Exclude unwanted string from Linux grep

[Gabriel9999]

I have a configuration file which is a simple text. I want to list some configuration line but except some sitring. How can I use Linux grep to exclude and search for given strings? Thanks in advance for your help!

[icecream-guy]

Have you checked MAN page for grep? there is option for this.

[Otanx]

The lazy man way;

Code Select Expand

cat file.txt | grep "match this" | grep -v "not this"

I used to have a sticky note with a drawing of a cat that said "gratuitous use of cat award" one of our devs gave me. It disappeared when we moved.

-Otanx

[Dieselboy]

I think egrep does it?

When I want to view a LONG config file that has like 10 lines of config and the rest are comments, I use this (which I stole from someone else)

Code Select Expand

egrep -v "\#|^$" someconfig.conf

Dont forget you can use regex as well. And dont foget to check the man pages! Usually they have examples there and if you were to do a linux exam this is all that you're allowed to check. So get used to it

Code Select Expand

man grep

man egrep

[samueltarcin9999]

There are different ways to exclude and grep given a text file or input stream. I generally prefer the most basic one where use two grep where the first one is for exclude with -v option and pipe to second one where I grep for my string.   grep -v 'able' config.txt | grep 'system'  For more information look https://www.yjastar.com/ku/introduction-to-linux-grep-command-with-examples/