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2<head>
3<title>pcre2_substitute specification</title>
4</head>
5<body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
6<h1>pcre2_substitute man page</h1>
7<p>
8Return to the <a href="index.html">PCRE2 index page</a>.
9</p>
10<p>
11This page is part of the PCRE2 HTML documentation. It was generated
12automatically from the original man page. If there is any nonsense in it,
13please consult the man page, in case the conversion went wrong.
14<br>
15<br><b>
16SYNOPSIS
17</b><br>
18<P>
19<b>#include &#60;pcre2.h&#62;</b>
20</P>
21<P>
22<b>int pcre2_substitute(const pcre2_code *<i>code</i>, PCRE2_SPTR <i>subject</i>,</b>
23<b>  PCRE2_SIZE <i>length</i>, PCRE2_SIZE <i>startoffset</i>,</b>
24<b>  uint32_t <i>options</i>, pcre2_match_data *<i>match_data</i>,</b>
25<b>  pcre2_match_context *<i>mcontext</i>, PCRE2_SPTR <i>replacement</i>,</b>
26<b>  PCRE2_SIZE <i>rlength</i>, PCRE2_UCHAR *<i>outputbuffer</i>,</b>
27<b>  PCRE2_SIZE *<i>outlengthptr</i>);</b>
28</P>
29<br><b>
30DESCRIPTION
31</b><br>
32<P>
33This function matches a compiled regular expression against a given subject
34string, using a matching algorithm that is similar to Perl's. It then makes a
35copy of the subject, substituting a replacement string for what was matched.
36Its arguments are:
37<pre>
38  <i>code</i>          Points to the compiled pattern
39  <i>subject</i>       Points to the subject string
40  <i>length</i>        Length of the subject string
41  <i>startoffset</i>   Offset in the subject at which to start matching
42  <i>options</i>       Option bits
43  <i>match_data</i>    Points to a match data block, or is NULL
44  <i>mcontext</i>      Points to a match context, or is NULL
45  <i>replacement</i>   Points to the replacement string
46  <i>rlength</i>       Length of the replacement string
47  <i>outputbuffer</i>  Points to the output buffer
48  <i>outlengthptr</i>  Points to the length of the output buffer
49</pre>
50A match data block is needed only if you want to inspect the data from the
51final match that is returned in that block or if PCRE2_SUBSTITUTE_MATCHED is
52set. A match context is needed only if you want to:
53<pre>
54  Set up a callout function
55  Set a matching offset limit
56  Change the backtracking match limit
57  Change the backtracking depth limit
58  Set custom memory management in the match context
59</pre>
60The <i>length</i>, <i>startoffset</i> and <i>rlength</i> values are code units,
61not characters, as is the contents of the variable pointed at by
62<i>outlengthptr</i>. This variable must contain the length of the output buffer
63when the function is called. If the function is successful, the value is
64changed to the length of the new string, excluding the trailing zero that is
65automatically added.
66</P>
67<P>
68The subject and replacement lengths can be given as PCRE2_ZERO_TERMINATED for
69zero-terminated strings. The options are:
70<pre>
71  PCRE2_ANCHORED             Match only at the first position
72  PCRE2_ENDANCHORED          Pattern can match only at end of subject
73  PCRE2_NOTBOL               Subject is not the beginning of a line
74  PCRE2_NOTEOL               Subject is not the end of a line
75  PCRE2_NOTEMPTY             An empty string is not a valid match
76  PCRE2_NOTEMPTY_ATSTART     An empty string at the start of the subject is not a valid match
77  PCRE2_NO_JIT               Do not use JIT matching
78  PCRE2_NO_UTF_CHECK         Do not check the subject or replacement for UTF validity (only relevant if
79                              PCRE2_UTF was set at compile time)
80  PCRE2_SUBSTITUTE_EXTENDED  Do extended replacement processing
81  PCRE2_SUBSTITUTE_GLOBAL    Replace all occurrences in the subject
82  PCRE2_SUBSTITUTE_LITERAL   The replacement string is literal
83  PCRE2_SUBSTITUTE_MATCHED   Use pre-existing match data for 1st match
84  PCRE2_SUBSTITUTE_OVERFLOW_LENGTH  If overflow, compute needed length
85  PCRE2_SUBSTITUTE_REPLACEMENT_ONLY  Return only replacement string(s)
86  PCRE2_SUBSTITUTE_UNKNOWN_UNSET  Treat unknown group as unset
87  PCRE2_SUBSTITUTE_UNSET_EMPTY  Simple unset insert = empty string
88</pre>
89If PCRE2_SUBSTITUTE_LITERAL is set, PCRE2_SUBSTITUTE_EXTENDED,
90PCRE2_SUBSTITUTE_UNKNOWN_UNSET, and PCRE2_SUBSTITUTE_UNSET_EMPTY are ignored.
91</P>
92<P>
93If PCRE2_SUBSTITUTE_MATCHED is set, <i>match_data</i> must be non-zero; its
94contents must be the result of a call to <b>pcre2_match()</b> using the same
95pattern and subject.
96</P>
97<P>
98The function returns the number of substitutions, which may be zero if there
99are no matches. The result may be greater than one only when
100PCRE2_SUBSTITUTE_GLOBAL is set. In the event of an error, a negative error code
101is returned.
102</P>
103<P>
104There is a complete description of the PCRE2 native API in the
105<a href="pcre2api.html"><b>pcre2api</b></a>
106page and a description of the POSIX API in the
107<a href="pcre2posix.html"><b>pcre2posix</b></a>
108page.
109<p>
110Return to the <a href="index.html">PCRE2 index page</a>.
111</p>
112