#include <pcre.h>
void pcre_free_substring(const char *stringptr);
void pcre16_free_substring(PCRE_SPTR16 stringptr);
void pcre32_free_substring(PCRE_SPTR32 stringptr);
This is a convenience function for freeing the store obtained by a previous call to pcre[16|32]_get_substring() or pcre[16|32]_get_named_substring(). Its only argument is a pointer to the string.
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.