        documentation for details of partial matching.
+        that were  not  supported  for  partial  matching.  From  release  8.00
+        onwards, there are no restrictions on partial matching.
           PCRE_ERROR_INTERNAL       (-14)
-Line 1731 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2473 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           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
+        description above.
+          PCRE_ERROR_BADNEWLINE     (-23)
+        An invalid combination of PCRE_NEWLINE_xxx options was given.
+          PCRE_ERROR_BADOFFSET      (-24)
+        The value of startoffset was negative or greater than the length of the
+        subject, that is, the value in length.
+          PCRE_ERROR_SHORTUTF8      (-25)
+        The  subject  string ended with an incomplete (truncated) UTF-8 charac-
+        ter, and the PCRE_PARTIAL_HARD option was  set.  Without  this  option,
+        PCRE_ERROR_BADUTF8 is returned in this situation.
+        Error numbers -16 to -20 and -22 are not used by pcre_exec().
  EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
-Line 1753 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
+Line 2518 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
         string_list() are provided for extracting captured substrings  as  new,
         separate,  zero-terminated strings. These functions identify substrings
         by number. The next section describes functions  for  extracting  named
-        substrings.  A  substring  that  contains  a  binary  zero is correctly
+        substrings.
-        extracted and has a further zero added on the end, but  the  result  is
-        not, of course, a C string.
+        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
+        string.   However,  you  can  process such a string by referring to the
+        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
+        end of the final string is not independently indicated.
         The  first  three  arguments  are the same for all three of these func-
         tions: subject is the subject string that has  just  been  successfully
-Line 1775 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
+Line 2546 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
         buffersize, while for pcre_get_substring() a new  block  of  memory  is
         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 terminating zero, or one of
+        the terminating zero, or one of these error codes:
           PCRE_ERROR_NOMEMORY       (-6)
-Line 1791 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
+Line 2562 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
         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 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
+        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  which  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 1830 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
+Line 2602 
 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+)...
-        the number of the subpattern called "xxx" is 2. You can find the number
+        the number of the subpattern called "xxx" is 2. If the name is known to
-        from the name by calling pcre_get_stringnumber(). The first argument is
+        be unique (PCRE_DUPNAMES was not set), you can find the number from the
-        the  compiled  pattern,  and  the  second is the name. The yield of the
+        name by calling pcre_get_stringnumber(). The first argument is the com-
-        function is the subpattern number, or  PCRE_ERROR_NOSUBSTRING  (-7)  if
+        piled pattern, and the second is the name. The yield of the function is
-        there is no subpattern of that name.
+        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
-Line 1858 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
+Line 2631 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
         These functions call pcre_get_stringnumber(), and if it succeeds,  they
         then  call  pcre_copy_substring() or pcre_get_substring(), as appropri-
-        ate.
+        ate. NOTE: If PCRE_DUPNAMES is set and there are duplicate  names,  the
+        behaviour may not be what you want (see the next section).
+        Warning: If the pattern uses the (?| feature to set up multiple subpat-
+        terns with the same number, as described in the  section  on  duplicate
+        subpattern  numbers  in  the  pcrepattern page, you cannot use names to
+        distinguish the different subpatterns, because names are  not  included
+        in  the compiled code. The matching process uses only numbers. For this
+        reason, the use of different names for subpatterns of the  same  number
+        causes an error at compile time.
+ 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
+        subpatterns are not required to be unique. (Duplicate names are  always
+        allowed  for subpatterns with the same number, created by using the (?|
+        feature. Indeed, if such subpatterns are named, they  are  required  to
+        use the same names.)
+        Normally, patterns with duplicate names are such that in any one match,
+        only one of the named subpatterns participates. An example is shown  in
+        the pcrepattern documentation.
+        When    duplicates   are   present,   pcre_copy_named_substring()   and
+        pcre_get_named_substring() return the first substring corresponding  to
+        the  given  name  that  is set. If none are set, PCRE_ERROR_NOSUBSTRING
+        (-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
+        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
+        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
+        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-
+        tion entitled Information about a  pattern.   Given  all  the  relevant
+        entries  for the name, you can extract each of their numbers, and hence
+        the captured data, if any.
