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

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-revision 358 by ph10,
Wed Jul  9 11:03:07 2008 UTC
+revision 453 by ph10,
Fri Sep 18 19:12:35 2009 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.
  -----------------------------------------------------------------------------
-Line 24 
 INTRODUCTION
+Line 25 
 INTRODUCTION
         tax items, and there is an option for  requesting  some  minor  changes
         that give better JavaScript compatibility.
-        The  current  implementation of PCRE (release 7.x) corresponds approxi-
+        The  current implementation of PCRE (release 8.xx) corresponds approxi-
         mately with Perl 5.10, including support for UTF-8 encoded strings  and
         Unicode general category properties. However, UTF-8 and Unicode support
         has to be explicitly enabled; it is not the default. The Unicode tables
-        correspond to Unicode release 5.0.0.
+        correspond to Unicode release 5.1.
         In  addition to the Perl-compatible matching function, PCRE contains an
         alternative matching function that matches the same  compiled  patterns
-Line 71 
 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
-Line 81 
 USER DOCUMENTATION
+Line 83 
 USER DOCUMENTATION
           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 90 
 USER DOCUMENTATION
+Line 93 
 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
           pcretest          description of the pcretest testing command
-Line 136 
 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 just strings of bytes.
-        If  you compile PCRE with UTF-8 support, but do not use it at run time,
+        If you compile PCRE with UTF-8 support, but do not use it at run  time,
-        the library will be a bit bigger, but the additional run time  overhead
+        the  library will be a bit bigger, but the additional run time overhead
         is limited to testing the PCRE_UTF8 flag occasionally, so should not be
         very big.
         If PCRE is built with Unicode character property support (which implies
-        UTF-8  support),  the  escape sequences \p{..}, \P{..}, and \X are sup-
+        UTF-8 support), the escape sequences \p{..}, \P{..}, and  \X  are  sup-
         ported.  The available properties that can be tested are limited to the
-        general  category  properties such as Lu for an upper case letter or Nd
+        general category properties such as Lu for an upper case letter  or  Nd
-        for a decimal number, the Unicode script names such as Arabic  or  Han,
+        for  a  decimal number, the Unicode script names such as Arabic or Han,
-        and  the  derived  properties  Any  and L&. A full list is given in the
+        and the derived properties Any and L&. A full  list  is  given  in  the
         pcrepattern documentation. Only the short names for properties are sup-
-        ported.  For example, \p{L} matches a letter. Its Perl synonym, \p{Let-
+        ported. For example, \p{L} matches a letter. Its Perl synonym,  \p{Let-
-        ter}, is not supported.  Furthermore,  in  Perl,  many  properties  may
+        ter},  is  not  supported.   Furthermore,  in Perl, many properties may
-        optionally  be  prefixed by "Is", for compatibility with Perl 5.6. PCRE
+        optionally be prefixed by "Is", for compatibility with Perl  5.6.  PCRE
         does not support this.
     Validity of UTF-8 strings
-        When you set the PCRE_UTF8 flag, the strings  passed  as  patterns  and
+        When  you  set  the  PCRE_UTF8 flag, the strings passed as patterns and
         subjects are (by default) checked for validity on entry to the relevant
-        functions. From release 7.3 of PCRE, the check is according  the  rules
+        functions.  From  release 7.3 of PCRE, the check is according the rules
-        of  RFC  3629, which are themselves derived from the Unicode specifica-
+        of RFC 3629, which are themselves derived from the  Unicode  specifica-
-        tion. Earlier releases of PCRE followed the rules of  RFC  2279,  which
+        tion.  Earlier  releases  of PCRE followed the rules of RFC 2279, which
-        allows  the  full range of 31-bit values (0 to 0x7FFFFFFF). The current
+        allows the full range of 31-bit values (0 to 0x7FFFFFFF).  The  current
         check allows only values in the range U+0 to U+10FFFF, excluding U+D800
         to U+DFFF.
-        The  excluded  code  points are the "Low Surrogate Area" of Unicode, of
+        The excluded code points are the "Low Surrogate Area"  of  Unicode,  of
-        which the Unicode Standard says this: "The Low Surrogate Area does  not
+        which  the Unicode Standard says this: "The Low Surrogate Area does not
-        contain  any  character  assignments,  consequently  no  character code
+        contain any  character  assignments,  consequently  no  character  code
         charts or namelists are provided for this area. Surrogates are reserved
-        for  use  with  UTF-16 and then must be used in pairs." The code points
+        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
+        that  are  encoded  by  UTF-16  pairs are available as independent code
-        points  in  the  UTF-8  encoding.  (In other words, the whole surrogate
+        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
+        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
+        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
+        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,
+        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-
+        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,
+        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
+        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.
+        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
+        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
+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
-. An unbraced hexadecimal escape sequence (such  as  \xb3)  matches  a
+.  An  unbraced  hexadecimal  escape sequence (such as \xb3) matches a
         two-byte UTF-8 character if the value is greater than 127.
-.  Octal  numbers  up to \777 are recognized, and match two-byte UTF-8
+. Octal numbers up to \777 are recognized, and  match  two-byte  UTF-8
         characters for values greater than \177.
-. Repeat quantifiers apply to complete UTF-8 characters, not to  indi-
+.  Repeat quantifiers apply to complete UTF-8 characters, not to indi-
         vidual bytes, for example: \x{100}{3}.
-.  The dot metacharacter matches one UTF-8 character instead of a sin-
+. The dot metacharacter matches one UTF-8 character instead of a  sin-
         gle byte.
-. The escape sequence \C can be used to match a single byte  in  UTF-8
+.  The  escape sequence \C can be used to match a single byte in UTF-8
-        mode,  but  its  use can lead to some strange effects. This facility is
+        mode, but its use can lead to some strange effects.  This  facility  is
         not available in the alternative matching function, pcre_dfa_exec().
-. The character escapes \b, \B, \d, \D, \s, \S, \w, and  \W  correctly
+.  The  character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly
-        test  characters of any code value, but the characters that PCRE recog-
+        test characters of any code value, but the characters that PCRE  recog-
-        nizes as digits, spaces, or word characters  remain  the  same  set  as
+        nizes  as  digits,  spaces,  or  word characters remain the same set as
         before, all with values less than 256. This remains true even when PCRE
-        includes Unicode property support, because to do otherwise  would  slow
+        includes  Unicode  property support, because to do otherwise would slow
-        down  PCRE in many common cases. If you really want to test for a wider
+        down PCRE in many common cases. If you really want to test for a  wider
-        sense of, say, "digit", you must use Unicode  property  tests  such  as
+        sense  of,  say,  "digit",  you must use Unicode property tests such as
-        \p{Nd}.
+        \p{Nd}. Note that this also applies to \b, because  it  is  defined  in
+        terms of \w and \W.
 .  Similarly,  characters that match the POSIX named character classes
         are all low-valued characters.
-Line 258 
 AUTHOR
+Line 263 
 AUTHOR
  REVISION
-        Last updated: 12 April 2008
+        Last updated: 01 September 2009
-        Copyright (c) 1997-2008 University of Cambridge.
+        Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREBUILD(3)                                                      PCREBUILD(3)
-Line 277 
 PCRE BUILD-TIME OPTIONS
+Line 282 
 PCRE BUILD-TIME OPTIONS
         script,  where the optional features are selected or deselected by pro-
         viding options to configure before running the make  command.  However,
         the  same  options  can be selected in both Unix-like and non-Unix-like
-        environments using the GUI facility of  CMakeSetup  if  you  are  using
+        environments using the GUI facility of cmake-gui if you are using CMake
-        CMake instead of configure to build PCRE.
+        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
+        ones  such  as  the  selection  of  the  installation directory) can be
         obtained by running
           ./configure --help
-        The  following  sections  include  descriptions  of options whose names
+        The following sections include  descriptions  of  options  whose  names
         begin with --enable or --disable. These settings specify changes to the
-        defaults  for  the configure command. Because of the way that configure
+        defaults for the configure command. Because of the way  that  configure
-        works, --enable and --disable always come in pairs, so  the  complemen-
+        works,  --enable  and --disable always come in pairs, so the complemen-
-        tary  option always exists as well, but as it specifies the default, it
+        tary option always exists as well, but as it specifies the default,  it
         is not described.
-Line 307 
 C++ SUPPORT
+Line 317 
 C++ SUPPORT
  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
+        to  the  configure  command.  Of  itself, this does not make PCRE treat
-        strings  as UTF-8. As well as compiling PCRE with this option, you also
+        strings as UTF-8. As well as compiling PCRE with this option, you  also
-        have have to set the PCRE_UTF8 option when you call the  pcre_compile()
+        have  have to set the PCRE_UTF8 option when you call the pcre_compile()
         function.
+        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
-        UTF-8  support allows PCRE to process character values greater than 255
+        UTF-8 support allows PCRE to process character values greater than  255
-        in the strings that it handles. On its own, however, it does  not  pro-
+        in  the  strings that it handles. On its own, however, it does not pro-
         vide any facilities for accessing the properties of such characters. If
-        you want to be able to use the pattern escapes \P, \p,  and  \X,  which
+        you  want  to  be able to use the pattern escapes \P, \p, and \X, which
         refer to Unicode character properties, you must add
           --enable-unicode-properties
-        to  the configure command. This implies UTF-8 support, even if you have
+        to the configure command. This implies UTF-8 support, even if you  have
         not explicitly requested it.
-        Including Unicode property support adds around 30K  of  tables  to  the
+        Including  Unicode  property  support  adds around 30K of tables to the
-        PCRE  library.  Only  the general category properties such as Lu and Nd
+        PCRE library. Only the general category properties such as  Lu  and  Nd
         are supported. Details are given in the pcrepattern documentation.
  CODE VALUE OF NEWLINE
-        By default, PCRE interprets character 10 (linefeed, LF)  as  indicating
+        By  default,  PCRE interprets the linefeed (LF) character as indicating
-        the  end  of  a line. This is the normal newline character on Unix-like
+        the end of a line. This is the normal newline  character  on  Unix-like
-        systems. You can compile PCRE to use character 13 (carriage return, CR)
+        systems.  You  can compile PCRE to use carriage return (CR) instead, by
-        instead, by adding
+        adding
           --enable-newline-is-cr
-        to  the  configure  command.  There  is  also  a --enable-newline-is-lf
+        to the  configure  command.  There  is  also  a  --enable-newline-is-lf
         option, which explicitly specifies linefeed as the newline character.
         Alternatively, you can specify that line endings are to be indicated by
-Line 356 
 CODE VALUE OF NEWLINE
+Line 372 
 CODE VALUE OF NEWLINE
           --enable-newline-is-anycrlf
-        which  causes  PCRE  to recognize any of the three sequences CR, LF, or
+        which causes PCRE to recognize any of the three sequences  CR,  LF,  or
         CRLF as indicating a line ending. Finally, a fifth option, specified by
           --enable-newline-is-any
-Line 516 
 USING EBCDIC CODE
+Line 532 
 USING EBCDIC CODE
         to the configure command. This setting implies --enable-rebuild-charta-
         bles. You should only use it if you know that  you  are  in  an  EBCDIC
-        environment (for example, an IBM mainframe operating system).
+        environment  (for  example,  an  IBM  mainframe  operating system). The
+        --enable-ebcdic option is incompatible with --enable-utf8.
  PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT
-Line 529 
 PCREGREP OPTIONS FOR COMPRESSED FILE SUP
+Line 546 
 PCREGREP OPTIONS FOR COMPRESSED FILE SUP
           --enable-pcregrep-libbz2
         to the configure command. These options naturally require that the rel-
-        evant libraries are installed on your system. Configuration  will  fail
+        evant  libraries  are installed on your system. Configuration will fail
         if they are not.
-Line 539 
 PCRETEST OPTION FOR LIBREADLINE SUPPORT
+Line 556 
 PCRETEST OPTION FOR LIBREADLINE SUPPORT
           --enable-pcretest-libreadline
-        to  the  configure  command,  pcretest  is  linked with the libreadline
+        to the configure command,  pcretest  is  linked  with  the  libreadline
-        library, and when its input is from a terminal, it reads it  using  the
+        library,  and  when its input is from a terminal, it reads it using the
         readline() function. This provides line-editing and history facilities.
         Note that libreadline is GPL-licenced, so if you distribute a binary of
         pcretest linked in this way, there may be licensing issues.
-        Setting  this  option  causes  the -lreadline option to be added to the
+        Setting this option causes the -lreadline option to  be  added  to  the
-        pcretest build. In many operating environments with  a  sytem-installed
+        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
+        an  unmodified  distribution version of readline is in use), some extra
-        configuration  may  be necessary. The INSTALL file for libreadline says
+        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
+        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"
-Line 578 
 AUTHOR
+Line 595 
 AUTHOR
  REVISION
-        Last updated: 13 April 2008
+        Last updated: 06 September 2009
-        Copyright (c) 1997-2008 University of Cambridge.
+        Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREMATCHING(3)                                                PCREMATCHING(3)
-Line 684 
 THE ALTERNATIVE MATCHING ALGORITHM
+Line 701 
 THE ALTERNATIVE MATCHING ALGORITHM
         at the fourth character of the subject. The algorithm does not automat-
         ically move on to find matches that start at later positions.
+        Although the general principle of this matching algorithm  is  that  it
+        scans  the subject string only once, without backtracking, there is one
+        exception: when a lookbehind assertion is  encountered,  the  preceding
+        characters have to be re-inspected.
         There are a number of features of PCRE regular expressions that are not
         supported by the alternative matching algorithm. They are as follows:
-.  Because  the  algorithm  finds  all possible matches, the greedy or
+. Because the algorithm finds all  possible  matches,  the  greedy  or
-        ungreedy nature of repetition quantifiers is not relevant.  Greedy  and
+        ungreedy  nature  of repetition quantifiers is not relevant. Greedy and
         ungreedy quantifiers are treated in exactly the same way. However, pos-
-        sessive quantifiers can make a difference when what follows could  also
+        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
+        This pattern matches "aaab!" but not "aaa!", which would be matched  by
-        a non-possessive quantifier. Similarly, if an atomic group is  present,
+        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,
+        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
+        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
+        is  not  straightforward  to  keep track of captured substrings for the
-        different  matching  possibilities,  and  PCRE's implementation of this
+        different matching possibilities, and  PCRE's  implementation  of  this
         algorithm does not attempt to do this. This means that no captured sub-
         strings are available.
-.  Because no substrings are captured, back references within the pat-
+. Because no substrings are captured, back references within the  pat-
         tern are not supported, and cause errors if encountered.
-. For the same reason, conditional expressions that use  a  backrefer-
+.  For  the same reason, conditional expressions that use a backrefer-
-        ence  as  the  condition or test for a specific group recursion are not
+        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
+.  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
+        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
+. Callouts are supported, but the value of the  capture_top  field  is
         always 1, and the value of the capture_last field is always -1.
-. The \C escape sequence, which (in the standard algorithm) matches  a
+.  The \C escape sequence, which (in the standard algorithm) matches a
-        single  byte, even in UTF-8 mode, is not supported because the alterna-
+        single byte, even in UTF-8 mode, is not supported because the  alterna-
-        tive algorithm moves through the subject  string  one  character  at  a
+        tive  algorithm  moves  through  the  subject string one character at a
         time, for all active paths through the tree.
-.  Except for (*FAIL), the backtracking control verbs such as (*PRUNE)
+. Except for (*FAIL), the backtracking control verbs such as  (*PRUNE)
-        are not supported. (*FAIL) is supported, and  behaves  like  a  failing
+        are  not  supported.  (*FAIL)  is supported, and behaves like a failing
         negative assertion.
  ADVANTAGES OF THE ALTERNATIVE ALGORITHM
-        Using  the alternative matching algorithm provides the following advan-
+        Using the alternative matching algorithm provides the following  advan-
         tages:
 . All possible matches (at a single point in the subject) are automat-
-        ically  found,  and  in particular, the longest match is found. To find
+        ically found, and in particular, the longest match is  found.  To  find
         more than one match using the standard algorithm, you have to do kludgy
         things with callouts.
-.  There is much better support for partial matching. The restrictions
+. 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 alternative algorithm.
+        subject strings to the matching function in  several  pieces,  checking
-        For non-anchored patterns, the starting position of a partial match  is
-        available.
-.  Because  the  alternative  algorithm  scans the subject string just
-        once, and never needs to backtrack, it is possible to  pass  very  long
-        subject  strings  to  the matching function in several pieces, checking
         for partial matching each time.
-Line 758 
 DISADVANTAGES OF THE ALTERNATIVE ALGORIT
+Line 774 
 DISADVANTAGES OF THE ALTERNATIVE ALGORIT
         The alternative algorithm suffers from a number of disadvantages:
-. It is substantially slower than  the  standard  algorithm.  This  is
+.  It  is  substantially  slower  than the standard algorithm. This is
-        partly  because  it has to search for all possible matches, but is also
+        partly because it has to search for all possible matches, but  is  also
         because it is less susceptible to optimization.
 . Capturing parentheses and back references are not supported.
-Line 777 
 AUTHOR
+Line 793 
 AUTHOR
  REVISION
-        Last updated: 19 April 2008
+        Last updated: 05 September 2009
-        Copyright (c) 1997-2008 University of Cambridge.
+        Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREAPI(3)                                                          PCREAPI(3)
-Line 889 
 PCRE API OVERVIEW
+Line 905 
 PCRE API OVERVIEW
         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
-        compile and 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. The alternative algorithm finds all possible matches (at  a  given
+        ing.  The  alternative algorithm finds all possible matches (at a given
-        point  in  the subject), and scans the subject just once. However, this
+        point in the subject), and scans the subject just  once  (unless  there
-        algorithm does not return captured substrings. A description of the two
+        are  lookbehind  assertions).  However,  this algorithm does not return
-        matching  algorithms and their advantages and disadvantages is given in
+        captured substrings. A description of the two matching  algorithms  and
-        the pcrematching documentation.
+        their  advantages  and disadvantages is given in the pcrematching docu-
+        mentation.
         In addition to the main compiling and  matching  functions,  there  are
         convenience functions for extracting captured substrings from a subject
-Line 999 
 MULTITHREADING
+Line 1017 
 MULTITHREADING
         pcre_malloc, pcre_free, pcre_stack_malloc, and pcre_stack_free, and the
         callout function pointed to by pcre_callout, are shared by all threads.
-        The compiled form of a regular expression is not altered during  match-
+        The  compiled form of a regular expression is not altered during match-
         ing, so the same compiled pattern can safely be used by several threads
         at once.
-Line 1007 
 MULTITHREADING
+Line 1025 
 MULTITHREADING
  SAVING PRECOMPILED PATTERNS FOR LATER USE
         The compiled form of a regular expression can be saved and re-used at a
-        later  time,  possibly by a different program, and even on a host other
+        later time, possibly by a different program, and even on a  host  other
-        than the one on which  it  was  compiled.  Details  are  given  in  the
+        than  the  one  on  which  it  was  compiled.  Details are given in the
-        pcreprecompile  documentation.  However, compiling a regular expression
+        pcreprecompile documentation. However, compiling a  regular  expression
-        with one version of PCRE for use with a different version is not  guar-
+        with  one version of PCRE for use with a different version is not guar-
         anteed to work and may cause crashes.
