Trying to debug an encoding problem? The following will try to figure out what encoding was used and what encoding should have been used.

use 5.008;

use strict;
use warnings;

use Encode qw( encode decode );

use charnames qw( :full );

my $expected
    = "\N{LATIN CAPITAL LETTER I WITH CIRCUMFLEX}";

my $got
    = "\N{LATIN CAPITAL LETTER A WITH TILDE}"
    . "\N{LATIN CAPITAL LETTER Z WITH CARON}";

my @encs = (
    'US-ASCII',
    ( map "UTF-$_",      qw( 7 8 16be 16le 32be 32le ) ),
    ( map "UCS-$_",      qw( 2be 2le 4be 4le         ) ),
    ( map "iso-8859-$_", 1..11, 13..16                 ),
    ( map "Windows-$_",  437, 737, 775, 850, 852, 855,    # OEM pages
                         857, 858, 860, 861, 862, 863,
                         865, 866, 869,
                         874, 932, 936, 949, 950,         # ANSI pages
                         1250..1258,                   ),
);

for my $enc_for_enc (@encs) {
    my $encoded = encode($enc_for_enc, $expected);

    for my $enc_for_dec (@encs) {
        my $decoded = decode($enc_for_dec, $encoded);

        next if $decoded ne $got;

        print("$enc_for_enc as $enc_for_dec:\n");

        for ($decoded =~ /./sg) {
            my $code = ord;
            my $name = charnames::viacode($code);
            printf("(U+%04X) %s\n", $code, $name);
        }

        print("\n");
    }
}
[download]

UTF-8 as Windows-1252:
(U+00C3) LATIN CAPITAL LETTER A WITH TILDE
(U+017D) LATIN CAPITAL LETTER Z WITH CARON
[download]

Known bugs and limitations:

• Doesn't provide a means to specify input without modifying the program.
• Doesn't handle different codepoints that produce similar graphemes.
• Should display nearest matches if there aren't any exact matches.