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PCRE2_SUBSTITUTE(3) FreeBSD Library Functions Manual PCRE2_SUBSTITUTE(3)
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
(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.
PCRE2 10.35 22 January 2020 PCRE2_SUBSTITUTE(3)