#!/usr/bin/perl

use strict;
use warnings;

use encoding 'UTF-8';
#use encoding 'utf8';
#use utf8;

use Devel::Peek qw( Dump );

my $word = "État";  # UTF-8 encoding of "État"
my $char = "É";     # UTF-8 encoding of "É"

Dump($word);
print("String Length: ", length($word), "\n");
print("\n");

Dump($char);
print("String Length: ", length($char), "\n");
print("\n");

if ($word =~ /$char/) {
   print "Matches\n";
} else {
   print "Does not match\n";
}

if ($word =~ /\Q$char/) {
   print "Matches\n";
} else {
   print "Does not match\n";
}

if (substr($word, 0, 1) eq $char) {
   print "Equal\n";
} else {
   print "Not equal\n";
}
[download]

SV = PV(0x22608c) at 0x225f9c
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)               <-- That's good
  PV = 0x1822634 "\303\211tat"\0 [UTF8 "\x{c9}tat"]   <-- That's good
  CUR = 5
  LEN = 8
String Length: 4                                      <-- That's good

SV = PV(0x2260a4) at 0x225f3c
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK,UTF8)               <-- That's good
  PV = 0x22f43c "\303\211"\0 [UTF8 "\x{c9}"]          <-- That's good
  CUR = 2
  LEN = 4
String Length: 1                                      <-- That's good

Does not match                                        <-- WTF?
Does not match                                        <-- WTF?
Equal                                                 <-- That's good
[download]

Replacing use encoding 'UTF-8'; with use encoding 'utf8'; yields the same results.

Replacing use encoding 'UTF-8'; with use utf8; produces the same dumps, but the matches succeed.

My suggestion:

• Use use utf8; to treat the source as UTF-8.
• Use binmode(STDOUT, ":utf8"); to output UTF-8.

Hi Ikegami,

your code seems to rather clearly bring to light a bug with the 'encoding' pragma. Did you maybe try to submit it to the author of the 'encoding.pm' module ?

Seems to be Dan Kogai, an e-mail (don't know if valid) is available on CPAN.

Well... the thing is that I must keep use encoding 'UTF-8' with CGI and CGI:FastTemplate in order to make my utf8 templates properly managed... additionnaly I need use locale; in order to use my locale collation. For the utf8 templates I tried unsuccessfully the following:use open ":utf8"; binmode(STDIN,":utf8"); binmode(STDOUT, ":utf8"); I suspect that the "automatic" string upgrade when concatenation occurs which is enabled with use encoding 'utf8' is mandatory for utf8 templates to work (haven't checked its code though).