  FINDING ALL POSSIBLE MATCHES
-Line 1887 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2704 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
              int *workspace, int wscount);
         The  function  pcre_dfa_exec()  is  called  to  match  a subject string
-        against a compiled pattern, using a "DFA" matching algorithm. This  has
+        against a compiled pattern, using a matching algorithm that  scans  the
-        different  characteristics to the normal algorithm, and is not compati-
+        subject  string  just  once, and does not backtrack. This has different
-        ble with Perl. Some of the features of PCRE patterns are not supported.
+        characteristics to the normal algorithm, and  is  not  compatible  with
-        Nevertheless, there are times when this kind of matching can be useful.
+        Perl.  Some  of the features of PCRE patterns are not supported. Never-
-        For a discussion of the two matching algorithms, see  the  pcrematching
+        theless, there are times when this kind of matching can be useful.  For
-        documentation.
+        a  discussion  of  the  two matching algorithms, and a list of features
+        that pcre_dfa_exec() does not support, see the pcrematching  documenta-
+        tion.
         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-
-Line 1904 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2723 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
         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
-        lot of possible matches.
+        lot of potential matches.
-        Here is an example of a simple call to pcre_exec():
+        Here is an example of a simple call to pcre_dfa_exec():
           int rc;
           int ovector[10];
           int wspace[20];
-          rc = pcre_exec(
+          rc = pcre_dfa_exec(
             re,             /* result of pcre_compile() */
             NULL,           /* we didn't study the pattern */
             "some string",  /* the subject string */
-Line 1926 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2745 
 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
-        zero. The only bits that may be  set  are  PCRE_ANCHORED,  PCRE_NOTBOL,
+        zero. The only bits  that  may  be  set  are  PCRE_ANCHORED,  PCRE_NEW-
-        PCRE_NOTEOL,     PCRE_NOTEMPTY,    PCRE_NO_UTF8_CHECK,    PCRE_PARTIAL,
+        LINE_xxx,        PCRE_NOTBOL,        PCRE_NOTEOL,        PCRE_NOTEMPTY,
-        PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All  but  the  last  three  of
+        PCRE_NOTEMPTY_ATSTART,      PCRE_NO_UTF8_CHECK,       PCRE_BSR_ANYCRLF,
-        these  are  the  same  as  for pcre_exec(), so their description is not
+        PCRE_BSR_UNICODE,  PCRE_NO_START_OPTIMIZE, PCRE_PARTIAL_HARD, PCRE_PAR-
-        repeated here.
+        TIAL_SOFT, PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART.  All but  the  last
+        four  of  these  are  exactly  the  same  as  for pcre_exec(), so their
-          PCRE_PARTIAL
+        description is not repeated here.
-        This has the same general effect as it does for  pcre_exec(),  but  the
+          PCRE_PARTIAL_HARD
-        details   are   slightly   different.  When  PCRE_PARTIAL  is  set  for
+          PCRE_PARTIAL_SOFT
-        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
+        These have the same general effect as they do for pcre_exec(), but  the
-        been no complete matches, but there is still at least one matching pos-
+        details  are  slightly  different.  When  PCRE_PARTIAL_HARD  is set for
-        sibility.  The portion of the string that provided the partial match is
+        pcre_dfa_exec(), it returns PCRE_ERROR_PARTIAL if the end of  the  sub-
-        set as the first matching string.
+        ject  is  reached  and there is still at least one matching possibility
+        that requires additional characters. This happens even if some complete
+        matches have also been found. When PCRE_PARTIAL_SOFT is set, the return
+        code PCRE_ERROR_NOMATCH is converted into 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 possibility. The  portion  of  the
+        string  that  was inspected when the longest partial match was found is
+        set as the first matching string  in  both  cases.   There  is  a  more
+        detailed  discussion  of partial and multi-segment matching, with exam-
+        ples, in the pcrepartial documentation.
           PCRE_DFA_SHORTEST
         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 DFA
+        stop as soon as it has found one match. Because of the way the alterna-
-        algorithm works, this is necessarily the shortest possible match at the
+        tive algorithm works, this is necessarily the shortest  possible  match
-        first possible matching point in the subject string.
