Bash_Scripts/Templates/Functions/Arg-Parsing.bash

#!/bin/bash --posix



usage() {
  # Print out usage instructions for the local script
  #
  # Arguments:
  #   None
  #
  # Usage:
  #   usage
  #
  # POSIX Compliant:
  #   Yes
  #
  printf "Usage: %s\n" \
  "$(basename ${0}) -i \"this is some input\" -t \"this is some more example input\"
  --input <string> | -i <string>
    Example:
      --input \"this is an example input\"
  --test <string> | -t <string>
    Example:
      --test \"this is more example input\""
}

parse_args() {
  # Parse input arguments
  #
  # Arguments:
  #   Consult the `usage` function
  #
  # Usage:
  #   parse_args "$@"
  #     - All arguments should be ingested by parse_args first for variable setting
  #
  # POSIX Compliant:
  #   Yes
  #

  while :; do
    case ${1} in
      -h | -\? | --help)
        usage # Display a usage synopsis.
        exit
        ;;
      --) # End of all options.
        break
        ;;
      -i | --input)
        echo "${1}"
        ;;
      -t | --test)
        echo "${1}"
        ;;
      -?*)
        printf 'Unknown option: %s\n' "$1" >&2
        usage
        exit 1
        ;;
      *) # Default case: No more options, so break out of the loop.
        break ;;
    esac
    shift
  done
}

parse_args "$@"