DESCRIPTION

This is a convenience function for extracting a captured substring. The arguments are:

 subject       Subject that has been successfully matched
 ovector       Offset vector that pcre_exec() used
 stringcount   Value returned by pcre_exec()
 stringnumber  Number of the required substring
 stringptr     Where to put the string pointer

The memory in which the substring is placed is obtained by calling pcre_malloc(). The convenience function pcre_free_substring() can be used to free it when it is no longer needed. The yield of the function is the length of the substring, PCRE_ERROR_NOMEMORY if sufficient memory could not be obtained, or PCRE_ERROR_NOSUBSTRING if the string number is invalid.

There is a complete description of the PCRE native API in the pcreapi(3) page and a description of the POSIX API in the pcreposix(3) page.