PCRE\_DFA\_EXEC(3) Library Functions Manual PCRE\_DFA\_EXEC(3)

# [NAME](#NAME)

PCRE - Perl-compatible regular expressions

# [SYNOPSIS](#SYNOPSIS)

**#include <pcre.h>**

```
int pcre_dfa_exec(const pcre *code, const pcre_extra *extra,
     const char *subject, int length, int startoffset,
     int options, int *ovector, int ovecsize,
     int *workspace, int wscount);

int pcre16_dfa_exec(const pcre16 *code, const pcre16_extra *extra,
     PCRE_SPTR16 subject, int length, int startoffset,
     int options, int *ovector, int ovecsize,
     int *workspace, int wscount);

int pcre32_dfa_exec(const pcre32 *code, const pcre32_extra *extra,
     PCRE_SPTR32 subject, int length, int startoffset,
     int options, int *ovector, int ovecsize,
     int *workspace, int wscount);
```

# [DESCRIPTION](#DESCRIPTION)

This function matches a compiled regular expression against a given subject string, using an alternative matching algorithm that scans the subject string just once (*not* Perl-compatible). Note that the main, Perl-compatible, matching function is **pcre\[16|32]\_exec()**. The arguments for this function are:

*code* Points to the compiled pattern  
*extra* Points to an associated **pcre\[16|32]\_extra** structure,  
or is NULL  
*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  
*ovector* Points to a vector of ints for result offsets  
*ovecsize* Number of elements in the vector  
*workspace* Points to a vector of ints used as working space  
*wscount* Number of elements in the vector

The units for *length* and *startoffset* are bytes for **pcre\_exec()**, 16-bit data items for **pcre16\_exec()**, and 32-bit items for **pcre32\_exec()**. The options are:

PCRE\_ANCHORED Match only at the first position  
PCRE\_BSR\_ANYCRLF \\R matches only CR, LF, or CRLF  
PCRE\_BSR\_UNICODE \\R 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 is not the beginning of a line  
PCRE\_NOTEOL Subject 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  
even if there is a full match as well  
PCRE\_DFA\_SHORTEST Return only the shortest match  
PCRE\_DFA\_RESTART Restart after a partial match

There are restrictions on what may appear in a pattern when using this matching function. Details are given in the **pcrematching** documentation. For details of partial matching, see the **pcrepartial** page.

A **pcre\[16|32]\_extra** structure contains the following fields:

*flags* Bits indicating which fields are set  
*study\_data* Opaque data from **pcre\[16|32]\_study()**  
*match\_limit* Limit on internal resource use  
*match\_limit\_recursion* Limit on internal recursion depth  
*callout\_data* Opaque data passed back to callouts  
*tables* Points to character tables or is NULL  
*mark* For passing back a \*MARK pointer  
*executable\_jit* Opaque data from JIT compilation

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. For this matching function, the *match\_limit* and *match\_limit\_recursion* fields are not used, and must not be set. The PCRE\_EXTRA\_EXECUTABLE\_JIT flag and the corresponding variable are ignored.

There is a complete description of the PCRE native API in the **pcreapi** page and a description of the POSIX API in the **pcreposix** page.

12 May 2013 PCRE 8.33

---

Document: pcre_dfa_exec(3) from pcre 8.45-r11 (Chainguard OS)
Source: https://downloads.sourceforge.net/project/pcre/pcre/8.45/pcre-8.45.tar.bz2