Simple script starter

script.sh

#!/bin/bash
if [ "$#" -eq "0" ]
  then
    echo "Fetches a branch for a given repo, and then adds a link to it on the index"
    echo "of the given repo."
    echo ""
    echo "Usage:"
    echo ""
    echo "./fetch-branch.sh -d=/path/to/repo --r=ssh://me@git.example.com/project --b=master"
else
  while getopts ":d:r:b:" opt; do
    case $opt in
      d) dir="$OPTARG"
      ;;
      r) repo="$OPTARG"
      ;;
      b) branch="$OPTARG"
      ;;
      \?) echo "Invalid option -$OPTARG" >&2
      ;;
    esac
  done

  if [ -z "$dir" ]; then echo "The argument -d is not set. Execute with no arguments for usage."; exit 1; fi
  if [ -z "$repo" ]; then echo "The argument -r is not set. Execute with no arguments for usage."; exit 1; fi
  if [ -z "$branch" ]; then echo "The argument -b is not set. Execute with no arguments for usage."; exit 1; fi

  printf "Argument d is %s\n" "$d"
  printf "Argument r is %s\n" "$r"
  printf "Argument b is %s\n" "$b"
fi