Template for robust shell scripting

template.sh

#!/bin/bash

set -o nounset
set -o errtrace
set -o errexit
set -o pipefail

progname=$(basename $0)
default_name="Marley"

usage() {
  extra=${1:-''}
  cat <<END
Usage: $progname OPTIONS

  -h    Display this help text
  -n    Name (default is ${default_name})

$extra
END
  exit 1
}

while getopts "hn:" OPTION ; do
  case $OPTION in
    h)
      usage
      ;;
    n)
      name=$OPTARG
      ;;
    *)
      usage
      ;;
  esac
done

name=${name:-$default_name}

tempdir=$(mktemp -d /tmp/$progname.XXXXXX)
function cleanup() {
  rm -rf $tempdir
}
trap cleanup INT EXIT

echo "Hi ${name}" > $tempdir/output.txt
cat $tempdir/output.txt