pcre2/doc/pcre2_dfa_match.3

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.TH PCRE2_DFA_MATCH 3 "28 August 2021" "PCRE2 10.38"
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.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH SYNOPSIS
.rs
.sp
.B #include <pcre2.h>
.PP
.nf
.B int pcre2_dfa_match(const pcre2_code *\fIcode\fP, PCRE2_SPTR \fIsubject\fP,
.B " PCRE2_SIZE \fIlength\fP, PCRE2_SIZE \fIstartoffset\fP,"
.B " uint32_t \fIoptions\fP, pcre2_match_data *\fImatch_data\fP,"
.B " pcre2_match_context *\fImcontext\fP,"
.B " int *\fIworkspace\fP, PCRE2_SIZE \fIwscount\fP);"
.fi
.
.SH DESCRIPTION
.rs
.sp
This function matches a compiled regular expression against a given subject
string, using an alternative matching algorithm that scans the subject string
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just once (except when processing lookaround assertions). This function is
\fInot\fP Perl-compatible (the Perl-compatible matching function is
\fBpcre2_match()\fP). The arguments for this function are:
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.sp
\fIcode\fP Points to the compiled pattern
\fIsubject\fP Points to the subject string
\fIlength\fP Length of the subject string
\fIstartoffset\fP Offset in the subject at which to start matching
\fIoptions\fP Option bits
\fImatch_data\fP Points to a match data block, for results
\fImcontext\fP Points to a match context, or is NULL
\fIworkspace\fP Points to a vector of ints used as working space
\fIwscount\fP Number of elements in the vector
.sp
The size of output vector needed to contain all the results depends on the
number of simultaneous matches, not on the number of parentheses in the
pattern. Using \fBpcre2_match_data_create_from_pattern()\fP to create the match
data block is therefore not advisable when using this function.
.P
A match context is needed only if you want to set up a callout function or
specify the heap limit or the match or the recursion depth limits. The
\fIlength\fP and \fIstartoffset\fP values are code units, not characters. The
options are:
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.sp
PCRE2_ANCHORED Match only at the first position
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PCRE2_COPY_MATCHED_SUBJECT
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On success, make a private subject copy
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PCRE2_ENDANCHORED Pattern can match only at end of subject
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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
.\" JOIN
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PCRE2_NOTEMPTY_ATSTART An empty string at the start of the subject
is not a valid match
.\" JOIN
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PCRE2_NO_UTF_CHECK Do not check the subject for UTF
validity (only relevant if PCRE2_UTF
was set at compile time)
.\" JOIN
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PCRE2_PARTIAL_HARD Return PCRE2_ERROR_PARTIAL for a partial
match even if there is a full match
.\" JOIN
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PCRE2_PARTIAL_SOFT Return PCRE2_ERROR_PARTIAL for a partial
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match if no full matches are found
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PCRE2_DFA_RESTART Restart after a partial match
PCRE2_DFA_SHORTEST Return only the shortest match
.sp
There are restrictions on what may appear in a pattern when using this matching
function. Details are given in the
.\" HREF
\fBpcre2matching\fP
.\"
documentation. For details of partial matching, see the
.\" HREF
\fBpcre2partial\fP
.\"
page. There is a complete description of the PCRE2 native API in the
.\" HREF
\fBpcre2api\fP
.\"
page and a description of the POSIX API in the
.\" HREF
\fBpcre2posix\fP
.\"
page.