Linux sed command [SOLVED]

Athlantar

Hi all,

I suppose a linux forum would be abetter place to post this, but I love you all so much here.
I'm trying to write a bash script to take an ip address, and give me each component. This isnt for an assignment or anything, just for a personal project.

I've been messing with that damn sed command for hours trying to split the text up properly.
For instance, if I had the ip address 123.58.93.923 I would like one line of code to give me
123
another line to give me
58
another line to give me
93
and another to give me
923

I cant seem to write a piece of code that will isolate each component, and be able to handle if correctly if theres a different number of characters in each segmet. So if i refreshed my dynamic IP and it became 11.539.2.99, i woudl like the code to still break it up.

Perhaps this task is more difficult than its worth, but if anyone has a quick and easy solution, I'd be very appreciateive. the base code I've been working with is

wget -q -O - checkip.dyndns.org|sed -e 's/.*Current IP Address: //' -e 's/<.*$//'

Thanks amillion if anyone has any suggestions!

Barrakketh

Why restrict yourself to sed? I changed the sed command to egrep, but you can still substitute any command that will return an IP address.

wget -q -O - checkip.dyndns.org | egrep -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | awk -F '.' '{print $1"\n"$2"\n"$3"\n"$4}'

I typically use awk to split along whitespace (the default), but you can change the field separator with "-F".

ecco the dolphin

If you really want to use sed, you can go:

sed -e 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)/\1/g'
sed -e 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)/\2/g'
sed -e 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)/\3/g'
sed -e 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)/\4/g'

I'd recommend using "cut", actually. Slightly shorter than the sed and awk.

cut -d . -f 1
cut -d . -f 2
cut -d . -f 3
cut -d . -f 4

e.g. echo 213.4.55.11 | cut -d . -f 1

Athlantar wrote: »

I've been messing with that damn sed command for hours trying to split the text up properly.
For instance, if I had the ip address 123.58.93.923 I would like one line of code to give me
123
another line to give me
58
another line to give me
93
and another to give me
923

(bolded my emphasis) If you ever get anything like that, then the Internet has broken. :P

Athlantar

Thanks a ton you guys. Those work exactly like I wanted them to and provide me some very useful insight into the syntax of those seemingly simple but incredibly complex commands.

Thanks again! its great!