.TH PCRE2_SUBSTRING_LENGTH_BYNUMBER 3 "22 December 2014" "PCRE2 10.00" .SH NAME PCRE2 - Perl-compatible regular expressions (revised API) .SH SYNOPSIS .rs .sp .B #include <pcre2.h> .PP .nf .B int pcre2_substring_length_bynumber(pcre2_match_data *\fImatch_data\fP, .B " uint32_t \fInumber\fP, PCRE2_SIZE *\fIlength\fP);" .fi . .SH DESCRIPTION .rs .sp This function returns the length of a matched substring, identified by number. The arguments are: .sp \fImatch_data\fP The match data block for the match \fInumber\fP The substring number \fIlength\fP Where to return the length, or NULL .sp The third argument may be NULL if all you want to know is whether or not a substring is set. The yield is zero on success, or a negative error code otherwise. After a partial match, only substring 0 is available. .P There is a complete description of the PCRE2 native API in the .\" HREF \fBpcre2api\fP .\" page and a description of the POSIX API in the .\" HREF \fBpcre2posix\fP .\" page.