Retrieves the text matching the match_num'th capturing parentheses.
0 is the full text of the match, 1 is the first paren set, 2 the second, and so on.
If match_num is a valid sub pattern but it didn't match anything (e.g. sub pattern 1, matching "b" against "(a)?b") then an
empty string is returned. When a partial match is reported via
is_partial_match only the full text of the match can be queried (match_num must be `0`).
If the match was obtained using the DFA algorithm, that is using match_all or match_all_full, the retrieved string is not that of a set of parentheses but that of a matched substring. Substrings are matched in reverse order of length, so 0 is the longest match.
The string is fetched from the string passed to the match function, so you cannot call this function after freeing the string.
| this |
MatchInfo structure |
| match_num |
number of the sub expression |
|
The matched substring, or null if an error occurred. You have to free the string yourself |