-Line 1018 
 CHECKING BUILD-TIME OPTIONS
+Line 1036 
 CHECKING BUILD-TIME OPTIONS
         int pcre_config(int what, void *where);
-        The  function pcre_config() makes it possible for a PCRE client to dis-
+        The function pcre_config() makes it possible for a PCRE client to  dis-
         cover which optional features have been compiled into the PCRE library.
-        The  pcrebuild documentation has more details about these optional fea-
+        The pcrebuild documentation has more details about these optional  fea-
         tures.
-        The first argument for pcre_config() is an  integer,  specifying  which
+        The  first  argument  for pcre_config() is an integer, specifying which
         information is required; the second argument is a pointer to a variable
-        into which the information is  placed.  The  following  information  is
+        into  which  the  information  is  placed. The following information is
         available:
           PCRE_CONFIG_UTF8
-        The  output is an integer that is set to one if UTF-8 support is avail-
+        The output is an integer that is set to one if UTF-8 support is  avail-
         able; otherwise it is set to zero.
           PCRE_CONFIG_UNICODE_PROPERTIES
-        The output is an integer that is set to  one  if  support  for  Unicode
+        The  output  is  an  integer  that is set to one if support for Unicode
         character properties is available; otherwise it is set to zero.
           PCRE_CONFIG_NEWLINE
-        The  output  is  an integer whose value specifies the default character
+        The output is an integer whose value specifies  the  default  character
-        sequence that is recognized as meaning "newline". The four values  that
+        sequence  that is recognized as meaning "newline". The four values that
         are supported are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF,
-        and -1 for ANY. The default should normally be  the  standard  sequence
+        and  -1  for  ANY.  Though they are derived from ASCII, the same values
-        for your operating system.
+        are returned in EBCDIC environments. The default should normally corre-
+        spond to the standard sequence for your operating system.
           PCRE_CONFIG_BSR
-Line 1071 
 CHECKING BUILD-TIME OPTIONS
+Line 1090 
 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 an integer that gives the default limit for the depth  of
+        The output is a long integer that gives the default limit for the depth
-        recursion  when calling the internal matching function in a pcre_exec()
+        of   recursion  when  calling  the  internal  matching  function  in  a
-        execution. Further details are given with pcre_exec() below.
+        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 1105 
 COMPILING A PATTERN
+Line 1125 
 COMPILING A PATTERN
         Either of the functions pcre_compile() or pcre_compile2() can be called
         to compile a pattern into an internal form. The only difference between
-        the two interfaces is that pcre_compile2() has an additional  argument,
+        the  two interfaces is that pcre_compile2() has an additional argument,
         errorcodeptr, via which a numerical error code can be returned.
         The pattern is a C string terminated by a binary zero, and is passed in
-        the pattern argument. A pointer to a single block  of  memory  that  is
+        the  pattern  argument.  A  pointer to a single block of memory that is
-        obtained  via  pcre_malloc is returned. This contains the compiled code
+        obtained via pcre_malloc is returned. This contains the  compiled  code
         and related data. The pcre type is defined for the returned block; this
         is a typedef for a structure whose contents are not externally defined.
         It is up to the caller to free the memory (via pcre_free) when it is no
         longer required.
-        Although  the compiled code of a PCRE regex is relocatable, that is, it
+        Although the compiled code of a PCRE regex is relocatable, that is,  it
         does not depend on memory location, the complete pcre data block is not
-        fully  relocatable, because it may contain a copy of the tableptr argu-
+        fully relocatable, because it may contain a copy of the tableptr  argu-
         ment, which is an address (see below).
         The options argument contains various bit settings that affect the com-
-        pilation.  It  should be zero if no options are required. The available
+        pilation. It should be zero if no options are required.  The  available
-        options are described below. Some of them, in  particular,  those  that
+        options  are  described  below. Some of them (in particular, those that
-        are  compatible  with  Perl,  can also be set and unset from within the
+        are compatible with Perl, but also some others) 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  and PCRE_NEWLINE_xxx options can be set at the time
+        specifies their initial settings at the start of compilation and execu-
-        of matching as well as at compile time.
+        tion.  The PCRE_ANCHORED and PCRE_NEWLINE_xxx options can be set at the
+        time of matching as well as at compile time.
         If errptr is NULL, pcre_compile() returns NULL immediately.  Otherwise,
         if  compilation  of  a  pattern fails, pcre_compile() returns NULL, and
-Line 1335 
 COMPILING A PATTERN
+Line 1356 
 COMPILING A PATTERN
         and are therefore ignored.
         The newline option that is set at compile time becomes the default that
-        is  used for pcre_exec() and pcre_dfa_exec(), but it can be overridden.
+        is used for pcre_exec() and pcre_dfa_exec(), but it can be overridden.
           PCRE_NO_AUTO_CAPTURE
         If this option is set, it disables the use of numbered capturing paren-
-        theses  in the pattern. Any opening parenthesis that is not followed by
+        theses in the pattern. Any opening parenthesis that is not followed  by
-        ? behaves as if it were followed by ?: but named parentheses can  still
+        ?  behaves as if it were followed by ?: but named parentheses can still
-        be  used  for  capturing  (and  they acquire numbers in the usual way).
+        be used for capturing (and they acquire  numbers  in  the  usual  way).
         There is no equivalent of this option in Perl.
           PCRE_UNGREEDY
-        This option inverts the "greediness" of the quantifiers  so  that  they
+        This  option  inverts  the "greediness" of the quantifiers so that they
-        are  not greedy by default, but become greedy if followed by "?". It is
+        are not greedy by default, but become greedy if followed by "?". It  is
-        not compatible with Perl. It can also be set by a (?U)  option  setting
+        not  compatible  with Perl. It can also be set by a (?U) option setting
         within the pattern.
           PCRE_UTF8
-        This  option  causes PCRE to regard both the pattern and the subject as
+        This option causes PCRE to regard both the pattern and the  subject  as
-        strings of UTF-8 characters instead of single-byte  character  strings.
+        strings  of  UTF-8 characters instead of single-byte character strings.
-        However,  it is available only when PCRE is built to include UTF-8 sup-
+        However, it is available only when PCRE is built to include UTF-8  sup-
-        port. If not, the use of this option provokes an error. Details of  how
+        port.  If not, the use of this option provokes an error. Details of how
-        this  option  changes the behaviour of PCRE are given in the section on
+        this option changes the behaviour of PCRE are given in the  section  on
         UTF-8 support in the main pcre page.
           PCRE_NO_UTF8_CHECK
         When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is
-        automatically  checked.  There  is  a  discussion about the validity of
+        automatically checked. There is a  discussion  about  the  validity  of
-        UTF-8 strings in the main pcre page. If an invalid  UTF-8  sequence  of
+        UTF-8  strings  in  the main pcre page. If an invalid UTF-8 sequence of
-        bytes  is  found,  pcre_compile() returns an error. If you already know
+        bytes is found, pcre_compile() returns an error. If  you  already  know
         that your pattern is valid, and you want to skip this check for perfor-
-        mance  reasons,  you  can set the PCRE_NO_UTF8_CHECK option. When it is
+        mance reasons, you can set the PCRE_NO_UTF8_CHECK option.  When  it  is
-        set, the effect of passing an invalid UTF-8  string  as  a  pattern  is
+        set,  the  effect  of  passing  an invalid UTF-8 string as a pattern is
-        undefined.  It  may  cause your program to crash. Note that this option
+        undefined. It may cause your program to crash. Note  that  this  option
-        can also be passed to pcre_exec() and pcre_dfa_exec(), to suppress  the
+        can  also be passed to pcre_exec() and pcre_dfa_exec(), to suppress the
         UTF-8 validity checking of subject strings.
  COMPILATION ERROR CODES
-        The  following  table  lists  the  error  codes than may be returned by
+        The following table lists the error  codes  than  may  be  returned  by
-        pcre_compile2(), along with the error messages that may be returned  by
+        pcre_compile2(),  along with the error messages that may be returned by
-        both  compiling functions. As PCRE has developed, some error codes have
+        both compiling functions. As PCRE has developed, some error codes  have
         fallen out of use. To avoid confusion, they have not been re-used.
  no error
-Line 1435 
 COMPILATION ERROR CODES
+Line 1456 
 COMPILATION ERROR CODES
  [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
+  internal  error:  previously-checked  referenced  subpattern not
         found
  DEFINE group contains more than one branch
  repeating a DEFINE group is not allowed
-Line 1450 
 COMPILATION ERROR CODES
+Line 1471 
 COMPILATION ERROR CODES
  digit expected after (?+
  ] is an invalid data character in JavaScript compatibility mode
-        The  numbers  32  and 10000 in errors 48 and 49 are defaults; different
+        The numbers 32 and 10000 in errors 48 and 49  are  defaults;  different
         values may be used if the limits were changed when PCRE was built.
-Line 1459 
 STUDYING A PATTERN
+Line 1480 
 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(). However, a pcre_extra block  also  contains  other  fields
-        that can be set by the caller before the block  is  passed;  these  are
+        that  can  be  set  by the caller before the block is passed; these are
         described below in the section on matching a pattern.
-        If  studying  the  pattern  does not produce any additional information
+        If studying the pattern does not  produce  any  additional  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(), it  must  set  up
         its own pcre_extra block.
-        The second argument of pcre_study() contains option bits.  At  present,
+        The  second  argument of pcre_study() contains option bits. At present,
         no options are defined, and this argument should always be zero.
-        The  third argument for pcre_study() is a pointer for an error message.
+        The third argument for pcre_study() is a pointer for an error  message.
-        If studying succeeds (even if no data is  returned),  the  variable  it
+        If  studying  succeeds  (even  if no data is returned), the variable it
-        points  to  is  set  to NULL. Otherwise it is set to point to a textual
+        points to is set to NULL. Otherwise it is set to  point  to  a  textual
         error message. This is a static string that is part of the library. You
-        must  not  try  to  free it. You should test the error pointer for NULL
+        must not try to free it. You should test the  error  pointer  for  NULL
         after calling pcre_study(), to be sure that it has run successfully.
         This is a typical call to pcre_study():
-Line 1496 
 STUDYING A PATTERN
+Line 1517 
 STUDYING A PATTERN
             &error);        /* set to NULL or points to a message */
         At present, studying a pattern is useful only for non-anchored patterns
-        that  do not have a single fixed starting character. A bitmap of possi-
+        that do not have a single fixed starting character. A bitmap of  possi-
         ble starting bytes is created.
  LOCALE SUPPORT
-        PCRE handles caseless matching, and determines whether  characters  are
+        PCRE  handles  caseless matching, and determines whether characters are
-        letters,  digits, or whatever, by reference to a set of tables, indexed
+        letters, digits, or whatever, by reference to a set of tables,  indexed
-        by character value. When running in UTF-8 mode, this  applies  only  to
+        by  character  value.  When running in UTF-8 mode, this applies only to
-        characters  with  codes  less than 128. Higher-valued codes never match
+        characters with codes less than 128. Higher-valued  codes  never  match
-        escapes such as \w or \d, but can be tested with \p if  PCRE  is  built
+        escapes  such  as  \w or \d, but can be tested with \p if PCRE is built
-        with  Unicode  character property support. The use of locales with Uni-
+        with Unicode character property support. The use of locales  with  Uni-
-        code is discouraged. If you are handling characters with codes  greater
+        code  is discouraged. If you are handling characters with codes greater
-        than  128, you should either use UTF-8 and Unicode, or use locales, but
+        than 128, you should either use UTF-8 and Unicode, or use locales,  but
         not try to mix the two.
-        PCRE contains an internal set of tables that are used  when  the  final
+        PCRE  contains  an  internal set of tables that are used when the final
-        argument  of  pcre_compile()  is  NULL.  These  are sufficient for many
+        argument of pcre_compile() is  NULL.  These  are  sufficient  for  many
         applications.  Normally, the internal tables recognize only ASCII char-
         acters. However, when PCRE is built, it is possible to cause the inter-
         nal tables to be rebuilt in the default "C" locale of the local system,
         which may cause them to be different.
-        The  internal tables can always be overridden by tables supplied by the
+        The internal tables can always be overridden by tables supplied by  the
         application that calls PCRE. These may be created in a different locale
-        from  the  default.  As more and more applications change to using Uni-
+        from the default. As more and more applications change  to  using  Uni-
         code, the need for this locale support is expected to die away.
-        External tables are built by calling  the  pcre_maketables()  function,
+        External  tables  are  built by calling the pcre_maketables() function,
-        which  has no arguments, in the relevant locale. The result can then be
+        which has no arguments, in the relevant locale. The result can then  be
-        passed to pcre_compile() or pcre_exec()  as  often  as  necessary.  For
+        passed  to  pcre_compile()  or  pcre_exec()  as often as necessary. For
-        example,  to  build  and use tables that are appropriate for the French
+        example, to build and use tables that are appropriate  for  the  French
-        locale (where accented characters with  values  greater  than  128  are
+        locale  (where  accented  characters  with  values greater than 128 are
         treated as letters), the following code could be used:
           setlocale(LC_CTYPE, "fr_FR");
           tables = pcre_maketables();
           re = pcre_compile(..., tables);
-        The  locale  name "fr_FR" is used on Linux and other Unix-like systems;
+        The locale name "fr_FR" is used on Linux and other  Unix-like  systems;
         if you are using Windows, the name for the French locale is "french".
-        When pcre_maketables() runs, the tables are built  in  memory  that  is
+        When  pcre_maketables()  runs,  the  tables are built in memory that is
-        obtained  via  pcre_malloc. It is the caller's responsibility to ensure
+        obtained via pcre_malloc. It is the caller's responsibility  to  ensure
-        that the memory containing the tables remains available for as long  as
+        that  the memory containing the tables remains available for as long as
         it is needed.
         The pointer that is passed to pcre_compile() is saved with the compiled
-        pattern, and the same tables are used via this pointer by  pcre_study()
+        pattern,  and the same tables are used via this pointer by pcre_study()
         and normally also by pcre_exec(). Thus, by default, for any single pat-
         tern, compilation, studying and matching all happen in the same locale,
         but different patterns can be compiled in different locales.
-        It  is  possible to pass a table pointer or NULL (indicating the use of
+        It is possible to pass a table pointer or NULL (indicating the  use  of
-        the internal tables) to pcre_exec(). Although  not  intended  for  this
+        the  internal  tables)  to  pcre_exec(). Although not intended for this
-        purpose,  this facility could be used to match a pattern in a different
+        purpose, this facility could be used to match a pattern in a  different
         locale from the one in which it was compiled. Passing table pointers at
         run time is discussed below in the section on matching a pattern.
-Line 1561 
 INFORMATION ABOUT A PATTERN
+Line 1582 
 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 1577 
 INFORMATION ABOUT A PATTERN
+Line 1598 
 INFORMATION ABOUT A PATTERN
           PCRE_ERROR_BADMAGIC   the "magic number" was not found
           PCRE_ERROR_BADOPTION  the value of what was invalid
-        The "magic number" is placed at the start of each compiled  pattern  as
+        The  "magic  number" is placed at the start of each compiled pattern as
-        an  simple check against passing an arbitrary memory pointer. Here is a
+        an simple check against passing an arbitrary memory pointer. Here is  a
-        typical call of pcre_fullinfo(), to obtain the length of  the  compiled
+        typical  call  of pcre_fullinfo(), to obtain the length of the compiled
         pattern:
           int rc;
-Line 1590 
 INFORMATION ABOUT A PATTERN
+Line 1611 
 INFORMATION ABOUT A PATTERN
             PCRE_INFO_SIZE,   /* what is required */
             &length);         /* where to put the data */
-        The  possible  values for the third argument are defined in pcre.h, and
+        The possible values for the third argument are defined in  pcre.h,  and
         are as follows:
           PCRE_INFO_BACKREFMAX
-        Return the number of the highest back reference  in  the  pattern.  The
+        Return  the  number  of  the highest back reference in the pattern. The
-        fourth  argument  should  point to an int variable. Zero is returned if
+        fourth argument should point to an int variable. Zero  is  returned  if
         there are no back references.
           PCRE_INFO_CAPTURECOUNT
-        Return the number of capturing subpatterns in the pattern.  The  fourth
+        Return  the  number of capturing subpatterns in the pattern. The fourth
         argument should point to an int variable.
           PCRE_INFO_DEFAULT_TABLES
-        Return  a pointer to the internal default character tables within PCRE.
+        Return a pointer to the internal default character tables within  PCRE.
-        The fourth argument should point to an unsigned char *  variable.  This
+        The  fourth  argument should point to an unsigned char * variable. This
         information call is provided for internal use by the pcre_study() func-
-        tion. External callers can cause PCRE to use  its  internal  tables  by
+        tion.  External  callers  can  cause PCRE to use its internal tables by
         passing a NULL table pointer.
           PCRE_INFO_FIRSTBYTE
-        Return  information  about  the first byte of any matched string, for a
+        Return information about the first byte of any matched  string,  for  a
-        non-anchored pattern. The fourth argument should point to an int  vari-
+        non-anchored  pattern. The fourth argument should point to an int vari-
-        able.  (This option used to be called PCRE_INFO_FIRSTCHAR; the old name
+        able. (This option used to be called PCRE_INFO_FIRSTCHAR; the old  name
         is still recognized for backwards compatibility.)
-        If there is a fixed first byte, for example, from  a  pattern  such  as
+        If  there  is  a  fixed first byte, for example, from a pattern such as
         (cat|cow|coyote), its value is returned. Otherwise, if either
-        (a)  the pattern was compiled with the PCRE_MULTILINE option, and every
+        (a) the pattern was compiled with the PCRE_MULTILINE option, and  every
         branch starts with "^", or
         (b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not
         set (if it were set, the pattern would be anchored),
-        -1  is  returned, indicating that the pattern matches only at the start
+        -1 is returned, indicating that the pattern matches only at  the  start
-        of a subject string or after any newline within the  string.  Otherwise
+        of  a  subject string or after any newline within the string. Otherwise
         -2 is returned. For anchored patterns, -2 is returned.
           PCRE_INFO_FIRSTTABLE
-        If  the pattern was studied, and this resulted in the construction of a
+        If the pattern was studied, and this resulted in the construction of  a
 -bit table indicating a fixed set of bytes for the first byte in any
-        matching  string, a pointer to the table is returned. Otherwise NULL is
+        matching string, a pointer to the table is returned. Otherwise NULL  is
-        returned. The fourth argument should point to an unsigned char *  vari-
+        returned.  The fourth argument should point to an unsigned char * vari-
         able.
