A simple function for Bash to require specific commands

require.sh

#! /bin/bash
set -e

# This is a simply function to require a specific command
# The script will print an error message "Command x not found!" and exit if the command does not exist

function require()
{
  which $1 > /dev/null 2>&1 || (echo "Command '$1' not found!"; exit 1)
}

# Example usage:
# require java
# require curl
# require scp