Bash to generate critical CSS

bash-critical-css.sh

# check whether critical has been generated
if ! [ -x "$(command -v critical)" ]; then
  echo 'Error: critical CSS is not installed.' >&2
  exit 1
fi

# ask for website
echo "Website URL (without http / https):"
read -r url

# read the page
curl -L $url > temp.html

# screensize
echo Screen size:
read -r screen_size

# echo $url
# extract domain
domain=`expr "$url" : '\([\.a-z0-9\-]*\)'`

# echo $domain
# replace the CSS
perl -pi.bak -e "s/href\=\"\//href\=\"http\:\/\/${domain}\//g" temp.html

# generate critical CSS
critical temp.html > output.css --height $screen_size

pbcopy < output.css

rm temp.html temp.html.bak output.css