           PCRE_INFO_HASCRORLF
-        Return  1  if  the  pattern  contains any explicit matches for CR or LF
+        Return 1 if the pattern contains any explicit  matches  for  CR  or  LF
-        characters, otherwise 0. The fourth argument should  point  to  an  int
+        characters,  otherwise  0.  The  fourth argument should point to an int
-        variable.  An explicit match is either a literal CR or LF character, or
+        variable. An explicit match is either a literal CR or LF character,  or
         \r or \n.
           PCRE_INFO_JCHANGED
-        Return 1 if the (?J) or (?-J) option setting is used  in  the  pattern,
+        Return  1  if  the (?J) or (?-J) option setting is used in the pattern,
-        otherwise  0. The fourth argument should point to an int variable. (?J)
+        otherwise 0. The fourth argument should point to an int variable.  (?J)
         and (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
           PCRE_INFO_LASTLITERAL
-        Return the value of the rightmost literal byte that must exist  in  any
+        Return  the  value of the rightmost literal byte that must exist in any
-        matched  string,  other  than  at  its  start,  if such a byte has been
+        matched string, other than at its  start,  if  such  a  byte  has  been
         recorded. The fourth argument should point to an int variable. If there
-        is  no such byte, -1 is returned. For anchored patterns, a last literal
+        is no such byte, -1 is returned. For anchored patterns, a last  literal
-        byte is recorded only if it follows something of variable  length.  For
+        byte  is  recorded only if it follows something of variable length. For
         example, for the pattern /^a\d+z\d+/ the returned value is "z", but for
         /^a\dz\d/ the returned value is -1.
-Line 1667 
 INFORMATION ABOUT A PATTERN
+Line 1688 
 INFORMATION ABOUT A PATTERN
           PCRE_INFO_NAMEENTRYSIZE
           PCRE_INFO_NAMETABLE
-        PCRE supports the use of named as well as numbered capturing  parenthe-
+        PCRE  supports the use of named as well as numbered capturing parenthe-
-        ses.  The names are just an additional way of identifying the parenthe-
+        ses. The names are just an additional way of identifying the  parenthe-
         ses, which still acquire numbers. Several convenience functions such as
-        pcre_get_named_substring()  are  provided  for extracting captured sub-
+        pcre_get_named_substring() are provided for  extracting  captured  sub-
-        strings by name. It is also possible to extract the data  directly,  by
+        strings  by  name. It is also possible to extract the data directly, by
-        first  converting  the  name to a number in order to access the correct
+        first converting the name to a number in order to  access  the  correct
         pointers in the output vector (described with pcre_exec() below). To do
-        the  conversion,  you  need  to  use  the  name-to-number map, which is
+        the conversion, you need  to  use  the  name-to-number  map,  which  is
         described by these three values.
         The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT
         gives the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size
-        of each entry; both of these  return  an  int  value.  The  entry  size
+        of  each  entry;  both  of  these  return  an int value. The entry size
-        depends  on the length of the longest name. PCRE_INFO_NAMETABLE returns
+        depends on the length of the longest name. PCRE_INFO_NAMETABLE  returns
-        a pointer to the first entry of the table  (a  pointer  to  char).  The
+        a  pointer  to  the  first  entry of the table (a pointer to char). The
         first two bytes of each entry are the number of the capturing parenthe-
-        sis, most significant byte first. The rest of the entry is  the  corre-
+        sis,  most  significant byte first. The rest of the entry is the corre-
-        sponding  name,  zero  terminated. The names are in alphabetical order.
+        sponding name, zero terminated. The names are  in  alphabetical  order.
         When PCRE_DUPNAMES is set, duplicate names are in order of their paren-
-        theses  numbers.  For  example,  consider the following pattern (assume
+        theses numbers. For example, consider  the  following  pattern  (assume
-        PCRE_EXTENDED is  set,  so  white  space  -  including  newlines  -  is
+        PCRE_EXTENDED  is  set,  so  white  space  -  including  newlines  - is
         ignored):
           (?<date> (?<year>(\d\d)?\d\d) -
           (?<month>\d\d) - (?<day>\d\d) )
-        There  are  four  named subpatterns, so the table has four entries, and
+        There are four named subpatterns, so the table has  four  entries,  and
-        each entry in the table is eight bytes long. The table is  as  follows,
+        each  entry  in the table is eight bytes long. The table is as follows,
         with non-printing bytes shows in hexadecimal, and undefined bytes shown
         as ??:
-Line 1703 
 INFORMATION ABOUT A PATTERN
+Line 1724 
 INFORMATION ABOUT A PATTERN
 04 m  o  n  t  h  00
 02 y  e  a  r  00 ??
-        When writing code to extract data  from  named  subpatterns  using  the
+        When  writing  code  to  extract  data from named subpatterns using the
-        name-to-number  map,  remember that the length of the entries is likely
+        name-to-number map, remember that the length of the entries  is  likely
         to be different for each compiled pattern.
           PCRE_INFO_OKPARTIAL
-        Return 1 if the pattern can be used for partial matching, otherwise  0.
+        Return  1  if  the  pattern  can  be  used  for  partial  matching with
-        The  fourth  argument  should point to an int variable. The pcrepartial
+        pcre_exec(), otherwise 0. The fourth argument should point  to  an  int
-        documentation lists the restrictions that apply to patterns  when  par-
+        variable.  From  release  8.00,  this  always  returns  1,  because the
-        tial matching is used.
+        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
+        Return a copy of the options with which the pattern was  compiled.  The
-        fourth argument should point to an unsigned long  int  variable.  These
+        fourth  argument  should  point to an unsigned long int variable. These
         option bits are those specified in the call to pcre_compile(), modified
         by any top-level option settings at the start of the pattern itself. In
-        other  words,  they are the options that will be in force when matching
+        other words, they are the options that will be in force  when  matching
-        starts. For example, if the pattern /(?im)abc(?-i)d/ is  compiled  with
+        starts.  For  example, if the pattern /(?im)abc(?-i)d/ is compiled with
-        the  PCRE_EXTENDED option, the result is PCRE_CASELESS, PCRE_MULTILINE,
+        the PCRE_EXTENDED option, the result is PCRE_CASELESS,  PCRE_MULTILINE,
         and PCRE_EXTENDED.
-        A pattern is automatically anchored by PCRE if  all  of  its  top-level
+        A  pattern  is  automatically  anchored by PCRE if all of its top-level
         alternatives begin with one of the following:
           ^     unless PCRE_MULTILINE is set
-Line 1739 
 INFORMATION ABOUT A PATTERN
+Line 1762 
 INFORMATION ABOUT A PATTERN
           PCRE_INFO_SIZE
-        Return the size of the compiled pattern, that is, the  value  that  was
+        Return  the  size  of the compiled pattern, that is, the value that was
         passed as the argument to pcre_malloc() when PCRE was getting memory in
         which to place the compiled data. The fourth argument should point to a
         size_t variable.
-Line 1747 
 INFORMATION ABOUT A PATTERN
+Line 1770 
 INFORMATION ABOUT A PATTERN
           PCRE_INFO_STUDYSIZE
         Return the size of the data block pointed to by the study_data field in
-        a pcre_extra block. That is,  it  is  the  value  that  was  passed  to
+        a  pcre_extra  block.  That  is,  it  is  the  value that was passed to
         pcre_malloc() when PCRE was getting memory into which to place the data
-        created by pcre_study(). The fourth argument should point to  a  size_t
+        created  by  pcre_study(). The fourth argument should point to a size_t
         variable.
-Line 1757 
 OBSOLETE INFO FUNCTION
+Line 1780 
 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 1779 
 REFERENCE COUNTS
+Line 1802 
 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 1887 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 1910 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         the  total number of calls, because not all calls to match() are recur-
         sive.  This limit is of use only if it is set smaller than match_limit.
-        Limiting  the  recursion  depth  limits the amount of stack that can be
+        Limiting the recursion depth limits the amount of  stack  that  can  be
         used, or, when PCRE has been compiled to use memory on the heap instead
         of the stack, the amount of heap memory that can be used.
-        The  default  value  for  match_limit_recursion can be set when PCRE is
+        The default value for match_limit_recursion can be  set  when  PCRE  is
-        built; the default default  is  the  same  value  as  the  default  for
+        built;  the  default  default  is  the  same  value  as the default for
-        match_limit.  You can override the default by suppling pcre_exec() with
+        match_limit. You can override the default by suppling pcre_exec()  with
-        a  pcre_extra  block  in  which  match_limit_recursion  is   set,   and
+        a   pcre_extra   block  in  which  match_limit_recursion  is  set,  and
-        PCRE_EXTRA_MATCH_LIMIT_RECURSION  is  set  in  the  flags field. If the
+        PCRE_EXTRA_MATCH_LIMIT_RECURSION is set in  the  flags  field.  If  the
         limit is exceeded, pcre_exec() returns PCRE_ERROR_RECURSIONLIMIT.
-        The pcre_callout field is used in conjunction with the  "callout"  fea-
+        The  callout_data  field is used in conjunction with the "callout" fea-
-        ture, which is described in the pcrecallout documentation.
+        ture, and is described in the pcrecallout documentation.
-        The  tables  field  is  used  to  pass  a  character  tables pointer to
+        The tables field  is  used  to  pass  a  character  tables  pointer  to
-        pcre_exec(); this overrides the value that is stored with the  compiled
+        pcre_exec();  this overrides the value that is stored with the compiled
-        pattern.  A  non-NULL value is stored with the compiled pattern only if
+        pattern. A non-NULL value is stored with the compiled pattern  only  if
-        custom tables were supplied to pcre_compile() via  its  tableptr  argu-
+        custom  tables  were  supplied to pcre_compile() via its tableptr argu-
         ment.  If NULL is passed to pcre_exec() using this mechanism, it forces
-        PCRE's internal tables to be used. This facility is  helpful  when  re-
+        PCRE's  internal  tables  to be used. This facility is helpful when re-
-        using  patterns  that  have been saved after compiling with an external
+        using patterns that have been saved after compiling  with  an  external
-        set of tables, because the external tables  might  be  at  a  different
+        set  of  tables,  because  the  external tables might be at a different
-        address  when  pcre_exec() is called. See the pcreprecompile documenta-
+        address when pcre_exec() is called. See the  pcreprecompile  documenta-
         tion for a discussion of saving compiled patterns for later use.
     Option bits for pcre_exec()
-        The unused bits of the options argument for pcre_exec() must  be  zero.
+        The  unused  bits of the options argument for pcre_exec() must be zero.
-        The  only  bits  that  may  be set are PCRE_ANCHORED, PCRE_NEWLINE_xxx,
+        The only bits that may  be  set  are  PCRE_ANCHORED,  PCRE_NEWLINE_xxx,
-        PCRE_NOTBOL,   PCRE_NOTEOL,   PCRE_NOTEMPTY,   PCRE_NO_UTF8_CHECK   and
+        PCRE_NOTBOL,    PCRE_NOTEOL,    PCRE_NOTEMPTY,   PCRE_NOTEMPTY_ATSTART,
-        PCRE_PARTIAL.
+        PCRE_NO_START_OPTIMIZE,  PCRE_NO_UTF8_CHECK,   PCRE_PARTIAL_SOFT,   and
+        PCRE_PARTIAL_HARD.
           PCRE_ANCHORED
-Line 1997 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2021 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           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
         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.
+          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  a  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. When callouts
+        are in use, these optimizations can cause  them  to  be  skipped.  This
+        option  disables  the  "start-up" optimizations, causing performance to
+        suffer, but ensuring that the callouts do occur.
           PCRE_NO_UTF8_CHECK
-Line 2033 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2075 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         value  of startoffset that does not point to the start of a UTF-8 char-
         acter, is undefined. Your program may crash.
-          PCRE_PARTIAL
+          PCRE_PARTIAL_HARD
+          PCRE_PARTIAL_SOFT
-        This option turns on the  partial  matching  feature.  If  the  subject
+        These options turn on the partial matching feature. For backwards  com-
-        string  fails to match the pattern, but at some point during the match-
+        patibility,  PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A partial
-        ing process the end of the subject was reached (that  is,  the  subject
+        match occurs if the end of the subject string is reached  successfully,
-        partially  matches  the  pattern and the failure to match occurred only
+        but  there  are not enough subject characters to complete the match. If
-        because there were not enough subject characters), pcre_exec()  returns
+        this happens when PCRE_PARTIAL_HARD  is  set,  pcre_exec()  immediately
-        PCRE_ERROR_PARTIAL  instead of PCRE_ERROR_NOMATCH. When PCRE_PARTIAL is
+        returns  PCRE_ERROR_PARTIAL.  Otherwise,  if  PCRE_PARTIAL_SOFT is set,
-        used, there are restrictions on what may appear in the  pattern.  These
+        matching continues by testing any other alternatives. Only if they  all
-        are discussed in the pcrepartial documentation.
+        fail  is  PCRE_ERROR_PARTIAL  returned (instead of PCRE_ERROR_NOMATCH).
+        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 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.
+        In UTF-8 mode, the byte offset must point to the start of a UTF-8 char-
-        Unlike the pattern string, the subject may contain binary  zero  bytes.
+        acter.  Unlike  the pattern string, the subject may contain binary zero
-        When  the starting offset is zero, the search for a match starts at the
+        bytes. When the starting offset is zero, the search for a match  starts
-        beginning of the subject, and this is by far the most common case.
+        at  the  beginning  of  the subject, and this is by far the most common
+        case.
         A non-zero starting offset is useful when searching for  another  match
         in  the same subject by calling pcre_exec() again after a previous suc-
-Line 2087 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2134 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
         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-
         strings, each substring using a pair of integers. The  remaining  third
         of  the  vector is used as workspace by pcre_exec() while matching cap-
         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
         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
-        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 one more than the
+        The first pair of integers, ovector[0]  and  ovector[1],  identify  the
-        highest numbered pair that has been set. For example, if two substrings
+        portion  of  the subject string matched by the entire pattern. The next
-        have been captured, the returned value is 3. If there are no  capturing
+        pair is used for the first capturing subpattern, and so on.  The  value
-        subpatterns,  the return value from a successful match is 1, indicating
+        returned by pcre_exec() is one more than the highest numbered pair that
-        that just the first pair of offsets has been set.
+        has been set.  For example, if two substrings have been  captured,  the
+        returned  value is 3. If there are no capturing subpatterns, the return
+        value from a successful match is 1, indicating that just the first pair
+        of offsets has been set.
         If a capturing subpattern is matched repeatedly, it is the last portion
         of the string that it matched that is returned.
-        If  the vector is too small to hold all the captured substring offsets,
+        If the vector is too small to hold all the captured substring  offsets,
         it is used as far as possible (up to two-thirds of its length), and the
-        function  returns a value of zero. In particular, if the substring off-
+        function returns a value of zero. 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.
-        The pcre_info() function can be used to find  out  how  many  capturing
+        The  pcre_info()  function  can  be used to find out how many capturing
-        subpatterns  there  are  in  a  compiled pattern. The smallest size for
+        subpatterns there are in a compiled  pattern.  The  smallest  size  for
-        ovector that will allow for n captured substrings, in addition  to  the
+        ovector  that  will allow for n captured substrings, in addition to the
         offsets of the substring matched by the whole pattern, is (n+1)*3.
-        It  is  possible for capturing subpattern number n+1 to match some part
+        It is possible for capturing subpattern number n+1 to match  some  part
         of the subject when subpattern n has not been used at all. For example,
-        if  the  string  "abc"  is  matched against the pattern (a|(z))(bc) the
+        if the string "abc" is matched  against  the  pattern  (a|(z))(bc)  the
         return from the function is 4, and subpatterns 1 and 3 are matched, but
- is  not.  When  this happens, both values in the offset pairs corre-
+is not. When this happens, both values in  the  offset  pairs  corre-
         sponding to unused subpatterns are set to -1.
-        Offset values that correspond to unused subpatterns at the end  of  the
+        Offset  values  that correspond to unused subpatterns at the end of the
-        expression  are  also  set  to  -1. For example, if the string "abc" is
+        expression are also set to -1. For example,  if  the  string  "abc"  is
-        matched against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are  not
+        matched  against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not
-        matched.  The  return  from the function is 2, because the highest used
+        matched. The return from the function is 2, because  the  highest  used
         capturing subpattern number is 1. However, you can refer to the offsets
-        for  the  second  and third capturing subpatterns if you wish (assuming
+        for the second and third capturing subpatterns if  you  wish  (assuming
         the vector is large enough, of course).
-        Some convenience functions are provided  for  extracting  the  captured
+        Some  convenience  functions  are  provided for extracting the captured
         substrings as separate strings. These are described below.
     Error return values from pcre_exec()
-        If  pcre_exec()  fails, it returns a negative number. The following are
+        If pcre_exec() fails, it returns a negative number. The  following  are
         defined in the header file:
           PCRE_ERROR_NOMATCH        (-1)
-Line 2159 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2209 
 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 2168 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2218 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
           PCRE_ERROR_BADMAGIC       (-4)
-        PCRE  stores a 4-byte "magic number" at the start of the compiled code,
+        PCRE stores a 4-byte "magic number" at the start of the compiled  code,
         to catch the case when it is passed a junk pointer and to detect when a
         pattern that was compiled in an environment of one endianness is run in
-        an environment with the other endianness. This is the error  that  PCRE
+        an  environment  with the other endianness. This is the error that PCRE
         gives when the magic number is not present.
           PCRE_ERROR_UNKNOWN_OPCODE (-5)
         While running the pattern match, an unknown item was encountered in the
-        compiled pattern. This error could be caused by a bug  in  PCRE  or  by
+        compiled  pattern.  This  error  could be caused by a bug in PCRE or by
         overwriting of the compiled pattern.
           PCRE_ERROR_NOMEMORY       (-6)
-        If  a  pattern contains back references, but the ovector that is passed
+        If a pattern contains back references, but the ovector that  is  passed
         to pcre_exec() is not big enough to remember the referenced substrings,
-        PCRE  gets  a  block of memory at the start of matching to use for this
+        PCRE gets a block of memory at the start of matching to  use  for  this
-        purpose. If the call via pcre_malloc() fails, this error is given.  The
+        purpose.  If the call via pcre_malloc() fails, this error is given. The
         memory is automatically freed at the end of matching.
           PCRE_ERROR_NOSUBSTRING    (-7)
-        This  error is used by the pcre_copy_substring(), pcre_get_substring(),
+        This error is used by the pcre_copy_substring(),  pcre_get_substring(),
         and  pcre_get_substring_list()  functions  (see  below).  It  is  never
         returned by pcre_exec().
           PCRE_ERROR_MATCHLIMIT     (-8)
-        The  backtracking  limit,  as  specified  by the match_limit field in a
+        The backtracking limit, as specified by  the  match_limit  field  in  a
-        pcre_extra structure (or defaulted) was reached.  See  the  description
+        pcre_extra  structure  (or  defaulted) was reached. See the description
         above.
           PCRE_ERROR_CALLOUT        (-9)
         This error is never generated by pcre_exec() itself. It is provided for
-        use by callout functions that want to yield a distinctive  error  code.
