Regular Expressions 101

ERRORthe literal text ERROR (case sensitive)

\s+any whitespace character, repeated at least once

Negative Lookahead(?!MO already exist)

MO already existthe literal text MO already exist (case sensitive)

.*any character (except for line terminators), repeated any number of times

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

ERROR\s+(?!MO already exist).*$

New

ERROR  
we have an ERROR here da da da  
ERROR Parent MO not found  
ERROR anything else is here  
ERROR MO already exists