› perl -c pm-11102847.pl
Global symbol "$co" requires explicit package name (did you forget to declare "my $co"?) at pm-11102847.pl line 21.
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use File::Compare qw(compare);
my $r = compare 'filename1', 'filename2';
if ($r == 0) {
print 'same';
} elsif ($r == 1) {
print 'different';
} else {
die "error in comparison: $!";
}
##
##
use Digest::MD5 qw(md5);
use File::Slurper qw(read_binary);
if (md5(read_binary('filename1')) eq md5(read_binary('filename2'))) {
print 'same';
} else {
print 'different';
}