#!/bin/bash if [ $# != 1 ] then echo "Usage: $0 username" exit 1 fi if grep "$1" /etc/passwd then echo "Found $1 in /etc/passwd" fi
$ ./examples/script/testing_command.sh Gate _taskgated:*:13:13:Task Gate Daemon:/var/empty:/usr/bin/false found Gate in /etc/passwd
We can check the exit value of a command directly as the command is executed. The problem is that in many cases we are not interested in the output of the command, just if it was successful or not. Redirection to /dev/null can solve the problem by hiding the extra output.