+        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() returns a partial match, it is possible to call it
-        returns a partial match, it is possible to call it  again,  with  addi-
+        again, with additional subject characters, and have  it  continue  with
-        tional  subject  characters,  and have it continue with the same match.
+        the  same match. The PCRE_DFA_RESTART option requests this action; when
-        The PCRE_DFA_RESTART option requests this action; when it is  set,  the
+        it is set, the workspace and wscount options must  reference  the  same
-        workspace  and wscount options must reference the same vector as before
+        vector  as  before  because data about the match so far is left in them
-        because data about the match so far is left in  them  after  a  partial
+        after a partial match. There is more discussion of this facility in the
-        match.  There  is  more  discussion of this facility in the pcrepartial
+        pcrepartial documentation.
-        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 1980 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2807 
 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. All
+        the offset to the start, and the second is the offset to  the  end.  In
-        the strings have the same start offset. (Space could have been saved by
+        fact,  all  the  strings  have the same start offset. (Space could have
-        giving  this only once, but it was decided to retain some compatibility
+        been saved by giving this only once, but it was decided to retain  some
-        with the way pcre_exec() returns data, even though the meaning  of  the
+        compatibility  with  the  way pcre_exec() returns data, even though the
-        strings is different.)
+        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 in
+        This return is given if pcre_dfa_exec()  encounters  a  condition  item
-        a pattern that uses a back reference for the  condition.  This  is  not
+        that  uses  a back reference for the condition, or a test for recursion
-        supported.
+        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.
- Last updated: 16 May 2005
- Copyright (c) 1997-2005 University of Cambridge.
- -----------------------------------------------------------------------------
+ SEE ALSO
+        pcrebuild(3), pcrecallout(3), pcrecpp(3)(3), pcrematching(3),  pcrepar-
+        tial(3), pcreposix(3), pcreprecompile(3), pcresample(3), pcrestack(3).
+ AUTHOR
+        Philip Hazel
+        University Computing Service
+        Cambridge CB2 3QH, England.
+ REVISION
+        Last updated: 21 November 2010
+        Copyright (c) 1997-2010 University of Cambridge.
+ ------------------------------------------------------------------------------
+ PCRECALLOUT(3)                                                  PCRECALLOUT(3)
  NAME
-Line 2057 
 PCRE CALLOUTS
+Line 2902 
 PCRE CALLOUTS
         default value is zero.  For  example,  this  pattern  has  two  callout
         points:
-          (?C1)eabc(?C2)def
+          (?C1)abc(?C2)def
-        If  the  PCRE_AUTO_CALLOUT  option  bit  is  set when pcre_compile() is
+        If  the  PCRE_AUTO_CALLOUT  option  bit  is  set when pcre_compile() or
-        called, PCRE automatically  inserts  callouts,  all  with  number  255,
+        pcre_compile2() is called, PCRE  automatically  inserts  callouts,  all
-        before  each  item in the pattern. For example, if PCRE_AUTO_CALLOUT is
+        with  number  255,  before  each  item  in the pattern. For example, if
-        used with the pattern
+        PCRE_AUTO_CALLOUT is used with the pattern
           A(\d{2}|--)
-Line 2081 
 PCRE CALLOUTS
+Line 2926 
 PCRE CALLOUTS
  MISSING CALLOUTS
         You  should  be  aware  that,  because of optimizations in the way PCRE
-        matches patterns, callouts sometimes do not happen. For example, if the
+        matches patterns by default, callouts  sometimes  do  not  happen.  For
-        pattern is
+        example, if the pattern is
           ab(?C4)cd
-Line 2091 
 MISSING CALLOUTS
+Line 2936 
 MISSING CALLOUTS
         ever  start,  and  the  callout is never reached. However, with "abyd",
         though the result is still no match, the callout is obeyed.
+        If the pattern is studied, PCRE knows the minimum length of a  matching
+        string,  and will immediately give a "no match" return without actually
+        running a match if the subject is not long enough, or,  for  unanchored
+        patterns, if it has been scanned far enough.
+        You  can disable these optimizations by passing the PCRE_NO_START_OPTI-
+        MIZE option to pcre_compile(), pcre_exec(), or pcre_dfa_exec(),  or  by
+        starting the pattern with (*NO_START_OPT). This slows down the matching
+        process, but does ensure that callouts such as the  example  above  are
+        obeyed.
