.TH PCRE_EXEC 3 "12 May 2013" "PCRE 8.33"
.SH NAME
PCRE - Perl-compatible regular expressions
.SH SYNOPSIS
.rs
.sp
.B #include <pcre.h>
.PP
.nf
.B int pcre_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP,"
.B "     const char *\fIsubject\fP, int \fIlength\fP, int \fIstartoffset\fP,"
.B "     int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);"
.sp
.B int pcre16_exec(const pcre16 *\fIcode\fP, "const pcre16_extra *\fIextra\fP,"
.B "     PCRE_SPTR16 \fIsubject\fP, int \fIlength\fP, int \fIstartoffset\fP,"
.B "     int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);"
.sp
.B int pcre32_exec(const pcre32 *\fIcode\fP, "const pcre32_extra *\fIextra\fP,"
.B "     PCRE_SPTR32 \fIsubject\fP, int \fIlength\fP, int \fIstartoffset\fP,"
.B "     int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);"
.fi
.
.SH DESCRIPTION
.rs
.sp
This function matches a compiled regular expression against a given subject
string, using a matching algorithm that is similar to Perl's. It returns
offsets to captured substrings. Its arguments are:
.sp
  \fIcode\fP         Points to the compiled pattern
  \fIextra\fP        Points to an associated \fBpcre[16|32]_extra\fP structure,
                 or is NULL
  \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
  \fIovector\fP      Points to a vector of ints for result offsets
  \fIovecsize\fP     Number of elements in the vector (a multiple of 3)
.sp
The units for \fIlength\fP and \fIstartoffset\fP are bytes for
\fBpcre_exec()\fP, 16-bit data items for \fBpcre16_exec()\fP, and 32-bit items
for \fBpcre32_exec()\fP. The options are:
.sp
  PCRE_ANCHORED          Match only at the first position
  PCRE_BSR_ANYCRLF       \eR matches only CR, LF, or CRLF
  PCRE_BSR_UNICODE       \eR matches all Unicode line endings
  PCRE_NEWLINE_ANY       Recognize any Unicode newline sequence
  PCRE_NEWLINE_ANYCRLF   Recognize CR, LF, & CRLF as newline sequences
  PCRE_NEWLINE_CR        Recognize CR as the only newline sequence
  PCRE_NEWLINE_CRLF      Recognize CRLF as the only newline sequence
  PCRE_NEWLINE_LF        Recognize LF as the only newline sequence
  PCRE_NOTBOL            Subject string is not the beginning of a line
  PCRE_NOTEOL            Subject string is not the end of a line
  PCRE_NOTEMPTY          An empty string is not a valid match
  PCRE_NOTEMPTY_ATSTART  An empty string at the start of the subject
                           is not a valid match
  PCRE_NO_START_OPTIMIZE Do not do "start-match" optimizations
  PCRE_NO_UTF16_CHECK    Do not check the subject for UTF-16
                           validity (only relevant if PCRE_UTF16
                           was set at compile time)
  PCRE_NO_UTF32_CHECK    Do not check the subject for UTF-32
                           validity (only relevant if PCRE_UTF32
                           was set at compile time)
  PCRE_NO_UTF8_CHECK     Do not check the subject for UTF-8
                           validity (only relevant if PCRE_UTF8
                           was set at compile time)
  PCRE_PARTIAL           ) Return PCRE_ERROR_PARTIAL for a partial
  PCRE_PARTIAL_SOFT      )   match if no full matches are found
  PCRE_PARTIAL_HARD      Return PCRE_ERROR_PARTIAL for a partial match
                           if that is found before a full match
.sp
For details of partial matching, see the
.\" HREF
\fBpcrepartial\fP
.\"
page. A \fBpcre_extra\fP structure contains the following fields:
.sp
  \fIflags\fP            Bits indicating which fields are set
  \fIstudy_data\fP       Opaque data from \fBpcre[16|32]_study()\fP
  \fImatch_limit\fP      Limit on internal resource use
  \fImatch_limit_recursion\fP  Limit on internal recursion depth
  \fIcallout_data\fP     Opaque data passed back to callouts
  \fItables\fP           Points to character tables or is NULL
  \fImark\fP             For passing back a *MARK pointer
  \fIexecutable_jit\fP   Opaque data from JIT compilation
.sp
The flag bits are PCRE_EXTRA_STUDY_DATA, PCRE_EXTRA_MATCH_LIMIT,
PCRE_EXTRA_MATCH_LIMIT_RECURSION, PCRE_EXTRA_CALLOUT_DATA,
PCRE_EXTRA_TABLES, PCRE_EXTRA_MARK and PCRE_EXTRA_EXECUTABLE_JIT.
.P
There is a complete description of the PCRE native API in the
.\" HREF
\fBpcreapi\fP
.\"
page and a description of the POSIX API in the
.\" HREF
\fBpcreposix\fP
.\"
page.