[SOLVED] sed/awk : remove section from file

vrusu · 10-26-2010, 08:19 AM

Hi
I have a file like this:

[first]
a
b
c
[sec]
d
e
f
[n-th]
x
y
z

I would like to remove a section between [first] and [second]:
$cat test |sed '/\[first\]/,/\[sec\]/d'
d
e
f
[n-th]
x
y
z
Is almost what I want. I would like the section header to say in place.
Desired output:
[sec]
d
e
f
[n-th]
x
y
z

Thank you

GrapefruiTgirl · 10-26-2010, 08:38 AM

Code:

 awk  '{
if($0 ~ /\[first\]/){output="off"; next}
if($0 ~ /\[second\]/){output="on"; print; next}
if(output == "on"){print}
}' input-file

The above is an untested, but rather simple, way of (I believe) printing what you wish. If it doesn't work, and/or if you would like explanation of it, please explain or ask more.

There are myriad ways of accomplishing this so I look forward to seeing some other methods too.

Good luck!

EDIT: See the bold part - I fixed it.

grail · 10-26-2010, 08:46 AM

Code:

sed '/sec/,$!d' input_file

GrapefruiTgirl · 10-26-2010, 08:49 AM

Ahh, friend grail,

with another amazingly short working solution! Nice one! If we ever have a contest for "the most code written to perform a task", I'll get that one.