PCRE2 - Perl-compatible regular expressions (revised API) .rs #include <pcre2.h>

 PCRE2_SIZE pcre2_get_startchar(pcre2_match_data *match_data); 

. .rs After a successful call of pcre2_match() that was passed the match block that is this function's argument, this function returns the code unit offset of the character at which the successful match started. For a non-partial match, this can be different to the value of ovector[0] if the pattern contains the \eK escape sequence. After a partial match, however, this value is always the same as ovector[0] because \eK does not affect the result of a partial match.

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