PCRE - Perl-compatible regular expressions
#include <pcre.h>
const char *pcre_version(void);
const char *pcre16_version(void);
const char *pcre32_version(void);
This function (even in the 16-bit and 32-bit libraries) returns a zero-terminated, 8-bit character string that gives the version number of the PCRE library and the date of its release.
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.