Parse command-line arguments in bash easily

argument_parser.bash

# ./my_script.sh --arg1 value1 --arg2 value2 --arg3 value3
# ./my_script.sh -a value1 -b value2 -c value3

#!/usr/bin/env bash
while [[ "$#" -gt 0 ]]; do case $1 in
  -a|--arg1) var1="$2"; shift;;
  -b|--arg2) var2="$2"; shift;;
  -c|--arg3) var3="$2"; shift;;
  *) echo "Unknown parameter passed: $1"; exit 1;;
esac; shift; done

echo "this is value1: $var1"
echo "this is value1: $var2"
echo "this is value1: $var3"

# references: 
# https://stackoverflow.com/questions/192249/how-do-i-parse-command-line-arguments-in-bash/14203146
# https://gist.github.com/hfossli/4368aa5a577742c3c9f9266ed214aa58