Searching with Grep

Here, I am sharing a very useful and simple example of “GREP” command that can save you a lot of key presses. I know you might still remember the trusted grep command that you have learned in your RHCE Training or RHCSS Training.

Let me explain it with a example.

Suppose I want to look for “failed login” attempts on my server. I know I can just see the /var/log/secure file to check that. But /var/log/secure file in this case also contain a lot of other information which I might not be interested in right now.

I know you can use the “grep” command to filter the results. But you might be interested in a little more detail about that event. In this case line coming just after the searched word will be of interest.

So How can you do that?

Check this out:

grep -A 5 -i “failed password” /var/log/secure

This will give you the line containing “failed password” and 5 lines appearing just after it.

“LIKE” = Will make life more easier.

Grep Command Example

Grep Command Example