PCRE2 - Perl-compatible regular expressions (revised API)

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 \K escape sequence. After a partial match, however, this value is always the same as ovector[0] because \K does not affect the result of a partial match. 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. PCRE2 10.45 25 October 2014 PCRE2_GET_STARTCHAR(3)

PCRE2 - Perl-compatible regular expressions (revised API)