Template for writing new scripts

script_template.sh

#!/bin/bash
#scriptName.sh

# Bash scripting reference manual
# - http://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html

# Bash script set options
# - https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
set -o errexit
set -o errtrace
set -o pipefail

# Parameter expansion reference for "${1#*=}" etc
# - http://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html#Shell-Parameter-Expansion

############################################################
# Help                                                     #
############################################################
Help()
{
   # Display Help
   echo "Add description of the script functions here."
   echo
   echo "Syntax: scriptTemplate [-h | --help] [-e value | --echo value] [-v]"
   echo "options:"
   echo "  h     Print this help and exit."
   echo "  e     Echo value."
   echo "  v     Verbose mode set for echo parameter."
   echo
   echo "Note: parameters must be separated, such as -h -e -v, but order does not matter."
}

############################################################
# Main Program                                             #
############################################################

# display Help when nothing provided
if [ $# -eq 0 ]; then
	Help; exit 0;
fi

# iterate over parameters
while [ $# -gt 0 ]; do
  case "$1" in
    # help flag
		-h | --help)
			Help 
			exit 
		 ;;
    # argument flag - requires value
		-e | --echo) 
			if [[ "$1" != *=* ]]; then shift; fi # value is next arg if no '=' in parameter
			E="${1#*=}" 
			if [[ -z $E ]]; then echo "Value not provided for -e"; exit 1; fi
			;;
		# option flag
		-v | --version) 
			V=true 
			;;
		# catch the rest
    *)
			echo "Error: Invalid argument \"$1\""
			echo ""
			Help
      exit 1
      ;;
  esac
	shift
done

if [[ ! -z $E ]]; then
	if [[ "$V" = true ]]; then
		echo "verbose mode!"
	fi

	echo "$E"
fi