Bash script template with argument parsing

script.sh

#!/usr/bin/env bash

# ----------------------------------------------------------------------------
# script.sh: Bash script template with argument parsing
# 
# Author: Raphael Tang <[email protected]>
# ----------------------------------------------------------------------------
# Dependencies:
#  - dependency1
#  - dependency2

CLEAR='\033[0m'
RED='\033[0;31m'

function usage() {
  if [ -n "$1" ]; then
    echo -e "${RED}👉 $1${CLEAR}\n";
  fi
  
  cat << EOF
  Usage: $(basename $0) [REQUIRED -u url] [-n]
    -h, --help     Show this message
    -u, --url      (Required) URL
    -n, --nocaca   Won't display colored output, uses aalib instead
  
  Examples: $(basename $0) --nocaca -u "https://www.youtube.com/watch?v=5qap5aO4i9A"
EOF
}

# parse params
while [[ "$#" > 0 ]]; do case $1 in
      -h|--help)   usage; exit 0 ;;
      -u|--url)    URL="$2"; shift; shift ;;
      -n|--nocaca) NOCACA=1; shift ;;
      *)           usage "Unknown parameter passed: $1"; exit 1 ;;
esac; done

if [ -z "$URL" ]; then
  usage "No URL specified"
  exit 1
fi

if [ -n "$NOCACA" ]; then
  youtube-dl "$URL" -f worst -o - | mplayer -vo aa -monitorpixelaspect 0.5 -
else
  streamlink "$URL" worst --player mpv -a "--vo=caca"
fi