PCRE - Perl-compatible regular expressions .rs #include <pcre.h>

 int pcre_copy_substring(const char *subject, int *ovector,  " int stringcount, int stringnumber, char *buffer,"  " int buffersize);"  int pcre16_copy_substring(PCRE_SPTR16 subject, int *ovector,  " int stringcount, int stringnumber, PCRE_UCHAR16 *buffer,"  " int buffersize);"  int pcre32_copy_substring(PCRE_SPTR32 subject, int *ovector,  " int stringcount, int stringnumber, PCRE_UCHAR32 *buffer,"  " int buffersize);" 

. .rs This is a convenience function for extracting a captured substring into a given buffer. The arguments are: subject Subject that has been successfully matched ovector Offset vector that pcre[16|32]_exec() used stringcount Value returned by pcre[16|32]_exec() stringnumber Number of the required substring buffer Buffer to receive the string buffersize Size of buffer The yield is the length of the string, PCRE_ERROR_NOMEMORY if the buffer was too small, or PCRE_ERROR_NOSUBSTRING if the string number is invalid.

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