+        use  by  callout functions that want to yield a distinctive error code.
         See the pcrecallout documentation for details.
           PCRE_ERROR_BADUTF8        (-10)
-        A  string  that contains an invalid UTF-8 byte sequence was passed as a
+        A string that contains an invalid UTF-8 byte sequence was passed  as  a
         subject.
           PCRE_ERROR_BADUTF8_OFFSET (-11)
         The UTF-8 byte sequence that was passed as a subject was valid, but the
-        value  of startoffset did not point to the beginning of a UTF-8 charac-
+        value of startoffset did not point to the beginning of a UTF-8  charac-
         ter.
           PCRE_ERROR_PARTIAL        (-12)
-        The subject string did not match, but it did match partially.  See  the
+        The  subject  string did not match, but it did match partially. See the
         pcrepartial documentation for details of partial matching.
           PCRE_ERROR_BADPARTIAL     (-13)
-        The  PCRE_PARTIAL  option  was  used with a compiled pattern containing
+        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 2235 
 MATCHING A PATTERN: THE TRADITIONAL FUNC
+Line 2286 
 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
+        field  in  a  pcre_extra  structure (or defaulted) was reached. See the
         description above.
           PCRE_ERROR_BADNEWLINE     (-23)
-Line 2263 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
+Line 2314 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
         int pcre_get_substring_list(const char *subject,
              int *ovector, int stringcount, const char ***listptr);
-        Captured  substrings  can  be  accessed  directly  by using the offsets
+        Captured substrings can be  accessed  directly  by  using  the  offsets
-        returned by pcre_exec() in  ovector.  For  convenience,  the  functions
+        returned  by  pcre_exec()  in  ovector.  For convenience, the functions
         pcre_copy_substring(),    pcre_get_substring(),    and    pcre_get_sub-
-        string_list() are provided for extracting captured substrings  as  new,
+        string_list()  are  provided for extracting captured substrings as new,
-        separate,  zero-terminated strings. These functions identify substrings
+        separate, zero-terminated strings. These functions identify  substrings
-        by number. The next section describes functions  for  extracting  named
+        by  number.  The  next section describes functions for extracting named
         substrings.
-        A  substring that contains a binary zero is correctly extracted and has
+        A substring that contains a binary zero is correctly extracted and  has
-        a further zero added on the end, but the result is not, of course, a  C
+        a  further zero added on the end, but the result is not, of course, a C
-        string.   However,  you  can  process such a string by referring to the
+        string.  However, you can process such a string  by  referring  to  the
-        length that is  returned  by  pcre_copy_substring()  and  pcre_get_sub-
+        length  that  is  returned  by  pcre_copy_substring() and pcre_get_sub-
         string().  Unfortunately, the interface to pcre_get_substring_list() is
-        not adequate for handling strings containing binary zeros, because  the
+        not  adequate for handling strings containing binary zeros, because the
         end of the final string is not independently indicated.
-        The  first  three  arguments  are the same for all three of these func-
+        The first three arguments are the same for all  three  of  these  func-
-        tions: subject is the subject string that has  just  been  successfully
+        tions:  subject  is  the subject string that has just been successfully
         matched, ovector is a pointer to the vector of integer offsets that was
         passed to pcre_exec(), and stringcount is the number of substrings that
-        were  captured  by  the match, including the substring that matched the
+        were captured by the match, including the substring  that  matched  the
         entire regular expression. This is the value returned by pcre_exec() if
-        it  is greater than zero. If pcre_exec() returned zero, indicating that
+        it is greater than zero. If pcre_exec() returned zero, indicating  that
-        it ran out of space in ovector, the value passed as stringcount  should
+        it  ran out of space in ovector, the value passed as stringcount should
         be the number of elements in the vector divided by three.
-        The  functions pcre_copy_substring() and pcre_get_substring() extract a
+        The functions pcre_copy_substring() and pcre_get_substring() extract  a
-        single substring, whose number is given as  stringnumber.  A  value  of
+        single  substring,  whose  number  is given as stringnumber. A value of
-        zero  extracts  the  substring that matched the entire pattern, whereas
+        zero extracts the substring that matched the  entire  pattern,  whereas
-        higher values  extract  the  captured  substrings.  For  pcre_copy_sub-
+        higher  values  extract  the  captured  substrings.  For pcre_copy_sub-
-        string(),  the  string  is  placed  in buffer, whose length is given by
+        string(), the string is placed in buffer,  whose  length  is  given  by
-        buffersize, while for pcre_get_substring() a new  block  of  memory  is
+        buffersize,  while  for  pcre_get_substring()  a new block of memory is
-        obtained  via  pcre_malloc,  and its address is returned via stringptr.
+        obtained via pcre_malloc, and its address is  returned  via  stringptr.
-        The yield of the function is the length of the  string,  not  including
+        The  yield  of  the function is the length of the string, not including
         the terminating zero, or one of these error codes:
           PCRE_ERROR_NOMEMORY       (-6)
-        The  buffer  was too small for pcre_copy_substring(), or the attempt to
+        The buffer was too small for pcre_copy_substring(), or the  attempt  to
         get memory failed for pcre_get_substring().
           PCRE_ERROR_NOSUBSTRING    (-7)
         There is no substring whose number is stringnumber.
-        The pcre_get_substring_list()  function  extracts  all  available  sub-
+        The  pcre_get_substring_list()  function  extracts  all  available sub-
-        strings  and  builds  a list of pointers to them. All this is done in a
+        strings and builds a list of pointers to them. All this is  done  in  a
         single block of memory that is obtained via pcre_malloc. The address of
-        the  memory  block  is returned via listptr, which is also the start of
+        the memory block is returned via listptr, which is also  the  start  of
-        the list of string pointers. The end of the list is marked  by  a  NULL
+        the  list  of  string pointers. The end of the list is marked by a NULL
-        pointer.  The  yield  of  the function is zero if all went well, or the
+        pointer. The yield of the function is zero if all  went  well,  or  the
         error code
           PCRE_ERROR_NOMEMORY       (-6)
         if the attempt to get the memory block failed.
-        When any of these functions encounter a substring that is unset,  which
+        When  any of these functions encounter a substring that is unset, which
-        can  happen  when  capturing subpattern number n+1 matches some part of
+        can happen when capturing subpattern number n+1 matches  some  part  of
-        the subject, but subpattern n has not been used at all, they return  an
+        the  subject, but subpattern n has not been used at all, they return an
         empty string. This can be distinguished from a genuine zero-length sub-
-        string by inspecting the appropriate offset in ovector, which is  nega-
+        string  by inspecting the appropriate offset in ovector, which is nega-
         tive for unset substrings.
-        The  two convenience functions pcre_free_substring() and pcre_free_sub-
+        The two convenience functions pcre_free_substring() and  pcre_free_sub-
-        string_list() can be used to free the memory  returned  by  a  previous
+        string_list()  can  be  used  to free the memory returned by a previous
         call  of  pcre_get_substring()  or  pcre_get_substring_list(),  respec-
-        tively. They do nothing more than  call  the  function  pointed  to  by
+        tively.  They  do  nothing  more  than  call the function pointed to by
-        pcre_free,  which  of course could be called directly from a C program.
+        pcre_free, which of course could be called directly from a  C  program.
-        However, PCRE is used in some situations where it is linked via a  spe-
+        However,  PCRE is used in some situations where it is linked via a spe-
-        cial   interface  to  another  programming  language  that  cannot  use
+        cial  interface  to  another  programming  language  that  cannot   use
-        pcre_free directly; it is for these cases that the functions  are  pro-
+        pcre_free  directly;  it is for these cases that the functions are pro-
         vided.
-Line 2353 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
+Line 2404 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
              int stringcount, const char *stringname,
              const char **stringptr);
-        To  extract a substring by name, you first have to find associated num-
+        To extract a substring by name, you first have to find associated  num-
         ber.  For example, for this pattern
           (a+)b(?<xxx>\d+)...
-Line 2362 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
+Line 2413 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
         be unique (PCRE_DUPNAMES was not set), you can find the number from the
         name by calling pcre_get_stringnumber(). The first argument is the com-
         piled pattern, and the second is the name. The yield of the function is
-        the subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if  there  is  no
+        the  subpattern  number,  or PCRE_ERROR_NOSUBSTRING (-7) if there is no
         subpattern of that name.
         Given the number, you can extract the substring directly, or use one of
         the functions described in the previous section. For convenience, there
         are also two functions that do the whole job.
-        Most    of    the    arguments   of   pcre_copy_named_substring()   and
+        Most   of   the   arguments    of    pcre_copy_named_substring()    and
-        pcre_get_named_substring() are the same  as  those  for  the  similarly
+        pcre_get_named_substring()  are  the  same  as  those for the similarly
-        named  functions  that extract by number. As these are described in the
+        named functions that extract by number. As these are described  in  the
-        previous section, they are not re-described here. There  are  just  two
+        previous  section,  they  are not re-described here. There are just two
         differences:
-        First,  instead  of a substring number, a substring name is given. Sec-
+        First, instead of a substring number, a substring name is  given.  Sec-
         ond, there is an extra argument, given at the start, which is a pointer
-        to  the compiled pattern. This is needed in order to gain access to the
+        to the compiled pattern. This is needed in order to gain access to  the
         name-to-number translation table.
-        These functions call pcre_get_stringnumber(), and if it succeeds,  they
+        These  functions call pcre_get_stringnumber(), and if it succeeds, they
-        then  call  pcre_copy_substring() or pcre_get_substring(), as appropri-
+        then call pcre_copy_substring() or pcre_get_substring(),  as  appropri-
-        ate. NOTE: If PCRE_DUPNAMES is set and there are duplicate  names,  the
+        ate.  NOTE:  If PCRE_DUPNAMES is set and there are duplicate names, the
         behaviour may not be what you want (see the next section).
+        Warning: If the pattern uses the "(?|" feature to set up multiple  sub-
+        patterns  with  the  same  number,  you cannot use names to distinguish
+        them, because names are not included in the compiled code. The matching
+        process uses only numbers.
  DUPLICATE SUBPATTERN NAMES
-Line 2448 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2504 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
         characteristics to the normal algorithm, and  is  not  compatible  with
         Perl.  Some  of the features of PCRE patterns are not supported. Never-
         theless, there are times when this kind of matching can be useful.  For
-        a discussion of the two matching algorithms, see the pcrematching docu-
+        a  discussion  of  the  two matching algorithms, and a list of features
-        mentation.
+        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
+        The  arguments  for  the  pcre_dfa_exec()  function are the same as for
         pcre_exec(), plus two extras. The ovector argument is used in a differ-
-        ent way, and this is described below. The other  common  arguments  are
+        ent  way,  and  this is described below. The other common arguments are
-        used  in  the  same way as for pcre_exec(), so their description is not
+        used in the same way as for pcre_exec(), so their  description  is  not
         repeated here.
-        The two additional arguments provide workspace for  the  function.  The
+        The  two  additional  arguments provide workspace for the function. The
-        workspace  vector  should  contain at least 20 elements. It is used for
+        workspace vector should contain at least 20 elements. It  is  used  for
         keeping  track  of  multiple  paths  through  the  pattern  tree.  More
-        workspace  will  be  needed for patterns and subjects where there are a
+        workspace will be needed for patterns and subjects where  there  are  a
         lot of potential matches.
         Here is an example of a simple call to pcre_dfa_exec():
-Line 2482 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2539 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
     Option bits for pcre_dfa_exec()
-        The unused bits of the options argument  for  pcre_dfa_exec()  must  be
+        The  unused  bits  of  the options argument for pcre_dfa_exec() must be
-        zero.  The  only  bits  that  may  be  set are PCRE_ANCHORED, PCRE_NEW-
+        zero. The only bits  that  may  be  set  are  PCRE_ANCHORED,  PCRE_NEW-
-        LINE_xxx, PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY,  PCRE_NO_UTF8_CHECK,
+        LINE_xxx,        PCRE_NOTBOL,        PCRE_NOTEOL,        PCRE_NOTEMPTY,
-        PCRE_PARTIAL, PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All but the last
+        PCRE_NOTEMPTY_ATSTART, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_HARD, PCRE_PAR-
-        three of these are the same as for pcre_exec(), so their description is
+        TIAL_SOFT,  PCRE_DFA_SHORTEST,  and  PCRE_DFA_RESTART. All but the last
-        not repeated here.
+        four of these are  exactly  the  same  as  for  pcre_exec(),  so  their
+        description is not repeated here.
-          PCRE_PARTIAL
+          PCRE_PARTIAL_HARD
-        This  has  the  same general effect as it does for pcre_exec(), but the
+          PCRE_PARTIAL_SOFT
-        details  are  slightly  different.  When  PCRE_PARTIAL   is   set   for
-        pcre_dfa_exec(),  the  return code PCRE_ERROR_NOMATCH is converted into
+        These  have the same general effect as they do for pcre_exec(), but the
-        PCRE_ERROR_PARTIAL if the end of the subject  is  reached,  there  have
+        details are slightly  different.  When  PCRE_PARTIAL_HARD  is  set  for
-        been no complete matches, but there is still at least one matching pos-
+        pcre_dfa_exec(),  it  returns PCRE_ERROR_PARTIAL if the end of the sub-
-        sibility. The portion of the string that provided the partial match  is
+        ject is reached and there is still at least  one  matching  possibility
-        set as the first matching string.
+        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.
           PCRE_DFA_SHORTEST
-Line 2508 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2571 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
           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 2537 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
+Line 2599 
 MATCHING A PATTERN: THE ALTERNATIVE FUNC
           <something> <something else>
           <something> <something else> <something further>
-        On  success,  the  yield of the function is a number greater than zero,
+        On success, the yield of the function is a number  greater  than  zero,
-        which is the number of matched substrings.  The  substrings  themselves
+        which  is  the  number of matched substrings. The substrings themselves
-        are  returned  in  ovector. Each string uses two elements; the first is
+        are returned in ovector. Each string uses two elements;  the  first  is
-        the offset to the start, and the second is the offset to  the  end.  In
+        the  offset  to  the start, and the second is the offset to the end. In
-        fact,  all  the  strings  have the same start offset. (Space could have
+        fact, all the strings have the same start  offset.  (Space  could  have
-        been saved by giving this only once, but it was decided to retain  some
+        been  saved by giving this only once, but it was decided to retain some
-        compatibility  with  the  way pcre_exec() returns data, even though the
+        compatibility with the way pcre_exec() returns data,  even  though  the
         meaning of the strings is different.)
         The strings are returned in reverse order of length; that is, the long-
-        est  matching  string is given first. If there were too many matches to
+        est matching string is given first. If there were too many  matches  to
-        fit into ovector, the yield of the function is zero, and the vector  is
+        fit  into ovector, the yield of the function is zero, and the vector is
         filled with the longest matches.
     Error returns from pcre_dfa_exec()
-        The  pcre_dfa_exec()  function returns a negative number when it fails.
+        The pcre_dfa_exec() function returns a negative number when  it  fails.
-        Many of the errors are the same  as  for  pcre_exec(),  and  these  are
+        Many  of  the  errors  are  the  same as for pcre_exec(), and these are
-        described  above.   There are in addition the following errors that are
+        described above.  There are in addition the following errors  that  are
         specific to pcre_dfa_exec():
           PCRE_ERROR_DFA_UITEM      (-16)
-        This return is given if pcre_dfa_exec() encounters an item in the  pat-
+        This  return is given if pcre_dfa_exec() encounters an item in the pat-
-        tern  that  it  does not support, for instance, the use of \C or a back
+        tern that it does not support, for instance, the use of \C  or  a  back
         reference.
           PCRE_ERROR_DFA_UCOND      (-17)
-        This return is given if pcre_dfa_exec()  encounters  a  condition  item
+        This  return  is  given  if pcre_dfa_exec() encounters a condition item
-        that  uses  a back reference for the condition, or a test for recursion
+        that uses a back reference for the condition, or a test  for  recursion
         in a specific group. These are not supported.
           PCRE_ERROR_DFA_UMLIMIT    (-18)
-        This return is given if pcre_dfa_exec() is called with an  extra  block
+        This  return  is given if pcre_dfa_exec() is called with an extra block
         that contains a setting of the match_limit field. This is not supported
         (it is meaningless).
           PCRE_ERROR_DFA_WSSIZE     (-19)
-        This return is given if  pcre_dfa_exec()  runs  out  of  space  in  the
+        This  return  is  given  if  pcre_dfa_exec()  runs  out of space in the
         workspace vector.
           PCRE_ERROR_DFA_RECURSE    (-20)
-        When  a  recursive subpattern is processed, the matching function calls
+        When a recursive subpattern is processed, the matching  function  calls
-        itself recursively, using private vectors for  ovector  and  workspace.
+        itself  recursively,  using  private vectors for ovector and workspace.
-        This  error  is  given  if  the output vector is not large enough. This
+        This error is given if the output vector  is  not  large  enough.  This
         should be extremely rare, as a vector of size 1000 is used.
  SEE ALSO
-        pcrebuild(3), pcrecallout(3), pcrecpp(3)(3), pcrematching(3),  pcrepar-
+        pcrebuild(3),  pcrecallout(3), pcrecpp(3)(3), pcrematching(3), pcrepar-
-        tial(3),  pcreposix(3), pcreprecompile(3), pcresample(3), pcrestack(3).
+        tial(3), pcreposix(3), pcreprecompile(3), pcresample(3), pcrestack(3).
  AUTHOR
-Line 2604 
 AUTHOR
+Line 2666 
 AUTHOR
  REVISION
-        Last updated: 12 April 2008
+        Last updated: 11 September 2009
-        Copyright (c) 1997-2008 University of Cambridge.
+        Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCRECALLOUT(3)                                                  PCRECALLOUT(3)
-Line 2656 
 PCRE CALLOUTS
+Line 2718 
 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 2666 
 MISSING CALLOUTS
+Line 2728 
 MISSING CALLOUTS
         ever  start,  and  the  callout is never reached. However, with "abyd",
         though the result is still no match, the callout is obeyed.
+        You can disable these optimizations by passing the  PCRE_NO_START_OPTI-
+        MIZE  option  to  pcre_exec()  or  pcre_dfa_exec(). This slows down the
+        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 2688 
 THE CALLOUT INTERFACE
+Line 2755 
 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 2775 
 AUTHOR
+Line 2842 
 AUTHOR
  REVISION
-        Last updated: 29 May 2007
+        Last updated: 15 March 2009
-        Copyright (c) 1997-2007 University of Cambridge.
+        Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCRECOMPAT(3)                                                    PCRECOMPAT(3)
-Line 2792 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2859 
 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  mainly
         with  respect  to  Perl 5.8, though PCRE versions 7.0 and later contain
-        some features that are expected to be in the forthcoming Perl 5.10.
+        some features that are in Perl 5.10.
