A Bash script model with common options (verbose, force etc) & minimal functions (error, usage etc) to use and re-use to build your own shell scripts easily.

shell-script-model.sh

#!/usr/bin/env bash
#
# Bash script model
#
# A Bash script model with common options (verbose, force etc) 
# & minimal functions (error, usage etc)
# to use and re-use to build your own shell scripts easily. 
#
# To begin, run one of the followings:
#
#       ./shell-script-model.sh -h
#       ./shell-script-model.sh --help
#       ./shell-script-model.sh -x
#
# For last updates, see <https://gist.github.com/ee576171255463dbcc599454414ba8a5.git>
#

# bash options
#set -e
set -u
set -o pipefail

# edit the `SCRIPT_...` variables below to adapt to your script
SCRIPT_VERSION="0.0.1-dev"
SCRIPT_NAME="$0"
SCRIPT_PRESENTATION="This script is a bash script model."
IFS='' read -r -d '' SCRIPT_USAGE <<EOF
  usage:  $0 [-h | --help | -v/--verbose | -f/--force] [options [=value]]  <arguments>
   i.e.:  $0 test
options:
              -h  see a short usage string and exit with status 0
          --help  see a long help string and exit with status 0
    -v|--verbose  enable verbosity
      -f|--force  enable force
EOF
# This model is designed to use the followings by default:
#
#   -   the `-h` option shows a simple "usage" string and exits with status 0 (no error)
#   -   the `--help` option shows a long "help" string and exits with status 0 (no error)
#   -   the `-v` or `--verbose` options enables the `VERBOSE` boolean variable
#   -   the `-f` or `--force` options enables the `FORCE` boolean variable
#   -   the `-x` option enables the `DEBUG` boolean variable (for development)
#
SCRIPT_OPTS_SHORT='fhvx'
SCRIPT_OPTS_LONG='force,help,verbose'
export SCRIPT_VERSION SCRIPT_NAME SCRIPT_PRESENTATION SCRIPT_USAGE SCRIPT_OPTS_SHORT SCRIPT_OPTS_LONG

# environment
VERBOSE=false
FORCE=false
DEBUG=false
declare -a DEBUG_DATA

# internal tracelog function
traceback () {
    local -i start=$(( ${1:-0} + 1 ))
    local -i end=${#BASH_SOURCE[@]}
    local -i i=0
    local -i j=0
    echo "  Traceback (last call is first):" 1>&2
    for ((i=${start}; i < ${end}; i++)); do
        j=$(( $i - 1 ))
        local function="${FUNCNAME[$i]}"
        local file="${BASH_SOURCE[$i]}"
        local line="${BASH_LINENO[$j]}"
        echo "  # ${function}() in ${file}:${line}" 1>&2
    done
}

# usage: die <error string> [traces nb=1]
die () {
    {   echo '---'
        echo "!! > $1"
        traceback "${2:-1}"
        echo '---'
    } 1>&2
    exit 2
}

# usage: get_absolute_path <path>
get_absolute_path() {
    [ $# -eq 0 ] && die 'usage: get_absolute_path <path>';
    local cwd="$(pwd)"
    local path="$1"
    while [ -n "$path" ]; do
        cd "${path%/*}" 2>/dev/null;
        local name="${path##*/}"
        path="$($(type -p greadlink readlink | head -1) "$name" || true)"
    done
    pwd
    cd "$cwd"
}

# usage: usage
usage () {
    echo "${SCRIPT_USAGE}"
}

# usage: help
help () {
    cat <<EOT
## ${SCRIPT_NAME} - ${SCRIPT_VERSION} ##

${SCRIPT_PRESENTATION}

${SCRIPT_USAGE}

EOT
}

# usage: error [str='']
error () {
    {   echo '---'
        echo "> $*"
        echo '---'
        usage
    } 1>&2
    exit 1
}

# usage: verbose_echo <string to print if verbosity is on>
verbose_echo () {
    $VERBOSE && echo "$*";
}

# library dir
BASEDIR="$(get_absolute_path "${BASH_SOURCE[0]}")"

# arguments
PARSED_OPTS=$(
  getopt --name "$0" --options "$SCRIPT_OPTS_SHORT" --longoptions "$SCRIPT_OPTS_LONG" -- "$@"
) || error "script parameters error!";
eval "set -- $PARSED_OPTS";
for opt in "$@"; do
    case "$opt" in
        -f|--force)
            FORCE=true
            shift
            ;;
        -h)
            usage
            exit 0
            ;;
        --help)
            help
            exit 0
            ;;
        -v|--verbose)
            VERBOSE=true
            shift
            ;;
        -x)
            DEBUG=true
            shift
            ;;
        --)
            shift
            continue
            ;;
    esac
done
export VERBOSE FORCE DEBUG DEBUG_DATA

#### command starts here... ####

# some tests
echo 'YO'
verbose_echo 'YO (verbose)'
DEBUG_DATA+=( test1 )
DEBUG_DATA+=( test2 )

# loop over user arguments
for i in "$@"; do
    echo "> $i"
done

#### command ends here... ####

# debug environment
$DEBUG && (
    {   echo "[dbg] ////"
        echo "[dbg] > CALL REBUILT : $*"
        echo "[dbg] > VERBOSE      : $VERBOSE"
        echo "[dbg] > FORCE        : $FORCE"
        echo "[dbg] > DEBUG        : $DEBUG"
        echo "[dbg] > DEBUG DATA   : ${DEBUG_DATA[@]}"
        echo "[dbg] ////"
    } 1>&2
);

# exit status
exit 0

# vim: autoindent tabstop=4 shiftwidth=4 expandtab softtabstop=4 filetype=sh