[SOLVED] Remove matching line from file

tara · 04-04-2017, 01:19 AM

Hi,

I have the following line put in the /etc/sudoers in my kickstart file which after an action following installation is performed i wish to have the line removed.

Code:

echo "system  ALL=NOPASSWD: ALL" >> /etc/sudoers

I have tried a few different sed commands but I can't get any of them to work, not sure if it is because there is whitespace in the line or not.... The sed (or equivalent command needs to run in a script)

Any ideas would be greatly appreciated.

Thanks!

Turbocapitalist · 04-04-2017, 01:26 AM

Quote:

Originally Posted by tara

I have tried a few different sed commands but I can't get any of them to work, not sure if it is because there is whitespace in the line or not....

But the pattern you use should then take into account the possibility that there might be white space. Can you show what you have tried so far?

Also, which version of sed do you have and does it support the -i option?

pan64 · 04-04-2017, 01:30 AM

yes, how could you expect any fix/explanation if you won't show us what/how did you try?

tara · 04-04-2017, 01:33 AM

sed is version 4.2.2 and yes it supports -i

Does the whitespace have to match perfectly? i.e. 2 spaces, 3 spaces etc?

I have tried
sed -i '/ALL=NOPASSWD/d' /etc/sudoers

as well as putting in the entire line and neither option works.

I have also tried using '$d' to just delete the last line (which is not a nice why of doing it) but when it goes from my kickstart into my bash_profile the $d disappears....

tara · 04-04-2017, 01:34 AM

I'm happy to use grep or awk, just don't know which might be the best way...

pan64 · 04-04-2017, 01:37 AM

you can try it without -i, just to see what's happening:
sed '/ALL=NOPASSWD/d' /etc/sudoers
actually that should work, but it will remove all the lines containing your pattern.
white space and others are irrelevant here and now, you need to check only if that pattern matches.