matching UTF8 chars with regex

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

Hello friends, decoding a string seems to break regex matching.

use strict;
use warnings;
use encoding 'utf8';
use Encode;

my $raw = encode('cp1250', 'í');
my $letter = decode('cp1250', $raw);
if ($letter eq 'í') { print "yes\n" } else { print "no\n" }
if ($letter =~ /í/) { print "yes\n" } else { print "no\n" }

__OUTPUT__
yes
no
[download]

What does this mean? Is there a way to get it working?

Comment on matching UTF8 chars with regex Download Code

Replies are listed 'Best First'.
Re: matching UTF8 chars with regex by AltBlue (Chaplain) on May 19, 2007 at 02:37 UTC
encoding won't automatically upgrade your strings unless you turn it's source filter feature on: `use encoding 'utf8', Filter => 1;` should do it. -- altblue.	[reply] [d/l]
Re^2: matching UTF8 chars with regex by Sixtease (Friar) on May 19, 2007 at 02:54 UTC
Yes! Yes! Thanks a lot! It works now... and as I drown myself into the `encoding` documentation, I see I've been doing some nasty stuff all the time.	[reply] [d/l]
Re: matching UTF8 chars with regex by Joost (Canon) on May 19, 2007 at 01:29 UTC
If I substitute `use utf8;` for `use encoding 'utf8';` it works fine (perl 5.8.8/debian linux). I note that the documentation for encoding says: "allows you to write your script in non-ascii or non-utf8". Still, I would expect your code to work, assuming your script really is utf-8 encoded. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l] [select]
Re: matching UTF8 chars with regex by Juerd (Abbot) on Jun 13, 2007 at 19:54 UTC
"use encoding" is broken in several ways, and there will not be a fix soon. Stop using it if you can. And I'm quite sure that you can. If your source code is UTF-8 encoded, tell Perl by adding "use utf8;". If your input and output must be UTF-8 encoded, tell Perl by adding "binmode STDIN, ':encoding(UTF-8)'; binmode STDOUT, ':encoding(UTF-8)';". Just don't "use encoding", please. If you remove "use encoding 'utf8';" and add "use utf8;" in its place, your problem is gone. Juerd # { site => 'juerd.nl', do_not_use => 'spamtrap', perl6_server => 'feather' }	[reply]