NAME

       PCRE2 - Perl-compatible regular expressions (revised API)

SYNOPSIS

       #include <pcre2.h>

       int pcre2_substitute(const pcre2_code *code, PCRE2_SPTR subject,
         PCRE2_SIZE length, PCRE2_SIZE startoffset,
         uint32_t options, pcre2_match_data *match_data,
         pcre2_match_context *mcontext, PCRE2_SPTR replacement,
         PCRE2_SIZE rlength, PCRE2_UCHAR *outputbuffer,
         PCRE2_SIZE *outlengthptr);

DESCRIPTION

       This  function matches a compiled regular expression against a given subject string, using
       a matching algorithm that is similar to Perl's. It then  makes  a  copy  of  the  subject,
       substituting a replacement string for what was matched.  Its arguments are:

         code          Points to the compiled pattern
         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
         match_data    Points to a match data block, or is NULL
         mcontext      Points to a match context, or is NULL
         replacement   Points to the replacement string
         rlength       Length of the replacement string
         outputbuffer  Points to the output buffer
         outlengthptr  Points to the length of the output buffer

       A  match  data block is needed only if you want to inspect the data from the match that is
       returned in that block. A match context is needed only if you want to:

         Set up a callout function
         Set a matching offset limit
         Change the backtracking match limit
         Change the backtracking depth limit
         Set custom memory management in the match context

       The length, startoffset and rlength values are code  units,  not  characters,  as  is  the
       contents of the variable pointed at by outlengthptr, which is updated to the actual length
       of  the  new  string.   The  subject   and   replacement   lengths   can   be   given   as
       PCRE2_ZERO_TERMINATED for zero-terminated strings. The options are:

         PCRE2_ANCHORED             Match only at the first position
         PCRE2_ENDANCHORED          Pattern can match only at end of subject
         PCRE2_NOTBOL               Subject is not the beginning of a line
         PCRE2_NOTEOL               Subject is not the end of a line
         PCRE2_NOTEMPTY             An empty string is not a valid match
         PCRE2_NOTEMPTY_ATSTART     An empty string at the start of the
                                     subject is not a valid match
         PCRE2_NO_JIT               Do not use JIT matching
         PCRE2_NO_UTF_CHECK         Do not check the subject or replacement
                                     for UTF validity (only relevant if
                                     PCRE2_UTF was set at compile time)
         PCRE2_SUBSTITUTE_EXTENDED  Do extended replacement processing
         PCRE2_SUBSTITUTE_GLOBAL    Replace all occurrences in the subject
         PCRE2_SUBSTITUTE_OVERFLOW_LENGTH  If overflow, compute needed length
         PCRE2_SUBSTITUTE_UNKNOWN_UNSET  Treat unknown group as unset
         PCRE2_SUBSTITUTE_UNSET_EMPTY  Simple unset insert = empty string

       The  function  returns  the  number  of  substitutions, which may be zero if there were no
       matches. The result can be greater than one only when PCRE2_SUBSTITUTE_GLOBAL is  set.  In
       the event of an error, a negative error code is returned.

       There  is  a  complete  description  of  the  PCRE2  native API in the pcre2api page and a
       description of the POSIX API in the pcre2posix page.