get only first line using sed / awk

iffarrukh · 05-24-2012, 01:30 AM

Hi I have a file which contains IP address like this

192.168.28
192.168.28
192.168.28
192.168.28
192.168.28
192.168.28
192.168.28
0.0.0.0
0.0.0.0
0.0.0.0
192.168.8.
0.0.0.0
192.168.8.
0.0.0.0
0.0.0.0
0.0.0.0
0.0.0.0
0.0.0.0
192.168.28
192.168.28
192.168.28
192.168.28
192.168.28
0.0.0.0
192.168.28
192.168.28
192.168.28
192.168.28
192.168.28
192.168.28
0.0.0.0

I want to get only first IP address. I know they are all same but I need only one ( in the bold) using sed/awk or any other comamnd..

Any help would be great.

Thanks.
Sam

pan64 · 05-24-2012, 01:44 AM

have you tried sort -u or uniq?

colucix · 05-24-2012, 01:51 AM

To retrieve the first line of a file there are plenty of methods:

Code:

$ head -n1 file
$ sed -n 1p file
$ awk 'NR == 1' file

If you want to put the result in a variable, use command substitution.

David the H. · 05-24-2012, 06:13 PM

There's no need for an external program either.

Code:

read var <infile ; echo "$var"