linux man page for pcre_study

PCRE_STUDY(3)						     Library Functions Manual						     PCRE_STUDY(3)

NAME
       PCRE - Perl-compatible regular expressions

SYNOPSIS

       #include <pcre.h>

       pcre_extra *pcre_study(const pcre *code, int options,
	    const char **errptr);

DESCRIPTION

       This  function  studies	a  compiled pattern, to see if additional information can be extracted that might speed up matching. Its arguments
       are:

	 code	    A compiled regular expression
	 options    Options for pcre_study()
	 errptr     Where to put an error message

       If the function succeeds, it returns a value that can be passed to pcre_exec() via its extra argument.

       If the function returns NULL, either it could not find any additional information, or there was an error. You can tell  the  difference	by
       looking at the error value. It is NULL in first case.

       There are currently no options defined; the value of the second argument should always be zero.

       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.

																     PCRE_STUDY(3)