  THE CALLOUT INTERFACE
-        During matching, when PCRE reaches a callout point, the external  func-
+        During  matching, when PCRE reaches a callout point, the external func-
-        tion  defined by pcre_callout is called (if it is set). This applies to
+        tion defined by pcre_callout is called (if it is set). This applies  to
-        both the pcre_exec() and the pcre_dfa_exec()  matching  functions.  The
+        both  the  pcre_exec()  and the pcre_dfa_exec() matching functions. The
-        only  argument  to  the callout function is a pointer to a pcre_callout
+        only argument to the callout function is a pointer  to  a  pcre_callout
         block. This structure contains the following fields:
           int          version;
-Line 2113 
 THE CALLOUT INTERFACE
+Line 2969 
 THE CALLOUT INTERFACE
           int          pattern_position;
           int          next_item_length;
-        The version field is an integer containing the version  number  of  the
+        The  version  field  is an integer containing the version number of the
-        block  format. The initial version was 0; the current version is 1. The
+        block format. The initial version was 0; the current version is 1.  The
-        version number will change again in future  if  additional  fields  are
+        version  number  will  change  again in future if additional fields are
         added, but the intention is never to remove any of the existing fields.
         The callout_number field contains the number of the  callout,  as  com-
-Line 2132 
 THE CALLOUT INTERFACE
+Line 2988 
 THE CALLOUT INTERFACE
         The subject and subject_length fields contain copies of the values that
         were passed to pcre_exec().
-        The start_match field contains the offset within the subject  at  which
+        The start_match field normally contains the offset within  the  subject
-        the  current match attempt started. If the pattern is not anchored, the
+        at  which  the  current  match  attempt started. However, if the escape
-        callout function may be called several times from the same point in the
+        sequence \K has been encountered, this value is changed to reflect  the
-        pattern for different starting points in the subject.
+        modified  starting  point.  If the pattern is not anchored, the callout
+        function may be called several times from the same point in the pattern
+        for different starting points in the subject.
         The  current_position  field  contains the offset within the subject of
         the current match pointer.
-Line 2180 
 RETURN VALUES
+Line 3038 
 RETURN VALUES
         zero, matching fails at the current point, but  the  testing  of  other
         matching possibilities goes ahead, just as if a lookahead assertion had
         failed. If the value is less than zero, the  match  is  abandoned,  and
-        pcre_exec() (or pcre_dfa_exec()) returns the negative value.
+        pcre_exec() or pcre_dfa_exec() returns the negative value.
         Negative   values   should   normally   be   chosen  from  the  set  of
         PCRE_ERROR_xxx values. In particular, PCRE_ERROR_NOMATCH forces a stan-
-Line 2188 
 RETURN VALUES
+Line 3046 
 RETURN VALUES
         reserved for use by callout functions; it will never be  used  by  PCRE
         itself.
- Last updated: 28 February 2005
- Copyright (c) 1997-2005 University of Cambridge.
+ AUTHOR
- -----------------------------------------------------------------------------
+        Philip Hazel
+        University Computing Service
+        Cambridge CB2 3QH, England.
+ REVISION
+        Last updated: 21 November 2010
+        Copyright (c) 1997-2010 University of Cambridge.
+ ------------------------------------------------------------------------------
+ PCRECOMPAT(3)                                                    PCRECOMPAT(3)
  NAME
         PCRE - Perl-compatible regular expressions
-Line 2202 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 3072 
 DIFFERENCES BETWEEN PCRE AND PERL
         This  document describes the differences in the ways that PCRE and Perl
         handle regular expressions. The differences  described  here  are  with
-        respect to Perl 5.8.
+        respect to Perl versions 5.10 and above.
-.  PCRE does not have full UTF-8 support. Details of what it does have
+.  PCRE has only a subset of Perl's UTF-8 and Unicode support. Details
-        are given in the section on UTF-8 support in the main pcre page.
+        of what it does have are given in the section on UTF-8 support  in  the
+        main pcre page.
