In my last post, I discussed using sed, the stream editor to make configuration file changes via a bash script. There are two important factors to keep in mind:
- Many configuration files can only be modified as root, and
- The location of configuration files will vary depending on the Linux distribution.
Therefore it is important to test for both of these conditions at the beginning of your Bash script.
Test to ensure expected OS Distribution and Version
#Test to ensure expected OS Distribution and Version OSTEST=$(grep "Red Hat Enterprise Linux Server release 6." /etc/*release | wc -c) if [ $OSTEST == 0 ] then echo "Incorrect Operating System - Expected RHE6" exit 1 fi
The example above example is for Red Hat, so the string to grep will vary depending on the Linux distribution.
Test to Ensure Script is Run as Root
#Test to ensure script is run as root USERTEST=$(whoami) if [ $USERTEST != "root" ] then echo "Incorrect Permissions - Run this script as root" exit 1 fi
You may prefer a tight one-liner to test for root. In that case you can use something like:
# Check for root [ "$(id -u)" -ne 0 ] && echo "Incorrect Permissions - Run this script as root" && exit 1