Also have a look at File::LibMagic

#!/usr/bin/perl
use warnings;
use strict;

use File::LibMagic ':easy';

my @files = qw(
        /bin/ls
        /etc/localtime
        /etc/timezone
        /etc/motd
);


foreach my $file ( @files ) {

    print "$file:\n\t", MagicFile( $file ), "\n";
}
[download]

which yields

/bin/ls:
        ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for 
+GNU/Linux 2.6.8, dynamically linked (uses shared libs), stripped
/etc/localtime:
        timezone data
/etc/timezone:
        ASCII text
/etc/motd:
        symbolic link to `/var/run/motd'
[download]

on my Linux Box.

See Comparing different MIME type checking modules for three modules.

By the way, PerlMonks Discussion is for discussions about PerlMonks. I moved your post from there too Seekers of Perl Wisdom where it belongs.