 . PCRE does not allow repeat quantifiers on lookahead assertions. Perl
-        permits  them,  but they do not mean what you might think. For example,
+        permits them, but they do not mean what you might think.  For  example,
         (?!a){3} does not assert that the next three characters are not "a". It
         just asserts that the next character is not "a" three times.
-.  Capturing  subpatterns  that occur inside negative lookahead asser-
+. Capturing subpatterns that occur inside  negative  lookahead  asser-
-        tions are counted, but their entries in the offsets  vector  are  never
+        tions  are  counted,  but their entries in the offsets vector are never
-        set.  Perl sets its numerical variables from any such patterns that are
+        set. Perl sets its numerical variables from any such patterns that  are
         matched before the assertion fails to match something (thereby succeed-
-        ing),  but  only  if the negative lookahead assertion contains just one
+        ing), but only if the negative lookahead assertion  contains  just  one
         branch.
-. Though binary zero characters are supported in the  subject  string,
+.  Though  binary zero characters are supported in the subject string,
         they are not allowed in a pattern string because it is passed as a nor-
         mal C string, terminated by zero. The escape sequence \0 can be used in
         the pattern to represent a binary zero.
-.  The  following Perl escape sequences are not supported: \l, \u, \L,
+. The following Perl escape sequences are not supported: \l,  \u,  \L,
         \U, and \N. In fact these are implemented by Perl's general string-han-
-        dling  and are not part of its pattern matching engine. If any of these
+        dling and are not part of its pattern matching engine. If any of  these
         are encountered by PCRE, an error is generated.
-. The Perl escape sequences \p, \P, and \X are supported only if  PCRE
+.  The Perl escape sequences \p, \P, and \X are supported only if PCRE
-        is  built  with Unicode character property support. The properties that
+        is built with Unicode character property support. The  properties  that
-        can be tested with \p and \P are limited to the general category  prop-
+        can  be tested with \p and \P are limited to the general category prop-
-        erties such as Lu and Nd.
+        erties such as Lu and Nd, script names such as Greek or  Han,  and  the
+        derived  properties  Any  and  L&. PCRE does support the Cs (surrogate)
+        property, which Perl does not; the  Perl  documentation  says  "Because
+        Perl hides the need for the user to understand the internal representa-
+        tion of Unicode characters, there is no need to implement the  somewhat
+        messy concept of surrogates."
 . PCRE does support the \Q...\E escape for quoting substrings. Charac-
         ters in between are treated as literals.  This  is  slightly  different
-Line 2250 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 3126 
 DIFFERENCES BETWEEN PCRE AND PERL
         The  \Q...\E  sequence  is recognized both inside and outside character
         classes.
-. Fairly obviously, PCRE does not support the (?{code}) and (?p{code})
+. Fairly obviously, PCRE does not support the (?{code}) and (??{code})
-        constructions.  However,  there is support for recursive patterns using
+        constructions.  However,  there is support for recursive patterns. This
-        the non-Perl items (?R),  (?number),  and  (?P>name).  Also,  the  PCRE
+        is not available in Perl 5.8, but it is in Perl 5.10.  Also,  the  PCRE
         "callout"  feature allows an external function to be called during pat-
         tern matching. See the pcrecallout documentation for details.
-. There are some differences that are concerned with the  settings  of
+. Subpatterns that are called  recursively  or  as  "subroutines"  are
+        always  treated  as  atomic  groups  in  PCRE. This is like Python, but
+        unlike Perl. There is a discussion of an example that explains this  in
+        more  detail  in  the section on recursion differences from Perl in the
+        pcrepattern page.
+. There are some differences that are concerned with the settings  of
         captured  strings  when  part  of  a  pattern is repeated. For example,
         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's handling of duplicate subpattern numbers and duplicate sub-
-        ities:
+        pattern names is not as general as Perl's. This is a consequence of the
+        fact the PCRE works internally just with numbers, using an external ta-
-        (a) Although lookbehind assertions must  match  fixed  length  strings,
+        ble to translate between numbers and names. In  particular,  a  pattern
-        each alternative branch of a lookbehind assertion can match a different
+        such  as  (?|(?<a>A)|(?<b)B),  where the two capturing parentheses have
-        length of string. Perl requires them all to have the same length.
