I would like to do something if grep finds the word nameserver. I was reading this thread so I tried it with a few changes.

http://www.unix.com/shell-programmin...ing-there.html

I am not seeing any output or receiving any error messages. Can someone tell me what is wrong with this shellscript?

#!/bin/bash
grep -q 'nameserver' resolv.conf
if [[ $? -eq 0 ]] ;
then
    # do stuff to file
    echo "nameserver found"
else
    echo "nameserver not found"
fi

grep -q 'nameserver' resolv.conf && echo "Pattern Found" || echo "Pattern Not Found"

For me it works. If file resolv.conf does not exist in the current directory, the response is:

grep: resolv.conf: No such file or directory
nameserver not found

nameserver not found

nameserver found

if  ! grep -q 'nameserver' resolv.conf then 
  echo "nameserver found"
else
  echo "nameserver not found"
fi

How exactly does that work? I remember seeing this also while I was looking.

[ -f /etc/passwd ] && echo "File exists" || echo "File does not exists"

Originally Posted by hfreyer For me it works. If file resolv.conf does not exist in the current directory, the response is: Code: grep: resolv.conf: No such file or directory nameserver not found If resolv.conf exists in the current directory and does not contain string nameserver: Code: nameserver not found If resolv.conf exists in the current directory and contains string nameserver: Code: nameserver found Are you calling the script from command line ? Without any redirection ?

If the previous command is successful ( grep command ) then the below will execute

&& echo "Pattern Found"

|| echo "Pattern Not Found"

That use of ! is incorrect. The logical inversion of the exit status yields: if grep failed to find "nameserver" then echo "nameserver found".

Regards,
Alister