 . PCRE has only a subset of Perl's UTF-8 and Unicode support.  Details
         of  what  it does have are given in the section on UTF-8 support in the
-Line 2824 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2891 
 DIFFERENCES BETWEEN PCRE AND PERL
         is  built  with Unicode character property support. The properties that
         can be tested with \p and \P are limited to the general category  prop-
         erties  such  as  Lu and Nd, script names such as Greek or Han, and the
-        derived properties Any and L&.
+        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 2844 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2915 
 DIFFERENCES BETWEEN PCRE AND PERL
 . Fairly obviously, PCRE does not support the (?{code}) and (??{code})
         constructions. However, there is support for recursive  patterns.  This
-        is  not available in Perl 5.8, but will be in Perl 5.10. 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.
 .  Subpatterns  that  are  called  recursively or as "subroutines" are
         always treated as atomic groups in  PCRE.  This  is  like  Python,  but
-        unlike Perl.
+        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
+        pcrecompat page.
 .  There are some differences that are concerned with the settings of
         captured strings when part of  a  pattern  is  repeated.  For  example,
-Line 2859 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2932 
 DIFFERENCES BETWEEN PCRE AND PERL
 .  PCRE  does  support  Perl  5.10's  backtracking  verbs  (*ACCEPT),
         (*FAIL),  (*F),  (*COMMIT), (*PRUNE), (*SKIP), and (*THEN), but only in
-        the forms without an  argument.  PCRE  does  not  support  (*MARK).  If
+        the forms without an argument. PCRE does not support (*MARK).
-        (*ACCEPT)  is within capturing parentheses, PCRE does not set that cap-
-        ture group; this is different to Perl.
 . PCRE provides some extensions to the Perl regular expression facil-
         ities.   Perl  5.10  will  include new features that are not in earlier
-Line 2886 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2957 
 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 escape sequence can be restricted to match only CR,  LF,  or
+        (g)  The  \R escape sequence can be restricted to match only CR, LF, or
         CRLF by the PCRE_BSR_ANYCRLF option.
         (h) The callout facility is PCRE-specific.
-Line 2899 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2971 
 DIFFERENCES BETWEEN PCRE AND PERL
         (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 alternative matching function (pcre_dfa_exec())  matches  in  a
+        (k)  The  alternative  matching function (pcre_dfa_exec()) matches in a
         different way and is not Perl-compatible.
-        (l)  PCRE  recognizes some special sequences such as (*CR) at the start
+        (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.
-Line 2916 
 AUTHOR
+Line 2988 
 AUTHOR
  REVISION
-        Last updated: 11 September 2007
+        Last updated: 18 September 2009
-        Copyright (c) 1997-2007 University of Cambridge.
+        Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCREPATTERN(3)                                                  PCREPATTERN(3)
-Line 2948 
 PCRE REGULAR EXPRESSION DETAILS
+Line 3020 
 PCRE REGULAR EXPRESSION DETAILS
         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
-        pcre_compile()  with  the  PCRE_UTF8  option.  How this affects pattern
+        pcre_compile()  with  the  PCRE_UTF8  option.  There  is also a special
-        matching is mentioned in several places below. There is also a  summary
+        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.
         The remainder of this document discusses the  patterns  that  are  sup-
         ported  by  PCRE when its main matching function, pcre_exec(), is used.
-Line 3055 
 CHARACTERS AND METACHARACTERS
+Line 3133 
 CHARACTERS AND METACHARACTERS
                    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 non-alphanumeric character, it takes away any  special  meaning  that
-        character may have. This  use  of  backslash  as  an  escape  character
+        character  may  have.  This  use  of  backslash  as an escape 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
+        If  a  pattern is compiled with the PCRE_EXTENDED option, whitespace in
-        the  pattern (other than in a character class) and characters between a
+        the pattern (other than in a character class) and characters between  a
         # outside a character class and the next newline are ignored. An escap-
-        ing  backslash  can  be  used to include a whitespace or # character as
+        ing backslash can be used to include a whitespace  or  #  character  as
         part of the pattern.
-        If you want to remove the special meaning from a  sequence  of  charac-
+        If  you  want  to remove the special meaning from a sequence of charac-
-        ters,  you can do so by putting them between \Q and \E. This is differ-
+        ters, you can do so by putting them between \Q and \E. This is  differ-
-        ent from Perl in that $ and  @  are  handled  as  literals  in  \Q...\E
+        ent  from  Perl  in  that  $  and  @ are handled as literals in \Q...\E
-        sequences  in  PCRE, whereas in Perl, $ and @ cause variable interpola-
+        sequences in PCRE, whereas in Perl, $ and @ cause  variable  interpola-
         tion. Note the following examples:
           Pattern            PCRE matches   Perl matches
-Line 3091 
 BACKSLASH
+Line 3169 
 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.
     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 usually easier  to  use  one  of  the  following  escape
         sequences than the binary character it represents:
           \a        alarm, that is, the BEL character (hex 07)
-Line 3114 
 BACKSLASH
+Line 3192 
 BACKSLASH
           \xhh      character with hex code hh
           \x{hhh..} character with hex code hhh..
-        The precise effect of \cx is as follows: if x is a lower  case  letter,
+        The  precise  effect of \cx is as follows: if x is a lower case letter,
-        it  is converted to upper case. Then bit 6 of the character (hex 40) is
+        it is converted to upper case. Then bit 6 of the character (hex 40)  is
-        inverted.  Thus \cz becomes hex 1A, but \c{ becomes hex 3B,  while  \c;
+        inverted.   Thus  \cz becomes hex 1A, but \c{ becomes hex 3B, while \c;
         becomes hex 7B.
-        After  \x, from zero to two hexadecimal digits are read (letters can be
+        After \x, from zero to two hexadecimal digits are read (letters can  be
-        in upper or lower case). Any number of hexadecimal  digits  may  appear
+        in  upper  or  lower case). Any number of hexadecimal digits may appear
-        between  \x{  and  },  but the value of the character code must be less
+        between \x{ and }, but the value of the character  code  must  be  less
         than 256 in non-UTF-8 mode, and less than 2**31 in UTF-8 mode. That is,
-        the  maximum value in hexadecimal is 7FFFFFFF. Note that this is bigger
+        the maximum value in hexadecimal is 7FFFFFFF. Note that this is  bigger
         than the largest Unicode code point, which is 10FFFF.
-        If characters other than hexadecimal digits appear between \x{  and  },
+        If  characters  other than hexadecimal digits appear between \x{ and },
         or if there is no terminating }, this form of escape is not recognized.
-        Instead, the initial \x will be  interpreted  as  a  basic  hexadecimal
+        Instead,  the  initial  \x  will  be interpreted as a basic hexadecimal
-        escape,  with  no  following  digits, giving a character whose value is
+        escape, with no following digits, giving a  character  whose  value  is
         zero.
         Characters whose value is less than 256 can be defined by either of the
-        two  syntaxes  for  \x. There is no difference in the way they are han-
+        two syntaxes for \x. There is no difference in the way  they  are  han-
         dled. For example, \xdc is exactly the same as \x{dc}.
-        After \0 up to two further octal digits are read. If  there  are  fewer
+        After  \0  up  to two further octal digits are read. If there are fewer
-        than  two  digits,  just  those  that  are  present  are used. Thus the
+        than two digits, just  those  that  are  present  are  used.  Thus  the
         sequence \0\x\07 specifies two binary zeros followed by a BEL character
-        (code  value 7). Make sure you supply two digits after the initial zero
+        (code value 7). Make sure you supply two digits after the initial  zero
         if the pattern character that follows is itself an octal digit.
         The handling of a backslash followed by a digit other than 0 is compli-
         cated.  Outside a character class, PCRE reads it and any following dig-
-        its as a decimal number. If the number is less than  10,  or  if  there
+        its  as  a  decimal  number. If the number is less than 10, or if there
         have been at least that many previous capturing left parentheses in the
-        expression, the entire  sequence  is  taken  as  a  back  reference.  A
+        expression,  the  entire  sequence  is  taken  as  a  back reference. A
-        description  of how this works is given later, following the discussion
+        description of how this works is given later, following the  discussion
         of parenthesized subpatterns.
-        Inside a character class, or if the decimal number is  greater  than  9
+        Inside  a  character  class, or if the decimal number is greater than 9
-        and  there have not been that many capturing subpatterns, PCRE re-reads
+        and there have not been that many capturing subpatterns, PCRE  re-reads
         up to three octal digits following the backslash, and uses them to gen-
-        erate  a data character. Any subsequent digits stand for themselves. In
+        erate a data character. Any subsequent digits stand for themselves.  In
-        non-UTF-8 mode, the value of a character specified  in  octal  must  be
+        non-UTF-8  mode,  the  value  of a character specified in octal must be
-        less  than  \400.  In  UTF-8 mode, values up to \777 are permitted. For
+        less than \400. In UTF-8 mode, values up to  \777  are  permitted.  For
         example:
           \040   is another way of writing a space
-Line 3173 
 BACKSLASH
+Line 3251 
 BACKSLASH
           \81    is either a back reference, or a binary zero
                     followed by the two characters "8" and "1"
-        Note that octal values of 100 or greater must not be  introduced  by  a
+        Note  that  octal  values of 100 or greater must not be introduced by a
         leading zero, because no more than three octal digits are ever read.
         All the sequences that define a single character value can be used both
-        inside and outside character classes. In addition, inside  a  character
+        inside  and  outside character classes. In addition, inside a character
-        class,  the  sequence \b is interpreted as the backspace character (hex
+        class, the sequence \b is interpreted as the backspace  character  (hex
-), and the sequences \R and \X are interpreted as the characters  "R"
+),  and the sequences \R and \X are interpreted as the characters "R"
-        and  "X", respectively. Outside a character class, these sequences have
+        and "X", respectively. Outside a character class, these sequences  have
         different meanings (see below).
     Absolute and relative back references
-        The sequence \g followed by an unsigned or a negative  number,  option-
+        The  sequence  \g followed by an unsigned or a negative number, option-
-        ally  enclosed  in braces, is an absolute or relative back reference. A
+        ally enclosed in braces, is an absolute or relative back  reference.  A
         named back reference can be coded as \g{name}. Back references are dis-
         cussed later, following the discussion of parenthesized subpatterns.
     Absolute and relative subroutine calls
-        For  compatibility with Oniguruma, the non-Perl syntax \g followed by a
+        For compatibility with Oniguruma, the non-Perl syntax \g followed by  a
         name or a number enclosed either in angle brackets or single quotes, is
-        an  alternative  syntax for referencing a subpattern as a "subroutine".
+        an alternative syntax for referencing a subpattern as  a  "subroutine".
-        Details are discussed later.   Note  that  \g{...}  (Perl  syntax)  and
+        Details  are  discussed  later.   Note  that  \g{...} (Perl syntax) and
-        \g<...>  (Oniguruma  syntax)  are  not synonymous. The former is a back
+        \g<...> (Oniguruma syntax) are not synonymous. The  former  is  a  back
         reference; the latter is a subroutine call.
     Generic character types
-Line 3216 
 BACKSLASH
+Line 3294 
 BACKSLASH
           \W     any "non-word" character
         Each pair of escape sequences partitions the complete set of characters
-        into two disjoint sets. Any given character matches one, and only  one,
+        into  two disjoint sets. Any given character matches one, and only one,
         of each pair.
         These character type sequences can appear both inside and outside char-
-        acter classes. They each match one character of the  appropriate  type.
+        acter  classes.  They each match one character of the appropriate type.
-        If  the current matching point is at the end of the subject string, all
+        If the current matching point is at the end of the subject string,  all
         of them fail, since there is no character to match.
-        For compatibility with Perl, \s does not match the VT  character  (code
+        For  compatibility  with Perl, \s does not match the VT character (code
-).   This makes it different from the the POSIX "space" class. The \s
+).  This makes it different from the the POSIX "space" class. The  \s
-        characters are HT (9), LF (10), FF (12), CR (13), and  space  (32).  If
+        characters  are  HT  (9), LF (10), FF (12), CR (13), and space (32). If
         "use locale;" is included in a Perl script, \s may match the VT charac-
         ter. In PCRE, it never does.
-        In UTF-8 mode, characters with values greater than 128 never match  \d,
+        In  UTF-8 mode, characters with values greater than 128 never match \d,
         \s, or \w, and always match \D, \S, and \W. This is true even when Uni-
-        code character property support is available.  These  sequences  retain
+        code  character  property  support is available. These sequences retain
         their original meanings from before UTF-8 support was available, mainly
-        for efficiency reasons.
+        for  efficiency  reasons. Note that this also affects \b, because it is
+        defined in terms of \w and \W.
         The sequences \h, \H, \v, and \V are Perl 5.10 features. In contrast to
         the  other  sequences, these do match certain high-valued codepoints in
-Line 3428 
 BACKSLASH
+Line 3507 
 BACKSLASH
         U+D800 to U+DFFF. Such characters are not valid in UTF-8  strings  (see
         RFC 3629) and so cannot be tested by PCRE, unless UTF-8 validity check-
         ing has been turned off (see the discussion  of  PCRE_NO_UTF8_CHECK  in
-        the pcreapi page).
+        the pcreapi page). Perl does not support the Cs property.
-        The  long  synonyms  for  these  properties that Perl supports (such as
+        The  long  synonyms  for  property  names  that  Perl supports (such as
         \p{Letter}) are not supported by PCRE, nor is it  permitted  to  prefix
         any of these properties with "Is".
-Line 3760 
 POSIX CHARACTER CLASSES
+Line 3839 
 POSIX CHARACTER CLASSES
  VERTICAL BAR
-        Vertical  bar characters are used to separate alternative patterns. For
+        Vertical bar characters are used to separate alternative patterns.  For
         example, the pattern
           gilbert|sullivan
-        matches either "gilbert" or "sullivan". Any number of alternatives  may
+        matches  either "gilbert" or "sullivan". Any number of alternatives may
-        appear,  and  an  empty  alternative  is  permitted (matching the empty
+        appear, and an empty  alternative  is  permitted  (matching  the  empty
         string). The matching process tries each alternative in turn, from left
-        to  right, and the first one that succeeds is used. If the alternatives
+        to right, and the first one that succeeds is used. If the  alternatives
-        are within a subpattern (defined below), "succeeds" means matching  the
+        are  within a subpattern (defined below), "succeeds" means matching the
-        rest  of the main pattern as well as the alternative in the subpattern.
+        rest of the main pattern as well as the alternative in the subpattern.
  INTERNAL OPTION SETTING
-Line 3796 
 INTERNAL OPTION SETTING
+Line 3875 
 INTERNAL OPTION SETTING
         can  be changed in the same way as the Perl-compatible options by using
         the characters J, U and X respectively.
-        When an option change occurs at top level (that is, not inside  subpat-
+        When one of these option changes occurs at  top  level  (that  is,  not
-        tern  parentheses),  the change applies to the remainder of the pattern
+        inside  subpattern parentheses), the change applies to the remainder of
-        that follows.  If the change is placed right at the start of a pattern,
+        the pattern that follows. If the change is placed right at the start of
-        PCRE extracts it into the global options (and it will therefore show up
+        a pattern, PCRE extracts it into the global options (and it will there-
-        in data extracted by the pcre_fullinfo() function).
+        fore show up in data extracted by the pcre_fullinfo() function).
         An option change within a subpattern (see below for  a  description  of
         subpatterns) affects only that part of the current pattern that follows
-Line 3823 
 INTERNAL OPTION SETTING
+Line 3902 
 INTERNAL OPTION SETTING
         Note:  There  are  other  PCRE-specific  options that can be set by the
         application when the compile or match functions  are  called.  In  some
-        cases  the  pattern  can  contain special leading sequences to override
+        cases the pattern can contain special leading sequences such as (*CRLF)
-        what the application has set or what has been  defaulted.  Details  are
+        to override what the application has set or what  has  been  defaulted.
-        given in the section entitled "Newline sequences" above.
+        Details  are  given  in the section entitled "Newline sequences" above.
+        There is also the (*UTF8) leading sequence that  can  be  used  to  set
+        UTF-8 mode; this is equivalent to setting the PCRE_UTF8 option.
  SUBPATTERNS
-Line 3964 
 NAMED SUBPATTERNS
+Line 4045 
 NAMED SUBPATTERNS
         lowest  number  is used. For further details of the interfaces for han-
         dling named subpatterns, see the pcreapi documentation.
+        Warning: You cannot use different names to distinguish between two sub-
+        patterns  with  the same number (see the previous section) because PCRE
+        uses only the numbers when matching.
  REPETITION
-Line 4004 
 REPETITION
+Line 4089 
 REPETITION
         the syntax of a quantifier, is taken as a literal character. For  exam-
         ple, {,6} is not a quantifier, but a literal string of four characters.
-        In UTF-8 mode, quantifiers apply to UTF-8  characters  rather  than  to
+        In  UTF-8  mode,  quantifiers  apply to UTF-8 characters rather than to
         individual bytes. Thus, for example, \x{100}{2} matches two UTF-8 char-
         acters, each of which is represented by a two-byte sequence. Similarly,
         when Unicode property support is available, \X{3} matches three Unicode
-        extended sequences, each of which may be several bytes long  (and  they
+        extended  sequences,  each of which may be several bytes long (and they
         may be of different lengths).
         The quantifier {0} is permitted, causing the expression to behave as if
         the previous item and the quantifier were not present. This may be use-
-        ful  for  subpatterns that are referenced as subroutines from elsewhere
+        ful for subpatterns that are referenced as subroutines  from  elsewhere
         in the pattern. Items other than subpatterns that have a {0} quantifier
         are omitted from the compiled pattern.
-        For  convenience, the three most common quantifiers have single-charac-
+        For convenience, the three most common quantifiers have  single-charac-
         ter abbreviations:
           *    is equivalent to {0,}
           +    is equivalent to {1,}
           ?    is equivalent to {0,1}
-        It is possible to construct infinite loops by  following  a  subpattern
+        It  is  possible  to construct infinite loops by following a subpattern
         that can match no characters with a quantifier that has no upper limit,
         for example:
           (a?)*
         Earlier versions of Perl and PCRE used to give an error at compile time
-        for  such  patterns. However, because there are cases where this can be
+        for such patterns. However, because there are cases where this  can  be
-        useful, such patterns are now accepted, but if any  repetition  of  the
+        useful,  such  patterns  are now accepted, but if any repetition of the
-        subpattern  does in fact match no characters, the loop is forcibly bro-
+        subpattern does in fact match no characters, the loop is forcibly  bro-
         ken.
-        By default, the quantifiers are "greedy", that is, they match  as  much
+        By  default,  the quantifiers are "greedy", that is, they match as much
-        as  possible  (up  to  the  maximum number of permitted times), without
+        as possible (up to the maximum  number  of  permitted  times),  without
-        causing the rest of the pattern to fail. The classic example  of  where
+        causing  the  rest of the pattern to fail. The classic example of where
         this gives problems is in trying to match comments in C programs. These
-        appear between /* and */ and within the comment,  individual  *  and  /
+        appear  between  /*  and  */ and within the comment, individual * and /
-        characters  may  appear. An attempt to match C comments by applying the
+        characters may appear. An attempt to match C comments by  applying  the
         pattern
           /\*.*\*/
-Line 4050 
 REPETITION
+Line 4135 
 REPETITION
           /* first comment */  not comment  /* second comment */
-        fails, because it matches the entire string owing to the greediness  of
+        fails,  because it matches the entire string owing to the greediness of
         the .*  item.
-        However,  if  a quantifier is followed by a question mark, it ceases to
+        However, if a quantifier is followed by a question mark, it  ceases  to
         be greedy, and instead matches the minimum number of times possible, so
         the pattern
           /\*.*?\*/
-        does  the  right  thing with the C comments. The meaning of the various
+        does the right thing with the C comments. The meaning  of  the  various
-        quantifiers is not otherwise changed,  just  the  preferred  number  of
+        quantifiers  is  not  otherwise  changed,  just the preferred number of
-        matches.   Do  not  confuse this use of question mark with its use as a
+        matches.  Do not confuse this use of question mark with its  use  as  a
-        quantifier in its own right. Because it has two uses, it can  sometimes
+        quantifier  in its own right. Because it has two uses, it can sometimes
         appear doubled, as in
           \d??\d
-Line 4070 
 REPETITION
+Line 4155 
 REPETITION
         which matches one digit by preference, but can match two if that is the
         only way the rest of the pattern matches.
-        If the PCRE_UNGREEDY option is set (an option that is not available  in
+        If  the PCRE_UNGREEDY option is set (an option that is not available in
-        Perl),  the  quantifiers are not greedy by default, but individual ones
+        Perl), the quantifiers are not greedy by default, but  individual  ones
-        can be made greedy by following them with a  question  mark.  In  other
+        can  be  made  greedy  by following them with a question mark. In other
         words, it inverts the default behaviour.
-        When  a  parenthesized  subpattern  is quantified with a minimum repeat
+        When a parenthesized subpattern is quantified  with  a  minimum  repeat
-        count that is greater than 1 or with a limited maximum, more memory  is
+        count  that is greater than 1 or with a limited maximum, more memory is
-        required  for  the  compiled  pattern, in proportion to the size of the
+        required for the compiled pattern, in proportion to  the  size  of  the
         minimum or maximum.
         If a pattern starts with .* or .{0,} and the PCRE_DOTALL option (equiv-
-        alent  to  Perl's  /s) is set, thus allowing the dot to match newlines,
+        alent to Perl's /s) is set, thus allowing the dot  to  match  newlines,
-        the pattern is implicitly anchored, because whatever  follows  will  be
+        the  pattern  is  implicitly anchored, because whatever follows will be
-        tried  against every character position in the subject string, so there
+        tried against every character position in the subject string, so  there
-        is no point in retrying the overall match at  any  position  after  the
+        is  no  point  in  retrying the overall match at any position after the
-        first.  PCRE  normally treats such a pattern as though it were preceded
+        first. PCRE normally treats such a pattern as though it  were  preceded
         by \A.
-        In cases where it is known that the subject  string  contains  no  new-
+        In  cases  where  it  is known that the subject string contains no new-
-        lines,  it  is  worth setting PCRE_DOTALL in order to obtain this opti-
+        lines, it is worth setting PCRE_DOTALL in order to  obtain  this  opti-
         mization, or alternatively using ^ to indicate anchoring explicitly.
-        However, there is one situation where the optimization cannot be  used.
+        However,  there is one situation where the optimization cannot be used.
-        When  .*   is  inside  capturing  parentheses that are the subject of a
+        When .*  is inside capturing parentheses that  are  the  subject  of  a
-        backreference elsewhere in the pattern, a match at the start  may  fail
+        backreference  elsewhere  in the pattern, a match at the start may fail
         where a later one succeeds. Consider, for example:
           (.*)abc\1
-        If  the subject is "xyz123abc123" the match point is the fourth charac-
+        If the subject is "xyz123abc123" the match point is the fourth  charac-
         ter. For this reason, such a pattern is not implicitly anchored.
         When a capturing subpattern is repeated, the value captured is the sub-
-Line 4108 
 REPETITION
+Line 4193 
 REPETITION
           (tweedle[dume]{3}\s*)+
         has matched "tweedledum tweedledee" the value of the captured substring
-        is "tweedledee". However, if there are  nested  capturing  subpatterns,
+        is  "tweedledee".  However,  if there are nested capturing subpatterns,
-        the  corresponding captured values may have been set in previous itera-
+        the corresponding captured values may have been set in previous  itera-
         tions. For example, after
           /(a|(b))+/
-Line 4119 
 REPETITION
+Line 4204 
 REPETITION
  ATOMIC GROUPING AND POSSESSIVE QUANTIFIERS
-        With both maximizing ("greedy") and minimizing ("ungreedy"  or  "lazy")
+        With  both  maximizing ("greedy") and minimizing ("ungreedy" or "lazy")
-        repetition,  failure  of what follows normally causes the repeated item
+        repetition, failure of what follows normally causes the  repeated  item
-        to be re-evaluated to see if a different number of repeats  allows  the
+        to  be  re-evaluated to see if a different number of repeats allows the
-        rest  of  the pattern to match. Sometimes it is useful to prevent this,
+        rest of the pattern to match. Sometimes it is useful to  prevent  this,
-        either to change the nature of the match, or to cause it  fail  earlier
+        either  to  change the nature of the match, or to cause it fail earlier
-        than  it otherwise might, when the author of the pattern knows there is
+        than it otherwise might, when the author of the pattern knows there  is
         no point in carrying on.
-        Consider, for example, the pattern \d+foo when applied to  the  subject
+        Consider,  for  example, the pattern \d+foo when applied to the subject
         line
 bar
         After matching all 6 digits and then failing to match "foo", the normal
-        action of the matcher is to try again with only 5 digits  matching  the
+        action  of  the matcher is to try again with only 5 digits matching the
-        \d+  item,  and  then  with  4,  and  so on, before ultimately failing.
+        \d+ item, and then with  4,  and  so  on,  before  ultimately  failing.
-        "Atomic grouping" (a term taken from Jeffrey  Friedl's  book)  provides
+        "Atomic  grouping"  (a  term taken from Jeffrey Friedl's book) provides
-        the  means for specifying that once a subpattern has matched, it is not
+        the means for specifying that once a subpattern has matched, it is  not
         to be re-evaluated in this way.
-        If we use atomic grouping for the previous example, the  matcher  gives
+        If  we  use atomic grouping for the previous example, the matcher gives
-        up  immediately  on failing to match "foo" the first time. The notation
+        up immediately on failing to match "foo" the first time.  The  notation
         is a kind of special parenthesis, starting with (?> as in this example:
           (?>\d+)foo
-Line 4218 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
+Line 4303 
 ATOMIC GROUPING AND POSSESSIVE QUANTIFIE
           ((?>\D+)|<\d+>)*[!?]
-        sequences of non-digits cannot be broken, and failure happens  quickly.
+        sequences of non-digits cannot be broken, and failure happens quickly.
  BACK REFERENCES
         Outside a character class, a backslash followed by a digit greater than
 (and possibly further digits) is a back reference to a capturing sub-
-        pattern  earlier  (that is, to its left) in the pattern, provided there
+        pattern earlier (that is, to its left) in the pattern,  provided  there
         have been that many previous capturing left parentheses.
         However, if the decimal number following the backslash is less than 10,
-        it  is  always  taken  as a back reference, and causes an error only if
+        it is always taken as a back reference, and causes  an  error  only  if
-        there are not that many capturing left parentheses in the  entire  pat-
+        there  are  not that many capturing left parentheses in the entire pat-
-        tern.  In  other words, the parentheses that are referenced need not be
+        tern. In other words, the parentheses that are referenced need  not  be
-        to the left of the reference for numbers less than 10. A "forward  back
+        to  the left of the reference for numbers less than 10. A "forward back
-        reference"  of  this  type can make sense when a repetition is involved
+        reference" of this type can make sense when a  repetition  is  involved
-        and the subpattern to the right has participated in an  earlier  itera-
+        and  the  subpattern to the right has participated in an earlier itera-
         tion.
-        It  is  not  possible to have a numerical "forward back reference" to a
+        It is not possible to have a numerical "forward back  reference"  to  a
-        subpattern whose number is 10 or  more  using  this  syntax  because  a
+        subpattern  whose  number  is  10  or  more using this syntax because a
-        sequence  such  as  \50 is interpreted as a character defined in octal.
+        sequence such as \50 is interpreted as a character  defined  in  octal.
         See the subsection entitled "Non-printing characters" above for further
-        details  of  the  handling of digits following a backslash. There is no
+        details of the handling of digits following a backslash.  There  is  no
-        such problem when named parentheses are used. A back reference  to  any
+        such  problem  when named parentheses are used. A back reference to any
         subpattern is possible using named parentheses (see below).
-        Another  way  of  avoiding  the ambiguity inherent in the use of digits
+        Another way of avoiding the ambiguity inherent in  the  use  of  digits
         following a backslash is to use the \g escape sequence, which is a fea-
-        ture  introduced  in  Perl  5.10.  This  escape  must be followed by an
+        ture introduced in Perl 5.10.  This  escape  must  be  followed  by  an
-        unsigned number or a negative number, optionally  enclosed  in  braces.
+        unsigned  number  or  a negative number, optionally enclosed in braces.
         These examples are all identical:
           (ring), \1
           (ring), \g1
           (ring), \g{1}
-        An  unsigned number specifies an absolute reference without the ambigu-
+        An unsigned number specifies an absolute reference without the  ambigu-
         ity that is present in the older syntax. It is also useful when literal
         digits follow the reference. A negative number is a relative reference.
         Consider this example:
-Line 4263 
 BACK REFERENCES
+Line 4348 
 BACK REFERENCES
           (abc(def)ghi)\g{-1}
         The sequence \g{-1} is a reference to the most recently started captur-
-        ing  subpattern  before \g, that is, is it equivalent to \2. Similarly,
+        ing subpattern before \g, that is, is it equivalent to  \2.  Similarly,
         \g{-2} would be equivalent to \1. The use of relative references can be
-        helpful  in  long  patterns,  and  also in patterns that are created by
+        helpful in long patterns, and also in  patterns  that  are  created  by
         joining together fragments that contain references within themselves.
-        A back reference matches whatever actually matched the  capturing  sub-
+        A  back  reference matches whatever actually matched the capturing sub-
-        pattern  in  the  current subject string, rather than anything matching
+        pattern in the current subject string, rather  than  anything  matching
         the subpattern itself (see "Subpatterns as subroutines" below for a way
         of doing that). So the pattern
           (sens|respons)e and \1ibility
-        matches  "sense and sensibility" and "response and responsibility", but
+        matches "sense and sensibility" and "response and responsibility",  but
-        not "sense and responsibility". If caseful matching is in force at  the
+        not  "sense and responsibility". If caseful matching is in force at the
-        time  of the back reference, the case of letters is relevant. For exam-
+        time of the back reference, the case of letters is relevant. For  exam-
         ple,
           ((?i)rah)\s+\1
-        matches "rah rah" and "RAH RAH", but not "RAH  rah",  even  though  the
+        matches  "rah  rah"  and  "RAH RAH", but not "RAH rah", even though the
         original capturing subpattern is matched caselessly.
-        There  are  several  different ways of writing back references to named
+        There are several different ways of writing back  references  to  named
-        subpatterns. The .NET syntax \k{name} and the Perl syntax  \k<name>  or
+        subpatterns.  The  .NET syntax \k{name} and the Perl syntax \k<name> or
-        \k'name'  are supported, as is the Python syntax (?P=name). Perl 5.10's
+        \k'name' are supported, as is the Python syntax (?P=name). Perl  5.10's
         unified back reference syntax, in which \g can be used for both numeric
-        and  named  references,  is  also supported. We could rewrite the above
+        and named references, is also supported. We  could  rewrite  the  above
         example in any of the following ways:
           (?<p1>(?i)rah)\s+\k<p1>
-Line 4297 
 BACK REFERENCES
+Line 4382 
 BACK REFERENCES
           (?P<p1>(?i)rah)\s+(?P=p1)
           (?<p1>(?i)rah)\s+\g{p1}
-        A subpattern that is referenced by  name  may  appear  in  the  pattern
+        A  subpattern  that  is  referenced  by  name may appear in the pattern
         before or after the reference.
-        There  may be more than one back reference to the same subpattern. If a
+        There may be more than one back reference to the same subpattern. If  a
-        subpattern has not actually been used in a particular match,  any  back
+        subpattern  has  not actually been used in a particular match, any back
         references to it always fail. For example, the pattern
           (a|(bc))\2
-        always  fails if it starts to match "a" rather than "bc". Because there
+        always fails if it starts to match "a" rather than "bc". Because  there
-        may be many capturing parentheses in a pattern,  all  digits  following
+        may  be  many  capturing parentheses in a pattern, all digits following
-        the  backslash  are taken as part of a potential back reference number.
+        the backslash are taken as part of a potential back  reference  number.
         If the pattern continues with a digit character, some delimiter must be
-        used  to  terminate  the back reference. If the PCRE_EXTENDED option is
+        used to terminate the back reference. If the  PCRE_EXTENDED  option  is
-        set, this can be whitespace.  Otherwise an  empty  comment  (see  "Com-
+        set,  this  can  be  whitespace.  Otherwise an empty comment (see "Com-
         ments" below) can be used.
-        A  back reference that occurs inside the parentheses to which it refers
+        A back reference that occurs inside the parentheses to which it  refers
-        fails when the subpattern is first used, so, for example,  (a\1)  never
+        fails  when  the subpattern is first used, so, for example, (a\1) never
-        matches.   However,  such references can be useful inside repeated sub-
+        matches.  However, such references can be useful inside  repeated  sub-
         patterns. For example, the pattern
           (a|b\1)+
         matches any number of "a"s and also "aba", "ababbaa" etc. At each iter-
-        ation  of  the  subpattern,  the  back  reference matches the character
+        ation of the subpattern,  the  back  reference  matches  the  character
-        string corresponding to the previous iteration. In order  for  this  to
+        string  corresponding  to  the previous iteration. In order for this to
-        work,  the  pattern must be such that the first iteration does not need
+        work, the pattern must be such that the first iteration does  not  need
-        to match the back reference. This can be done using alternation, as  in
+        to  match the back reference. This can be done using alternation, as in
         the example above, or by a quantifier with a minimum of zero.
  ASSERTIONS
-        An  assertion  is  a  test on the characters following or preceding the
+        An assertion is a test on the characters  following  or  preceding  the
-        current matching point that does not actually consume  any  characters.
+        current  matching  point that does not actually consume any characters.
-        The  simple  assertions  coded  as  \b, \B, \A, \G, \Z, \z, ^ and $ are
+        The simple assertions coded as \b, \B, \A, \G, \Z,  \z,  ^  and  $  are
         described above.
-        More complicated assertions are coded as  subpatterns.  There  are  two
+        More  complicated  assertions  are  coded as subpatterns. There are two
-        kinds:  those  that  look  ahead of the current position in the subject
+        kinds: those that look ahead of the current  position  in  the  subject
-        string, and those that look  behind  it.  An  assertion  subpattern  is
+        string,  and  those  that  look  behind  it. An assertion subpattern is
-        matched  in  the  normal way, except that it does not cause the current
+        matched in the normal way, except that it does not  cause  the  current
         matching position to be changed.
-        Assertion subpatterns are not capturing subpatterns,  and  may  not  be
+        Assertion  subpatterns  are  not  capturing subpatterns, and may not be
-        repeated,  because  it  makes no sense to assert the same thing several
+        repeated, because it makes no sense to assert the  same  thing  several
-        times. If any kind of assertion contains capturing  subpatterns  within
+        times.  If  any kind of assertion contains capturing subpatterns within
-        it,  these are counted for the purposes of numbering the capturing sub-
+        it, these are counted for the purposes of numbering the capturing  sub-
         patterns in the whole pattern.  However, substring capturing is carried
-        out  only  for  positive assertions, because it does not make sense for
+        out only for positive assertions, because it does not  make  sense  for
         negative assertions.
     Lookahead assertions
-Line 4357 
 ASSERTIONS
+Line 4442 
 ASSERTIONS
           \w+(?=;)
-        matches  a word followed by a semicolon, but does not include the semi-
+        matches a word followed by a semicolon, but does not include the  semi-
         colon in the match, and
           foo(?!bar)
-        matches any occurrence of "foo" that is not  followed  by  "bar".  Note
+        matches  any  occurrence  of  "foo" that is not followed by "bar". Note
         that the apparently similar pattern
           (?!foo)bar
-        does  not  find  an  occurrence  of "bar" that is preceded by something
+        does not find an occurrence of "bar"  that  is  preceded  by  something
-        other than "foo"; it finds any occurrence of "bar" whatsoever,  because
+        other  than "foo"; it finds any occurrence of "bar" whatsoever, because
         the assertion (?!foo) is always true when the next three characters are
         "bar". A lookbehind assertion is needed to achieve the other effect.
         If you want to force a matching failure at some point in a pattern, the
-        most  convenient  way  to  do  it  is with (?!) because an empty string
+        most convenient way to do it is  with  (?!)  because  an  empty  string
-        always matches, so an assertion that requires there not to be an  empty
+        always  matches, so an assertion that requires there not to be an empty
         string must always fail.
     Lookbehind assertions
-        Lookbehind  assertions start with (?<= for positive assertions and (?<!
+        Lookbehind assertions start with (?<= for positive assertions and  (?<!
         for negative assertions. For example,
           (?<!foo)bar
-        does find an occurrence of "bar" that is not  preceded  by  "foo".  The
+        does  find  an  occurrence  of "bar" that is not preceded by "foo". The
-        contents  of  a  lookbehind  assertion are restricted such that all the
+        contents of a lookbehind assertion are restricted  such  that  all  the
         strings it matches must have a fixed length. However, if there are sev-
-        eral  top-level  alternatives,  they  do  not all have to have the same
+        eral top-level alternatives, they do not all  have  to  have  the  same
         fixed length. Thus
           (?<=bullock|donkey)
-Line 4396 
 ASSERTIONS
+Line 4481 
 ASSERTIONS
           (?<!dogs?|cats?)
-        causes an error at compile time. Branches that match  different  length
+        causes  an  error at compile time. Branches that match different length
-        strings  are permitted only at the top level of a lookbehind assertion.
+        strings are permitted only at the top level of a lookbehind  assertion.
-        This is an extension compared with  Perl  (at  least  for  5.8),  which
+        This  is  an  extension  compared  with  Perl (at least for 5.8), which
-        requires  all branches to match the same length of string. An assertion
+        requires all branches to match the same length of string. An  assertion
         such as
           (?<=ab(c|de))
-        is not permitted, because its single top-level  branch  can  match  two
+        is  not  permitted,  because  its single top-level branch can match two
-        different  lengths,  but  it is acceptable if rewritten to use two top-
+        different lengths, but it is acceptable if rewritten to  use  two  top-
         level branches:
           (?<=abc|abde)
         In some cases, the Perl 5.10 escape sequence \K (see above) can be used
-        instead  of  a lookbehind assertion; this is not restricted to a fixed-
+        instead of a lookbehind assertion; this is not restricted to  a  fixed-
         length.
-        The implementation of lookbehind assertions is, for  each  alternative,
+        The  implementation  of lookbehind assertions is, for each alternative,
-        to  temporarily  move the current position back by the fixed length and
+        to temporarily move the current position back by the fixed  length  and
         then try to match. If there are insufficient characters before the cur-
         rent position, the assertion fails.
         PCRE does not allow the \C escape (which matches a single byte in UTF-8
-        mode) to appear in lookbehind assertions, because it makes it  impossi-
+        mode)  to appear in lookbehind assertions, because it makes it impossi-
-        ble  to  calculate the length of the lookbehind. The \X and \R escapes,
+        ble to calculate the length of the lookbehind. The \X and  \R  escapes,
         which can match different numbers of bytes, are also not permitted.
-        Possessive quantifiers can  be  used  in  conjunction  with  lookbehind
+        Possessive  quantifiers  can  be  used  in  conjunction with lookbehind
-        assertions  to  specify  efficient  matching  at the end of the subject
+        assertions to specify efficient matching at  the  end  of  the  subject
         string. Consider a simple pattern such as
           abcd$
-        when applied to a long string that does  not  match.  Because  matching
+        when  applied  to  a  long string that does not match. Because matching
         proceeds from left to right, PCRE will look for each "a" in the subject
-        and then see if what follows matches the rest of the  pattern.  If  the
+        and  then  see  if what follows matches the rest of the pattern. If the
         pattern is specified as
           ^.*abcd$
-        the  initial .* matches the entire string at first, but when this fails
+        the initial .* matches the entire string at first, but when this  fails
         (because there is no following "a"), it backtracks to match all but the
-        last  character,  then all but the last two characters, and so on. Once
+        last character, then all but the last two characters, and so  on.  Once
-        again the search for "a" covers the entire string, from right to  left,
+        again  the search for "a" covers the entire string, from right to left,
         so we are no better off. However, if the pattern is written as
           ^.*+(?<=abcd)
-        there  can  be  no backtracking for the .*+ item; it can match only the
+        there can be no backtracking for the .*+ item; it can  match  only  the
-        entire string. The subsequent lookbehind assertion does a  single  test
+        entire  string.  The subsequent lookbehind assertion does a single test
-        on  the last four characters. If it fails, the match fails immediately.
+        on the last four characters. If it fails, the match fails  immediately.
-        For long strings, this approach makes a significant difference  to  the
+        For  long  strings, this approach makes a significant difference to the
         processing time.
     Using multiple assertions
-Line 4457 
 ASSERTIONS
+Line 4542 
 ASSERTIONS
           (?<=\d{3})(?<!999)foo
-        matches  "foo" preceded by three digits that are not "999". Notice that
+        matches "foo" preceded by three digits that are not "999". Notice  that
-        each of the assertions is applied independently at the  same  point  in
+        each  of  the  assertions is applied independently at the same point in
-        the  subject  string.  First  there  is a check that the previous three
+        the subject string. First there is a  check  that  the  previous  three
-        characters are all digits, and then there is  a  check  that  the  same
+        characters  are  all  digits,  and  then there is a check that the same
         three characters are not "999".  This pattern does not match "foo" pre-
-        ceded by six characters, the first of which are  digits  and  the  last
+        ceded  by  six  characters,  the first of which are digits and the last
-        three  of  which  are not "999". For example, it doesn't match "123abc-
+        three of which are not "999". For example, it  doesn't  match  "123abc-
         foo". A pattern to do that is
           (?<=\d{3}...)(?<!999)foo
-        This time the first assertion looks at the  preceding  six  characters,
+        This  time  the  first assertion looks at the preceding six characters,
         checking that the first three are digits, and then the second assertion
         checks that the preceding three characters are not "999".
-Line 4476 
 ASSERTIONS
+Line 4561 
 ASSERTIONS
           (?<=(?<!foo)bar)baz
-        matches an occurrence of "baz" that is preceded by "bar" which in  turn
+        matches  an occurrence of "baz" that is preceded by "bar" which in turn
         is not preceded by "foo", while
           (?<=\d{3}(?!999)...)foo
-        is  another pattern that matches "foo" preceded by three digits and any
+        is another pattern that matches "foo" preceded by three digits and  any
         three characters that are not "999".
  CONDITIONAL SUBPATTERNS
-        It is possible to cause the matching process to obey a subpattern  con-
+        It  is possible to cause the matching process to obey a subpattern con-
-        ditionally  or to choose between two alternative subpatterns, depending
+        ditionally or to choose between two alternative subpatterns,  depending
-        on the result of an assertion, or whether a previous capturing  subpat-
+        on  the result of an assertion, or whether a previous capturing subpat-
-        tern  matched  or not. The two possible forms of conditional subpattern
+        tern matched or not. The two possible forms of  conditional  subpattern
         are
           (?(condition)yes-pattern)
           (?(condition)yes-pattern|no-pattern)
-        If the condition is satisfied, the yes-pattern is used;  otherwise  the
+        If  the  condition is satisfied, the yes-pattern is used; otherwise the
-        no-pattern  (if  present)  is used. If there are more than two alterna-
+        no-pattern (if present) is used. If there are more  than  two  alterna-
         tives in the subpattern, a compile-time error occurs.
-        There are four kinds of condition: references  to  subpatterns,  refer-
+        There  are  four  kinds of condition: references to subpatterns, refer-
         ences to recursion, a pseudo-condition called DEFINE, and assertions.
     Checking for a used subpattern by number
-        If  the  text between the parentheses consists of a sequence of digits,
+        If the text between the parentheses consists of a sequence  of  digits,
-        the condition is true if the capturing subpattern of  that  number  has
+        the  condition  is  true if the capturing subpattern of that number has
-        previously  matched.  An  alternative notation is to precede the digits
+        previously matched. An alternative notation is to  precede  the  digits
         with a plus or minus sign. In this case, the subpattern number is rela-
         tive rather than absolute.  The most recently opened parentheses can be
-        referenced by (?(-1), the next most recent by (?(-2),  and  so  on.  In
+        referenced  by  (?(-1),  the  next most recent by (?(-2), and so on. In
         looping constructs it can also make sense to refer to subsequent groups
         with constructs such as (?(+2).
-        Consider the following pattern, which  contains  non-significant  white
+        Consider  the  following  pattern, which contains non-significant white
         space to make it more readable (assume the PCRE_EXTENDED option) and to
         divide it into three parts for ease of discussion:
           ( \( )?    [^()]+    (?(1) \) )
-        The first part matches an optional opening  parenthesis,  and  if  that
+        The  first  part  matches  an optional opening parenthesis, and if that
         character is present, sets it as the first captured substring. The sec-
-        ond part matches one or more characters that are not  parentheses.  The
+        ond  part  matches one or more characters that are not parentheses. The
         third part is a conditional subpattern that tests whether the first set
         of parentheses matched or not. If they did, that is, if subject started
         with an opening parenthesis, the condition is true, and so the yes-pat-
-        tern is executed and a  closing  parenthesis  is  required.  Otherwise,
+        tern  is  executed  and  a  closing parenthesis is required. Otherwise,
-        since  no-pattern  is  not  present, the subpattern matches nothing. In
+        since no-pattern is not present, the  subpattern  matches  nothing.  In
-        other words,  this  pattern  matches  a  sequence  of  non-parentheses,
+        other  words,  this  pattern  matches  a  sequence  of non-parentheses,
         optionally enclosed in parentheses.
-        If  you  were  embedding  this pattern in a larger one, you could use a
+        If you were embedding this pattern in a larger one,  you  could  use  a
         relative reference:
           ...other stuff... ( \( )?    [^()]+    (?(-1) \) ) ...
-        This makes the fragment independent of the parentheses  in  the  larger
+        This  makes  the  fragment independent of the parentheses in the larger
         pattern.
     Checking for a used subpattern by name
-        Perl  uses  the  syntax  (?(<name>)...) or (?('name')...) to test for a
+        Perl uses the syntax (?(<name>)...) or (?('name')...)  to  test  for  a
-        used subpattern by name. For compatibility  with  earlier  versions  of
+        used  subpattern  by  name.  For compatibility with earlier versions of
-        PCRE,  which  had this facility before Perl, the syntax (?(name)...) is
+        PCRE, which had this facility before Perl, the syntax  (?(name)...)  is
-        also recognized. However, there is a possible ambiguity with this  syn-
+        also  recognized. However, there is a possible ambiguity with this syn-
-        tax,  because  subpattern  names  may  consist entirely of digits. PCRE
+        tax, because subpattern names may  consist  entirely  of  digits.  PCRE
-        looks first for a named subpattern; if it cannot find one and the  name
+        looks  first for a named subpattern; if it cannot find one and the name
-        consists  entirely  of digits, PCRE looks for a subpattern of that num-
+        consists entirely of digits, PCRE looks for a subpattern of  that  num-
-        ber, which must be greater than zero. Using subpattern names that  con-
+        ber,  which must be greater than zero. Using subpattern names that con-
         sist entirely of digits is not recommended.
         Rewriting the above example to use a named subpattern gives this:
-Line 4559 
 CONDITIONAL SUBPATTERNS
+Line 4644 
 CONDITIONAL SUBPATTERNS
     Checking for pattern recursion
         If the condition is the string (R), and there is no subpattern with the
-        name R, the condition is true if a recursive call to the whole  pattern
+        name  R, the condition is true if a recursive call to the whole pattern
         or any subpattern has been made. If digits or a name preceded by amper-
         sand follow the letter R, for example:
           (?(R3)...) or (?(R&name)...)
-        the condition is true if the most recent recursion is into the  subpat-
+        the  condition is true if the most recent recursion is into the subpat-
-        tern  whose  number or name is given. This condition does not check the
+        tern whose number or name is given. This condition does not  check  the
         entire recursion stack.
-        At "top level", all these recursion test conditions are  false.  Recur-
+        At  "top  level", all these recursion test conditions are false. Recur-
         sive patterns are described below.
     Defining subpatterns for use by reference only
-        If  the  condition  is  the string (DEFINE), and there is no subpattern
+        If the condition is the string (DEFINE), and  there  is  no  subpattern
-        with the name DEFINE, the condition is  always  false.  In  this  case,
+        with  the  name  DEFINE,  the  condition is always false. In this case,
-        there  may  be  only  one  alternative  in the subpattern. It is always
+        there may be only one alternative  in  the  subpattern.  It  is  always
-        skipped if control reaches this point  in  the  pattern;  the  idea  of
+        skipped  if  control  reaches  this  point  in the pattern; the idea of
-        DEFINE  is that it can be used to define "subroutines" that can be ref-
+        DEFINE is that it can be used to define "subroutines" that can be  ref-
-        erenced from elsewhere. (The use of "subroutines" is described  below.)
+        erenced  from elsewhere. (The use of "subroutines" is described below.)
-        For  example,  a pattern to match an IPv4 address could be written like
+        For example, a pattern to match an IPv4 address could be  written  like
         this (ignore whitespace and line breaks):
           (?(DEFINE) (?<byte> 2[0-4]\d | 25[0-5] | 1\d\d | [1-9]?\d) )
           \b (?&byte) (\.(?&byte)){3} \b
-        The first part of the pattern is a DEFINE group inside which a  another
+        The  first part of the pattern is a DEFINE group inside which a another
-        group  named "byte" is defined. This matches an individual component of
+        group named "byte" is defined. This matches an individual component  of
-        an IPv4 address (a number less than 256). When  matching  takes  place,
+        an  IPv4  address  (a number less than 256). When matching takes place,
-        this  part  of  the pattern is skipped because DEFINE acts like a false
+        this part of the pattern is skipped because DEFINE acts  like  a  false
         condition.
         The rest of the pattern uses references to the named group to match the
-        four  dot-separated  components of an IPv4 address, insisting on a word
+        four dot-separated components of an IPv4 address, insisting on  a  word
         boundary at each end.
     Assertion conditions
-        If the condition is not in any of the above  formats,  it  must  be  an
+        If  the  condition  is  not  in any of the above formats, it must be an
-        assertion.   This may be a positive or negative lookahead or lookbehind
+        assertion.  This may be a positive or negative lookahead or  lookbehind
-        assertion. Consider  this  pattern,  again  containing  non-significant
+        assertion.  Consider  this  pattern,  again  containing non-significant
         white space, and with the two alternatives on the second line:
           (?(?=[^a-z]*[a-z])
           \d{2}-[a-z]{3}-\d{2}  |  \d{2}-\d{2}-\d{2} )
-        The  condition  is  a  positive  lookahead  assertion  that  matches an
+        The condition  is  a  positive  lookahead  assertion  that  matches  an
-        optional sequence of non-letters followed by a letter. In other  words,
+        optional  sequence of non-letters followed by a letter. In other words,
-        it  tests  for the presence of at least one letter in the subject. If a
+        it tests for the presence of at least one letter in the subject.  If  a
-        letter is found, the subject is matched against the first  alternative;
+        letter  is found, the subject is matched against the first alternative;
-        otherwise  it  is  matched  against  the  second.  This pattern matches
+        otherwise it is  matched  against  the  second.  This  pattern  matches
-        strings in one of the two forms dd-aaa-dd or dd-dd-dd,  where  aaa  are
+        strings  in  one  of the two forms dd-aaa-dd or dd-dd-dd, where aaa are
         letters and dd are digits.
  COMMENTS
-        The  sequence (?# marks the start of a comment that continues up to the
+        The sequence (?# marks the start of a comment that continues up to  the
-        next closing parenthesis. Nested parentheses  are  not  permitted.  The
+        next  closing  parenthesis.  Nested  parentheses are not permitted. The
-        characters  that make up a comment play no part in the pattern matching
+        characters that make up a comment play no part in the pattern  matching
         at all.
-        If the PCRE_EXTENDED option is set, an unescaped # character outside  a
+        If  the PCRE_EXTENDED option is set, an unescaped # character outside a
-        character  class  introduces  a  comment  that continues to immediately
+        character class introduces a  comment  that  continues  to  immediately
         after the next newline in the pattern.
  RECURSIVE PATTERNS
-        Consider the problem of matching a string in parentheses, allowing  for
+        Consider  the problem of matching a string in parentheses, allowing for
-        unlimited  nested  parentheses.  Without the use of recursion, the best
+        unlimited nested parentheses. Without the use of  recursion,  the  best
-        that can be done is to use a pattern that  matches  up  to  some  fixed
+        that  can  be  done  is  to use a pattern that matches up to some fixed
-        depth  of  nesting.  It  is not possible to handle an arbitrary nesting
+        depth of nesting. It is not possible to  handle  an  arbitrary  nesting
         depth.
         For some time, Perl has provided a facility that allows regular expres-
-        sions  to recurse (amongst other things). It does this by interpolating
+        sions to recurse (amongst other things). It does this by  interpolating
-        Perl code in the expression at run time, and the code can refer to  the
+        Perl  code in the expression at run time, and the code can refer to the
         expression itself. A Perl pattern using code interpolation to solve the
         parentheses problem can be created like this:
-Line 4647 
 RECURSIVE PATTERNS
+Line 4732 
 RECURSIVE PATTERNS
         refers recursively to the pattern in which it appears.
         Obviously, PCRE cannot support the interpolation of Perl code. Instead,
-        it supports special syntax for recursion of  the  entire  pattern,  and
+        it  supports  special  syntax  for recursion of the entire pattern, and
-        also  for  individual  subpattern  recursion. After its introduction in
+        also for individual subpattern recursion.  After  its  introduction  in
-        PCRE and Python, this kind of recursion was  introduced  into  Perl  at
+        PCRE  and  Python,  this  kind of recursion was subsequently introduced
-        release 5.10.
+        into Perl at release 5.10.
-        A  special  item  that consists of (? followed by a number greater than
+        A special item that consists of (? followed by a  number  greater  than
         zero and a closing parenthesis is a recursive call of the subpattern of
-        the  given  number, provided that it occurs inside that subpattern. (If
+        the given number, provided that it occurs inside that  subpattern.  (If
-        not, it is a "subroutine" call, which is described  in  the  next  sec-
+        not,  it  is  a  "subroutine" call, which is described in the next sec-
-        tion.)  The special item (?R) or (?0) is a recursive call of the entire
+        tion.) The special item (?R) or (?0) is a recursive call of the  entire
         regular expression.
-        In PCRE (like Python, but unlike Perl), a recursive subpattern call  is
-        always treated as an atomic group. That is, once it has matched some of
-        the subject string, it is never re-entered, even if it contains untried
-        alternatives and there is a subsequent matching failure.
         This  PCRE  pattern  solves  the nested parentheses problem (assume the
         PCRE_EXTENDED option is set so that white space is ignored):
-Line 4752 
 RECURSIVE PATTERNS
+Line 4832 
 RECURSIVE PATTERNS
         two different alternatives for the recursive and  non-recursive  cases.
         The (?R) item is the actual recursive call.
+    Recursion difference from Perl
+        In  PCRE (like Python, but unlike Perl), a recursive subpattern call is
+        always treated as an atomic group. That is, once it has matched some of
+        the subject string, it is never re-entered, even if it contains untried
+        alternatives and there is a subsequent matching failure.  This  can  be
+        illustrated  by the following pattern, which purports to match a palin-
+        dromic string that contains an odd number of characters  (for  example,
+        "a", "aba", "abcba", "abcdcba"):
+          ^(.|(.)(?1)\2)$
+        The idea is that it either matches a single character, or two identical
+        characters surrounding a sub-palindrome. In Perl, this  pattern  works;
+        in  PCRE  it  does  not if the pattern is longer than three characters.
+        Consider the subject string "abcba":
+        At the top level, the first character is matched, but as it is  not  at
+        the end of the string, the first alternative fails; the second alterna-
+        tive is taken and the recursion kicks in. The recursive call to subpat-
+        tern  1  successfully  matches the next character ("b"). (Note that the
+        beginning and end of line tests are not part of the recursion).
+        Back at the top level, the next character ("c") is compared  with  what
+        subpattern  2 matched, which was "a". This fails. Because the recursion
+        is treated as an atomic group, there are now  no  backtracking  points,
+        and  so  the  entire  match fails. (Perl is able, at this point, to re-
+        enter the recursion and try the second alternative.)  However,  if  the
+        pattern is written with the alternatives in the other order, things are
+        different:
+          ^((.)(?1)\2|.)$
+        This time, the recursing alternative is tried first, and  continues  to
+        recurse  until  it runs out of characters, at which point the recursion
+        fails. But this time we do have  another  alternative  to  try  at  the
+        higher  level.  That  is  the  big difference: in the previous case the
+        remaining alternative is at a deeper recursion level, which PCRE cannot
+        use.
+        To change the pattern so that matches all palindromic strings, not just
+        those with an odd number of characters, it is tempting  to  change  the
+        pattern to this:
+          ^((.)(?1)\2|.?)$
+        Again,  this  works  in Perl, but not in PCRE, and for the same reason.
+        When a deeper recursion has matched a single character,  it  cannot  be
+        entered  again  in  order  to match an empty string. The solution is to
+        separate the two cases, and write out the odd and even cases as  alter-
+        natives at the higher level:
+          ^(?:((.)(?1)\2|)|((.)(?3)\4|.))
+        If  you  want  to match typical palindromic phrases, the pattern has to
+        ignore all non-word characters, which can be done like this:
+          ^\W*+(?:((.)\W*+(?1)\W*+\2|)|((.)\W*+(?3)\W*+4|\W*+.\W*+))\W*+$
+        If run with the PCRE_CASELESS option, this pattern matches phrases such
+        as "A man, a plan, a canal: Panama!" and it works well in both PCRE and
+        Perl. Note the use of the possessive quantifier *+ to avoid  backtrack-
+        ing  into  sequences of non-word characters. Without this, PCRE takes a
+        great deal longer (ten times or more) to  match  typical  phrases,  and
+        Perl takes so long that you think it has gone into a loop.
  SUBPATTERNS AS SUBROUTINES
-Line 4864 
 BACKTRACKING CONTROL
+Line 5010 
 BACKTRACKING CONTROL
         (*FAIL), which behaves like a failing negative assertion, they cause an
         error if encountered by pcre_dfa_exec().
-        The new verbs make use of what was previously invalid syntax: an  open-
+        If any of these verbs are used in an assertion subpattern, their effect
+        is  confined  to that subpattern; it does not extend to the surrounding
+        pattern.  Note that assertion subpatterns are processed as anchored  at
+        the point where they are tested.
+        The  new verbs make use of what was previously invalid syntax: an open-
         ing parenthesis followed by an asterisk. In Perl, they are generally of
         the form (*VERB:ARG) but PCRE does not support the use of arguments, so
-        its  general  form is just (*VERB). Any number of these verbs may occur
+        its general form is just (*VERB). Any number of these verbs  may  occur
         in a pattern. There are two kinds:
     Verbs that act immediately
-Line 4876 
 BACKTRACKING CONTROL
+Line 5027 
 BACKTRACKING CONTROL
            (*ACCEPT)
-        This verb causes the match to end successfully, skipping the  remainder
+        This  verb causes the match to end successfully, skipping the remainder
-        of  the pattern. When inside a recursion, only the innermost pattern is
+        of the pattern. When inside a recursion, only the innermost pattern  is
-        ended immediately. PCRE differs  from  Perl  in  what  happens  if  the
+        ended  immediately.  If  the (*ACCEPT) is inside capturing parentheses,
-        (*ACCEPT)  is inside capturing parentheses. In Perl, the data so far is
+        the data so far is captured. (This feature was added to PCRE at release
-        captured: in PCRE no data is captured. For example:
+.00.) For example:
-          A(A|B(*ACCEPT)|C)D
+          A((?:A|B(*ACCEPT)|C)D)
-        This matches "AB", "AAD", or "ACD", but when it matches "AB",  no  data
+        This  matches  "AB", "AAD", or "ACD"; when it matches "AB", "B" is cap-
-        is captured.
+        tured by the outer parentheses.
           (*FAIL) or (*F)
-        This  verb  causes the match to fail, forcing backtracking to occur. It
+        This verb causes the match to fail, forcing backtracking to  occur.  It
-        is equivalent to (?!) but easier to read. The Perl documentation  notes
+        is  equivalent to (?!) but easier to read. The Perl documentation notes
-        that  it  is  probably  useful only when combined with (?{}) or (??{}).
+        that it is probably useful only when combined  with  (?{})  or  (??{}).
-        Those are, of course, Perl features that are not present in  PCRE.  The
+        Those  are,  of course, Perl features that are not present in PCRE. The
-        nearest  equivalent is the callout feature, as for example in this pat-
+        nearest equivalent is the callout feature, as for example in this  pat-
         tern:
           a+(?C)(*FAIL)
-        A match with the string "aaaa" always fails, but the callout  is  taken
+        A  match  with the string "aaaa" always fails, but the callout is taken
         before each backtrack happens (in this example, 10 times).
     Verbs that act after backtracking
         The following verbs do nothing when they are encountered. Matching con-
-        tinues with what follows, but if there is no subsequent match, a  fail-
+        tinues  with what follows, but if there is no subsequent match, a fail-
-        ure  is  forced.   The  verbs  differ  in  exactly what kind of failure
+        ure is forced.  The verbs  differ  in  exactly  what  kind  of  failure
         occurs.
           (*COMMIT)
-        This verb causes the whole match to fail outright if the  rest  of  the
+        This  verb  causes  the whole match to fail outright if the rest of the
-        pattern  does  not match. Even if the pattern is unanchored, no further
+        pattern does not match. Even if the pattern is unanchored,  no  further
-        attempts to find a match by advancing the start point take place.  Once
+        attempts  to find a match by advancing the start point take place. Once
-        (*COMMIT)  has been passed, pcre_exec() is committed to finding a match
+        (*COMMIT) has been passed, pcre_exec() is committed to finding a  match
         at the current starting point, or not at all. For example:
           a+(*COMMIT)b
-        This matches "xxaab" but not "aacaab". It can be thought of as  a  kind
+        This  matches  "xxaab" but not "aacaab". It can be thought of as a kind
         of dynamic anchor, or "I've started, so I must finish."
           (*PRUNE)
-        This  verb causes the match to fail at the current position if the rest
+        This verb causes the match to fail at the current position if the  rest
         of the pattern does not match. If the pattern is unanchored, the normal
-        "bumpalong"  advance to the next starting character then happens. Back-
+        "bumpalong" advance to the next starting character then happens.  Back-
-        tracking can occur as usual to the left of (*PRUNE), or  when  matching
+        tracking  can  occur as usual to the left of (*PRUNE), or when matching
-        to  the right of (*PRUNE), but if there is no match to the right, back-
+        to the right of (*PRUNE), but if there is no match to the right,  back-
-        tracking cannot cross (*PRUNE).  In simple cases, the use  of  (*PRUNE)
+        tracking  cannot  cross (*PRUNE).  In simple cases, the use of (*PRUNE)
         is just an alternative to an atomic group or possessive quantifier, but
-        there are some uses of (*PRUNE) that cannot be expressed in  any  other
+        there  are  some uses of (*PRUNE) that cannot be expressed in any other
         way.
           (*SKIP)
-        This  verb  is like (*PRUNE), except that if the pattern is unanchored,
+        This verb is like (*PRUNE), except that if the pattern  is  unanchored,
-        the "bumpalong" advance is not to the next character, but to the  posi-
+        the  "bumpalong" advance is not to the next character, but to the posi-
-        tion  in  the  subject where (*SKIP) was encountered. (*SKIP) signifies
+        tion in the subject where (*SKIP) was  encountered.  (*SKIP)  signifies
-        that whatever text was matched leading up to it cannot  be  part  of  a
+        that  whatever  text  was  matched leading up to it cannot be part of a
         successful match. Consider:
           a+(*SKIP)b
-        If  the  subject  is  "aaaac...",  after  the first match attempt fails
+        If the subject is "aaaac...",  after  the  first  match  attempt  fails
-        (starting at the first character in the  string),  the  starting  point
+        (starting  at  the  first  character in the string), the starting point
         skips on to start the next attempt at "c". Note that a possessive quan-
-        tifer does not have the same effect in this example; although it  would
+        tifer  does not have the same effect in this example; although it would
-        suppress  backtracking  during  the  first  match  attempt,  the second
+        suppress backtracking  during  the  first  match  attempt,  the  second
-        attempt would start at the second character instead of skipping  on  to
+        attempt  would  start at the second character instead of skipping on to
         "c".
           (*THEN)
         This verb causes a skip to the next alternation if the rest of the pat-
         tern does not match. That is, it cancels pending backtracking, but only
-        within  the  current  alternation.  Its name comes from the observation
+        within the current alternation. Its name  comes  from  the  observation
         that it can be used for a pattern-based if-then-else block:
           ( COND1 (*THEN) FOO | COND2 (*THEN) BAR | COND3 (*THEN) BAZ ) ...
-        If the COND1 pattern matches, FOO is tried (and possibly further  items
+        If  the COND1 pattern matches, FOO is tried (and possibly further items
-        after  the  end  of  the group if FOO succeeds); on failure the matcher
+        after the end of the group if FOO succeeds);  on  failure  the  matcher
-        skips to the second alternative and tries COND2,  without  backtracking
+        skips  to  the second alternative and tries COND2, without backtracking
-        into  COND1.  If  (*THEN)  is  used outside of any alternation, it acts
+        into COND1. If (*THEN) is used outside  of  any  alternation,  it  acts
         exactly like (*PRUNE).
-Line 4981 
 AUTHOR
+Line 5132 
 AUTHOR
  REVISION
-        Last updated: 19 April 2008
+        Last updated: 18 September 2009
-        Copyright (c) 1997-2008 University of Cambridge.
+        Copyright (c) 1997-2009 University of Cambridge.
  ------------------------------------------------------------------------------
  PCRESYNTAX(3)                                                    PCRESYNTAX(3)
-Line 5094 
 GENERAL CATEGORY PROPERTY CODES FOR \p a
+Line 5245 
 GENERAL CATEGORY PROPERTY CODES FOR \p a
  SCRIPT NAMES FOR \p AND \P
         Arabic,  Armenian,  Balinese,  Bengali,  Bopomofo,  Braille,  Buginese,
-        Buhid,  Canadian_Aboriginal,  Cherokee,  Common,   Coptic,   Cuneiform,
+        Buhid, Canadian_Aboriginal, Carian, Cham, Cherokee, Common, Coptic, Cu-
-        Cypriot, Cyrillic, Deseret, Devanagari, Ethiopic, Georgian, Glagolitic,
+        neiform,  Cypriot,  Cyrillic,  Deseret, Devanagari, Ethiopic, Georgian,
-        Gothic, Greek, Gujarati, Gurmukhi, Han, Hangul, Hanunoo, Hebrew,  Hira-
+        Glagolitic, Gothic, Greek, Gujarati, Gurmukhi,  Han,  Hangul,  Hanunoo,
-        gana,  Inherited,  Kannada,  Katakana,  Kharoshthi,  Khmer, Lao, Latin,
+        Hebrew,  Hiragana,  Inherited, Kannada, Katakana, Kayah_Li, Kharoshthi,
-        Limbu,  Linear_B,  Malayalam,  Mongolian,  Myanmar,  New_Tai_Lue,  Nko,
+        Khmer, Lao, Latin, Lepcha, Limbu, Linear_B, Lycian, Lydian,  Malayalam,
-        Ogham,  Old_Italic,  Old_Persian, Oriya, Osmanya, Phags_Pa, Phoenician,
+        Mongolian,  Myanmar,  New_Tai_Lue, Nko, Ogham, Old_Italic, Old_Persian,
-        Runic,  Shavian,  Sinhala,  Syloti_Nagri,  Syriac,  Tagalog,  Tagbanwa,
+        Ol_Chiki, Oriya, Osmanya, Phags_Pa, Phoenician, Rejang, Runic, Saurash-
-        Tai_Le, Tamil, Telugu, Thaana, Thai, Tibetan, Tifinagh, Ugaritic, Yi.
+        tra,  Shavian,  Sinhala,  Sudanese, Syloti_Nagri, Syriac, Tagalog, Tag-
+        banwa,  Tai_Le,  Tamil,  Telugu,  Thaana,  Thai,   Tibetan,   Tifinagh,
+        Ugaritic, Vai, Yi.
  CHARACTER CLASSES
-Line 5153 
 QUANTIFIERS
+Line 5306 
 QUANTIFIERS
  ANCHORS AND SIMPLE ASSERTIONS
-          \b          word boundary
+          \b          word boundary (only ASCII letters recognized)
           \B          not a word boundary
           ^           start of subject
                        also after internal newline in multiline mode
-Line 5179 
 ALTERNATION
+Line 5332 
 ALTERNATION
  CAPTURING
-          (...)          capturing group
+          (...)           capturing group
-          (?<name>...)   named capturing group (Perl)
+          (?<name>...)    named capturing group (Perl)
-          (?'name'...)   named capturing group (Perl)
+          (?'name'...)    named capturing group (Perl)
-          (?P<name>...)  named capturing group (Python)
+          (?P<name>...)   named capturing group (Python)
-          (?:...)        non-capturing group
+          (?:...)         non-capturing group
-          (?|...)        non-capturing group; reset group numbers for
+          (?|...)         non-capturing group; reset group numbers for
-                          capturing groups in each alternative
+                           capturing groups in each alternative
  ATOMIC GROUPS
-          (?>...)        atomic, non-capturing group
+          (?>...)         atomic, non-capturing group
  COMMENT
-          (?#....)       comment (not nestable)
+          (?#....)        comment (not nestable)
  OPTION SETTING
-          (?i)           caseless
+          (?i)            caseless
-          (?J)           allow duplicate names
+          (?J)            allow duplicate names
-          (?m)           multiline
+          (?m)            multiline
-          (?s)           single line (dotall)
+          (?s)            single line (dotall)
-          (?U)           default ungreedy (lazy)
+          (?U)            default ungreedy (lazy)
-          (?x)           extended (ignore white space)
+          (?x)            extended (ignore white space)
-          (?-...)        unset option(s)
+          (?-...)         unset option(s)
+        The following is recognized only at the start of a pattern or after one
+        of the newline-setting options with similar syntax:
+          (*UTF8)         set UTF-8 mode
  LOOKAHEAD AND LOOKBEHIND ASSERTIONS
-          (?=...)        positive look ahead
+          (?=...)         positive look ahead
-          (?!...)        negative look ahead
+          (?!...)         negative look ahead
-          (?<=...)       positive look behind
+          (?<=...)        positive look behind
-          (?<!...)       negative look behind
+          (?<!...)        negative look behind
         Each top-level branch of a look behind must be of a fixed length.
  BACKREFERENCES
-          \n             reference by number (can be ambiguous)
+          \n              reference by number (can be ambiguous)
-          \gn            reference by number
+          \gn             reference by number
-          \g{n}          reference by number
+          \g{n}           reference by number
-          \g{-n}         relative reference by number
+          \g{-n}          relative reference by number
-          \k<name>       reference by name (Perl)
+          \k<name>        reference by name (Perl)
-          \k'name'       reference by name (Perl)
+          \k'name'        reference by name (Perl)
-          \g{name}       reference by name (Perl)
+          \g{name}        reference by name (Perl)
-          \k{name}       reference by name (.NET)
+          \k{name}        reference by name (.NET)
-          (?P=name)      reference by name (Python)
+          (?P=name)       reference by name (Python)
  SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)
-          (?R)           recurse whole pattern
+          (?R)            recurse whole pattern
-          (?n)           call subpattern by absolute number
+          (?n)            call subpattern by absolute number
-          (?+n)          call subpattern by relative number
+          (?+n)           call subpattern by relative number
-          (?-n)          call subpattern by relative number
+          (?-n)           call subpattern by relative number
-          (?&name)       call subpattern by name (Perl)
+          (?&name)        call subpattern by name (Perl)
-          (?P>name)      call subpattern by name (Python)
+          (?P>name)       call subpattern by name (Python)
-          \g<name>       call subpattern by name (Oniguruma)
+          \g<name>        call subpattern by name (Oniguruma)
-          \g'name'       call subpattern by name (Oniguruma)
+          \g'name'        call subpattern by name (Oniguruma)
-          \g<n>          call subpattern by absolute number (Oniguruma)
+          \g<n>           call subpattern by absolute number (Oniguruma)
-          \g'n'          call subpattern by absolute number (Oniguruma)
+          \g'n'           call subpattern by absolute number (Oniguruma)
-          \g<+n>         call subpattern by relative number (PCRE extension)
+          \g<+n>          call subpattern by relative number (PCRE extension)
-          \g'+n'         call subpattern by relative number (PCRE extension)
+          \g'+n'          call subpattern by relative number (PCRE extension)
-          \g<-n>         call subpattern by relative number (PCRE extension)
+          \g<-n>          call subpattern by relative number (PCRE extension)
-          \g'-n'         call subpattern by relative number (PCRE extension)
+          \g'-n'          call subpattern by relative number (PCRE extension)
  CONDITIONAL PATTERNS
-Line 5255 
 CONDITIONAL PATTERNS
+Line 5413 
 CONDITIONAL PATTERNS
           (?(condition)yes-pattern)
           (?(condition)yes-pattern|no-pattern)
-          (?(n)...       absolute reference condition
+          (?(n)...        absolute reference condition
-          (?(+n)...      relative reference condition
+          (?(+n)...       relative reference condition
-          (?(-n)...      relative reference condition
+          (?(-n)...       relative reference condition
-          (?(<name>)...  named reference condition (Perl)
+          (?(<name>)...   named reference condition (Perl)
-          (?('name')...  named reference condition (Perl)
+          (?('name')...   named reference condition (Perl)
-          (?(name)...    named reference condition (PCRE)
+          (?(name)...     named reference condition (PCRE)
-          (?(R)...       overall recursion condition
+          (?(R)...        overall recursion condition
-          (?(Rn)...      specific group recursion condition
+          (?(Rn)...       specific group recursion condition
-          (?(R&name)...  specific recursion condition
+          (?(R&name)...   specific recursion condition
-          (?(DEFINE)...  define subpattern for reference
+          (?(DEFINE)...   define subpattern for reference
-          (?(assert)...  assertion condition
+          (?(assert)...   assertion condition
  BACKTRACKING CONTROL
         The following act immediately they are reached:
-          (*ACCEPT)      force successful match
+          (*ACCEPT)       force successful match
-          (*FAIL)        force backtrack; synonym (*F)
+          (*FAIL)         force backtrack; synonym (*F)
-        The following act only when a subsequent match failure causes  a  back-
+        The  following  act only when a subsequent match failure causes a back-
         track to reach them. They all force a match failure, but they differ in
         what happens afterwards. Those that advance the start-of-match point do
         so only if the pattern is not anchored.
-          (*COMMIT)      overall failure, no advance of starting point
+          (*COMMIT)       overall failure, no advance of starting point
-          (*PRUNE)       advance to next starting character
+          (*PRUNE)        advance to next starting character
-          (*SKIP)        advance start to current matching position
+          (*SKIP)         advance start to current matching position
-          (*THEN)        local failure, backtrack to next alternation
+          (*THEN)         local failure, backtrack to next alternation
  NEWLINE CONVENTIONS
-        These  are  recognized only at the very start of the pattern or after a
+        These are recognized only at the very start of the pattern or  after  a
-        (*BSR_...) option.
+        (*BSR_...) or (*UTF8) option.