+        the same number but different names, is not supported,  and  causes  an
+        error  at compile time. If it were allowed, it would not be possible to
+        distinguish which parentheses matched, because both names map  to  cap-
+        turing subpattern number 1. To avoid this confusing situation, an error
+        is given at compile time.
+. Perl recognizes comments in some  places  that  PCRE  doesn't,  for
+        example, between the ( and ? at the start of a subpattern.
+. PCRE provides some extensions to the Perl regular expression facil-
+        ities.  Perl 5.10 includes new features that are not  in  earlier  ver-
+        sions  of  Perl, some of which (such as named parentheses) have been in
+        PCRE for some time. This list is with respect to Perl 5.10:
+        (a) Although lookbehind assertions in  PCRE  must  match  fixed  length
+        strings,  each alternative branch of a lookbehind assertion can match a
+        different length of string. Perl requires them all  to  have  the  same
+        length.
-        (b) If PCRE_DOLLAR_ENDONLY is set and PCRE_MULTILINE is not set, the  $
+        (b)  If PCRE_DOLLAR_ENDONLY is set and PCRE_MULTILINE is not set, the $
         meta-character matches only at the very end of the string.
         (c) If PCRE_EXTRA is set, a backslash followed by a letter with no spe-
-        cial meaning is faulted.
+        cial meaning is faulted. Otherwise, like Perl, the backslash is quietly
+        ignored.  (Perl can be made to issue a warning.)
         (d) If PCRE_UNGREEDY is set, the greediness of the  repetition  quanti-
         fiers is inverted, that is, by default they are not greedy, but if fol-
-Line 2281 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 3181 
 DIFFERENCES BETWEEN PCRE AND PERL
         (e) PCRE_ANCHORED can be used at matching time to force a pattern to be
         tried only at the first matching position in the subject string.
-        (f)  The PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NO_AUTO_CAP-
+        (f) The PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,
-        TURE options for pcre_exec() have no Perl equivalents.
+        and PCRE_NO_AUTO_CAPTURE options for pcre_exec() have no  Perl  equiva-
+        lents.
-        (g) The (?R), (?number), and (?P>name) constructs allows for  recursive
+        (g)  The  \R escape sequence can be restricted to match only CR, LF, or
-        pattern  matching  (Perl  can  do  this using the (?p{code}) construct,
+        CRLF by the PCRE_BSR_ANYCRLF option.
-        which PCRE cannot support.)
-        (h) PCRE supports named capturing substrings, using the Python  syntax.
+        (h) The callout facility is PCRE-specific.
-        (i)  PCRE  supports  the  possessive quantifier "++" syntax, taken from
+        (i) The partial matching facility is PCRE-specific.
-        Sun's Java package.
-        (j) The (R) condition, for testing recursion, is a PCRE extension.
+        (j) Patterns compiled by PCRE can be saved and re-used at a later time,
+        even on different hosts that have the other endianness.
-        (k) The callout facility is PCRE-specific.
+        (k)  The  alternative  matching function (pcre_dfa_exec()) matches in a
+        different way and is not Perl-compatible.
-        (l) The partial matching facility is PCRE-specific.
+        (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.
-        (m) Patterns compiled by PCRE can be saved and re-used at a later time,
-        even on different hosts that have the other endianness.
-        (n)  The  alternative  matching function (pcre_dfa_exec()) matches in a
+ AUTHOR
-        different way and is not Perl-compatible.
- Last updated: 28 February 2005
+        Philip Hazel
- Copyright (c) 1997-2005 University of Cambridge.
+        University Computing Service
- -----------------------------------------------------------------------------
+        Cambridge CB2 3QH, England.
+ REVISION
+        Last updated: 31 October 2010
+        Copyright (c) 1997-2010 University of Cambridge.
+ ------------------------------------------------------------------------------
+ PCREPATTERN(3)                                                  PCREPATTERN(3)
  NAME
         PCRE - Perl-compatible regular expressions
-Line 2317 
 NAME
+Line 3226 
 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. PCRE tries to match Perl syntax and
-        examples.  Jeffrey Friedl's "Mastering Regular Expressions",  published
+        semantics as closely as it can. PCRE  also  supports  some  alternative
-        by  O'Reilly, covers regular expressions in great detail. This descrip-
+        regular  expression  syntax (which does not conflict with the Perl syn-
-        tion of PCRE's regular expressions is intended as reference material.
