Regular expression: matching only if not ending in particular sequence

Question

I would like to test a url that does NOT end in .html

This is the pattern I come up with:

[/\\w\\.-]+[^\\.html$]

T

Answer 1

You can use a negative lookbehind assertion if your regular expression engine supports it:

^[/\w\.-]+(?

If you don't have lookbehind assertions but you do have lookaheads then you can use that instead:

^(?!.*\.html$)[/\w\.-]+$

See it working online: rubular