Minify javascript and css using Google closure compiler and closure stylesheets.

minify.sh

#!/bin/sh

#set defaults
ini=build.ini
csspath=../static/css/
jspath=../static/js/
jsout=../static/js/compiled.js
cssout=../static/css/compiled.css
js=
css=

#Get arguments and set vars appropriately
while [ "$1" != "" ]
do
  if [ "$1" = "--help" ]
  then
     echo --Usage--
     echo build -j "path/to/java" -i "path/to/ini" --jspath "path/to/js/files" --csspath "path/to/css/files" --jsout "path/to/js/output.js" --cssout "path/to/css/output.css"
     echo --Params--
     echo Note: All parameters are optional
     echo -j        Specify path to java, where 'bin' directory resides
     echo -i        Specfiy path and filename of ini file default build.ini
     echo --jspath    Specify path to the js files whose names are defined in the ini file
     echo --csspath    As above, for css files
     echo --jsout    Specify output path and filename for the compiled js file
     echo --cssout    As above, for css
     exit 0
  elif [ "$1" = "-i" ]
  then
     ini=$2
  elif [ "$1" = "-j" ]
  then
     java_home=$2
  elif [ "$1" = "--jspath" ]
  then
     jspath=$2
  elif [ "$1" = "--csspath" ]
  then
     csspath=$2
  elif [ "$1" = "--jsout" ]
  then
     jsout=$2
  elif [ "$1" = "--cssout" ]
  then
     cssout=$2
  fi
  shift
  shift
done

#Read in paths from specified ini file
OIFS=$IFS
IFS="="
while read LINE
do
  set $LINE
  if [ "$1" = "js" ]
  then
     js="$js --js=$jspath$2"
  elif [ "$1" = "css" ]
  then
     css="$css $csspath$2"
  fi
done < $ini
IFS=$OIFS

#Remove leading spaces
js=`echo $js|sed 's/^ *//g'`
css=`echo $css|sed 's/^ *//g'`

#Perform compilation
java -jar compiler.jar --compilation_level SIMPLE_OPTIMIZATIONS $js --js_output_file=$jsout
java -jar compiler_css.jar --allow-unrecognized-functions $css -o $cssout

I know that years have gone, but what is compiler_css.jar and where did you get it from?

That was the Google Closure Stylesheet tool. See this post for more details: https://artandlogic.com/2013/05/minification-smaller-quicker-is-better/