Q: (To paraphrase...) Why does /foo | bar/ match any line with foo or bar, and not a line with the bitwise OR of 'foo ' and ' bar'? A: Because in a regular expression, | separates two distinct options. | in a regex says that the regex matches if the stuff on the left or right matches. I don't even know how you *do* a bitwise OR in perl... But I expect it's documented. Peter