BASH - check as root and command

v_simple.sh

#!/bin/bash
# 
# name: TODO_NAME
#
# description:TODO_DESC
# default log file: /var/log/TODO_LOG
#
# Copyright 2016 TODO, Inc.
# TODO_NAME <TODO_MAIL>
# 

# VARS  
# Using MY_ in order to avoid any collision.
MY_LOGFILE="/var/log/TODO_LOG"
MY_REQUIRED_COMMANDS='rpm tee sed' # All these commands are available in minimal installation

# Function without funciton keyword - not only for BASH

check_running_as_root(){
    if [ "$EUID" -ne 0 ]; then
        echo "This script require root privilages. Please run as root or via sudo."
        exit 1 
    fi 
    # This is first command so we setup information to log
    echo "Started $0 at $(date)"  | tee $MY_LOGFILE
}
check_required_commands(){
    for my_command in $MY_REQUIRED_COMMANDS; do
        hash $my_command 2>/dev/null || { echo "Script require $my_command command! Aborting."; exit 1; }
    done
}
check_running_as_root
check_required_commands