explain()

explain.pl

# Given a string, print out the codepoints that it currently compromises of. If
# you pass it a bytestring, you will get the bytes. If you pass it a character
# string, you will get the characters. This can be helpful when you're not sure
# if your terminal is playing around with the output.

sub explain {
    # We will build up the output in $explain
    my $explain;
    # Split the first argument in to characters
    for my $char ( split(//, shift() ) ) {
        # Take its ordinal
        my $ord = ord($char);
        # If it lies outside the printable range
        if ( $ord > 126 || $ord < 32 ) {
            # Then append its hex value to our output
            $explain .= sprintf('\x{%x}', $ord);
        # Otherwise, just put the character literal in
        } else {
            $explain .= $char;
        }
    }
    return $explain;
}

# Example

use Unicode::Normalize;
my $brel = "Qui s'enfuit déjà"; # A byte string
print explain($brel) . "\n";    # Qui s'enfuit d\x{c3}\x{a9}j\x{c3}\x{a0}
utf8::decode( $brel );          # Decode - byte string -> char string
print explain($brel) . "\n";    # Qui s'enfuit d\x{e9}j\x{e0}
$brel = NFD( $brel );           # Decompose the characters
print explain($brel) . "\n";    # Qui s'enfuit de\x{301}ja\x{300}
utf8::encode($brel);            # Encode - char string -> byte string
print explain($brel) . "\n";    # Qui s'enfuit de\x{cc}\x{81}ja\x{cc}\x{80}