Question

Okay so I can’t figure this out. Like a file that I using grep in order to get certain information has it set-up like this.

#aaaa
<numbers 123456>

blah
blah
blah

#bbbb
<numbers 2156488>

blah
blah
blah

#cccc
<numbers 5478624>

blah
blah
blah

What I am doing is I am greping for aaaa or bbbb or cccc and the information that i really need is the numbers. As in when i grep for aaaa the thing i want to obtain is really just the numbers right below it. In this case it would 123456

I know how to grep for aaaa but i don’t know how to go to the next line and cut the number.

Answer 1

You can use the -C option of grep to show one line of context. Then you can tail on the last line (-n 1), cut using spaces and selecting the second field, cut again using > and selecting the first field. Thus:

$ grep aaaa file -C 1 | tail -n 1 | cut -f2 -d' ' | cut -d'>' -f1
123456

will give back the number you’re requesting.

The most important part is the -C option of grep