NAME

       PCRE - Perl-compatible regular expressions

SYNOPSIS

       #include <pcre.h>

       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 pcre16_dfa_exec(const pcre16 *code, const pcre16_extra *extra,
            PCRE_SPTR16 subject, int length, int startoffset,
            int options, int *ovector, int ovecsize,
            int *workspace, int wscount);

       int pcre32_dfa_exec(const pcre32 *code, const pcre32_extra *extra,
            PCRE_SPTR32 subject, int length, int startoffset,
            int options, int *ovector, int ovecsize,
            int *workspace, int wscount);

DESCRIPTION

       This  function matches a compiled regular expression against a given subject string, using
       an alternative matching algorithm that scans the  subject  string  just  once  (not  Perl-
       compatible). Note that the main, Perl-compatible, matching function is pcre[16|32]_exec().
       The arguments for this function are:

         code         Points to the compiled pattern
         extra        Points to an associated pcre[16|32]_extra structure,
                        or is NULL
         subject      Points to the subject string
         length       Length of the subject string
         startoffset  Offset in the subject at which to start matching
         options      Option bits
         ovector      Points to a vector of ints for result offsets
         ovecsize     Number of elements in the vector
         workspace    Points to a vector of ints used as working space
         wscount      Number of elements in the vector

       The units for length and startoffset are bytes for  pcre_exec(),  16-bit  data  items  for
       pcre16_exec(), and 32-bit items for pcre32_exec(). The options are:

         PCRE_ANCHORED          Match only at the first position
         PCRE_BSR_ANYCRLF       \R matches only CR, LF, or CRLF
         PCRE_BSR_UNICODE       \R matches all Unicode line endings
         PCRE_NEWLINE_ANY       Recognize any Unicode newline sequence
         PCRE_NEWLINE_ANYCRLF   Recognize CR, LF, & CRLF as newline sequences
         PCRE_NEWLINE_CR        Recognize CR as the only newline sequence
         PCRE_NEWLINE_CRLF      Recognize CRLF as the only newline sequence
         PCRE_NEWLINE_LF        Recognize LF as the only newline sequence
         PCRE_NOTBOL            Subject is not the beginning of a line
         PCRE_NOTEOL            Subject is not the end of a line
         PCRE_NOTEMPTY          An empty string is not a valid match
         PCRE_NOTEMPTY_ATSTART  An empty string at the start of the subject
                                  is not a valid match
         PCRE_NO_START_OPTIMIZE Do not do "start-match" optimizations
         PCRE_NO_UTF16_CHECK    Do not check the subject for UTF-16
                                  validity (only relevant if PCRE_UTF16
                                  was set at compile time)
         PCRE_NO_UTF32_CHECK    Do not check the subject for UTF-32
                                  validity (only relevant if PCRE_UTF32
                                  was set at compile time)
         PCRE_NO_UTF8_CHECK     Do not check the subject for UTF-8
                                  validity (only relevant if PCRE_UTF8
                                  was set at compile time)
         PCRE_PARTIAL           ) Return PCRE_ERROR_PARTIAL for a partial
         PCRE_PARTIAL_SOFT      )   match if no full matches are found
         PCRE_PARTIAL_HARD      Return PCRE_ERROR_PARTIAL for a partial match
                                  even if there is a full match as well
         PCRE_DFA_SHORTEST      Return only the shortest match
         PCRE_DFA_RESTART       Restart after a partial match

       There  are restrictions on what may appear in a pattern when using this matching function.
       Details are given in the pcrematching documentation. For details of partial matching,  see
       the pcrepartial page.

       A pcre[16|32]_extra structure contains the following fields:

         flags            Bits indicating which fields are set
         study_data       Opaque data from pcre[16|32]_study()
         match_limit      Limit on internal resource use
         match_limit_recursion  Limit on internal recursion depth
         callout_data     Opaque data passed back to callouts
         tables           Points to character tables or is NULL
         mark             For passing back a *MARK pointer
         executable_jit   Opaque data from JIT compilation

       The       flag      bits      are      PCRE_EXTRA_STUDY_DATA,      PCRE_EXTRA_MATCH_LIMIT,
       PCRE_EXTRA_MATCH_LIMIT_RECURSION,       PCRE_EXTRA_CALLOUT_DATA,        PCRE_EXTRA_TABLES,
       PCRE_EXTRA_MARK and PCRE_EXTRA_EXECUTABLE_JIT. For this matching function, the match_limit
       and  match_limit_recursion  fields  are   not   used,   and   must   not   be   set.   The
       PCRE_EXTRA_EXECUTABLE_JIT flag and the corresponding variable are ignored.

       There  is  a  complete  description  of  the  PCRE  native  API  in the pcreapi page and a
       description of the POSIX API in the pcreposix page.