On 1/12/07, Dan Drake wrote: > I'm looking for a regular expression that's guaranteed to never match > anything. How about "(?!)" ? For the record, I googled '"regular expression" "never matches"', and came up with the following from a paper about creating a regex debugger in perl (http://perl.plover.com/Rx/paper/): ". . . (?!) is a pattern that never matches anything, so when the regex engine reaches it, it is forced to backtrack. " sm