Matching last value in reg expression

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Matching last value in reg expression by Abigail-II (Bishop) on Sep 30, 2003 at 14:04 UTC
Well, it's a way, but I would write the block as: `for (@files) { my @matches = /(.{8}-.{3}-i32)/g; my $last_match = $matches [-1]; print $last_match, "\n"; }` [download] You're not doing anything with $match, and I wouldn't assing the @_. Furthermore, why use @stats if all you care about is a single scalar? It's confusing and is less efficient. Also, if you are going to match against $_, no need to bind it. Note also that there is no need to backwhack a dash in a regular expression outside of character classes. But you can eliminate the intermediate array: `my $last_match = (/(.{8}-.{3}-i32)/g) [-1];` [download] Or, if you are certain there is a match: `1 while /(.{8}-.{3}-i32)/g; my $last_match = $1;` [download] You might even be able to use: `my ($last_match) = /.*(.{8}-.{3}-i32)/;` [download] although in some cases that might be slower, or (in case of possible overlapping matches) give you a different answer. The latter two have the advantage that they don't create an intermediate array or list, which, if there are lots and lots of matches, could be a win. Abigail	[reply] [d/l] [select]
Re: Re: Matching last value in reg expression by Anonymous Monk on Sep 30, 2003 at 17:20 UTC
Thank you for you explanation.	[reply]
Re: Matching last value in reg expression by broquaint (Abbot) on Sep 30, 2003 at 14:02 UTC
Just take advantage of the fact that a regex match in list context will return what was captured in the parentheses (if any) as a list e.g `my($match) = reverse /(.{8}-.{3}-i32)/g;` [download] See. `perlop` for more info on the behaviour of `m//`. Also, you don't need to escape the dashes in that regex as they only have a special meaning in character class, see. `perlre` for more info. HTH `_________ broquaint`	[reply] [d/l]