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regexperlregex-lookarounds

Perl Regex "Not" (negative lookahead)

I'm not terribly certain what the correct wording for this type of regex would be, but basically what I'm trying to do is match any string that starts with "/" but is not followed by "bob/", as an example.

So these would match:

/tom/
/tim/
/steve

But these would not

tom
tim
/bob/

I'm sure the answer is terribly simple, but I had a difficult time searching for "regex not" anywhere. I'm sure there is a fancier word for what I want that would pull good results, but I'm not sure what it would be.

Edit: I've changed the title to indicate the correct name for what I was looking for

Solution

  • You can use a negative lookahead (documented under "Extended Patterns" in perlre):

    /^\/(?!bob\/)/