How do I handle binary data correctly?

Perl is binary clean, so this shouldn't be a problem. For example, this works fine (assuming the files are found): 

    if (`cat /vmunix` =~ /gzip/) {
	print "Your kernel is GNU-zip enabled!\n";
    }

On some systems, however, you have to play tedious games with ``text'' versus ``binary'' files. See binmode.

If you're concerned about 8-bit ASCII data, then see the perllocale manpage.

If you want to deal with multi-byte characters, however, there are some gotchas. See the section on Regular Expressions.