Top "Negative-lookahead" questions

Regex: what does (?! ...) mean?

The following regex finds text between substrings FTW and ODP. /FTW(((?!FTW|ODP).)+)ODP+/ What does the (?!...) do?

regex negative-lookahead

Regex to match all permutations of {1,2,3,4} without repetition

I am implementing the following problem in ruby. Here's the pattern that I want : 1234, 1324, 1432, 1423, 2341 and so on i.e. the …

regex permutation lookahead negative-lookahead

How to exclude a string in the middle of a RegEx string?

I have a lot of PHP class files, that contain methods like findFoo(). I want to find (with the RegEx …

regex regex-negation regex-lookarounds negative-lookahead negative-lookbehind

using regex to skip ahead all characters until a specific sequence of letters is found using negative lookahead

I'm alright with basic regular expressions, but I get a bit lost around pos/neg look aheads/behinds. I'm trying …

php regex negative-lookahead

Javascript regex: find a word NOT followed by space character

I need javascript regex that will match words that are NOT followed by space character and has @ before, like this: @…

javascript regex negative-lookahead negative-lookbehind

Is there a way to do negative lookahead in vim regex?

In Vim, is there a way to search for lines that match say abc but do not also contain xyz …

regex vim negative-lookahead