Bash Script Template

script.bash

#!/usr/bin/env bash
# Author: Brennan Fee
# License: MIT License
# Version: 0.1
# Date: 2023-06-23

# Bash strict mode
([[ -n ${ZSH_EVAL_CONTEXT:-} && ${ZSH_EVAL_CONTEXT:-} =~ :file$ ]] \
  || [[ -n ${BASH_VERSION:-} ]] && (return 0 2> /dev/null)) && SOURCED=true || SOURCED=false
if ! ${SOURCED}; then
  set -o errexit  # same as set -e
  set -o nounset  # same as set -u
  set -o errtrace # same as set -E
  set -o pipefail
  set -o posix
  #set -o xtrace # same as set -x, turn on for debugging

  shopt -s inherit_errexit
  shopt -s extdebug
  IFS=$(printf '\n\t')
fi
# END Bash scrict mode

SCRIPT_APP=$(basename "$0")
SCRIPT_AUTHOR="Brennan Fee"
SCRIPT_LICENSE="MIT License"
SCRIPT_VERSION="0.2"
SCRIPT_DATE="2023-06-23"

SCRIPT_DIR="$(cd -P "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

source "$(xdg-user-dir DOTFILES)/bash/script-tools.bash"
EXIT_CODE="0"

## Defaults
# TODO: replace with default paramters
HELP="false"

#### START: Process arguments
# TODO: Added input options

ARGS=$(getopt --name "${SCRIPT_APP}" --options hv --longoptions "help,version" -- "$@")

# TODO: Remove this if passing in no arguments or flags is an error condition and should not show help
# shellcheck disable=SC2181
if [[ $? -ne 0 ]]; then
  show_help
fi

eval set -- "${ARGS}"
unset ARGS

## Process "options" and "flags"
while true; do
  case "$1" in
  '-h' | '--help')
    HELP="true"
    show_help
    ;;
  '-v' | '--version')
    show_version
    ;;
  # Reading a "flag" example 
  #'-f' | '--flag')
  #  FLAG="true"
  #  shift
  #  continue
  #  ;;
  # Reading an "option" example, "--option value", $2 contains the passed in value
  #'-o' | '--option')
  #  OPTION=$2
  #  shift 2
  #  continue
  #  ;;
  '--')
    shift
    break
    ;;
  *)
    error_msg "Unknown option: $1"
    ;;
  esac
done

## Now process positional arguments

ARG_COUNT=1
for arg; do
  case "${ARG_COUNT}" in
  1)
    # Example, normalize to lower case
    ARG_1=$(echo "${arg}" | tr "[:upper:]" "[:lower:]")
    ;;
  2)
    break
    ;;
  *)
    error_msg "Internal Argument Error"
    ;;
  esac
  ARG_COUNT=$((ARG_COUNT + 1))
done
unset ARG_COUNT

#### END: Process arguments

#### START: Help

function show_version() {
  print_status "${SCRIPT_APP}"
  print_status "Author: ${SCRIPT_AUTHOR}    License: ${SCRIPT_LICENSE}"
  print_stauts "Version: ${SCRIPT_VERSION}    Date: ${SCRIPT_DATE}"
  print_blank_line
  
  exit 0
}

function show_help() {
  if [[ "${HELP}" == "false" ]]; then
    print_warning "Incorrect parameters or options provided."
    print_blank_line
  fi
  
  print_status "${SCRIPT_APP}"
  print_status "Author: ${SCRIPT_AUTHOR}    License: ${SCRIPT_LICENSE}"
  print_stauts "Version: ${SCRIPT_VERSION}    Date: ${SCRIPT_DATE}"
  print_blank_line
  
  # TODO: Write help
  
  if [[ "${HELP}" == "false" ]]; then
    exit 1
  else
    exit 0
  fi
}

#### END: Help

function main() {
}

main "$@"