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 final match
       that is returned in that block or if PCRE2_SUBSTITUTE_MATCHED is set. 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. This variable must contain the length
       of the output buffer when the function is called. If the function is successful, the value
       is changed to the  length  of  the  new  string,  excluding  the  trailing  zero  that  is
       automatically added.

       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                  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 for UTF validity in
                                             the subject or replacement
                                             (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_LITERAL           The replacement string is literal
         PCRE2_SUBSTITUTE_MATCHED           Use pre-existing match data for
                                             first match
         PCRE2_SUBSTITUTE_OVERFLOW_LENGTH   If overflow, compute needed length
         PCRE2_SUBSTITUTE_REPLACEMENT_ONLY  Return only replacement string(s)
         PCRE2_SUBSTITUTE_UNKNOWN_UNSET     Treat unknown group as unset
         PCRE2_SUBSTITUTE_UNSET_EMPTY       Simple unset insert = empty string

       If        PCRE2_SUBSTITUTE_LITERAL        is        set,        PCRE2_SUBSTITUTE_EXTENDED,
       PCRE2_SUBSTITUTE_UNKNOWN_UNSET, and PCRE2_SUBSTITUTE_UNSET_EMPTY are ignored.

       If  PCRE2_SUBSTITUTE_MATCHED is set, match_data must be non-NULL; its contents must be the
       result of a call to pcre2_match() using the same pattern and subject.

       The function returns the number of substitutions, which  may  be  zero  if  there  are  no
       matches.  The  result may 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.