shell-scripting-templates/simpleScriptTemplate.sh

#!/usr/bin/env bash

# ##################################################
#
version="1.0.0"              # Sets version variable
#
# HISTORY:
#
# * DATE - v1.0.0  - First Creation
#
# ##################################################


function mainScript() {
 echo -n
}

function trapCleanup() {
  echo ""
  # Delete temp files, if any
  if [ -d "${tmpDir}" ] ; then
    rm -r "${tmpDir}"
  fi
  die "Exit trapped. In function: '${FUNCNAME[*]}'"
}

function safeExit() {
  # Delete temp files, if any
  if [ -d "${tmpDir}" ] ; then
    rm -r "${tmpDir}"
  fi
  trap - INT TERM EXIT
  exit
}

# Set Base Variables
# ----------------------
scriptName=$(basename "$0")

# Set Flags
quiet=false
printLog=false
verbose=false
force=false
strict=false
debug=false
args=()

# Set Colors
bold=$(tput bold)
reset=$(tput sgr0)
purple=$(tput setaf 171)
red=$(tput setaf 1)
green=$(tput setaf 76)
tan=$(tput setaf 3)
blue=$(tput setaf 38)
underline=$(tput sgr 0 1)

# Set Temp Directory
tmpDir="/tmp/${scriptName}.$RANDOM.$RANDOM.$RANDOM.$$"
(umask 077 && mkdir "${tmpDir}") || {
  die "Could not create temporary directory! Exiting."
}

# Logging
# -----------------------------------
# Log is only used when the '-l' flag is set.
logFile="${HOME}/Library/Logs/${scriptBasename}.log"


# Options and Usage
# -----------------------------------
usage() {
  echo -n "${scriptName} [OPTION]... [FILE]...

This is a script template.  Edit this description to print help to users.

 ${bold}Options:${reset}
  -u, --username    Username for script
  -p, --password    User password
  --force           Skip all user interaction.  Implied 'Yes' to all actions.
  -q, --quiet       Quiet (no output)
  -l, --log         Print log to file
  -s, --strict      Exit script with null variables.  i.e 'set -o nounset'
  -v, --verbose     Output more information. (Items echoed to 'verbose')
  -d, --debug       Runs script in BASH debug mode (set -x)
  -h, --help        Display this help and exit
      --version     Output version information and exit
"
}

# Iterate over options breaking -ab into -a -b when needed and --foo=bar into
# --foo bar
optstring=h
unset options
while (($#)); do
  case $1 in
    # If option is of type -ab
    -[!-]?*)
      # Loop over each character starting with the second
      for ((i=1; i < ${#1}; i++)); do
        c=${1:i:1}

        # Add current char to options
        options+=("-$c")

        # If option takes a required argument, and it's not the last char make
        # the rest of the string its argument
        if [[ $optstring = *"$c:"* && ${1:i+1} ]]; then
          options+=("${1:i+1}")
          break
        fi
      done
      ;;

    # If option is of type --foo=bar
    --?*=*) options+=("${1%%=*}" "${1#*=}") ;;
    # add --endopts for --
    --) options+=(--endopts) ;;
    # Otherwise, nothing special
    *) options+=("$1") ;;
  esac
  shift
done
set -- "${options[@]}"
unset options

# Print help if no arguments were passed.
# Uncomment to force arguments when invoking the script
# -------------------------------------
[[ $# -eq 0 ]] && set -- "--help"

# Read the options and set stuff
while [[ $1 = -?* ]]; do
  case $1 in
    -h|--help) usage >&2; safeExit ;;
    --version) echo "$(basename $0) ${version}"; safeExit ;;
    -u|--username) shift; username=${1} ;;
    -p|--password) shift; echo "Enter Pass: "; stty -echo; read PASS; stty echo;
      echo ;;
    -v|--verbose) verbose=true ;;
    -l|--log) printLog=true ;;
    -q|--quiet) quiet=true ;;
    -s|--strict) strict=true;;
    -d|--debug) debug=true;;
    --force) force=true ;;
    --endopts) shift; break ;;
    *) die "invalid option: '$1'." ;;
  esac
  shift
done

# Store the remaining part as arguments.
args+=("$@")


# Logging & Feedback
# -----------------------------------------------------
function _alert() {
  if [ "${1}" = "error" ]; then local color="${bold}${red}"; fi
  if [ "${1}" = "warning" ]; then local color="${red}"; fi
  if [ "${1}" = "success" ]; then local color="${green}"; fi
  if [ "${1}" = "debug" ]; then local color="${purple}"; fi
  if [ "${1}" = "header" ]; then local color="${bold}${tan}"; fi
  if [ "${1}" = "input" ]; then local color="${bold}"; fi
  if [ "${1}" = "info" ] || [ "${1}" = "notice" ]; then local color=""; fi
  # Don't use colors on pipes or non-recognized terminals
  if [[ "${TERM}" != "xterm"* ]] || [ -t 1 ]; then color=""; reset=""; fi

  # Print to console when script is not 'quiet'
  if ${quiet}; then return; else
   echo -e "$(date +"%r") ${color}$(printf "[%7s]" "${1}") ${_message}${reset}";
  fi

  # Print to Logfile
  if ${printLog} && [ "${1}" != "input" ]; then
    color=""; reset="" # Don't use colors in logs
    echo -e "$(date +"%m-%d-%Y %r") $(printf "[%7s]" "${1}") ${_message}" >> "${logFile}";
  fi
}

function die ()       { local _message="${*} Exiting."; echo -e "$(_alert error)"; safeExit;}
function error ()     { local _message="${*}"; echo -e "$(_alert error)"; }
function warning ()   { local _message="${*}"; echo -e "$(_alert warning)"; }
function notice ()    { local _message="${*}"; echo -e "$(_alert notice)"; }
function info ()      { local _message="${*}"; echo -e "$(_alert info)"; }
function debug ()     { local _message="${*}"; echo -e "$(_alert debug)"; }
function success ()   { local _message="${*}"; echo -e "$(_alert success)"; }
function input()      { local _message="${*}"; echo -n "$(_alert input)"; }
function header()     { local _message="== ${*} ==  "; echo -e "$(_alert header)"; }
function verbose()    { if ${verbose}; then debug "$@"; fi }

# SEEKING CONFIRMATION
# ------------------------------------------------------
function seek_confirmation() {
  # echo ""
  input "$@"
  if "${force}"; then
    notice "Forcing confirmation with '--force' flag set"
  else
    read -p " (y/n) " -n 1
    echo ""
  fi
}
function is_confirmed() {
  if "${force}"; then
    return 0
  else
    if [[ "${REPLY}" =~ ^[Yy]$ ]]; then
      return 0
    fi
    return 1
  fi
}
function is_not_confirmed() {
  if "${force}"; then
    return 1
  else
    if [[ "${REPLY}" =~ ^[Nn]$ ]]; then
      return 0
    fi
    return 1
  fi
}


# Trap bad exits with your cleanup function
trap trapCleanup EXIT INT TERM

# Set IFS to preferred implementation
IFS=$' \n\t'

# Exit on error. Append '||true' when you run the script if you expect an error.
set -o errexit

# Run in debug mode, if set
if ${debug}; then set -x ; fi

# Exit on empty variable
if ${strict}; then set -o nounset ; fi

# Bash will remember & return the highest exitcode in a chain of pipes.
# This way you can catch the error in case mysqldump fails in `mysqldump |gzip`, for example.
set -o pipefail

# Run your script
mainScript

# Exit cleanly
safeExit