pcre2_substring_get_bynumber - Man Page

#include <pcre2.h>

int pcre2_substring_get_bynumber(pcre2_match_data *match_data,
  uint32_t number, PCRE2_UCHAR **bufferptr, PCRE2_SIZE *bufflen);

This is a convenience function for extracting a captured substring by number into newly acquired memory. The arguments are:

 match_data    The match data for the match
 number        Number of the required substring
 bufferptr     Where to put the string pointer
 bufflen       Where to put the string length

The memory in which the substring is placed is obtained by calling the same memory allocation function that was used for the match data block. The convenience function pcre2_substring_free() can be used to free it when it is no longer needed. 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      memory could not be obtained

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.