-$md5cmd =~ /not found/ and $md5cmd = `which md5`;
-$md5cmd =~ /not found/ and die 'no md5 checksum program found, please install md5 or md5sum';
+$md5cmd or $md5cmd = `which md5`;
+$md5cmd or die 'no md5 checksum program found, please install md5 or md5sum';
+chomp $md5cmd;