pcre2_substring_copy_bynumber - Man Page

#include <pcre2.h>

int pcre2_substring_copy_bynumber(pcre2_match_data *match_data,
  uint32_t number, PCRE2_UCHAR *buffer,
  PCRE2_SIZE *bufflen);

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

 match_data    The match data block for the match
 number        Number of the required substring
 buffer        Buffer to receive the string
 bufflen       Length of buffer

The bufflen variable is updated with the length of the extracted string, excluding the terminating zero. The yield of the function is zero for success or one of the following error numbers:

 PCRE2_ERROR_NOSUBSTRING   there are no groups of that number
 PCRE2_ERROR_UNAVAILBLE    the ovector was too small for that group
 PCRE2_ERROR_UNSET         the group did not participate in the match
 PCRE2_ERROR_NOMEMORY      the buffer is too small

There is a complete description of the PCRE2 native API in the pcre2api page and a description of the POSIX API in the pcre2posix page.