CODEWITHSUNDEEP
regexperlstring-matching
Ali
Ali

Reputation: 73

Regex to match several strings but not specific ones

I'm working with Perl to search and match for strings on each line that match a criteria and would like to omit the lines that contain a specific string. What I mean is: Say I'm matching the string Mouse, but I'd like to omit if the line matches X123Y. Either strings can be found anywhere on the line.

Stackoverflow Mouse forum.       <--Match
Stackoverflow -Mouse- forum.     <--Match
Stackoverflow X123Y forum Mouse. <--Should not Match
Stackoverflow XYZ forum Mouse.   <--Should not Match

I hoped this would solve it since I'm using negative lookahead but doesn't seem to do the trick. 

(?i)(\WMouse\W|(?!(X123Y|XYZ)).*$)

I'm doing something fundamentally wrong I suppose, but cannot see it now.

Any help?

Upvotes: 5

Views: 129

Answers (2)

Federico Piazza
Federico Piazza

Reputation: 31025

You can use the discard technique to keep with the content you want and discard the patterns you don't.

For example, using this regex:

.*X123Y.*|.*XYZ.*|(.*Mouse.*)

You will grab the content for the rightest pattern and discard the others..

Working demo

enter image description here

The idea is to use:

discard patt 1 | discard patt 2 | discard patt n | (grab this pattern)

Upvotes: 1

anubhava
anubhava

Reputation: 785286

This regex should work for you:

^(?=.*?Mouse)(?:(?!(?:X123|XYZ)).)*$

RegEx Demo

Upvotes: 4

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