# pcre2_substitute

## 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.
    


* * *