OSX/Bash argument parsing

bash_args_template.sh

#!/bin/bash -e

# cobbled together from various of stackoverflow posts

# saner programming env: these switches turn some bugs into errors
set -o errexit -o pipefail -o noclobber -o nounset

# -allow a command to fail with !’s side effect on errexit
# -use return value from ${PIPESTATUS[0]}, because ! hosed $?
! getopt --test > /dev/null
if [[ ${PIPESTATUS[0]} -ne 4 ]]; then
    echo '`getopt --test` failed in this environment.'
    echo 'On OSX, try the following commands'
    echo ' brew install gnu-getopt'
    echo ' sudo echo '"'"'export PATH="/usr/local/opt/gnu-getopt/bin:$PATH"'"'"'>> ~/.bash_profile'
    echo ' sudo echo '"'"'export FLAGS_GETOPT_CMD="$(brew --prefix gnu-getopt)/bin/getopt"'"'"' >> ~/.bash_profile'
    echo ' then run ". ~/.bash_profile"'
    exit 1
fi

USAGE="$(basename "$0") [-h] [-e name]

where:
    -h  show this help text
    -e/--environment  set environment to attempt to deploy"

OPTIONS=dhe:o:v
LONGOPTS=debug,environment,output:,verbose

# -regarding ! and PIPESTATUS see above
# -temporarily store output to be able to check for errors
# -activate quoting/enhanced mode (e.g. by writing out “--options”)
# -pass arguments only via   -- "$@"   to separate them correctly
! PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@")
if [[ ${PIPESTATUS[0]} -ne 0 ]]; then
    # e.g. return value is 1
    #  then getopt has complained about wrong arguments to stdout
    exit 2
fi
# read getopt’s output this way to handle the quoting right:
eval set -- "$PARSED"

d=n v=n environment=

while true; do
    case "$1" in
        -h|--help)
            echo "$USAGE"
            exit
            ;;
        -d|--debug)
            d=y
            shift
            ;;
        -v|--verbose)
            v=y
            shift
            ;;
        -e|--environment)
            environment="$2"
            shift 2
            ;;
        *)
            break
            ;;
        --)
            shift
            break
            ;;
    esac
done

# TODO: print out help message? etc..
if [[ -z $environment ]]; then
    echo "$0: Please input an environment name."
    echo ""
    echo "Usage:"
    echo "$USAGE"
    exit 4
fi