programming-examples/perl/String/Convert mixed-case input.pl

 while ($Input = <>) {
        print "\L$Input\E";
        print "\L$Input";
        chop $Input;
        if ("\L$Input" eq "lowercase") {
            print "Found lowercase\n";
        }
        print "\U$Input\n";
        if ("\U$Input" eq "UPPERCASE") {
            print "Found UPPERCASE\n";
        }
    }