+        tax) in order to provide some compatibility with regular expressions in
+        Python, .NET, and Oniguruma.
+        Perl's  regular expressions are described in its own documentation, and
+        regular expressions in general are covered in a number of  books,  some
+        of  which  have  copious  examples. 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
-        this, you must build PCRE to  include  UTF-8  support,  and  then  call
+        this, PCRE must be built to include UTF-8 support, and  you  must  call
-        pcre_compile()  with  the  PCRE_UTF8  option.  How this affects pattern
+        pcre_compile()  or  pcre_compile2() with the PCRE_UTF8 option. There is
-        matching is mentioned in several places below. There is also a  summary
+        also a special sequence that can be given at the start of a pattern:
-        of  UTF-8  features  in  the  section on UTF-8 support in the main pcre
-        page.
+          (*UTF8)
+        Starting a pattern with this sequence  is  equivalent  to  setting  the
+        PCRE_UTF8  option.  This  feature  is  not Perl-compatible. How setting
+        UTF-8 mode affects pattern matching  is  mentioned  in  several  places
+        below.  There  is  also  a  summary of UTF-8 features in the section on
+        UTF-8 support in the main pcre page.
+        Another special sequence that may appear at the start of a  pattern  or
+        in combination with (*UTF8) is:
-        The remainder of this document discusses the  patterns  that  are  sup-
+          (*UCP)
-        ported  by  PCRE when its main matching function, pcre_exec(), is used.
-        From  release  6.0,   PCRE   offers   a   second   matching   function,
+        This  has  the  same  effect  as setting the PCRE_UCP option: it causes
-        pcre_dfa_exec(),  which matches using a different algorithm that is not
+        sequences such as \d and \w to  use  Unicode  properties  to  determine
-        Perl-compatible. The advantages and disadvantages  of  the  alternative
+        character types, instead of recognizing only characters with codes less
-        function, and how it differs from the normal function, are discussed in
+        than 128 via a lookup table.
-        the pcrematching page.
+        If a pattern starts with (*NO_START_OPT), it has  the  same  effect  as
+        setting the PCRE_NO_START_OPTIMIZE option either at compile or matching
+        time. There are also some more of these special sequences that are con-
+        cerned with the handling of newlines; they are described below.
+        The  remainder  of  this  document discusses the patterns that are sup-
+        ported by PCRE when its main matching function, pcre_exec(),  is  used.
+        From   release   6.0,   PCRE   offers   a   second  matching  function,
+        pcre_dfa_exec(), which matches using a different algorithm that is  not
+        Perl-compatible. Some of the features discussed below are not available
+        when pcre_dfa_exec() is used. The advantages and disadvantages  of  the
+        alternative  function, and how it differs from the normal function, are
+        discussed in the pcrematching page.
+ NEWLINE CONVENTIONS
+        PCRE supports five different conventions for indicating line breaks  in
+        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()  or
+        pcre_compile2().  For example, on a Unix system where LF is the default
+        newline sequence, the pattern
+          (*CR)a.b
+        changes the convention to CR. That pattern matches "a\nb" because LF is
+        no  longer  a  newline. Note that these special settings, which are not
+        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 affects the interpretation of the dot  metachar-
+        acter  when  PCRE_DOTALL is not set, and also the behaviour of \N. How-
+        ever, it does not affect  what  the  \R  escape  sequence  matches.  By
+        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 setting can be com-
+        bined with a change of newline convention.
+ CHARACTERS AND METACHARACTERS
         A regular expression is a pattern that is  matched  against  a  subject
         string  from  left  to right. Most characters stand for themselves in a
-Line 2364 
 PCRE REGULAR EXPRESSION DETAILS
+Line 3345 
 PCRE REGULAR EXPRESSION DETAILS
         There are two different sets of metacharacters: those that  are  recog-
         nized  anywhere in the pattern except within square brackets, and those
-        that are recognized in square brackets. Outside  square  brackets,  the
+        that are recognized within square brackets.  Outside  square  brackets,
-        metacharacters are as follows:
+        the metacharacters are as follows:
           \      general escape character with several uses
           ^      assert start of string (or line, in multiline mode)
-Line 2393 
 PCRE REGULAR EXPRESSION DETAILS
+Line 3374 
 PCRE REGULAR EXPRESSION DETAILS
                    syntax)
           ]      terminates the character class
-        The following sections describe the use of each of the  metacharacters.
