bash script use cut command at variable and store result at another variable

Question

I have a config.txt file with IP addresses as content like this

10.10.10.1:80 10.10.10.13:8080 10.10.10.11:443 10.10.10.12:80 

I want to ping every ip address in that file

#!/bin/bash file=config.txt  for line in `cat $file` do   ##this line is not correct, should strip :port and store to ip var   ip=$line|cut -d\: -f1   ping $ip done 

I'm a beginner, sorry for such a question but I couldn't find it out myself.

Answer 1

The awk solution is what I would use, but if you want to understand your problems with bash, here is a revised version of your script.

#!/bin/bash -vx  ##config file with ip addresses like 10.10.10.1:80 file=config.txt  while read line ; do   ##this line is not correct, should strip :port and store to ip var   ip=$( echo "$line" |cut -d\: -f1 )   ping $ip done < ${file} 

You could write your top line as

for line in $(cat $file) ; do ... 

(but not recommended).

You needed command substitution $( ... ) to get the value assigned to $ip

reading lines from a file is usually considered more efficient with the while read line ... done < ${file} pattern.

I hope this helps.

Answer 2

You can avoid the loop and cut etc by using:

awk -F ':' '{system("ping " $1);}' config.txt 

However it would be better if you post a snippet of your config.txt