A shell script to fetch metadata for Y*uTube videos

ytjson

#!/bin/sh
#
# Given a Y*uTube video ID, this grabs JSON metadata from publically available
# HTML. No API!
#
# Requires:
# * curl
# * node
# * pup https://github.com/ericchiang/pup
#
# It sends JSON to standard out, so with jq you can do things like:
#
# % ./ytjson XaDfGFW6MZo | jq '.args | .title, .length_seconds, .view_count'
# Gastr del Sol - Ursus Arctos Wonderfilis (1995/09/23)
# 31476
# 580

usage() {
  >&2 echo "usage: $0 videoid"
  exit 111
}

videoid=$1

if [ -z "$videoid" ]; then
  usage
fi

tmp_script=$(mktemp)

cat <<EOJS > $tmp_script
window = {};

yt = {
  setConfig: function() {},
  setMsg: function() {},
  pushConfigArray: function() {}
};

EOJS

curl --silent "https://www.youtube.com/watch?v=$videoid" |
  pup 'script:contains("length_seconds") text{}' >> $tmp_script

echo 'console.log(JSON.stringify(ytplayer.config));' >> $tmp_script

node $tmp_script