Bash colors

#!/bin/bash
RED="\e[0;31m"
GREEN="\e[0;32m"
YELLOW="\e[0;33m"
BLUE="\e[0;34m"
BACK="\e[0m"


fail() {
    echo -e "${RED}FAIL${BACK}: $*"
}
#-------------------------------------------------------------------------------
highlight() {
    echo -e "${YELLOW}$*${BACK}"
}
#-------------------------------------------------------------------------------
dothis() {
    echo -e "${BLUE}$*${BACK}"
}
#-------------------------------------------------------------------------------
debug() {
    [[ -z "$DEBUG" ]] || echo D: $* >&2
}
  
#===============================================================================
# Check that we're running on Linux
if [[ $(uname -s) != Linux || -n "$SIMULATE_FAILURE" ]] ; then
    fail "You need to run this on Linux machine you intend to use for the class, not on $(uname -s)"
    exit 1
fi

#===============================================================================
# The minimum version of bash required to run this script is bash v4
if bash --version | egrep -q 'GNU bash, version [1-3]' ; then
    fail "This script requires at least version 4 of bash"
    fail "You are running: $(bash --version | head -1)"
    exit 1
fi

#===============================================================================
check_root() {
    if [[ $USER == root ]] ; then
        warn "This script is intended to be run as a regular user (not as root)"
        exit 1
    fi
}
#===============================================================================