+        The following sections describe the use of each of the metacharacters.
  BACKSLASH
         The backslash character has several uses. Firstly, if it is followed by
-        a non-alphanumeric character, it takes away any  special  meaning  that
+        a character that is not a number or a letter, it takes away any special
-        character  may  have.  This  use  of  backslash  as an escape character
+        meaning that character may have. This use of  backslash  as  an  escape
-        applies both inside and outside character classes.
+        character applies both inside and outside character classes.
-        For example, if you want to match a * character, you write  \*  in  the
+        For  example,  if  you want to match a * character, you write \* in the
-        pattern.   This  escaping  action  applies whether or not the following
+        pattern.  This escaping action applies whether  or  not  the  following
-        character would otherwise be interpreted as a metacharacter, so  it  is
+        character  would  otherwise be interpreted as a metacharacter, so it is
-        always  safe  to  precede  a non-alphanumeric with backslash to specify
+        always safe to precede a non-alphanumeric  with  backslash  to  specify
-        that it stands for itself. In particular, if you want to match a  back-
+        that  it stands for itself. In particular, if you want to match a back-
         slash, you write \\.
-        If  a  pattern is compiled with the PCRE_EXTENDED option, whitespace in
+        In UTF-8 mode, only ASCII numbers and letters have any special  meaning
-        the pattern (other than in a character class) and characters between  a
+        after  a  backslash.  All  other characters (in particular, those whose
-        # outside a character class and the next newline character are ignored.
+        codepoints are greater than 127) are treated as literals.
-        An escaping backslash can be used to include a whitespace or #  charac-
-        ter as part of the pattern.
+        If a pattern is compiled with the PCRE_EXTENDED option,  whitespace  in
+        the  pattern (other than in a character class) and characters between a
-        If  you  want  to remove the special meaning from a sequence of charac-
+        # outside a character class and the next newline are ignored. An escap-
-        ters, you can do so by putting them between \Q and \E. This is  differ-
+        ing  backslash  can  be  used to include a whitespace or # character as
-        ent  from  Perl  in  that  $  and  @ are handled as literals in \Q...\E
+        part of the pattern.
-        sequences in PCRE, whereas in Perl, $ and @ cause  variable  interpola-
+        If you want to remove the special meaning from a  sequence  of  charac-
+        ters,  you can do so by putting them between \Q and \E. This is differ-
+        ent from Perl in that $ and  @  are  handled  as  literals  in  \Q...\E
+        sequences  in  PCRE, whereas in Perl, $ and @ cause variable interpola-
         tion. Note the following examples:
           Pattern            PCRE matches   Perl matches
-Line 2429 
 BACKSLASH
+Line 3414 
 BACKSLASH
           \Qabc\$xyz\E       abc\$xyz       abc\$xyz
           \Qabc\E\$\Qxyz\E   abc$xyz        abc$xyz
-        The  \Q...\E  sequence  is recognized both inside and outside character
+        The \Q...\E sequence is recognized both inside  and  outside  character
-        classes.
+        classes.  An isolated \E that is not preceded by \Q is ignored.
     Non-printing characters
         A second use of backslash provides a way of encoding non-printing char-
-        acters  in patterns in a visible manner. There is no restriction on the
+        acters in patterns in a visible manner. There is no restriction on  the
-        appearance of non-printing characters, apart from the binary zero  that
+        appearance  of non-printing characters, apart from the binary zero that
-        terminates  a  pattern,  but  when  a pattern is being prepared by text
+        terminates a pattern, but when a pattern  is  being  prepared  by  text
-        editing, it is usually easier  to  use  one  of  the  following  escape
+        editing,  it  is  often  easier  to  use  one  of  the following escape
         sequences than the binary character it represents: