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-revision 75 by nigel,
Sat Feb 24 21:40:37 2007 UTC
+revision 77 by nigel,
Sat Feb 24 21:40:45 2007 UTC
 Line 6 
 synopses of each function in the library
  separate text files for the pcregrep and pcretest commands.
  -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
  NAME
         PCRE - Perl-compatible regular expressions
  INTRODUCTION
         The  PCRE  library is a set of functions that implement regular expres-
         sion pattern matching using the same syntax and semantics as Perl, with
         just  a  few  differences.  The current implementation of PCRE (release
 .x) corresponds approximately with Perl  5.8,  including  support  for
         UTF-8 encoded strings and Unicode general category properties. However,
         this support has to be explicitly enabled; it is not the default.
+        In addition to the Perl-compatible matching function,  PCRE  also  con-
+        tains  an  alternative matching function that matches the same compiled
+        patterns in a different way. In certain circumstances, the  alternative
+        function  has  some  advantages.  For  a discussion of the two matching
+        algorithms, see the pcrematching page.
         PCRE is written in C and released as a C library. A  number  of  people
-        have  written  wrappers and interfaces of various kinds. A C++ class is
+        have  written  wrappers and interfaces of various kinds. In particular,
-        included in these contributions, which can  be  found  in  the  Contrib
+        Google Inc.  have provided a comprehensive C++  wrapper.  This  is  now
-        directory at the primary FTP site, which is:
+        included as part of the PCRE distribution. The pcrecpp page has details
+        of this interface. Other people's contributions can  be  found  in  the
+        Contrib directory at the primary FTP site, which is:
         ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre
-Line 40 
 INTRODUCTION
+Line 47 
 INTRODUCTION
         ing  PCRE for various operating systems can be found in the README file
         in the source distribution.
+        The library contains a number of undocumented  internal  functions  and
+        data  tables  that  are  used by more than one of the exported external
+        functions, but which are not intended  for  use  by  external  callers.
+        Their  names  all begin with "_pcre_", which hopefully will not provoke
+        any name clashes.
  USER DOCUMENTATION
-Line 50 
 USER DOCUMENTATION
+Line 63 
 USER DOCUMENTATION
         of searching. The sections are as follows:
           pcre              this document
-          pcreapi           details of PCRE's native API
+          pcreapi           details of PCRE's native C API
           pcrebuild         options for building PCRE
           pcrecallout       details of the callout feature
           pcrecompat        discussion of Perl compatibility
+          pcrecpp           details of the C++ wrapper
           pcregrep          description of the pcregrep command
+          pcrematching      discussion of the two matching algorithms
           pcrepartial       details of the partial matching facility
           pcrepattern       syntax and semantics of supported
                               regular expressions
           pcreperform       discussion of performance issues
-          pcreposix         the POSIX-compatible API
+          pcreposix         the POSIX-compatible C API
           pcreprecompile    details of saving and re-using precompiled patterns
           pcresample        discussion of the sample program
           pcretest          description of the pcretest testing command
         In  addition,  in the "man" and HTML formats, there is a short page for
-        each library function, listing its arguments and results.
+        each C library function, listing its arguments and results.
  LIMITATIONS
-Line 90 
 LIMITATIONS
+Line 105 
 LIMITATIONS
         tern, is 200.
         The  maximum  length of a subject string is the largest positive number
-        that an integer variable can hold. However, PCRE uses recursion to han-
+        that an integer variable can hold. However, when using the  traditional
-        dle  subpatterns  and indefinite repetition. This means that the avail-
+        matching function, PCRE uses recursion to handle subpatterns and indef-
-        able stack space may limit the size of a subject  string  that  can  be
+        inite repetition.  This means that the available stack space may  limit
-        processed by certain patterns.
+        the size of a subject string that can be processed by certain patterns.
  UTF-8 AND UNICODE PROPERTY SUPPORT
-        From  release  3.3,  PCRE  has  had  some support for character strings
+        From release 3.3, PCRE has  had  some  support  for  character  strings
-        encoded in the UTF-8 format. For release 4.0 this was greatly  extended
+        encoded  in the UTF-8 format. For release 4.0 this was greatly extended
-        to  cover  most common requirements, and in release 5.0 additional sup-
+        to cover most common requirements, and in release 5.0  additional  sup-
         port for Unicode general category properties was added.
-        In order process UTF-8 strings, you must build PCRE  to  include  UTF-8
+        In  order  process  UTF-8 strings, you must build PCRE to include UTF-8
-        support  in  the  code,  and, in addition, you must call pcre_compile()
+        support in the code, and, in addition,  you  must  call  pcre_compile()
-        with the PCRE_UTF8 option flag. When you do this, both the pattern  and
+        with  the PCRE_UTF8 option flag. When you do this, both the pattern and
-        any  subject  strings  that are matched against it are treated as UTF-8
+        any subject strings that are matched against it are  treated  as  UTF-8
         strings instead of just strings of bytes.
-        If you compile PCRE with UTF-8 support, but do not use it at run  time,
+        If  you compile PCRE with UTF-8 support, but do not use it at run time,
-        the  library will be a bit bigger, but the additional run time overhead
+        the library will be a bit bigger, but the additional run time  overhead
-        is limited to testing the PCRE_UTF8 flag in several places,  so  should
+        is  limited  to testing the PCRE_UTF8 flag in several places, so should
         not be very large.
         If PCRE is built with Unicode character property support (which implies
-        UTF-8 support), the escape sequences \p{..}, \P{..}, and  \X  are  sup-
+        UTF-8  support),  the  escape sequences \p{..}, \P{..}, and \X are sup-
         ported.  The available properties that can be tested are limited to the
-        general category properties such as Lu for an upper case letter  or  Nd
+        general  category  properties such as Lu for an upper case letter or Nd
-        for  a decimal number. A full list is given in the pcrepattern documen-
+        for a decimal number. A full list is given in the pcrepattern  documen-
         tation. The PCRE library is increased in size by about 90K when Unicode
         property support is included.
         The following comments apply when PCRE is running in UTF-8 mode:
-.  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 checked for validity on entry to the  relevant  functions.
+        subjects  are  checked for validity on entry to the relevant functions.
         If an invalid UTF-8 string is passed, an error return is given. In some
-        situations, you may already know  that  your  strings  are  valid,  and
+        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,
+        you  set  the  PCRE_NO_UTF8_CHECK  flag at compile time or at run time,
-        PCRE  assumes  that  the  pattern or subject it is given (respectively)
+        PCRE assumes that the pattern or subject  it  is  given  (respectively)
-        contains only valid UTF-8 codes. In this case, it does not diagnose  an
+        contains  only valid UTF-8 codes. In this case, it does not diagnose an
-        invalid  UTF-8 string. If you pass an invalid UTF-8 string to PCRE when
+        invalid UTF-8 string. If you pass an invalid UTF-8 string to PCRE  when
-        PCRE_NO_UTF8_CHECK is set, the results are undefined. Your program  may
+        PCRE_NO_UTF8_CHECK  is set, the results are undefined. Your program may
         crash.
 . In a pattern, the escape sequence \x{...}, where the contents of the
-        braces is a string of hexadecimal digits, is  interpreted  as  a  UTF-8
+        braces  is  a  string  of hexadecimal digits, is interpreted as a UTF-8
-        character  whose code number is the given hexadecimal number, for exam-
+        character whose code number is the given hexadecimal number, for  exam-
-        ple: \x{1234}. If a non-hexadecimal digit appears between  the  braces,
+        ple:  \x{1234}.  If a non-hexadecimal digit appears between the braces,
         the item is not recognized.  This escape sequence can be used either as
         a literal, or within a character class.
-. The original hexadecimal escape sequence, \xhh, matches  a  two-byte
+.  The  original hexadecimal escape sequence, \xhh, matches a two-byte
         UTF-8 character if the value is greater than 127.
-.  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.
+        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
         test  characters of any code value, but the characters that PCRE recog-
-Line 177 
 UTF-8 AND UNICODE PROPERTY SUPPORT
+Line 193 
 UTF-8 AND UNICODE PROPERTY SUPPORT
  AUTHOR
-        Philip Hazel <ph10@cam.ac.uk>
+        Philip Hazel
         University Computing Service,
         Cambridge CB2 3QG, England.
-        Phone: +44 1223 334714
- Last updated: 09 September 2004
+        Putting  an actual email address here seems to have been a spam magnet,
- Copyright (c) 1997-2004 University of Cambridge.
+        so I've taken it away. If you want to email me, use my initial and sur-
- -----------------------------------------------------------------------------
+        name, separated by a dot, at the domain ucs.cam.ac.uk.
- PCRE(3)                                                                PCRE(3)
+ Last updated: 07 March 2005
+ Copyright (c) 1997-2005 University of Cambridge.
+ -----------------------------------------------------------------------------
  NAME
         PCRE - Perl-compatible regular expressions
  PCRE BUILD-TIME OPTIONS
         This  document  describes  the  optional  features  of PCRE that can be
-Line 287 
 POSIX MALLOC USAGE
+Line 305 
 POSIX MALLOC USAGE
  LIMITING PCRE RESOURCE USAGE
         Internally,  PCRE has a function called match(), which it calls repeat-
-        edly (possibly recursively) when matching a pattern. By controlling the
+        edly  (possibly  recursively)  when  matching  a   pattern   with   the
-        maximum  number  of  times  this function may be called during a single
+        pcre_exec()  function.  By controlling the maximum number of times this
-        matching operation, a limit can be placed on the resources  used  by  a
+        function may be called during a single matching operation, a limit  can
-        single  call  to  pcre_exec(). The limit can be changed at run time, as
+        be  placed  on  the resources used by a single call to pcre_exec(). The
-        described in the pcreapi documentation. The default is 10 million,  but
+        limit can be changed at run time, as described in the pcreapi  documen-
-        this can be changed by adding a setting such as
+        tation.  The default is 10 million, but this can be changed by adding a
+        setting such as
           --with-match-limit=500000
-        to the configure command.
+        to  the  configure  command.  This  setting  has  no  effect   on   the
+        pcre_dfa_exec() matching function.
  HANDLING VERY LARGE PATTERNS
-Line 324 
 HANDLING VERY LARGE PATTERNS
+Line 344 
 HANDLING VERY LARGE PATTERNS
  AVOIDING EXCESSIVE STACK USAGE
-        PCRE  implements  backtracking while matching by making recursive calls
+        When matching with the pcre_exec() function, PCRE implements backtrack-
-        to an internal function called match(). In environments where the  size
+        ing by making recursive calls to an internal function  called  match().
-        of the stack is limited, this can severely limit PCRE's operation. (The
+        In  environments  where  the size of the stack is limited, this can se-
-        Unix environment does not usually suffer from this problem.) An  alter-
+        verely limit PCRE's operation. (The Unix environment does  not  usually
-        native  approach  that  uses  memory  from  the  heap to remember data,
+        suffer  from  this  problem.)  An alternative approach that uses memory
-        instead of using recursive function calls, has been implemented to work
+        from the heap to remember data, instead  of  using  recursive  function
-        round  this  problem. If you want to build a version of PCRE that works
+        calls,  has been implemented to work round this problem. If you want to
-        this way, add
+        build a version of PCRE that works this way, add
           --disable-stack-for-recursion
-Line 342 
 AVOIDING EXCESSIVE STACK USAGE
+Line 362 
 AVOIDING EXCESSIVE STACK USAGE
         the blocks are always freed in reverse order. A calling  program  might
         be  able  to implement optimized functions that perform better than the
         standard malloc() and  free()  functions.  PCRE  runs  noticeably  more
-        slowly when built in this way.
+        slowly when built in this way. This option affects only the pcre_exec()
+        function; it is not relevant for the the pcre_dfa_exec() function.
  USING EBCDIC CODE
-        PCRE  assumes  by  default that it will run in an environment where the
+        PCRE assumes by default that it will run in an  environment  where  the
-        character code is ASCII (or Unicode, which is  a  superset  of  ASCII).
+        character  code  is  ASCII  (or Unicode, which is a superset of ASCII).
-        PCRE  can,  however,  be  compiled  to  run in an EBCDIC environment by
+        PCRE can, however, be compiled to  run  in  an  EBCDIC  environment  by
         adding
           --enable-ebcdic
         to the configure command.
- Last updated: 09 September 2004
+ Last updated: 28 February 2005
- Copyright (c) 1997-2004 University of Cambridge.
+ Copyright (c) 1997-2005 University of Cambridge.
  -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
+ NAME
+        PCRE - Perl-compatible regular expressions
+ PCRE MATCHING ALGORITHMS
+        This document describes the two different algorithms that are available
+        in PCRE for matching a compiled regular expression against a given sub-
+        ject  string.  The  "standard"  algorithm  is  the  one provided by the
+        pcre_exec() function.  This works in the same was  as  Perl's  matching
+        function, and provides a Perl-compatible matching operation.
+        An  alternative  algorithm is provided by the pcre_dfa_exec() function;
+        this operates in a different way, and is not  Perl-compatible.  It  has
+        advantages  and disadvantages compared with the standard algorithm, and
+        these are described below.
+        When there is only one possible way in which a given subject string can
+        match  a pattern, the two algorithms give the same answer. A difference
+        arises, however, when there are multiple possibilities. For example, if
+        the pattern
+          ^<.*>
+        is matched against the string
+          <something> <something else> <something further>
+        there are three possible answers. The standard algorithm finds only one
+        of them, whereas the DFA algorithm finds all three.
+ REGULAR EXPRESSIONS AS TREES
+        The set of strings that are matched by a regular expression can be rep-
+        resented  as  a  tree structure. An unlimited repetition in the pattern
+        makes the tree of infinite size, but it is still a tree.  Matching  the
+        pattern  to a given subject string (from a given starting point) can be
+        thought of as a search of the tree.  There are  two  standard  ways  to
+        search  a  tree: depth-first and breadth-first, and these correspond to
+        the two matching algorithms provided by PCRE.
+ THE STANDARD MATCHING ALGORITHM
+        In the terminology of Jeffrey Friedl's book Mastering  Regular  Expres-
+        sions,  the  standard  algorithm  is  an "NFA algorithm". It conducts a
+        depth-first search of the pattern tree. That is, it  proceeds  along  a
+        single path through the tree, checking that the subject matches what is
+        required. When there is a mismatch, the algorithm  tries  any  alterna-
+        tives  at  the  current point, and if they all fail, it backs up to the
+        previous branch point in the  tree,  and  tries  the  next  alternative
+        branch  at  that  level.  This often involves backing up (moving to the
+        left) in the subject string as well.  The  order  in  which  repetition
+        branches  are  tried  is controlled by the greedy or ungreedy nature of
+        the quantifier.
+        If a leaf node is reached, a matching string has  been  found,  and  at
+        that  point the algorithm stops. Thus, if there is more than one possi-
+        ble match, this algorithm returns the first one that it finds.  Whether
+        this  is the shortest, the longest, or some intermediate length depends
+        on the way the greedy and ungreedy repetition quantifiers are specified
+        in the pattern.
+        Because  it  ends  up  with a single path through the tree, it is rela-
+        tively straightforward for this algorithm to keep  track  of  the  sub-
+        strings  that  are  matched  by portions of the pattern in parentheses.
+        This provides support for capturing parentheses and back references.
+ THE DFA MATCHING ALGORITHM
+        DFA stands for "deterministic finite automaton", but you do not need to
+        understand the origins of that name. This algorithm conducts a breadth-
+        first search of the tree. Starting from the first matching point in the
+        subject,  it scans the subject string from left to right, once, charac-
+        ter by character, and as it does  this,  it  remembers  all  the  paths
+        through the tree that represent valid matches.
+        The  scan  continues until either the end of the subject is reached, or
+        there are no more unterminated paths. At this point,  terminated  paths
+        represent  the different matching possibilities (if there are none, the
+        match has failed).  Thus, if there is more  than  one  possible  match,
+        this algorithm finds all of them, and in particular, it finds the long-
+        est. In PCRE, there is an option to stop the algorithm after the  first
+        match (which is necessarily the shortest) has been found.
+        Note that all the matches that are found start at the same point in the
+        subject. If the pattern
+          cat(er(pillar)?)
+        is matched against the string "the caterpillar catchment",  the  result
+        will  be the three strings "cat", "cater", and "caterpillar" that start
+        at the fourth character of the subject. The algorithm does not automat-
+        ically move on to find matches that start at later positions.
+        There are a number of features of PCRE regular expressions that are not
+        supported by the DFA matching algorithm. They are as follows:
+. Because the algorithm finds all  possible  matches,  the  greedy  or
+        ungreedy  nature  of repetition quantifiers is not relevant. Greedy and
+        ungreedy quantifiers are treated in exactly the same way.
+. When dealing with multiple paths through the tree simultaneously, it
+        is  not  straightforward  to  keep track of captured substrings for the
+        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-
+        tern are not supported, and cause errors if encountered.
+.  For  the same reason, conditional expressions that use a backrefer-
+        ence as the condition are not supported.
+. Callouts are supported, but the value of the  capture_top  field  is
+        always 1, and the value of the capture_last field is always -1.
+.  The \C escape sequence, which (in the standard algorithm) matches a
+        single byte, even in UTF-8 mode, is not supported because the DFA algo-
+        rithm moves through the subject string one character at a time, for all
+        active paths through the tree.
+ ADVANTAGES OF THE DFA ALGORITHM
+        Using the DFA matching algorithm provides the following advantages:
+. All possible matches (at a single point in the subject) are automat-
+        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
+        on the content of the pattern that apply when using the standard  algo-
+        rithm  for partial matching do not apply to the DFA algorithm. For non-
+        anchored patterns, the starting position of a partial match  is  avail-
+        able.
+.  Because  the  DFA 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 par-
+        tial matching each time.
+ DISADVANTAGES OF THE DFA ALGORITHM
+        The DFA algorithm suffers from a number of disadvantages:
+. It is substantially slower than  the  standard  algorithm.  This  is
+        partly  because  it has to search for all possible matches, but is also
+        because it is less susceptible to optimization.
+. Capturing parentheses and back references are not supported.
+. The "atomic group" feature of PCRE regular expressions is supported,
+        but  does not provide the advantage that it does for the standard algo-
+        rithm.
+ Last updated: 28 February 2005
+ Copyright (c) 1997-2005 University of Cambridge.
+ -----------------------------------------------------------------------------
  NAME
         PCRE - Perl-compatible regular expressions
  PCRE NATIVE API
         #include <pcre.h>
-Line 375 
 PCRE NATIVE API
+Line 561 
 PCRE NATIVE API
              const char **errptr, int *erroffset,
              const unsigned char *tableptr);
+        pcre *pcre_compile2(const char *pattern, int options,
+             int *errorcodeptr,
+             const char **errptr, int *erroffset,
+             const unsigned char *tableptr);
         pcre_extra *pcre_study(const pcre *code, int options,
              const char **errptr);
-Line 382 
 PCRE NATIVE API
+Line 573 
 PCRE NATIVE API
              const char *subject, int length, int startoffset,
              int options, int *ovector, int ovecsize);
+        int pcre_dfa_exec(const pcre *code, const pcre_extra *extra,
+             const char *subject, int length, int startoffset,
+             int options, int *ovector, int ovecsize,
+             int *workspace, int wscount);
         int pcre_copy_named_substring(const pcre *code,
              const char *subject, int *ovector,
              int stringcount, const char *stringname,
-Line 417 
 PCRE NATIVE API
+Line 613 
 PCRE NATIVE API
         int pcre_info(const pcre *code, int *optptr, int *firstcharptr);
+        int pcre_refcount(pcre *code, int adjust);
         int pcre_config(int what, void *where);
         char *pcre_version(void);
-Line 436 
 PCRE API OVERVIEW
+Line 634 
 PCRE API OVERVIEW
         PCRE has its own native API, which is described in this document. There
         is also a set of wrapper functions that correspond to the POSIX regular
-        expression API.  These are described in the pcreposix documentation.
+        expression  API.  These  are  described in the pcreposix documentation.
+        Both of these APIs define a set of C function calls. A C++  wrapper  is
+        distributed with PCRE. It is documented in the pcrecpp page.
-        The  native  API  function  prototypes  are  defined in the header file
+        The  native  API  C  function prototypes are defined in the header file
-        pcre.h, and on Unix systems the library itself is  called  libpcre.  It
+        pcre.h, and on Unix systems the library itself is called  libpcre.   It
         can normally be accessed by adding -lpcre to the command for linking an
         application  that  uses  PCRE.  The  header  file  defines  the  macros
         PCRE_MAJOR  and  PCRE_MINOR to contain the major and minor release num-
         bers for the library.  Applications can use these  to  include  support
         for different releases of PCRE.
-        The  functions  pcre_compile(),  pcre_study(), and pcre_exec() are used
+        The   functions   pcre_compile(),  pcre_compile2(),  pcre_study(),  and
-        for compiling and matching regular expressions. A sample  program  that
+        pcre_exec() are used for compiling and matching regular expressions  in
-        demonstrates  the  simplest  way  of using them is provided in the file
+        a  Perl-compatible  manner. A sample program that demonstrates the sim-
-        called pcredemo.c in the source distribution. The pcresample documenta-
+        plest way of using them is provided in the file  called  pcredemo.c  in
-        tion describes how to run it.
+        the  source distribution. The pcresample documentation describes how to
+        run it.
-        In  addition  to  the  main compiling and matching functions, there are
-        convenience functions for extracting captured substrings from a matched
+        A second matching function, pcre_dfa_exec(), which is not Perl-compati-
-        subject string.  They are:
+        ble,  is  also provided. This uses a different algorithm for the match-
+        ing. This allows it to find all possible matches (at a given  point  in
+        the  subject),  not  just  one. However, this algorithm does not return
+        captured substrings. A description of the two matching  algorithms  and
+        their  advantages  and disadvantages is given in the pcrematching docu-
+        mentation.
+        In addition to the main compiling and  matching  functions,  there  are
+        convenience functions for extracting captured substrings from a subject
+        string that is matched by pcre_exec(). They are:
           pcre_copy_substring()
           pcre_copy_named_substring()
-Line 466 
 PCRE API OVERVIEW
+Line 675 
 PCRE API OVERVIEW
         pcre_free_substring() and pcre_free_substring_list() are also provided,
         to free the memory used for extracted strings.
-        The function pcre_maketables() is used to  build  a  set  of  character
+        The  function  pcre_maketables()  is  used  to build a set of character
-        tables   in  the  current  locale  for  passing  to  pcre_compile()  or
+        tables  in  the  current  locale   for   passing   to   pcre_compile(),
-        pcre_exec().  This is an optional facility that is  provided  for  spe-
+        pcre_exec(),  or  pcre_dfa_exec(). This is an optional facility that is
-        cialist use. Most commonly, no special tables are passed, in which case
+        provided for specialist use.  Most  commonly,  no  special  tables  are
-        internal tables that are generated when PCRE is built are used.
+        passed,  in  which case internal tables that are generated when PCRE is
+        built are used.
         The function pcre_fullinfo() is used to find out  information  about  a
         compiled  pattern; pcre_info() is an obsolete version that returns only
-Line 478 
 PCRE API OVERVIEW
+Line 688 
 PCRE API OVERVIEW
         patibility.   The function pcre_version() returns a pointer to a string
         containing the version of PCRE and its date of release.
+        The function pcre_refcount() maintains a  reference  count  in  a  data
+        block  containing  a compiled pattern. This is provided for the benefit
+        of object-oriented applications.
         The global variables pcre_malloc and pcre_free  initially  contain  the
         entry  points  of  the  standard malloc() and free() functions, respec-
         tively. PCRE calls the memory management functions via these variables,
-Line 487 
 PCRE API OVERVIEW
+Line 701 
 PCRE API OVERVIEW
         The global variables pcre_stack_malloc  and  pcre_stack_free  are  also
         indirections  to  memory  management functions. These special functions
         are used only when PCRE is compiled to use  the  heap  for  remembering
-        data,  instead  of recursive function calls. This is a non-standard way
+        data, instead of recursive function calls, when running the pcre_exec()
-        of building PCRE, for use in environments  that  have  limited  stacks.
+        function. This is a non-standard way of building PCRE, for use in envi-
-        Because  of  the greater use of memory management, it runs more slowly.
+        ronments that have limited stacks. Because of the greater use of memory
-        Separate functions are provided so that special-purpose  external  code
+        management, it runs more slowly.  Separate functions  are  provided  so
-        can be used for this case. When used, these functions are always called
+        that  special-purpose  external  code  can  be used for this case. When
-        in a stack-like manner (last obtained, first  freed),  and  always  for
+        used, these functions are always called in a  stack-like  manner  (last
-        memory blocks of the same size.
+        obtained,  first freed), and always for memory blocks of the same size.
         The global variable pcre_callout initially contains NULL. It can be set
-        by the caller to a "callout" function, which PCRE  will  then  call  at
+        by  the  caller  to  a "callout" function, which PCRE will then call at
-        specified  points during a matching operation. Details are given in the
+        specified points during a matching operation. Details are given in  the
         pcrecallout documentation.
  MULTITHREADING
-        The PCRE functions can be used in  multi-threading  applications,  with
+        The  PCRE  functions  can be used in multi-threading applications, with
         the  proviso  that  the  memory  management  functions  pointed  to  by
         pcre_malloc, pcre_free, pcre_stack_malloc, and pcre_stack_free, and the
         callout function pointed to by pcre_callout, are shared by all threads.
-        The compiled form of a regular expression is not altered during  match-
+        The  compiled form of a regular expression is not altered during match-
         ing, so the same compiled pattern can safely be used by several threads
         at once.
-Line 516 
 MULTITHREADING
+Line 730 
 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.
-Line 525 
 CHECKING BUILD-TIME OPTIONS
+Line 739 
 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 that is set to the value of the code that is
+        The output is an integer that is set to the value of the code  that  is
-        used for the newline character. It is either linefeed (10) or  carriage
+        used  for the newline character. It is either linefeed (10) or carriage
-        return  (13),  and  should  normally be the standard character for your
+        return (13), and should normally be the  standard  character  for  your
         operating system.
           PCRE_CONFIG_LINK_SIZE
-        The output is an integer that contains the number  of  bytes  used  for
+        The  output  is  an  integer that contains the number of bytes used for
         internal linkage in compiled regular expressions. The value is 2, 3, or
-. Larger values allow larger regular expressions to  be  compiled,  at
+.  Larger  values  allow larger regular expressions to be compiled, at
-        the  expense  of  slower matching. The default value of 2 is sufficient
+        the expense of slower matching. The default value of  2  is  sufficient
-        for all but the most massive patterns, since  it  allows  the  compiled
+        for  all  but  the  most massive patterns, since it allows the compiled
         pattern to be up to 64K in size.
           PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
-        The  output  is  an integer that contains the threshold above which the
+        The output is an integer that contains the threshold  above  which  the
-        POSIX interface uses malloc() for output vectors. Further  details  are
+        POSIX  interface  uses malloc() for output vectors. Further details are
         given in the pcreposix documentation.
           PCRE_CONFIG_MATCH_LIMIT
         The output is an integer that gives the default limit for the number of
-        internal matching function calls in a  pcre_exec()  execution.  Further
+        internal  matching  function  calls in a pcre_exec() execution. Further
         details are given with pcre_exec() below.
           PCRE_CONFIG_STACKRECURSE
-        The  output  is  an integer that is set to one if internal recursion is
+        The output is an integer that is set to one if internal recursion  when
-        implemented by recursive function calls that use the stack to  remember
+        running pcre_exec() is implemented by recursive function calls that use
-        their state. This is the usual way that PCRE is compiled. The output is
+        the stack to remember their state. This is the usual way that  PCRE  is
-        zero if PCRE was compiled to use blocks of data on the heap instead  of
+        compiled. The output is zero if PCRE was compiled to use blocks of data
-        recursive   function   calls.   In  this  case,  pcre_stack_malloc  and
+        on the  heap  instead  of  recursive  function  calls.  In  this  case,
-        pcre_stack_free are called to manage memory blocks on  the  heap,  thus
+        pcre_stack_malloc  and  pcre_stack_free  are  called  to  manage memory
-        avoiding the use of the stack.
+        blocks on the heap, thus avoiding the use of the stack.
  COMPILING A PATTERN
-Line 590 
 COMPILING A PATTERN
+Line 804 
 COMPILING A PATTERN
              const char **errptr, int *erroffset,
              const unsigned char *tableptr);
-        The  function  pcre_compile()  is  called  to compile a pattern into an
+        pcre *pcre_compile2(const char *pattern, int options,
-        internal form. The pattern is a C string terminated by a  binary  zero,
+             int *errorcodeptr,
-        and  is  passed in the pattern argument. A pointer to a single block of
+             const char **errptr, int *erroffset,
-        memory that is obtained via pcre_malloc is returned. This contains  the
+             const unsigned char *tableptr);
-        compiled  code  and  related  data.  The  pcre  type is defined for the
-        returned block; this is a typedef for a structure  whose  contents  are
-        not  externally defined. It is up to the caller to free the memory when
-        it is no longer required.
-        Although the compiled code of a PCRE regex is relocatable, that is,  it
+        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,
+        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
+        obtained  via  pcre_malloc is returned. This contains the compiled code
+        and related data. The pcre type is defined for the returned block; this
+        is a typedef for a structure whose contents are not externally defined.
+        It is up to the caller  to  free  the  memory  when  it  is  no  longer
+        required.
+        Although  the compiled code of a PCRE regex is relocatable, that is, it
         does not depend on memory location, the complete pcre data block is not
-        fully relocatable, because it may contain a copy of the tableptr  argu-
+        fully  relocatable, because it may contain a copy of the tableptr argu-
         ment, which is an address (see below).
         The options argument contains independent bits that affect the compila-
-        tion. It should be zero if  no  options  are  required.  The  available
+        tion.  It  should  be  zero  if  no options are required. The available
-        options  are  described  below. Some of them, in particular, those that
+        options are described below. Some of them, in  particular,  those  that
-        are compatible with Perl, can also be set and  unset  from  within  the
+        are  compatible  with  Perl,  can also be set and unset from within the
-        pattern  (see  the  detailed  description in the pcrepattern documenta-
+        pattern (see the detailed description  in  the  pcrepattern  documenta-
-        tion). For these options, the contents of the options  argument  speci-
+        tion).  For  these options, the contents of the options argument speci-
-        fies  their initial settings at the start of compilation and execution.
+        fies their initial settings at the start of compilation and  execution.
-        The PCRE_ANCHORED option can be set at the time of matching as well  as
+        The  PCRE_ANCHORED option can be set at the time of matching as well as
         at compile time.
         If errptr is NULL, pcre_compile() returns NULL immediately.  Otherwise,
-        if compilation of a pattern fails,  pcre_compile()  returns  NULL,  and
+        if  compilation  of  a  pattern fails, pcre_compile() returns NULL, and
         sets the variable pointed to by errptr to point to a textual error mes-
-        sage. The offset from the start of the pattern to the  character  where
+        sage.  The  offset from the start of the pattern to the character where
-        the  error  was  discovered  is  placed  in  the variable pointed to by
+        the error was discovered is  placed  in  the  variable  pointed  to  by
-        erroffset, which must not be NULL. If it  is,  an  immediate  error  is
+        erroffset,  which  must  not  be  NULL. If it is, an immediate error is
         given.
+        If pcre_compile2() is used instead of pcre_compile(),  and  the  error-
+        codeptr  argument is not NULL, a non-zero error code number is returned
+        via this argument in the event of an error. This is in addition to  the
+        textual error message. Error codes and messages are listed below.
         If  the  final  argument, tableptr, is NULL, PCRE uses a default set of
         character tables that are  built  when  PCRE  is  compiled,  using  the
         default  C  locale.  Otherwise, tableptr must be an address that is the
-Line 664 
 COMPILING A PATTERN
+Line 892 
 COMPILING A PATTERN
         If  this  bit is set, letters in the pattern match both upper and lower
         case letters. It is equivalent to Perl's  /i  option,  and  it  can  be
-        changed  within  a  pattern  by  a (?i) option setting. When running in
+        changed  within a pattern by a (?i) option setting. In UTF-8 mode, PCRE
-        UTF-8 mode, case support for high-valued characters is  available  only
+        always understands the concept of case for characters whose values  are
-        when PCRE is built with Unicode character property support.
+        less  than 128, so caseless matching is always possible. For characters
+        with higher values, the concept of case is supported if  PCRE  is  com-
+        piled  with Unicode property support, but not otherwise. If you want to
+        use caseless matching for characters 128 and  above,  you  must  ensure
+        that  PCRE  is  compiled  with Unicode property support as well as with
+        UTF-8 support.
           PCRE_DOLLAR_ENDONLY
-        If  this bit is set, a dollar metacharacter in the pattern matches only
+        If this bit is set, a dollar metacharacter in the pattern matches  only
-        at the end of the subject string. Without this option,  a  dollar  also
+        at  the  end  of the subject string. Without this option, a dollar also
-        matches  immediately before the final character if it is a newline (but
+        matches immediately before the final character if it is a newline  (but
-        not before any  other  newlines).  The  PCRE_DOLLAR_ENDONLY  option  is
+        not  before  any  other  newlines).  The  PCRE_DOLLAR_ENDONLY option is
         ignored if PCRE_MULTILINE is set. There is no equivalent to this option
         in Perl, and no way to set it within a pattern.
           PCRE_DOTALL
         If this bit is set, a dot metacharater in the pattern matches all char-
-        acters,  including  newlines.  Without  it, newlines are excluded. This
+        acters, including newlines. Without it,  newlines  are  excluded.  This
-        option is equivalent to Perl's /s option, and it can be changed  within
+        option  is equivalent to Perl's /s option, and it can be changed within
-        a  pattern  by  a  (?s)  option  setting. A negative class such as [^a]
+        a pattern by a (?s) option setting.  A  negative  class  such  as  [^a]
-        always matches a newline character, independent of the setting of  this
+        always  matches a newline character, independent of the setting of this
         option.
           PCRE_EXTENDED
-        If  this  bit  is  set,  whitespace  data characters in the pattern are
+        If this bit is set, whitespace  data  characters  in  the  pattern  are
-        totally ignored except  when  escaped  or  inside  a  character  class.
+        totally ignored except when escaped or inside a character class. White-
-        Whitespace  does  not  include the VT character (code 11). In addition,
+        space does not include the VT character (code 11). In addition, charac-
-        characters between an unescaped # outside a  character  class  and  the
+        ters between an unescaped # outside a character class and the next new-
-        next newline character, inclusive, are also ignored. This is equivalent
+        line character, inclusive, are also  ignored.  This  is  equivalent  to
-        to Perl's /x option, and it can be changed within a pattern by  a  (?x)
+        Perl's  /x  option,  and  it  can be changed within a pattern by a (?x)
         option setting.
-        This  option  makes  it possible to include comments inside complicated
+        This option makes it possible to include  comments  inside  complicated
-        patterns.  Note, however, that this applies only  to  data  characters.
+        patterns.   Note,  however,  that this applies only to data characters.
-        Whitespace   characters  may  never  appear  within  special  character
+        Whitespace  characters  may  never  appear  within  special   character
-        sequences in a pattern, for  example  within  the  sequence  (?(  which
+        sequences  in  a  pattern,  for  example  within the sequence (?( which
         introduces a conditional subpattern.
           PCRE_EXTRA
-        This  option  was invented in order to turn on additional functionality
+        This option was invented in order to turn on  additional  functionality
-        of PCRE that is incompatible with Perl, but it  is  currently  of  very
+        of  PCRE  that  is  incompatible with Perl, but it is currently of very
-        little  use. When set, any backslash in a pattern that is followed by a
+        little use. When set, any backslash in a pattern that is followed by  a
-        letter that has no special meaning  causes  an  error,  thus  reserving
+        letter  that  has  no  special  meaning causes an error, thus reserving
-        these  combinations  for  future  expansion.  By default, as in Perl, a
+        these combinations for future expansion. By  default,  as  in  Perl,  a
-        backslash followed by a letter with no special meaning is treated as  a
+        backslash  followed by a letter with no special meaning is treated as a
-        literal.  There  are  at  present  no other features controlled by this
+        literal. There are at present no  other  features  controlled  by  this
         option. It can also be set by a (?X) option setting within a pattern.
+          PCRE_FIRSTLINE
+        If  this  option  is  set,  an  unanchored pattern is required to match
+        before or at the first newline character in the subject string,  though
+        the matched text may continue over the newline.
           PCRE_MULTILINE
-        By default, PCRE treats the subject string as consisting  of  a  single
+        By  default,  PCRE  treats the subject string as consisting of a single
-        line  of characters (even if it actually contains newlines). The "start
+        line of characters (even if it actually contains newlines). The  "start
-        of line" metacharacter (^) matches only at the  start  of  the  string,
+        of  line"  metacharacter  (^)  matches only at the start of the string,
-        while  the  "end  of line" metacharacter ($) matches only at the end of
+        while the "end of line" metacharacter ($) matches only at  the  end  of
         the string, or before a terminating newline (unless PCRE_DOLLAR_ENDONLY
         is set). This is the same as Perl.
-        When  PCRE_MULTILINE  it  is set, the "start of line" and "end of line"
+        When PCRE_MULTILINE it is set, the "start of line" and  "end  of  line"
-        constructs match immediately following or immediately before  any  new-
+        constructs  match  immediately following or immediately before any new-
-        line  in the subject string, respectively, as well as at the very start
+        line in the subject string, respectively, as well as at the very  start
-        and end. This is equivalent to Perl's /m option, and it can be  changed
+        and  end. This is equivalent to Perl's /m option, and it can be changed
         within a pattern by a (?m) option setting. If there are no "\n" charac-
-        ters in a subject string, or no occurrences of ^ or  $  in  a  pattern,
+        ters  in  a  subject  string, or no occurrences of ^ or $ in a pattern,
         setting PCRE_MULTILINE has no effect.
           PCRE_NO_AUTO_CAPTURE
         If this option is set, it disables the use of numbered capturing paren-
-        theses in the pattern. Any opening parenthesis that is not followed  by
+        theses  in the pattern. Any opening parenthesis that is not followed by
-        ?  behaves as if it were followed by ?: but named parentheses can still
+        ? behaves as if it were followed by ?: but named parentheses can  still
-        be used for capturing (and they acquire  numbers  in  the  usual  way).
+        be  used  for  capturing  (and  they acquire numbers in the usual way).
         There is no equivalent of this option in Perl.
           PCRE_UNGREEDY
-        This  option  inverts  the "greediness" of the quantifiers so that they
+        This option inverts the "greediness" of the quantifiers  so  that  they
-        are not greedy by default, but become greedy if followed by "?". It  is
+        are  not greedy by default, but become greedy if followed by "?". It is
-        not  compatible  with Perl. It can also be set by a (?U) option setting
+        not compatible with Perl. It can also be set by a (?U)  option  setting
         within the pattern.
           PCRE_UTF8
-        This option causes PCRE to regard both the pattern and the  subject  as
+        This  option  causes PCRE to regard both the pattern and the subject as
-        strings  of  UTF-8 characters instead of single-byte character strings.
+        strings of UTF-8 characters instead of single-byte  character  strings.
-        However, it is available only when PCRE is built to include UTF-8  sup-
+        However,  it is available only when PCRE is built to include UTF-8 sup-
-        port.  If not, the use of this option provokes an error. Details of how
+        port. If not, the use of this option provokes an error. Details of  how
-        this option changes the behaviour of PCRE are given in the  section  on
+        this  option  changes the behaviour of PCRE are given in the section on
         UTF-8 support in the main pcre page.
           PCRE_NO_UTF8_CHECK
         When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is
-        automatically checked. If an invalid UTF-8 sequence of bytes is  found,
+        automatically  checked. If an invalid UTF-8 sequence of bytes is found,
-        pcre_compile()  returns an error. If you already know that your pattern
+        pcre_compile() returns an error. If you already know that your  pattern
-        is valid, and you want to skip this check for performance reasons,  you
+        is  valid, and you want to skip this check for performance reasons, you
-        can  set  the  PCRE_NO_UTF8_CHECK option. When it is set, the effect of
+        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 undefined. It may cause
-        your  program  to  crash.   Note that this option can also be passed to
+        your program to crash.  Note that this option can  also  be  passed  to
-        pcre_exec(),  to  suppress  the  UTF-8  validity  checking  of  subject
+        pcre_exec()  and pcre_dfa_exec(), to suppress the UTF-8 validity check-
-        strings.
+        ing of subject strings.
+ COMPILATION ERROR CODES
+        The following table lists the error  codes  than  may  be  returned  by
+        pcre_compile2(),  along with the error messages that may be returned by
+        both compiling functions.
+ no error
+ \ at end of pattern
+ \c at end of pattern
+ unrecognized character follows \
+ numbers out of order in {} quantifier
+ number too big in {} quantifier
+ missing terminating ] for character class
+ invalid escape sequence in character class
+ range out of order in character class
+ nothing to repeat
+ operand of unlimited repeat could match the empty string
+ internal error: unexpected repeat
+ unrecognized character after (?
+ POSIX named classes are supported only within a class
+ missing )
+ reference to non-existent subpattern
+ erroffset passed as NULL
+ unknown option bit(s) set
+ missing ) after comment
+ parentheses nested too deeply
+ regular expression too large
+ failed to get memory
+ unmatched parentheses
+ internal error: code overflow
+ unrecognized character after (?<
+ lookbehind assertion is not fixed length
+ malformed number after (?(
+ conditional group contains more than two branches
+ assertion expected after (?(
+ (?R or (?digits must be followed by )
+ unknown POSIX class name
+ POSIX collating elements are not supported
+ this version of PCRE is not compiled with PCRE_UTF8 support
+ spare error
+ character value in \x{...} sequence is too large
+ invalid condition (?(0)
+ \C not allowed in lookbehind assertion
+ PCRE does not support \L, \l, \N, \U, or \u
+ number after (?C is > 255
+ closing ) for (?C expected
+ recursive call could loop indefinitely
+ unrecognized character after (?P
+ syntax error after (?P
+ two named groups have the same name
+ invalid UTF-8 string
+ support for \P, \p, and \X has not been compiled
+ malformed \P or \p sequence
+ unknown property name after \P or \p
  STUDYING A PATTERN
-        pcre_extra *pcre_study(const pcre *code, int options,
+        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 points to a textual  error  mes-
+        points  to  is set to NULL. Otherwise it points to a textual error mes-
-        sage.  You should therefore test the error pointer for NULL after call-
+        sage. You should therefore test the error pointer for NULL after  call-
         ing pcre_study(), to be sure that it has run successfully.
         This is a typical call to pcre_study():
-Line 808 
 STUDYING A PATTERN
+Line 1103 
 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.)
+        with Unicode character property support.
-        An  internal set of tables is created in the default C locale when PCRE
+        An internal set of tables is created in the default C locale when  PCRE
-        is built. This is used when the final  argument  of  pcre_compile()  is
+        is  built.  This  is  used when the final argument of pcre_compile() is
-        NULL,  and  is  sufficient for many applications. An alternative set of
+        NULL, and is sufficient for many applications. An  alternative  set  of
-        tables can, however, be supplied. These may be created in  a  different
+        tables  can,  however, be supplied. These may be created in a different
-        locale  from the default. As more and more applications change to using
+        locale from the default. As more and more applications change to  using
         Unicode, 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);
-        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 862 
 INFORMATION ABOUT A PATTERN
+Line 1157 
 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 878 
 INFORMATION ABOUT A PATTERN
+Line 1173 
 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 891 
 INFORMATION ABOUT A PATTERN
+Line 1186 
 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_DEFAULTTABLES
+          PCRE_INFO_DEFAULT_TABLES
-        Return a pointer to the internal default character tables within  PCRE.
+        Return  a pointer to the internal default character tables within PCRE.
-        The  fourth  argument should point to an unsigned char * variable. This
+        The fourth argument should point to an unsigned char *  variable.  This
         information call is provided for internal use by the pcre_study() func-
-        tion.  External  callers  can  cause PCRE to use its internal tables by
+        tion. External callers can cause PCRE to use  its  internal  tables  by
         passing a NULL table pointer.
           PCRE_INFO_FIRSTBYTE
-        Return information about the first byte of any matched  string,  for  a
+        Return  information  about  the first byte of any matched string, for a
-        non-anchored    pattern.    (This    option    used    to   be   called
+        non-anchored   pattern.   (This    option    used    to    be    called
-        PCRE_INFO_FIRSTCHAR; the old name is  still  recognized  for  backwards
+        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), it is returned in the integer pointed  to  by  where.
+        (cat|cow|coyote),  it  is  returned in the integer pointed to by where.
         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_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 956 
 INFORMATION ABOUT A PATTERN
+Line 1251 
 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.  A  convenience  function  called
-        pcre_get_named_substring() is provided  for  extracting  an  individual
+        pcre_get_named_substring()  is  provided  for  extracting an individual
-        captured  substring  by  name.  It is also possible to extract the data
+        captured substring by name. It is also possible  to  extract  the  data
-        directly, by first converting the name to a number in order  to  access
+        directly,  by  first converting the name to a number in order to access
-        the  correct  pointers in the output vector (described with pcre_exec()
+        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,
+        below).  To  do 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.
-        For  example,  consider  the following pattern (assume PCRE_EXTENDED is
+        For example, consider the following pattern  (assume  PCRE_EXTENDED  is
         set, so white space - including newlines - is ignored):
           (?P<date> (?P<year>(\d\d)?\d\d) -
           (?P<month>\d\d) - (?P<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 990 
 INFORMATION ABOUT A PATTERN
+Line 1285 
 INFORMATION ABOUT A PATTERN
 04 m  o  n  t  h  00
 02 y  e  a  r  00 ??
-        When  writing  code  to  extract  data from named subpatterns using the
+        When writing code to extract data  from  named  subpatterns  using  the
         name-to-number map, remember that the length of each entry is likely to
         be different for each compiled pattern.
           PCRE_INFO_OPTIONS
-        Return  a  copy of the options with which the pattern was compiled. The
+        Return a copy of the options with which the pattern was  compiled.  The
-        fourth argument should point to an unsigned long  int  variable.  These
+        fourth  argument  should  point to an unsigned long int variable. These
         option bits are those specified in the call to pcre_compile(), modified
         by any top-level option settings within the pattern itself.
-        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 1015 
 INFORMATION ABOUT A PATTERN
+Line 1310 
 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 1023 
 INFORMATION ABOUT A PATTERN
+Line 1318 
 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 1033 
 OBSOLETE INFO FUNCTION
+Line 1328 
 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).
- MATCHING A PATTERN
+ REFERENCE COUNTS
+        int pcre_refcount(pcre *code, int adjust);
+        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,
+        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
+        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 outside these limits, it is forced to the appropriate limit value.
+        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
+        whose byte-order is different. (This seems a highly unlikely scenario.)
+ MATCHING A PATTERN: THE TRADITIONAL FUNCTION
         int pcre_exec(const pcre *code, const pcre_extra *extra,
              const char *subject, int length, int startoffset,
              int options, int *ovector, int ovecsize);
-        The  function pcre_exec() is called to match a subject string against a
+        The function pcre_exec() is called to match a subject string against  a
-        compiled pattern, which is passed in the code argument. If the  pattern
+        compiled  pattern, which is passed in the code argument. If the pattern
         has been studied, the result of the study should be passed in the extra
-        argument.
+        argument.  This  function is the main matching facility of the library,
+        and it operates in a Perl-like manner. For specialist use there is also
+        an  alternative matching function, which is described below in the sec-
+        tion about the pcre_dfa_exec() function.
         In most applications, the pattern will have been compiled (and  option-
         ally  studied)  in the same process that calls pcre_exec(). However, it
-Line 1080 
 MATCHING A PATTERN
+Line 1400 
 MATCHING A PATTERN
 ,              /* start at offset 0 in the subject */
 ,              /* default options */
             ovector,        /* vector of integers for substring information */
-);            /* number of elements in the vector  (NOT  size  in
+);            /* number of elements (NOT size in bytes) */
-        bytes) */
     Extra data for pcre_exec()
-        If  the  extra argument is not NULL, it must point to a pcre_extra data
+        If the extra argument is not NULL, it must point to a  pcre_extra  data
-        block. The pcre_study() function returns such a block (when it  doesn't
+        block.  The pcre_study() function returns such a block (when it doesn't
-        return  NULL), but you can also create one for yourself, and pass addi-
+        return NULL), but you can also create one for yourself, and pass  addi-
-        tional information in it. The fields in a pcre_extra block are as  fol-
+        tional  information in it. The fields in a pcre_extra block are as fol-
         lows:
           unsigned long int flags;
-Line 1097 
 MATCHING A PATTERN
+Line 1416 
 MATCHING A PATTERN
           void *callout_data;
           const unsigned char *tables;
-        The  flags  field  is a bitmap that specifies which of the other fields
+        The flags field is a bitmap that specifies which of  the  other  fields
         are set. The flag bits are:
           PCRE_EXTRA_STUDY_DATA
-Line 1105 
 MATCHING A PATTERN
+Line 1424 
 MATCHING A PATTERN
           PCRE_EXTRA_CALLOUT_DATA
           PCRE_EXTRA_TABLES
-        Other flag bits should be set to zero. The study_data field is  set  in
+        Other  flag  bits should be set to zero. The study_data field is set in
-        the  pcre_extra  block  that is returned by pcre_study(), together with
+        the pcre_extra block that is returned by  pcre_study(),  together  with
         the appropriate flag bit. You should not set this yourself, but you may
-        add  to  the  block by setting the other fields and their corresponding
+        add to the block by setting the other fields  and  their  corresponding
         flag bits.
         The match_limit field provides a means of preventing PCRE from using up
-        a  vast amount of resources when running patterns that are not going to
+        a vast amount of resources when running patterns that are not going  to
-        match, but which have a very large number  of  possibilities  in  their
+        match,  but  which  have  a very large number of possibilities in their
-        search  trees.  The  classic  example  is  the  use of nested unlimited
+        search trees. The classic  example  is  the  use  of  nested  unlimited
         repeats.
-        Internally, PCRE uses a function called match() which it calls  repeat-
+        Internally,  PCRE uses a function called match() which it calls repeat-
-        edly  (sometimes  recursively).  The  limit is imposed on the number of
+        edly (sometimes recursively). The limit is imposed  on  the  number  of
-        times this function is called during a match, which has the  effect  of
+        times  this  function is called during a match, which has the effect of
-        limiting  the amount of recursion and backtracking that can take place.
+        limiting the amount of recursion and backtracking that can take  place.
         For patterns that are not anchored, the count starts from zero for each
         position in the subject string.
-        The  default  limit  for the library can be set when PCRE is built; the
+        The default limit for the library can be set when PCRE  is  built;  the
-        default default is 10 million, which handles all but the  most  extreme
+        default  default  is 10 million, which handles all but the most extreme
-        cases.  You  can  reduce  the  default  by  suppling pcre_exec() with a
+        cases. You can reduce  the  default  by  suppling  pcre_exec()  with  a
-        pcre_extra block in which match_limit is set to a  smaller  value,  and
+        pcre_extra  block  in  which match_limit is set to a smaller value, and
-        PCRE_EXTRA_MATCH_LIMIT  is  set  in  the  flags  field. If the limit is
+        PCRE_EXTRA_MATCH_LIMIT is set in the  flags  field.  If  the  limit  is
         exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
-        The pcre_callout field is used in conjunction with the  "callout"  fea-
+        The  pcre_callout  field is used in conjunction with the "callout" fea-
         ture, which is described in the pcrecallout documentation.
-        The  tables  field  is  used  to  pass  a  character  tables pointer to
+        The tables field  is  used  to  pass  a  character  tables  pointer  to
-        pcre_exec(); this overrides the value that is stored with the  compiled
+        pcre_exec();  this overrides the value that is stored with the compiled
-        pattern.  A  non-NULL value is stored with the compiled pattern only if
+        pattern. A non-NULL value is stored with the compiled pattern  only  if
-        custom tables were supplied to pcre_compile() via  its  tableptr  argu-
+        custom  tables  were  supplied to pcre_compile() via its tableptr argu-
         ment.  If NULL is passed to pcre_exec() using this mechanism, it forces
-        PCRE's internal tables to be used. This facility is  helpful  when  re-
+        PCRE's  internal  tables  to be used. This facility is helpful when re-
-        using  patterns  that  have been saved after compiling with an external
+        using patterns that have been saved after compiling  with  an  external
-        set of tables, because the external tables  might  be  at  a  different
+        set  of  tables,  because  the  external tables might be at a different
-        address  when  pcre_exec() is called. See the pcreprecompile documenta-
+        address when pcre_exec() is called. See the  pcreprecompile  documenta-
         tion for a discussion of saving compiled patterns for later use.
     Option bits for pcre_exec()
-        The unused bits of the options argument for pcre_exec() must  be  zero.
+        The  unused  bits of the options argument for pcre_exec() must be zero.
-        The   only  bits  that  may  be  set  are  PCRE_ANCHORED,  PCRE_NOTBOL,
+        The  only  bits  that  may  be  set  are  PCRE_ANCHORED,   PCRE_NOTBOL,
         PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.
           PCRE_ANCHORED
-        The PCRE_ANCHORED option limits pcre_exec() to matching  at  the  first
+        The  PCRE_ANCHORED  option  limits pcre_exec() to matching at the first
-        matching  position.  If  a  pattern was compiled with PCRE_ANCHORED, or
+        matching position. If a pattern was  compiled  with  PCRE_ANCHORED,  or
-        turned out to be anchored by virtue of its contents, it cannot be  made
+        turned  out to be anchored by virtue of its contents, it cannot be made
         unachored at matching time.
           PCRE_NOTBOL
         This option specifies that first character of the subject string is not
-        the beginning of a line, so the  circumflex  metacharacter  should  not
+        the  beginning  of  a  line, so the circumflex metacharacter should not
-        match  before it. Setting this without PCRE_MULTILINE (at compile time)
+        match before it. Setting this without PCRE_MULTILINE (at compile  time)
-        causes  circumflex  never  to  match.  This  option  affects  only  the
+        causes  circumflex  never to match. This option affects only the behav-
-        behaviour of the circumflex metacharacter. It does not affect \A.
+        iour of the circumflex metacharacter. It does not affect \A.
           PCRE_NOTEOL
         This option specifies that the end of the subject string is not the end
-        of a line, so the dollar metacharacter should not match it nor  (except
+        of  a line, so the dollar metacharacter should not match it nor (except
-        in  multiline mode) a newline immediately before it. Setting this with-
+        in multiline mode) a newline immediately before it. Setting this  with-
         out PCRE_MULTILINE (at compile time) causes dollar never to match. This
-        option  affects only the behaviour of the dollar metacharacter. It does
+        option affects only the behaviour of the dollar metacharacter. It  does
         not affect \Z or \z.
           PCRE_NOTEMPTY
         An empty string is not considered to be a valid match if this option is
-        set.  If  there are alternatives in the pattern, they are tried. If all
+        set. If there are alternatives in the pattern, they are tried.  If  all
-        the alternatives match the empty string, the entire  match  fails.  For
+        the  alternatives  match  the empty string, the entire match fails. For
         example, if the pattern
           a?b?
-        is  applied  to  a string not beginning with "a" or "b", it matches the
+        is applied to a string not beginning with "a" or "b",  it  matches  the
-        empty string at the start of the subject. With PCRE_NOTEMPTY set,  this
+        empty  string at the start of the subject. With PCRE_NOTEMPTY set, this
         match is not valid, so PCRE searches further into the string for occur-
         rences of "a" or "b".
         Perl has no direct equivalent of PCRE_NOTEMPTY, but it does make a spe-
-        cial  case  of  a  pattern match of the empty string within its split()
+        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
+        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 offset with PCRE_NOTEMPTY and PCRE_ANCHORED, and then
-        if  that  fails by advancing the starting offset (see below) and trying
+        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
         this in the pcredemo.c sample program.
           PCRE_NO_UTF8_CHECK
         When PCRE_UTF8 is set at compile time, the validity of the subject as a
-        UTF-8 string is automatically checked when pcre_exec() is  subsequently
+        UTF-8  string is automatically checked when pcre_exec() is subsequently
-        called.   The  value  of  startoffset is also checked to ensure that it
+        called.  The value of startoffset is also checked  to  ensure  that  it
-        points to the start of a UTF-8 character. If an invalid UTF-8  sequence
+        points  to the start of a UTF-8 character. If an invalid UTF-8 sequence
         of bytes is found, pcre_exec() returns the error PCRE_ERROR_BADUTF8. If
-        startoffset contains an  invalid  value,  PCRE_ERROR_BADUTF8_OFFSET  is
+        startoffset  contains  an  invalid  value, PCRE_ERROR_BADUTF8_OFFSET is
         returned.
-        If  you  already  know that your subject is valid, and you want to skip
+        If you already know that your subject is valid, and you  want  to  skip
-        these   checks   for   performance   reasons,   you   can    set    the
+        these    checks    for   performance   reasons,   you   can   set   the
-        PCRE_NO_UTF8_CHECK  option  when calling pcre_exec(). You might want to
+        PCRE_NO_UTF8_CHECK option when calling pcre_exec(). You might  want  to
-        do this for the second and subsequent calls to pcre_exec() if  you  are
+        do  this  for the second and subsequent calls to pcre_exec() if you are
-        making  repeated  calls  to  find  all  the matches in a single subject
+        making repeated calls to find all  the  matches  in  a  single  subject
-        string. However, you should be  sure  that  the  value  of  startoffset
+        string.  However,  you  should  be  sure  that the value of startoffset
-        points  to  the  start of a UTF-8 character. When PCRE_NO_UTF8_CHECK is
+        points to the start of a UTF-8 character.  When  PCRE_NO_UTF8_CHECK  is
-        set, the effect of passing an invalid UTF-8 string as a subject,  or  a
+        set,  the  effect of passing an invalid UTF-8 string as a subject, or a
-        value  of startoffset that does not point to the start of a UTF-8 char-
+        value of startoffset that does not point to the start of a UTF-8  char-
         acter, is undefined. Your program may crash.
           PCRE_PARTIAL
-        This option turns on the  partial  matching  feature.  If  the  subject
+        This  option  turns  on  the  partial  matching feature. If the subject
-        string  fails to match the pattern, but at some point during the match-
+        string fails to match the pattern, but at some point during the  match-
-        ing process the end of the subject was reached (that  is,  the  subject
+        ing  process  the  end of the subject was reached (that is, the subject
-        partially  matches  the  pattern and the failure to match occurred only
+        partially matches the pattern and the failure to  match  occurred  only
-        because there were not enough subject characters), pcre_exec()  returns
+        because  there were not enough subject characters), pcre_exec() returns
-        PCRE_ERROR_PARTIAL  instead of PCRE_ERROR_NOMATCH. When PCRE_PARTIAL is
+        PCRE_ERROR_PARTIAL instead of PCRE_ERROR_NOMATCH. When PCRE_PARTIAL  is
-        used, there are restrictions on what may appear in the  pattern.  These
+        used,  there  are restrictions on what may appear in the pattern. These
         are discussed in the pcrepartial documentation.
     The string to be matched by pcre_exec()
-        The  subject string is passed to pcre_exec() as a pointer in subject, a
+        The subject string is passed to pcre_exec() as a pointer in subject,  a
-        length in length, and a starting byte offset in startoffset.  In  UTF-8
+        length  in  length, and a starting byte offset in startoffset. In UTF-8
-        mode,  the  byte  offset  must point to the start of a UTF-8 character.
+        mode, the byte offset must point to the start  of  a  UTF-8  character.
-        Unlike the pattern string, the subject may contain binary  zero  bytes.
+        Unlike  the  pattern string, the subject may contain binary zero bytes.
-        When  the starting offset is zero, the search for a match starts at the
+        When the starting offset is zero, the search for a match starts at  the
         beginning of the subject, and this is by far the most common case.
-        A non-zero starting offset is useful when searching for  another  match
+        A  non-zero  starting offset is useful when searching for another match
-        in  the same subject by calling pcre_exec() again after a previous suc-
+        in the same subject by calling pcre_exec() again after a previous  suc-
-        cess.  Setting startoffset differs from just passing over  a  shortened
+        cess.   Setting  startoffset differs from just passing over a shortened
-        string  and  setting  PCRE_NOTBOL  in the case of a pattern that begins
+        string and setting PCRE_NOTBOL in the case of  a  pattern  that  begins
         with any kind of lookbehind. For example, consider the pattern
           \Biss\B
-        which finds occurrences of "iss" in the middle of  words.  (\B  matches
+        which  finds  occurrences  of "iss" in the middle of words. (\B matches
-        only  if  the  current position in the subject is not a word boundary.)
+        only if the current position in the subject is not  a  word  boundary.)
-        When applied to the string "Mississipi" the first call  to  pcre_exec()
+        When  applied  to the string "Mississipi" the first call to pcre_exec()
-        finds  the  first  occurrence. If pcre_exec() is called again with just
+        finds the first occurrence. If pcre_exec() is called  again  with  just
-        the remainder of the subject,  namely  "issipi",  it  does  not  match,
+        the  remainder  of  the  subject,  namely  "issipi", it does not match,
         because \B is always false at the start of the subject, which is deemed
-        to be a word boundary. However, if pcre_exec()  is  passed  the  entire
+        to  be  a  word  boundary. However, if pcre_exec() is passed the entire
         string again, but with startoffset set to 4, it finds the second occur-
-        rence of "iss" because it is able to look behind the starting point  to
+        rence  of "iss" because it is able to look behind the starting point to
         discover that it is preceded by a letter.
-        If  a  non-zero starting offset is passed when the pattern is anchored,
+        If a non-zero starting offset is passed when the pattern  is  anchored,
         one attempt to match at the given offset is made. This can only succeed
-        if  the  pattern  does  not require the match to be at the start of the
+        if the pattern does not require the match to be at  the  start  of  the
         subject.
     How pcre_exec() returns captured substrings
-        In general, a pattern matches a certain portion of the subject, and  in
+        In  general, a pattern matches a certain portion of the subject, and in
-        addition,  further  substrings  from  the  subject may be picked out by
+        addition, further substrings from the subject  may  be  picked  out  by
-        parts of the pattern. Following the usage  in  Jeffrey  Friedl's  book,
+        parts  of  the  pattern.  Following the usage in Jeffrey Friedl's book,
-        this  is  called "capturing" in what follows, and the phrase "capturing
+        this is called "capturing" in what follows, and the  phrase  "capturing
-        subpattern" is used for a fragment of a pattern that picks out  a  sub-
+        subpattern"  is  used for a fragment of a pattern that picks out a sub-
-        string.  PCRE  supports several other kinds of parenthesized subpattern
+        string. PCRE supports several other kinds of  parenthesized  subpattern
         that do not cause substrings to be captured.
-        Captured substrings are returned to the caller via a vector of  integer
+        Captured  substrings are returned to the caller via a vector of integer
-        offsets  whose  address is passed in ovector. The number of elements in
+        offsets whose address is passed in ovector. The number of  elements  in
-        the vector is passed in ovecsize, which must be a non-negative  number.
+        the  vector is passed in ovecsize, which must be a non-negative number.
         Note: this argument is NOT the size of ovector in bytes.
-        The  first  two-thirds of the vector is used to pass back captured sub-
+        The first two-thirds of the vector is used to pass back  captured  sub-
-        strings, each substring using a pair of integers. The  remaining  third
+        strings,  each  substring using a pair of integers. The remaining third
-        of  the  vector is used as workspace by pcre_exec() while matching cap-
+        of the vector is used as workspace by pcre_exec() while  matching  cap-
-        turing subpatterns, and is not available for passing back  information.
+        turing  subpatterns, and is not available for passing back information.
-        The  length passed in ovecsize should always be a multiple of three. If
+        The length passed in ovecsize should always be a multiple of three.  If
         it is not, it is rounded down.
-        When a match is successful, information about  captured  substrings  is
+        When  a  match  is successful, information about captured substrings is
-        returned  in  pairs  of integers, starting at the beginning of ovector,
+        returned in pairs of integers, starting at the  beginning  of  ovector,
-        and continuing up to two-thirds of its length at the  most.  The  first
+        and  continuing  up  to two-thirds of its length at the most. The first
         element of a pair is set to the offset of the first character in a sub-
-        string, and the second is set to the  offset  of  the  first  character
+        string,  and  the  second  is  set to the offset of the first character
-        after  the  end  of  a  substring. The first pair, ovector[0] and ovec-
+        after the end of a substring. The  first  pair,  ovector[0]  and  ovec-
-        tor[1], identify the portion of  the  subject  string  matched  by  the
+        tor[1],  identify  the  portion  of  the  subject string matched by the
-        entire  pattern.  The next pair is used for the first capturing subpat-
+        entire pattern. The next pair is used for the first  capturing  subpat-
-        tern, and so on. The value returned by pcre_exec()  is  the  number  of
+        tern,  and  so  on.  The value returned by pcre_exec() is the number of
-        pairs  that  have  been set. If there are no capturing subpatterns, the
+        pairs that have been set. If there are no  capturing  subpatterns,  the
-        return value from a successful match is 1,  indicating  that  just  the
+        return  value  from  a  successful match is 1, indicating that just the
         first pair of offsets has been set.
-        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  in  the  following
+        substrings  as  separate  strings. These are described in the following
         section.
-        It  is  possible  for  an capturing subpattern number n+1 to match some
+        It is possible for an capturing subpattern number  n+1  to  match  some
-        part of the subject when subpattern n has not been  used  at  all.  For
+        part  of  the  subject  when subpattern n has not been used at all. For
         example, if the string "abc" is matched against the pattern (a|(z))(bc)
-        subpatterns 1 and 3 are matched, but 2 is not. When this happens,  both
+        subpatterns  1 and 3 are matched, but 2 is not. When this happens, both
         offset values corresponding to the unused subpattern are set to -1.
         If a capturing subpattern is matched repeatedly, it is the last portion
         of the string that it matched that is returned.
-        If the vector is too small to hold all the captured substring  offsets,
+        If  the vector is too small to hold all the captured substring offsets,
         it is used as far as possible (up to two-thirds of its length), and the
-        function returns a value of zero. In particular, if the substring  off-
+        function  returns a value of zero. In particular, if the substring off-
         sets are not of interest, pcre_exec() may be called with ovector passed
-        as NULL and ovecsize as zero. However, if  the  pattern  contains  back
+        as  NULL  and  ovecsize  as zero. However, if the pattern contains back
-        references  and  the  ovector is not big enough to remember the related
+        references and the ovector is not big enough to  remember  the  related
-        substrings, PCRE has to get additional memory for use during  matching.
+        substrings,  PCRE has to get additional memory for use during matching.
         Thus it is usually advisable to supply an ovector.
-        Note  that  pcre_info() can be used to find out how many capturing sub-
+        Note that pcre_info() can be used to find out how many  capturing  sub-
         patterns there are in a compiled pattern. The smallest size for ovector
-        that  will  allow for n captured substrings, in addition to the offsets
+        that will allow for n captured substrings, in addition to  the  offsets
         of the substring matched by the whole pattern, is (n+1)*3.
     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 1336 
 MATCHING A PATTERN
+Line 1655 
 MATCHING A PATTERN
           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 1345 
 MATCHING A PATTERN
+Line 1664 
 MATCHING A PATTERN
           PCRE_ERROR_BADMAGIC       (-4)
-        PCRE stores a 4-byte "magic number" at the start of the compiled  code,
+        PCRE  stores a 4-byte "magic number" at the start of the compiled code,
         to catch the case when it is passed a junk pointer and to detect when a
         pattern that was compiled in an environment of one endianness is run in
-        an  environment  with the other endianness. This is the error that PCRE
+        an environment with the other endianness. This is the error  that  PCRE
         gives when the magic number is not present.
           PCRE_ERROR_UNKNOWN_NODE   (-5)
         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 recursion and backtracking limit, as specified by  the  match_limit
+        The  recursion  and backtracking limit, as specified by the match_limit
-        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_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)
+          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_BAD_PARTIAL (-13)
+          PCRE_ERROR_BADPARTIAL     (-13)
-        The PCRE_PARTIAL option was used with  a  compiled  pattern  containing
+        The  PCRE_PARTIAL  option  was  used with a compiled pattern containing
-        items  that are not supported for partial matching. See the pcrepartial
+        items that are not supported for partial matching. See the  pcrepartial
         documentation for details of partial matching.
-          PCRE_ERROR_INTERNAL (-14)
+          PCRE_ERROR_INTERNAL       (-14)
-        An unexpected internal error has occurred. This error could  be  caused
+        An  unexpected  internal error has occurred. This error could be caused
         by a bug in PCRE or by overwriting of the compiled pattern.
-          PCRE_ERROR_BADCOUNT (-15)
+          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.
  EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
-Line 1428 
 EXTRACTING CAPTURED SUBSTRINGS BY NUMBER
+Line 1747 
 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
+        substrings.  A  substring  that  contains  a  binary  zero is correctly
-        extracted  and  has  a further zero added on the end, but the result is
+        extracted and has a further zero added on the end, but  the  result  is
         not, of course, a C string.
-        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
           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
           PCRE_ERROR_NOMEMORY       (-6)
         if the attempt to get the memory block failed.
-        When any of these functions encounter a substring that is unset,  which
+        When  any of these functions encounter a substring that is unset, which
-        can  happen  when  capturing subpattern number n+1 matches some part of
+        can happen when capturing subpattern number n+1 matches  some  part  of
-        the subject, but subpattern n has not been used at all, they return  an
+        the  subject, but subpattern n has not been used at all, they return an
         empty string. This can be distinguished from a genuine zero-length sub-
-        string by inspecting the appropriate offset in ovector, which is  nega-
+        string  by inspecting the appropriate offset in ovector, which is nega-
         tive for unset substrings.
-        The  two convenience functions pcre_free_substring() and pcre_free_sub-
+        The two convenience functions pcre_free_substring() and  pcre_free_sub-
-        string_list() can be used to free the memory  returned  by  a  previous
+        string_list()  can  be  used  to free the memory returned by a previous
         call  of  pcre_get_substring()  or  pcre_get_substring_list(),  respec-
-        tively. They do nothing more than  call  the  function  pointed  to  by
+        tively.  They  do  nothing  more  than  call the function pointed to by
-        pcre_free,  which  of course could be called directly from a C program.
+        pcre_free, which of course could be called directly from a  C  program.
-        However, PCRE is used in some situations where it is linked via a  spe-
+        However,  PCRE is used in some situations where it is linked via a spe-
         cial  interface  to  another  programming  language  which  cannot  use
-        pcre_free directly; it is  for  these  cases  that  the  functions  are
+        pcre_free  directly;  it is for these cases that the functions are pro-
-        provided.
+        vided.
  EXTRACTING CAPTURED SUBSTRINGS BY NAME
-Line 1511 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
+Line 1830 
 EXTRACTING CAPTURED SUBSTRINGS BY NAME
              int stringcount, const char *stringname,
              const char **stringptr);
-        To  extract a substring by name, you first have to find associated num-
+        To extract a substring by name, you first have to find associated  num-
         ber.  For example, for this pattern
           (a+)b(?<xxx>\d+)...
         the number of the subpattern called "xxx" is 2. You can find the number
         from the name by calling pcre_get_stringnumber(). The first argument is
-        the compiled pattern, and the second is the  name.  The  yield  of  the
+        the  compiled  pattern,  and  the  second is the name. The yield of the
-        function  is  the  subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if
+        function is 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.
- Last updated: 09 September 2004
- Copyright (c) 1997-2004 University of Cambridge.
- -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
+ FINDING ALL POSSIBLE MATCHES
+        The traditional matching function uses a  similar  algorithm  to  Perl,
+        which stops when it finds the first match, starting at a given point in
+        the subject. If you want to find all possible matches, or  the  longest
+        possible  match,  consider using the alternative matching function (see
+        below) instead. If you cannot use the alternative function,  but  still
+        need  to  find all possible matches, you can kludge it up by making use
+        of the callout facility, which is described in the pcrecallout documen-
+        tation.
+        What you have to do is to insert a callout right at the end of the pat-
+        tern.  When your callout function is called, extract and save the  cur-
+        rent  matched  substring.  Then  return  1, which forces pcre_exec() to
+        backtrack and try other alternatives. Ultimately, when it runs  out  of
+        matches, pcre_exec() will yield PCRE_ERROR_NOMATCH.
+ MATCHING A PATTERN: THE ALTERNATIVE FUNCTION
+        int pcre_dfa_exec(const pcre *code, const pcre_extra *extra,
+             const char *subject, int length, int startoffset,
+             int options, int *ovector, int ovecsize,
+             int *workspace, int wscount);
+        The  function  pcre_dfa_exec()  is  called  to  match  a subject string
+        against a compiled pattern, using a "DFA" matching algorithm. This  has
+        different  characteristics to the normal algorithm, and is not compati-
+        ble with Perl. Some of the features of PCRE patterns are not supported.
+        Nevertheless, there are times when this kind of matching can be useful.
+        For a discussion of the two matching algorithms, see  the  pcrematching
+        documentation.
+        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
+        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
+        workspace vector should contain at least 20 elements. It  is  used  for
+        keeping  track  of  multiple  paths  through  the  pattern  tree.  More
+        workspace will be needed for patterns and subjects where  there  are  a
+        lot of possible matches.
+        Here is an example of a simple call to pcre_exec():
+          int rc;
+          int ovector[10];
+          int wspace[20];
+          rc = pcre_exec(
+            re,             /* result of pcre_compile() */
+            NULL,           /* we didn't study the pattern */
+            "some string",  /* the subject string */
+,             /* the length of the subject string */
+,              /* start at offset 0 in the subject */
+,              /* default options */
+            ovector,        /* vector of integers for substring information */
+,             /* number of elements (NOT size in bytes) */
+            wspace,         /* working space vector */
+);            /* number of elements (NOT size in bytes) */
+    Option bits for pcre_dfa_exec()
+        The  unused  bits  of  the options argument for pcre_dfa_exec() must be
+        zero. The only bits that may be  set  are  PCRE_ANCHORED,  PCRE_NOTBOL,
+        PCRE_NOTEOL,     PCRE_NOTEMPTY,    PCRE_NO_UTF8_CHECK,    PCRE_PARTIAL,
+        PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All  but  the  last  three  of
+        these  are  the  same  as  for pcre_exec(), so their description is not
+        repeated here.
+          PCRE_PARTIAL
+        This has the same general effect as it does for  pcre_exec(),  but  the
+        details   are   slightly   different.  When  PCRE_PARTIAL  is  set  for
+        pcre_dfa_exec(), the return code PCRE_ERROR_NOMATCH is  converted  into
+        PCRE_ERROR_PARTIAL  if  the  end  of the subject is reached, there have
+        been no complete matches, but there is still at least one matching pos-
+        sibility.  The portion of the string that provided the partial match is
+        set as the first matching string.
+          PCRE_DFA_SHORTEST
+        Setting the PCRE_DFA_SHORTEST option causes the matching  algorithm  to
+        stop  as  soon  as  it  has found one match. Because of the way the DFA
+        algorithm works, this is necessarily the shortest possible match at the
+        first possible matching point in the subject string.
+          PCRE_DFA_RESTART
+        When  pcre_dfa_exec()  is  called  with  the  PCRE_PARTIAL  option, and
+        returns a partial match, it is possible to call it  again,  with  addi-
+        tional  subject  characters,  and have it continue with the same match.
+        The PCRE_DFA_RESTART option requests this action; when it is  set,  the
+        workspace  and wscount options must reference the same vector as before
+        because data about the match so far is left in  them  after  a  partial
+        match.  There  is  more  discussion of this facility in the pcrepartial
+        documentation.
+    Successful returns from pcre_dfa_exec()
+        When pcre_dfa_exec() succeeds, it may have matched more than  one  sub-
+        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
+        matches  are all initial substrings of the longer matches. For example,
+        if the pattern
+          <.*>
+        is matched against the string
+          This is <something> <something else> <something further> no more
+        the three matched strings are
+          <something>
+          <something> <something else>
+          <something> <something else> <something further>
+        On success, the yield of the function is a number  greater  than  zero,
+        which  is  the  number of matched substrings. The substrings themselves
+        are returned in ovector. Each string uses two elements;  the  first  is
+        the  offset  to the start, and the second is the offset to the end. All
+        the strings have the same start offset. (Space could have 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 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
+        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.
+        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
+        specific to pcre_dfa_exec():
+          PCRE_ERROR_DFA_UITEM      (-16)
+        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
+        reference.
+          PCRE_ERROR_DFA_UCOND      (-17)
+        This  return is given if pcre_dfa_exec() encounters a condition item in
+        a pattern that uses a back reference for the  condition.  This  is  not
+        supported.
+          PCRE_ERROR_DFA_UMLIMIT    (-18)
+        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
+        workspace vector.
+          PCRE_ERROR_DFA_RECURSE    (-20)
+        When a recursive subpattern is processed, the matching  function  calls
+        itself  recursively,  using  private vectors for ovector and workspace.
+        This error is given if the output vector  is  not  large  enough.  This
+        should be extremely rare, as a vector of size 1000 is used.
+ Last updated: 16 May 2005
+ Copyright (c) 1997-2005 University of Cambridge.
+ -----------------------------------------------------------------------------
  NAME
         PCRE - Perl-compatible regular expressions
  PCRE CALLOUTS
         int (*pcre_callout)(pcre_callout_block *);
-Line 1606 
 MISSING CALLOUTS
+Line 2095 
 MISSING CALLOUTS
  THE CALLOUT INTERFACE
         During matching, when PCRE reaches a callout point, the external  func-
-        tion  defined  by pcre_callout is called (if it is set). The only argu-
+        tion  defined by pcre_callout is called (if it is set). This applies to
-        ment is a pointer to a pcre_callout block. This structure contains  the
+        both the pcre_exec() and the pcre_dfa_exec()  matching  functions.  The
-        following fields:
+        only  argument  to  the callout function is a pointer to a pcre_callout
+        block. This structure contains the following fields:
           int          version;
           int          callout_number;
-Line 1623 
 THE CALLOUT INTERFACE
+Line 2113 
 THE CALLOUT INTERFACE
           int          pattern_position;
           int          next_item_length;
-        The  version  field  is an integer containing the version number of the
+        The version field is an integer containing the version  number  of  the
-        block format. The initial version was 0; the current version is 1.  The
+        block  format. The initial version was 0; the current version is 1. The
-        version  number  will  change  again in future if additional fields are
+        version number will change again in future  if  additional  fields  are
         added, but the intention is never to remove any of the existing fields.
-        The  callout_number  field  contains the number of the callout, as com-
+        The callout_number field contains the number of the  callout,  as  com-
-        piled into the pattern (that is, the number after ?C for  manual  call-
+        piled  into  the pattern (that is, the number after ?C for manual call-
         outs, and 255 for automatically generated callouts).
-        The  offset_vector field is a pointer to the vector of offsets that was
+        The offset_vector field is a pointer to the vector of offsets that  was
-        passed by the caller to pcre_exec(). The contents can be  inspected  in
+        passed   by   the   caller  to  pcre_exec()  or  pcre_dfa_exec().  When
-        order  to extract substrings that have been matched so far, in the same
+        pcre_exec() is used, the contents can be inspected in order to  extract
-        way as for extracting substrings after a match has completed.
+        substrings  that  have  been  matched  so  far,  in the same way as for
+        extracting substrings after a match has completed. For  pcre_dfa_exec()
+        this field is not useful.
         The subject and subject_length fields contain copies of the values that
         were passed to pcre_exec().
-        The  start_match  field contains the offset within the subject at which
+        The start_match field contains the offset within the subject  at  which
-        the current match attempt started. If the pattern is not anchored,  the
+        the  current match attempt started. If the pattern is not anchored, the
         callout function may be called several times from the same point in the
         pattern for different starting points in the subject.
-        The current_position field contains the offset within  the  subject  of
+        The  current_position  field  contains the offset within the subject of
         the current match pointer.
-        The  capture_top field contains one more than the number of the highest
+        When the pcre_exec() function is used, the capture_top  field  contains
-        numbered captured substring so far. If no  substrings  have  been  cap-
+        one  more than the number of the highest numbered captured substring so
-        tured, the value of capture_top is one.
+        far. If no substrings have been captured, the value of  capture_top  is
+        one.  This  is always the case when pcre_dfa_exec() is used, because it
-        The  capture_last  field  contains the number of the most recently cap-
+        does not support captured substrings.
-        tured substring. If no substrings have been captured, its value is  -1.
+        The capture_last field contains the number of the  most  recently  cap-
-        The  callout_data  field contains a value that is passed to pcre_exec()
+        tured  substring. If no substrings have been captured, its value is -1.
-        by the caller specifically so that it can be passed back  in  callouts.
+        This is always the case when pcre_dfa_exec() is used.
-        It  is  passed  in the pcre_callout field of the pcre_extra data struc-
-        ture. If no such data was  passed,  the  value  of  callout_data  in  a
+        The callout_data field contains a value that is passed  to  pcre_exec()
-        pcre_callout  block  is  NULL. There is a description of the pcre_extra
+        or  pcre_dfa_exec() specifically so that it can be passed back in call-
+        outs. It is passed in the pcre_callout field  of  the  pcre_extra  data
+        structure.  If  no such data was passed, the value of callout_data in a
+        pcre_callout block is NULL. There is a description  of  the  pcre_extra
         structure in the pcreapi documentation.
-        The pattern_position field is present from version 1 of the  pcre_call-
+        The  pattern_position field is present from version 1 of the pcre_call-
         out structure. It contains the offset to the next item to be matched in
         the pattern string.
-        The next_item_length field is present from version 1 of the  pcre_call-
+        The  next_item_length field is present from version 1 of the pcre_call-
         out structure. It contains the length of the next item to be matched in
-        the pattern string. When the callout immediately precedes  an  alterna-
+        the  pattern  string. When the callout immediately precedes an alterna-
-        tion  bar, a closing parenthesis, or the end of the pattern, the length
+        tion bar, a closing parenthesis, or the end of the pattern, the  length
-        is zero. When the callout precedes an opening parenthesis,  the  length
+        is  zero.  When the callout precedes an opening parenthesis, the length
         is that of the entire subpattern.
-        The  pattern_position  and next_item_length fields are intended to help
+        The pattern_position and next_item_length fields are intended  to  help
-        in distinguishing between different automatic callouts, which all  have
+        in  distinguishing between different automatic callouts, which all have
         the same callout number. However, they are set for all callouts.
  RETURN VALUES
-        The  external callout function returns an integer to PCRE. If the value
+        The external callout function returns an integer to PCRE. If the  value
-        is zero, matching proceeds as normal. If  the  value  is  greater  than
+        is  zero,  matching  proceeds  as  normal. If the value is greater than
-        zero,  matching  fails  at  the current point, but backtracking to test
+        zero, matching fails at the current point, but  the  testing  of  other
-        other matching possibilities goes ahead, just as if a lookahead  asser-
+        matching possibilities goes ahead, just as if a lookahead assertion had
-        tion  had  failed.  If  the value is less than zero, the match is aban-
+        failed. If the value is less than zero, the  match  is  abandoned,  and
-        doned, and pcre_exec() returns the negative value.
+        pcre_exec() (or pcre_dfa_exec()) returns the negative value.
-        Negative  values  should  normally  be   chosen   from   the   set   of
+        Negative   values   should   normally   be   chosen  from  the  set  of
         PCRE_ERROR_xxx values. In particular, PCRE_ERROR_NOMATCH forces a stan-
-        dard "no  match"  failure.   The  error  number  PCRE_ERROR_CALLOUT  is
+        dard  "no  match"  failure.   The  error  number  PCRE_ERROR_CALLOUT is
-        reserved  for  use  by callout functions; it will never be used by PCRE
+        reserved for use by callout functions; it will never be  used  by  PCRE
         itself.
- Last updated: 09 September 2004
+ Last updated: 28 February 2005
- Copyright (c) 1997-2004 University of Cambridge.
+ Copyright (c) 1997-2005 University of Cambridge.
  -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
  NAME
         PCRE - Perl-compatible regular expressions
  DIFFERENCES BETWEEN PCRE AND PERL
         This  document describes the differences in the ways that PCRE and Perl
-Line 1808 
 DIFFERENCES BETWEEN PCRE AND PERL
+Line 2302 
 DIFFERENCES BETWEEN PCRE AND PERL
         (m) Patterns compiled by PCRE can be saved and re-used at a later time,
         even on different hosts that have the other endianness.
- Last updated: 09 September 2004
+        (n)  The  alternative  matching function (pcre_dfa_exec()) matches in a
- Copyright (c) 1997-2004 University of Cambridge.
+        different way and is not Perl-compatible.
- -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
+ Last updated: 28 February 2005
+ Copyright (c) 1997-2005 University of Cambridge.
+ -----------------------------------------------------------------------------
  NAME
         PCRE - Perl-compatible regular expressions
  PCRE REGULAR EXPRESSION DETAILS
         The  syntax  and semantics of the regular expressions supported by PCRE
-Line 1836 
 PCRE REGULAR EXPRESSION DETAILS
+Line 2332 
 PCRE REGULAR EXPRESSION DETAILS
         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.
+        From  release  6.0,   PCRE   offers   a   second   matching   function,
+        pcre_dfa_exec(),  which matches using a different algorithm that is not
+        Perl-compatible. The advantages and disadvantages  of  the  alternative
+        function, and how it differs from the normal function, are discussed in
+        the pcrematching page.
         A regular expression is a pattern that is  matched  against  a  subject
         string  from  left  to right. Most characters stand for themselves in a
         pattern, and match the corresponding characters in the  subject.  As  a
-Line 1843 
 PCRE REGULAR EXPRESSION DETAILS
+Line 2347 
 PCRE REGULAR EXPRESSION DETAILS
           The quick brown fox
-        matches  a portion of a subject string that is identical to itself. The
+        matches a portion of a subject string that is identical to itself. When
-        power of regular expressions comes from the ability to include alterna-
+        caseless matching is specified (the PCRE_CASELESS option), letters  are
-        tives  and repetitions in the pattern. These are encoded in the pattern
+        matched  independently  of case. In UTF-8 mode, PCRE always understands
-        by the use of metacharacters, which do not  stand  for  themselves  but
+        the concept of case for characters whose values are less than  128,  so
-        instead are interpreted in some special way.
+        caseless  matching  is always possible. For characters with higher val-
+        ues, the concept of case is supported if PCRE is compiled with  Unicode
-        There  are  two different sets of metacharacters: those that are recog-
+        property  support,  but  not  otherwise.   If  you want to use caseless
-        nized anywhere in the pattern except within square brackets, and  those
+        matching for characters 128 and above, you must  ensure  that  PCRE  is
-        that  are  recognized  in square brackets. Outside square brackets, the
+        compiled with Unicode property support as well as with UTF-8 support.
+        The  power  of  regular  expressions  comes from the ability to include
+        alternatives and repetitions in the pattern. These are encoded  in  the
+        pattern by the use of metacharacters, which do not stand for themselves
+        but instead are interpreted in some special way.
+        There are two different sets of metacharacters: those that  are  recog-
+        nized  anywhere in the pattern except within square brackets, and those
+        that are recognized in square brackets. Outside  square  brackets,  the
         metacharacters are as follows:
           \      general escape character with several uses
-Line 1870 
 PCRE REGULAR EXPRESSION DETAILS
+Line 2383 
 PCRE REGULAR EXPRESSION DETAILS
                  also "possessive quantifier"
           {      start min/max quantifier
-        Part of a pattern that is in square brackets  is  called  a  "character
+        Part  of  a  pattern  that is in square brackets is called a "character
         class". In a character class the only metacharacters are:
           \      general escape character
-Line 1880 
 PCRE REGULAR EXPRESSION DETAILS
+Line 2393 
 PCRE REGULAR EXPRESSION DETAILS
                    syntax)
           ]      terminates the character class
-        The  following sections describe the use of each of the metacharacters.
+        The following sections describe the use of each of the  metacharacters.
  BACKSLASH
         The backslash character has several uses. Firstly, if it is followed by
-        a  non-alphanumeric  character,  it takes away any special meaning that
+        a 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 character are ignored.
-        An  escaping backslash can be used to include a whitespace or # charac-
+        An escaping backslash can be used to include a whitespace or #  charac-
         ter 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 1916 
 BACKSLASH
+Line 2429 
 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 1939 
 BACKSLASH
+Line 2452 
 BACKSLASH
           \xhh      character with hex code hh
           \x{hhh..} character with hex code hhh... (UTF-8 mode only)
-        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). In UTF-8 mode, any number of hexadecimal  dig-
+        in  upper or lower case). In UTF-8 mode, any number of hexadecimal dig-
-        its  may  appear between \x{ and }, but the value of the character code
+        its may appear between \x{ and }, but the value of the  character  code
-        must be less than 2**31 (that is,  the  maximum  hexadecimal  value  is
+        must  be  less  than  2**31  (that is, the maximum hexadecimal value is
-FFFFFFF).  If  characters other than hexadecimal digits appear between
+FFFFFFF). If characters other than hexadecimal digits  appear  between
-        \x{ and }, or if there is no terminating }, this form of escape is  not
+        \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 hex-
+        recognized. Instead, the initial \x will  be  interpreted  as  a  basic
-        adecimal escape, with no following digits,  giving  a  character  whose
+        hexadecimal  escape, with no following digits, giving a character whose
         value is zero.
         Characters whose value is less than 256 can be defined by either of the
-        two syntaxes for \x when PCRE is in UTF-8 mode. There is no  difference
+        two  syntaxes for \x when PCRE is in UTF-8 mode. There is no difference
-        in  the  way they are handled. For example, \xdc is exactly the same as
+        in the way they are handled. For example, \xdc is exactly the  same  as
         \x{dc}.
-        After \0 up to two further octal digits are read.  In  both  cases,  if
+        After  \0  up  to  two further octal digits are read. In both cases, if
-        there  are fewer than two digits, just those that are present are used.
+        there are fewer than two digits, just those that are present are  used.
-        Thus the sequence \0\x\07 specifies two binary zeros followed by a  BEL
+        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
+        character (code value 7). Make sure you supply  two  digits  after  the
-        initial zero if the pattern character that follows is itself  an  octal
+        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 generates a sin-
+        up to three octal digits following the backslash, and generates a  sin-
         gle byte from the least significant 8 bits of the value. Any subsequent
         digits stand for themselves.  For example:
-Line 1995 
 BACKSLASH
+Line 2508 
 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 byte value  or  a  single  UTF-8
+        All  the  sequences  that  define a single byte value or a single UTF-8
         character (in UTF-8 mode) can be used both inside and outside character
-        classes. In addition, inside a character  class,  the  sequence  \b  is
+        classes.  In  addition,  inside  a  character class, the sequence \b is
         interpreted as the backspace character (hex 08), and the sequence \X is
-        interpreted as the character "X".  Outside  a  character  class,  these
+        interpreted  as  the  character  "X".  Outside a character class, these
         sequences have different meanings (see below).
     Generic character types
-        The  third  use of backslash is for specifying generic character types.
+        The third use of backslash is for specifying generic  character  types.
         The following are always recognized:
           \d     any decimal digit
-Line 2018 
 BACKSLASH
+Line 2531 
 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).
         A "word" character is an underscore or any character less than 256 that
-        is a letter or digit. The definition of  letters  and  digits  is  con-
+        is  a  letter  or  digit.  The definition of letters and digits is con-
-        trolled  by PCRE's low-valued character tables, and may vary if locale-
+        trolled by PCRE's low-valued character tables, and may vary if  locale-
-        specific matching is taking place (see "Locale support" in the  pcreapi
+        specific  matching is taking place (see "Locale support" in the pcreapi
-        page).  For  example,  in  the  "fr_FR" (French) locale, some character
+        page). For example, in the  "fr_FR"  (French)  locale,  some  character
-        codes greater than 128 are used for accented  letters,  and  these  are
+        codes  greater  than  128  are used for accented letters, and these are
         matched by \w.
-        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.
     Unicode character properties
         When PCRE is built with Unicode character property support, three addi-
-        tional escape sequences to match generic character types are  available
+        tional  escape sequences to match generic character types are available
         when UTF-8 mode is selected. They are:
          \p{xx}   a character with the xx property
          \P{xx}   a character without the xx property
          \X       an extended Unicode sequence
-        The  property  names represented by xx above are limited to the Unicode
+        The property names represented by xx above are limited to  the  Unicode
-        general category properties. Each character has exactly one such  prop-
+        general  category properties. Each character has exactly one such prop-
-        erty,  specified  by  a two-letter abbreviation. For compatibility with
+        erty, specified by a two-letter abbreviation.  For  compatibility  with
-        Perl, negation can be specified by including a circumflex  between  the
+        Perl,  negation  can be specified by including a circumflex between the
-        opening  brace  and the property name. For example, \p{^Lu} is the same
+        opening brace and the property name. For example, \p{^Lu} is  the  same
         as \P{Lu}.
-        If only one letter is specified with \p or  \P,  it  includes  all  the
+        If  only  one  letter  is  specified with \p or \P, it includes all the
         properties that start with that letter. In this case, in the absence of
         negation, the curly brackets in the escape sequence are optional; these
         two examples have the same effect:
-Line 2113 
 BACKSLASH
+Line 2626 
 BACKSLASH
           Zp    Paragraph separator
           Zs    Space separator
-        Extended  properties such as "Greek" or "InMusicalSymbols" are not sup-
+        Extended properties such as "Greek" or "InMusicalSymbols" are not  sup-
         ported by PCRE.
-        Specifying caseless matching does not affect  these  escape  sequences.
+        Specifying  caseless  matching  does not affect these escape sequences.
         For example, \p{Lu} always matches only upper case letters.
-        The  \X  escape  matches  any number of Unicode characters that form an
+        The \X escape matches any number of Unicode  characters  that  form  an
         extended Unicode sequence. \X is equivalent to
           (?>\PM\pM*)
-        That is, it matches a character without the "mark"  property,  followed
+        That  is,  it matches a character without the "mark" property, followed
-        by  zero  or  more  characters with the "mark" property, and treats the
+        by zero or more characters with the "mark"  property,  and  treats  the
-        sequence as an atomic group (see below).  Characters  with  the  "mark"
+        sequence  as  an  atomic group (see below).  Characters with the "mark"
         property are typically accents that affect the preceding character.
-        Matching  characters  by Unicode property is not fast, because PCRE has
+        Matching characters by Unicode property is not fast, because  PCRE  has
-        to search a structure that contains  data  for  over  fifteen  thousand
+        to  search  a  structure  that  contains data for over fifteen thousand
         characters. That is why the traditional escape sequences such as \d and
         \w do not use Unicode properties in PCRE.
     Simple assertions
         The fourth use of backslash is for certain simple assertions. An asser-
-        tion  specifies a condition that has to be met at a particular point in
+        tion specifies a condition that has to be met at a particular point  in
-        a match, without consuming any characters from the subject string.  The
+        a  match, without consuming any characters from the subject string. The
-        use  of subpatterns for more complicated assertions is described below.
+        use of subpatterns for more complicated assertions is described  below.
         The backslashed assertions are:
           \b     matches at a word boundary
-Line 2149 
 BACKSLASH
+Line 2662 
 BACKSLASH
           \z     matches at end of subject
           \G     matches at first matching position in subject
-        These assertions may not appear in character classes (but note that  \b
+        These  assertions may not appear in character classes (but note that \b
         has a different meaning, namely the backspace character, inside a char-
         acter class).
-        A word boundary is a position in the subject string where  the  current
+        A  word  boundary is a position in the subject string where the current
-        character  and  the previous character do not both match \w or \W (i.e.
+        character and the previous character do not both match \w or  \W  (i.e.
-        one matches \w and the other matches \W), or the start or  end  of  the
+        one  matches  \w  and the other matches \W), or the start or end of the
         string if the first or last character matches \w, respectively.
-        The  \A,  \Z,  and \z assertions differ from the traditional circumflex
+        The \A, \Z, and \z assertions differ from  the  traditional  circumflex
         and dollar (described in the next section) in that they only ever match
-        at  the  very start and end of the subject string, whatever options are
+        at the very start and end of the subject string, whatever  options  are
-        set. Thus, they are independent of multiline mode. These  three  asser-
+        set.  Thus,  they are independent of multiline mode. These three asser-
         tions are not affected by the PCRE_NOTBOL or PCRE_NOTEOL options, which
-        affect only the behaviour of the circumflex and dollar  metacharacters.
+        affect  only the behaviour of the circumflex and dollar metacharacters.
-        However,  if the startoffset argument of pcre_exec() is non-zero, indi-
+        However, if the startoffset argument of pcre_exec() is non-zero,  indi-
         cating that matching is to start at a point other than the beginning of
-        the  subject,  \A  can never match. The difference between \Z and \z is
+        the subject, \A can never match. The difference between \Z  and  \z  is
-        that \Z matches before a newline that is  the  last  character  of  the
+        that  \Z  matches  before  a  newline that is the last character of the
-        string  as well as at the end of the string, whereas \z matches only at
+        string as well as at the end of the string, whereas \z matches only  at
         the end.
-        The \G assertion is true only when the current matching position is  at
+        The  \G assertion is true only when the current matching position is at
-        the  start point of the match, as specified by the startoffset argument
+        the start point of the match, as specified by the startoffset  argument
-        of pcre_exec(). It differs from \A when the  value  of  startoffset  is
+        of  pcre_exec().  It  differs  from \A when the value of startoffset is
-        non-zero.  By calling pcre_exec() multiple times with appropriate argu-
+        non-zero. By calling pcre_exec() multiple times with appropriate  argu-
         ments, you can mimic Perl's /g option, and it is in this kind of imple-
         mentation where \G can be useful.
-        Note,  however,  that  PCRE's interpretation of \G, as the start of the
+        Note, however, that PCRE's interpretation of \G, as the  start  of  the
         current match, is subtly different from Perl's, which defines it as the
-        end  of  the  previous  match. In Perl, these can be different when the
+        end of the previous match. In Perl, these can  be  different  when  the
-        previously matched string was empty. Because PCRE does just  one  match
+        previously  matched  string was empty. Because PCRE does just one match
         at a time, it cannot reproduce this behaviour.
-        If  all  the alternatives of a pattern begin with \G, the expression is
+        If all the alternatives of a pattern begin with \G, the  expression  is
         anchored to the starting match position, and the "anchored" flag is set
         in the compiled regular expression.
-Line 2192 
 BACKSLASH
+Line 2705 
 BACKSLASH
  CIRCUMFLEX AND DOLLAR
         Outside a character class, in the default matching mode, the circumflex
-        character is an assertion that is true only  if  the  current  matching
+        character  is  an  assertion  that is true only if the current matching
-        point  is  at the start of the subject string. If the startoffset argu-
+        point is at the start of the subject string. If the  startoffset  argu-
-        ment of pcre_exec() is non-zero, circumflex  can  never  match  if  the
+        ment  of  pcre_exec()  is  non-zero,  circumflex can never match if the
-        PCRE_MULTILINE  option  is  unset. Inside a character class, circumflex
+        PCRE_MULTILINE option is unset. Inside a  character  class,  circumflex
         has an entirely different meaning (see below).
-        Circumflex need not be the first character of the pattern if  a  number
+        Circumflex  need  not be the first character of the pattern if a number
-        of  alternatives are involved, but it should be the first thing in each
+        of alternatives are involved, but it should be the first thing in  each
-        alternative in which it appears if the pattern is ever  to  match  that
+        alternative  in  which  it appears if the pattern is ever to match that
-        branch.  If all possible alternatives start with a circumflex, that is,
+        branch. If all possible alternatives start with a circumflex, that  is,
-        if the pattern is constrained to match only at the start  of  the  sub-
+        if  the  pattern  is constrained to match only at the start of the sub-
-        ject,  it  is  said  to be an "anchored" pattern. (There are also other
+        ject, it is said to be an "anchored" pattern.  (There  are  also  other
         constructs that can cause a pattern to be anchored.)
-        A dollar character is an assertion that is true  only  if  the  current
+        A  dollar  character  is  an assertion that is true only if the current
-        matching  point  is  at  the  end of the subject string, or immediately
+        matching point is at the end of  the  subject  string,  or  immediately
         before a newline character that is the last character in the string (by
-        default).  Dollar  need  not  be the last character of the pattern if a
+        default). Dollar need not be the last character of  the  pattern  if  a
-        number of alternatives are involved, but it should be the last item  in
+        number  of alternatives are involved, but it should be the last item in
-        any  branch  in  which  it appears.  Dollar has no special meaning in a
+        any branch in which it appears.  Dollar has no  special  meaning  in  a
         character class.
-        The meaning of dollar can be changed so that it  matches  only  at  the
+        The  meaning  of  dollar  can be changed so that it matches only at the
-        very  end  of  the string, by setting the PCRE_DOLLAR_ENDONLY option at
+        very end of the string, by setting the  PCRE_DOLLAR_ENDONLY  option  at
         compile time. This does not affect the \Z assertion.
         The meanings of the circumflex and dollar characters are changed if the
         PCRE_MULTILINE option is set. When this is the case, they match immedi-
-        ately after and  immediately  before  an  internal  newline  character,
+        ately  after  and  immediately  before  an  internal newline character,
-        respectively,  in addition to matching at the start and end of the sub-
+        respectively, in addition to matching at the start and end of the  sub-
-        ject string. For example,  the  pattern  /^abc$/  matches  the  subject
+        ject  string.  For  example,  the  pattern  /^abc$/ matches the subject
-        string  "def\nabc"  (where \n represents a newline character) in multi-
+        string "def\nabc" (where \n represents a newline character)  in  multi-
         line mode, but not otherwise.  Consequently, patterns that are anchored
-        in  single line mode because all branches start with ^ are not anchored
+        in single line mode because all branches start with ^ are not  anchored
-        in multiline mode, and a match for  circumflex  is  possible  when  the
+        in  multiline  mode,  and  a  match for circumflex is possible when the
-        startoffset   argument   of  pcre_exec()  is  non-zero.  The  PCRE_DOL-
+        startoffset  argument  of  pcre_exec()  is  non-zero.   The   PCRE_DOL-
         LAR_ENDONLY option is ignored if PCRE_MULTILINE is set.
-        Note that the sequences \A, \Z, and \z can be used to match  the  start
+        Note  that  the sequences \A, \Z, and \z can be used to match the start
-        and  end of the subject in both modes, and if all branches of a pattern
+        and end of the subject in both modes, and if all branches of a  pattern
-        start with \A it is always anchored, whether PCRE_MULTILINE is  set  or
+        start  with  \A it is always anchored, whether PCRE_MULTILINE is set or
         not.
  FULL STOP (PERIOD, DOT)
         Outside a character class, a dot in the pattern matches any one charac-
-        ter in the subject, including a non-printing  character,  but  not  (by
+        ter  in  the  subject,  including a non-printing character, but not (by
-        default)  newline.   In  UTF-8 mode, a dot matches any UTF-8 character,
+        default) newline.  In UTF-8 mode, a dot matches  any  UTF-8  character,
         which might be more than one byte long, except (by default) newline. If
-        the  PCRE_DOTALL  option  is set, dots match newlines as well. The han-
+        the PCRE_DOTALL option is set, dots match newlines as  well.  The  han-
-        dling of dot is entirely independent of the handling of circumflex  and
+        dling  of dot is entirely independent of the handling of circumflex and
-        dollar,  the  only  relationship  being  that they both involve newline
+        dollar, the only relationship being  that  they  both  involve  newline
         characters. Dot has no special meaning in a character class.
  MATCHING A SINGLE BYTE
         Outside a character class, the escape sequence \C matches any one byte,
-        both  in  and  out of UTF-8 mode. Unlike a dot, it can match a newline.
+        both in and out of UTF-8 mode. Unlike a dot, it can  match  a  newline.
-        The feature is provided in Perl in order to match individual  bytes  in
+        The  feature  is provided in Perl in order to match individual bytes in
-        UTF-8  mode.  Because  it  breaks  up  UTF-8 characters into individual
+        UTF-8 mode. Because it  breaks  up  UTF-8  characters  into  individual
-        bytes, what remains in the string may be a malformed UTF-8 string.  For
+        bytes,  what remains in the string may be a malformed UTF-8 string. For
         this reason, the \C escape sequence is best avoided.
-        PCRE  does  not  allow \C to appear in lookbehind assertions (described
+        PCRE does not allow \C to appear in  lookbehind  assertions  (described
-        below), because in UTF-8 mode this would make it impossible  to  calcu-
+        below),  because  in UTF-8 mode this would make it impossible to calcu-
         late the length of the lookbehind.
-Line 2267 
 SQUARE BRACKETS AND CHARACTER CLASSES
+Line 2780 
 SQUARE BRACKETS AND CHARACTER CLASSES
         An opening square bracket introduces a character class, terminated by a
         closing square bracket. A closing square bracket on its own is not spe-
         cial. If a closing square bracket is required as a member of the class,
-        it should be the first data character in the class  (after  an  initial
+        it  should  be  the first data character in the class (after an initial
         circumflex, if present) or escaped with a backslash.
-        A  character  class matches a single character in the subject. In UTF-8
+        A character class matches a single character in the subject.  In  UTF-8
-        mode, the character may occupy more than one byte. A matched  character
+        mode,  the character may occupy more than one byte. A matched character
         must be in the set of characters defined by the class, unless the first
-        character in the class definition is a circumflex, in  which  case  the
+        character  in  the  class definition is a circumflex, in which case the
-        subject  character  must  not  be in the set defined by the class. If a
+        subject character must not be in the set defined by  the  class.  If  a
-        circumflex is actually required as a member of the class, ensure it  is
+        circumflex  is actually required as a member of the class, ensure it is
         not the first character, or escape it with a backslash.
-        For  example, the character class [aeiou] matches any lower case vowel,
+        For example, the character class [aeiou] matches any lower case  vowel,
-        while [^aeiou] matches any character that is not a  lower  case  vowel.
+        while  [^aeiou]  matches  any character that is not a lower case vowel.
         Note that a circumflex is just a convenient notation for specifying the
-        characters that are in the class by enumerating those that are  not.  A
+        characters  that  are in the class by enumerating those that are not. A
-        class  that starts with a circumflex is not an assertion: it still con-
+        class that starts with a circumflex is not an assertion: it still  con-
-        sumes a character from the subject string, and therefore  it  fails  if
+        sumes  a  character  from the subject string, and therefore it fails if
         the current pointer is at the end of the string.
-        In  UTF-8 mode, characters with values greater than 255 can be included
+        In UTF-8 mode, characters with values greater than 255 can be  included
-        in a class as a literal string of bytes, or by using the  \x{  escaping
+        in  a  class as a literal string of bytes, or by using the \x{ escaping
         mechanism.
-        When  caseless  matching  is set, any letters in a class represent both
+        When caseless matching is set, any letters in a  class  represent  both
-        their upper case and lower case versions, so for  example,  a  caseless
+        their  upper  case  and lower case versions, so for example, a caseless
-        [aeiou]  matches  "A"  as well as "a", and a caseless [^aeiou] does not
+        [aeiou] matches "A" as well as "a", and a caseless  [^aeiou]  does  not
-        match "A", whereas a caseful version would. When running in UTF-8 mode,
+        match  "A", whereas a caseful version would. In UTF-8 mode, PCRE always
-        PCRE  supports  the  concept of case for characters with values greater
+        understands the concept of case for characters whose  values  are  less
-        than 128 only when it is compiled with Unicode property support.
+        than  128, so caseless matching is always possible. For characters with
+        higher values, the concept of case is supported  if  PCRE  is  compiled
+        with  Unicode  property support, but not otherwise.  If you want to use
+        caseless matching for characters 128 and above, you  must  ensure  that
+        PCRE  is  compiled  with Unicode property support as well as with UTF-8
+        support.
         The newline character is never treated in any special way in  character
         classes,  whatever  the  setting  of  the PCRE_DOTALL or PCRE_MULTILINE
-Line 3215 
 CALLOUTS
+Line 3733 
 CALLOUTS
         gether. A complete description of the interface to the callout function
         is given in the pcrecallout documentation.
- Last updated: 09 September 2004
+ Last updated: 28 February 2005
- Copyright (c) 1997-2004 University of Cambridge.
+ Copyright (c) 1997-2005 University of Cambridge.
  -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
  NAME
         PCRE - Perl-compatible regular expressions
  PARTIAL MATCHING IN PCRE
         In  normal  use  of  PCRE,  if  the  subject  string  that is passed to
-        pcre_exec() matches as far as it goes, but is too short  to  match  the
+        pcre_exec() or pcre_dfa_exec() matches as far as it goes,  but  is  too
-        entire pattern, PCRE_ERROR_NOMATCH is returned. There are circumstances
+        short  to  match  the  entire  pattern, PCRE_ERROR_NOMATCH is returned.
-        where it might be helpful to distinguish this case from other cases  in
+        There are circumstances where it might be helpful to  distinguish  this
-        which there is no match.
+        case from other cases in which there is no match.
         Consider, for example, an application where a human is required to type
         in data for a field with specific formatting requirements.  An  example
-Line 3248 
 PARTIAL MATCHING IN PCRE
+Line 3765 
 PARTIAL MATCHING IN PCRE
         until the entire string has been entered.
         PCRE supports the concept of partial matching by means of the PCRE_PAR-
-        TIAL  option,  which  can be set when calling pcre_exec(). When this is
+        TIAL   option,   which   can   be   set  when  calling  pcre_exec()  or
-        done,  the   return   code   PCRE_ERROR_NOMATCH   is   converted   into
+        pcre_dfa_exec(). When this flag is set for pcre_exec(), the return code
-        PCRE_ERROR_PARTIAL  if  at  any  time  during  the matching process the
+        PCRE_ERROR_NOMATCH  is converted into PCRE_ERROR_PARTIAL if at any time
-        entire subject string matched part of the pattern. No captured data  is
+        during the matching process the last part of the subject string matched
-        set when this occurs.
+        part  of  the  pattern. Unfortunately, for non-anchored matching, it is
+        not possible to obtain the position of the start of the partial  match.
+        No captured data is set when PCRE_ERROR_PARTIAL is returned.
+        When   PCRE_PARTIAL   is  set  for  pcre_dfa_exec(),  the  return  code
+        PCRE_ERROR_NOMATCH is converted into PCRE_ERROR_PARTIAL if the  end  of
+        the  subject is reached, there have been no complete matches, but there
+        is still at least one matching possibility. The portion of  the  string
+        that provided the partial match is set as the first matching string.
         Using PCRE_PARTIAL disables one of PCRE's optimizations. PCRE remembers
         the last literal byte in a pattern, and abandons  matching  immediately
-Line 3263 
 PARTIAL MATCHING IN PCRE
+Line 3788 
 PARTIAL MATCHING IN PCRE
  RESTRICTED PATTERNS FOR PCRE_PARTIAL
         Because of the way certain internal optimizations  are  implemented  in
-        PCRE,  the  PCRE_PARTIAL  option  cannot  be  used  with  all patterns.
+        the  pcre_exec()  function, the PCRE_PARTIAL option cannot be used with
-        Repeated single characters such as
+        all patterns. These restrictions do not apply when  pcre_dfa_exec()  is
+        used.  For pcre_exec(), repeated single characters such as
           a{2,4}
-Line 3272 
 RESTRICTED PATTERNS FOR PCRE_PARTIAL
+Line 3798 
 RESTRICTED PATTERNS FOR PCRE_PARTIAL
           \d+
-        are not permitted if the maximum number of occurrences is greater  than
+        are  not permitted if the maximum number of occurrences is greater than
         one.  Optional items such as \d? (where the maximum is one) are permit-
-        ted.  Quantifiers with any values are permitted after  parentheses,  so
+        ted.   Quantifiers  with any values are permitted after parentheses, so
         the invalid examples above can be coded thus:
           (a){2,4}
           (\d)+
-        These  constructions  run more slowly, but for the kinds of application
+        These constructions run more slowly, but for the kinds  of  application
-        that are envisaged for this facility, this is not felt to  be  a  major
+        that  are  envisaged  for this facility, this is not felt to be a major
         restriction.
-        If  PCRE_PARTIAL  is  set  for  a  pattern that does not conform to the
+        If PCRE_PARTIAL is set for a pattern  that  does  not  conform  to  the
-        restrictions, pcre_exec() returns the error code  PCRE_ERROR_BADPARTIAL
+        restrictions,  pcre_exec() returns the error code PCRE_ERROR_BADPARTIAL
         (-13).
  EXAMPLE OF PARTIAL MATCHING USING PCRETEST
-        If  the  escape  sequence  \P  is  present in a pcretest data line, the
+        If the escape sequence \P is present  in  a  pcretest  data  line,  the
         PCRE_PARTIAL flag is used for the match. Here is a run of pcretest that
         uses the date example quoted above:
-Line 3308 
 EXAMPLE OF PARTIAL MATCHING USING PCRETE
+Line 3834 
 EXAMPLE OF PARTIAL MATCHING USING PCRETE
           data> jP
           No match
-        The  first  data  string  is  matched completely, so pcretest shows the
+        The first data string is matched  completely,  so  pcretest  shows  the
-        matched substrings. The remaining four strings do not  match  the  com-
+        matched  substrings.  The  remaining four strings do not match the com-
-        plete pattern, but the first two are partial matches.
+        plete pattern, but the first two are partial matches.  The  same  test,
+        using  DFA  matching (by means of the \D escape sequence), produces the
+        following output:
- Last updated: 08 September 2004
+            re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/
- Copyright (c) 1997-2004 University of Cambridge.
+          data> 25jun04\P\D
- -----------------------------------------------------------------------------
+: 25jun04
+          data> 23dec3\P\D
+          Partial match: 23dec3
+          data> 3ju\P\D
+          Partial match: 3ju
+          data> 3juj\P\D
+          No match
+          data> j\P\D
+          No match
- PCRE(3)                                                                PCRE(3)
+        Notice that in this case the portion of the string that was matched  is
+        made available.
+ MULTI-SEGMENT MATCHING WITH pcre_dfa_exec()
+        When a partial match has been found using pcre_dfa_exec(), it is possi-
+        ble to continue the match by  providing  additional  subject  data  and
+        calling  pcre_dfa_exec() again with the PCRE_DFA_RESTART option and the
+        same working space (where details of the  previous  partial  match  are
+        stored).  Here  is  an  example  using  pcretest,  where  the \R escape
+        sequence sets the PCRE_DFA_RESTART option and the  \D  escape  sequence
+        requests the use of pcre_dfa_exec():
+            re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/
+          data> 23ja\P\D
+          Partial match: 23ja
+          data> n05\R\D
+: n05
+        The  first  call has "23ja" as the subject, and requests partial match-
+        ing; the second call  has  "n05"  as  the  subject  for  the  continued
+        (restarted)  match.   Notice  that when the match is complete, only the
+        last part is shown; PCRE does  not  retain  the  previously  partially-
+        matched  string. It is up to the calling program to do that if it needs
+        to.
+        This facility can  be  used  to  pass  very  long  subject  strings  to
+        pcre_dfa_exec(). However, some care is needed for certain types of pat-
+        tern.
+. If the pattern contains tests for the beginning or end  of  a  line,
+        you  need  to pass the PCRE_NOTBOL or PCRE_NOTEOL options, as appropri-
+        ate, when the subject string for any call does not contain  the  begin-
+        ning or end of a line.
+.  If  the  pattern contains backward assertions (including \b or \B),
+        you need to arrange for some overlap in the subject  strings  to  allow
+        for  this.  For example, you could pass the subject in chunks that were
+bytes long, but in a buffer of 700 bytes, with the starting  offset
+        set to 200 and the previous 200 bytes at the start of the buffer.
+.  Matching a subject string that is split into multiple segments does
+        not always produce exactly the same result as matching over one  single
+        long  string.   The  difference arises when there are multiple matching
+        possibilities, because a partial match result is given only when  there
+        are  no  completed  matches  in a call to fBpcre_dfa_exec(). This means
+        that as soon as the shortest match has been found,  continuation  to  a
+        new  subject  segment  is  no  longer possible.  Consider this pcretest
+        example:
+            re> /dog(sbody)?/
+          data> do\P\D
+          Partial match: do
+          data> gsb\R\P\D
+: g
+          data> dogsbody\D
+: dogsbody
+: dog
+        The pattern matches the words "dog" or "dogsbody". When the subject  is
+        presented  in  several  parts  ("do" and "gsb" being the first two) the
+        match stops when "dog" has been found, and it is not possible  to  con-
+        tinue.  On  the  other  hand,  if  "dogsbody"  is presented as a single
+        string, both matches are found.
+        Because of this phenomenon, it does not usually make  sense  to  end  a
+        pattern that is going to be matched in this way with a variable repeat.
+ Last updated: 28 February 2005
+ Copyright (c) 1997-2005 University of Cambridge.
+ -----------------------------------------------------------------------------
  NAME
         PCRE - Perl-compatible regular expressions
  SAVING AND RE-USING PRECOMPILED PCRE PATTERNS
         If  you  are running an application that uses a large number of regular
-Line 3391 
 SAVING A COMPILED PATTERN
+Line 3999 
 SAVING A COMPILED PATTERN
  RE-USING A PRECOMPILED PATTERN
         Re-using a precompiled pattern is straightforward. Having  reloaded  it
-        into main memory, you pass its pointer to pcre_exec() in the usual way.
+        into   main   memory,   you   pass   its   pointer  to  pcre_exec()  or
-        This should work even on another host, and even if that  host  has  the
+        pcre_dfa_exec() in the usual way. This  should  work  even  on  another
-        opposite endianness to the one where the pattern was compiled.
+        host,  and  even  if  that  host has the opposite endianness to the one
+        where the pattern was compiled.
-        However,  if  you  passed a pointer to custom character tables when the
-        pattern was compiled (the tableptr  argument  of  pcre_compile()),  you
+        However, if you passed a pointer to custom character  tables  when  the
-        must now pass a similar pointer to pcre_exec(), because the value saved
+        pattern  was  compiled  (the  tableptr argument of pcre_compile()), you
-        with the compiled pattern will obviously be  nonsense.  A  field  in  a
+        must now pass a similar  pointer  to  pcre_exec()  or  pcre_dfa_exec(),
-        pcre_extra()  block is used to pass this data, as described in the sec-
+        because  the  value  saved  with the compiled pattern will obviously be
-        tion on matching a pattern in the pcreapi documentation.
+        nonsense. A field in a pcre_extra() block is used to pass this data, as
+        described  in the section on matching a pattern in the pcreapi documen-
+        tation.
         If you did not provide custom character tables  when  the  pattern  was
         compiled,  the  pointer  in  the compiled pattern is NULL, which causes
-Line 3411 
 RE-USING A PRECOMPILED PATTERN
+Line 4021 
 RE-USING A PRECOMPILED PATTERN
         your own pcre_extra data block and set the study_data field to point to
         the  reloaded  study  data. You must also set the PCRE_EXTRA_STUDY_DATA
         bit in the flags field to indicate that study  data  is  present.  Then
-        pass the pcre_extra block to pcre_exec() in the usual way.
+        pass  the  pcre_extra  block  to  pcre_exec() or pcre_dfa_exec() in the
+        usual way.
  COMPATIBILITY WITH DIFFERENT PCRE RELEASES
-        The  layout  of the control block that is at the start of the data that
+        The layout of the control block that is at the start of the  data  that
-        makes up a compiled pattern was changed for release 5.0.  If  you  have
+        makes  up  a  compiled pattern was changed for release 5.0. If you have
-        any  saved  patterns  that  were compiled with previous releases (not a
+        any saved patterns that were compiled with  previous  releases  (not  a
-        facility that was previously advertised), you will  have  to  recompile
+        facility  that  was  previously advertised), you will have to recompile
-        them  for  release  5.0. However, from now on, it should be possible to
+        them for release 5.0. However, from now on, it should  be  possible  to
         make changes in a compabible manner.
- Last updated: 10 September 2004
+ Last updated: 28 February 2005
- Copyright (c) 1997-2004 University of Cambridge.
+ Copyright (c) 1997-2005 University of Cambridge.
  -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
  NAME
         PCRE - Perl-compatible regular expressions
  PCRE PERFORMANCE
         Certain  items  that may appear in regular expression patterns are more
-Line 3469 
 PCRE PERFORMANCE
+Line 4079 
 PCRE PERFORMANCE
         If you are using such a pattern with subject strings that do  not  con-
         tain newlines, the best performance is obtained by setting PCRE_DOTALL,
-        or starting the pattern with ^.* to indicate explicit  anchoring.  That
+        or starting the pattern with ^.* or ^.*? to indicate  explicit  anchor-
-        saves  PCRE from having to scan along the subject looking for a newline
+        ing.  That saves PCRE from having to scan along the subject looking for
-        to restart at.
+        a newline to restart at.
         Beware of patterns that contain nested indefinite  repeats.  These  can
         take  a  long time to run when applied to a string that does not match.
-Line 3492 
 PCRE PERFORMANCE
+Line 4102 
 PCRE PERFORMANCE
           (a+)*b
         where a literal character follows. Before  embarking  on  the  standard
-        matching  procedure,  PCRE  checks  that  there  is  a "b" later in the
+        matching  procedure,  PCRE checks that there is a "b" later in the sub-
-        subject string, and if there is not, it fails  the  match  immediately.
+        ject string, and if there is not, it fails the match immediately.  How-
-        However, when there is no following literal this optimization cannot be
+        ever,  when  there  is no following literal this optimization cannot be
         used. You can see the difference by comparing the behaviour of
           (a+)*\d
-Line 3506 
 PCRE PERFORMANCE
+Line 4116 
 PCRE PERFORMANCE
         In many cases, the solution to this kind of performance issue is to use
         an atomic group or a possessive quantifier.
- Last updated: 09 September 2004
+ Last updated: 28 February 2005
- Copyright (c) 1997-2004 University of Cambridge.
+ Copyright (c) 1997-2005 University of Cambridge.
  -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
  NAME
         PCRE - Perl-compatible regular expressions.
  SYNOPSIS OF POSIX API
         #include <pcreposix.h>
-Line 3537 
 DESCRIPTION
+Line 4146 
 DESCRIPTION
         This  set  of  functions provides a POSIX-style API to the PCRE regular
         expression package. See the pcreapi documentation for a description  of
-        PCRE's native API, which contains additional functionality.
+        PCRE's native API, which contains much additional functionality.
         The functions described here are just wrapper functions that ultimately
         call  the  PCRE  native  API.  Their  prototypes  are  defined  in  the
-Line 3581 
 COMPILING A PATTERN
+Line 4190 
 COMPILING A PATTERN
         The argument cflags is either zero, or contains one or more of the bits
         defined by the following macros:
+          REG_DOTALL
+        The PCRE_DOTALL option is set when the expression is passed for  compi-
+        lation  to the native function. Note that REG_DOTALL is not part of the
+        POSIX standard.
           REG_ICASE
         The PCRE_CASELESS option is set when the expression is passed for  com-
-Line 3692 
 MEMORY USAGE
+Line 4307 
 MEMORY USAGE
  AUTHOR
-        Philip Hazel <ph10@cam.ac.uk>
+        Philip Hazel
         University Computing Service,
         Cambridge CB2 3QG, England.
- Last updated: 07 September 2004
+ Last updated: 28 February 2005
- Copyright (c) 1997-2004 University of Cambridge.
+ Copyright (c) 1997-2005 University of Cambridge.
  -----------------------------------------------------------------------------
- PCRE(3)                                                                PCRE(3)
+ NAME
+        PCRE - Perl-compatible regular expressions.
+ SYNOPSIS OF C++ WRAPPER
+        #include <pcrecpp.h>
+ DESCRIPTION
+        The  C++  wrapper  for  PCRE was provided by Google Inc. This brief man
+        page was constructed from the notes in the pcrecpp.h file, which should
+        be consulted for further details.
+ MATCHING INTERFACE
+        The  "FullMatch" operation checks that supplied text matches a supplied
+        pattern exactly. If pointer arguments are supplied, it  copies  matched
+        sub-strings that match sub-patterns into them.
+          Example: successful match
+             pcrecpp::RE re("h.*o");
+             re.FullMatch("hello");
+          Example: unsuccessful match (requires full match):
+             pcrecpp::RE re("e");
+             !re.FullMatch("hello");
+          Example: creating a temporary RE object:
+             pcrecpp::RE("h.*o").FullMatch("hello");
+        You  can pass in a "const char*" or a "string" for "text". The examples
+        below tend to use a const char*. You can, as in the different  examples
+        above,  store the RE object explicitly in a variable or use a temporary
+        RE object. The examples below use one mode or  the  other  arbitrarily.
+        Either could correctly be used for any of these examples.
+        You must supply extra pointer arguments to extract matched subpieces.
+          Example: extracts "ruby" into "s" and 1234 into "i"
+             int i;
+             string s;
+             pcrecpp::RE re("(\\w+):(\\d+)");
+             re.FullMatch("ruby:1234", &s, &i);
+          Example: does not try to extract any extra sub-patterns
+             re.FullMatch("ruby:1234", &s);
+          Example: does not try to extract into NULL
+             re.FullMatch("ruby:1234", NULL, &i);
+          Example: integer overflow causes failure
+             !re.FullMatch("ruby:1234567891234", NULL, &i);
+          Example: fails because there aren't enough sub-patterns:
+             !pcrecpp::RE("\\w+:\\d+").FullMatch("ruby:1234", &s);
+          Example: fails because string cannot be stored in integer
+             !pcrecpp::RE("(.*)").FullMatch("ruby", &i);
+        The  provided  pointer  arguments can be pointers to any scalar numeric
+        type, or one of:
+           string        (matched piece is copied to string)
+           StringPiece   (StringPiece is mutated to point to matched piece)
+           T             (where "bool T::ParseFrom(const char*, int)" exists)
+           NULL          (the corresponding matched sub-pattern is not copied)
+        The function returns true iff all of the following conditions are  sat-
+        isfied:
+          a. "text" matches "pattern" exactly;
+          b. The number of matched sub-patterns is >= number of supplied
+             pointers;
+          c. The "i"th argument has a suitable type for holding the
+             string captured as the "i"th sub-pattern. If you pass in
+             NULL for the "i"th argument, or pass fewer arguments than
+             number of sub-patterns, "i"th captured sub-pattern is
+             ignored.
+        The  matching interface supports at most 16 arguments per call.  If you
+        need   more,   consider    using    the    more    general    interface
+        pcrecpp::RE::DoMatch. See pcrecpp.h for the signature for DoMatch.
+ PARTIAL MATCHES
+        You  can  use the "PartialMatch" operation when you want the pattern to
+        match any substring of the text.
+          Example: simple search for a string:
+             pcrecpp::RE("ell").PartialMatch("hello");
+          Example: find first number in a string:
+             int number;
+             pcrecpp::RE re("(\\d+)");
+             re.PartialMatch("x*100 + 20", &number);
+             assert(number == 100);
+ UTF-8 AND THE MATCHING INTERFACE
+        By default, pattern and text are plain text, one  byte  per  character.
+        The  UTF8  flag,  passed  to  the  constructor, causes both pattern and
+        string to be treated as UTF-8 text, still a byte stream but potentially
+        multiple  bytes  per character. In practice, the text is likelier to be
+        UTF-8 than the pattern, but the match returned may depend on  the  UTF8
+        flag,  so  always use it when matching UTF8 text. For example, "." will
+        match one byte normally but with UTF8 set may match up to  three  bytes
+        of a multi-byte character.
+          Example:
+             pcrecpp::RE_Options options;
+             options.set_utf8();
+             pcrecpp::RE re(utf8_pattern, options);
+             re.FullMatch(utf8_string);
+          Example: using the convenience function UTF8():
+             pcrecpp::RE re(utf8_pattern, pcrecpp::UTF8());
+             re.FullMatch(utf8_string);
+        NOTE: The UTF8 flag is ignored if pcre was not configured with the
+              --enable-utf8 flag.
+ SCANNING TEXT INCREMENTALLY
+        The  "Consume"  operation may be useful if you want to repeatedly match
+        regular expressions at the front of a string and skip over them as they
+        match.  This requires use of the "StringPiece" type, which represents a
+        sub-range of a real string. Like RE,  StringPiece  is  defined  in  the
+        pcrecpp namespace.
+          Example: read lines of the form "var = value" from a string.
+             string contents = ...;                 // Fill string somehow
+             pcrecpp::StringPiece input(contents);  // Wrap in a StringPiece
+             string var;
+             int value;
+             pcrecpp::RE re("(\\w+) = (\\d+)\n");
+             while (re.Consume(&input, &var, &value)) {
+               ...;
+             }
+        Each  successful  call  to  "Consume"  will  set  "var/value", and also
+        advance "input" so it points past the matched text.
+        The "FindAndConsume" operation is similar to  "Consume"  but  does  not
+        anchor  your  match  at  the  beginning of the string. For example, you
+        could extract all words from a string by repeatedly calling
+          pcrecpp::RE("(\\w+)").FindAndConsume(&input, &word)
+ PARSING HEX/OCTAL/C-RADIX NUMBERS
+        By default, if you pass a pointer to a numeric value, the corresponding
+        text  is  interpreted  as  a  base-10  number. You can instead wrap the
+        pointer with a call to one of the operators Hex(), Octal(), or CRadix()
+        to  interpret  the text in another base. The CRadix operator interprets
+        C-style "0" (base-8) and  "0x"  (base-16)  prefixes,  but  defaults  to
+        base-10.
+          Example:
+            int a, b, c, d;
+            pcrecpp::RE re("(.*) (.*) (.*) (.*)");
+            re.FullMatch("100 40 0100 0x40",
+                         pcrecpp::Octal(&a), pcrecpp::Hex(&b),
+                         pcrecpp::CRadix(&c), pcrecpp::CRadix(&d));
+        will leave 64 in a, b, c, and d.
+ REPLACING PARTS OF STRINGS
+        You  can  replace the first match of "pattern" in "str" with "rewrite".
+        Within "rewrite", backslash-escaped digits (\1 to \9) can  be  used  to
+        insert  text  matching  corresponding parenthesized group from the pat-
+        tern. \0 in "rewrite" refers to the entire matching text. For example:
+          string s = "yabba dabba doo";
+          pcrecpp::RE("b+").Replace("d", &s);
+        will leave "s" containing "yada dabba doo". The result is true  if  the
+        pattern matches and a replacement occurs, false otherwise.
+        GlobalReplace  is  like Replace except that it replaces all occurrences
+        of the pattern in the string with the  rewrite.  Replacements  are  not
+        subject to re-matching. For example:
+          string s = "yabba dabba doo";
+          pcrecpp::RE("b+").GlobalReplace("d", &s);
+        will  leave  "s"  containing  "yada dada doo". It returns the number of
+        replacements made.
+        Extract is like Replace, except that if the pattern matches,  "rewrite"
+        is  copied into "out" (an additional argument) with substitutions.  The
+        non-matching portions of "text" are ignored. Returns true iff  a  match
+        occurred and the extraction happened successfully;  if no match occurs,
+        the string is left unaffected.
+ AUTHOR
+        The C++ wrapper was contributed by Google Inc.
+        Copyright (c) 2005 Google Inc.
+ -----------------------------------------------------------------------------
  NAME
         PCRE - Perl-compatible regular expressions
  PCRE SAMPLE PROGRAM
         A simple, complete demonstration program, to get you started with using

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