smushit.sh

#!/bin/bash
#
# Home-rolled Smush.it, by Alex Dunae (http://dialect.ca). Modified by Abidkecil
#
# N.B. This script works for me; it may not work for you.
# Since it overwrites your images with the optimized version, you should
# backup your files before running this script and do a trial run before
# getting too excited.  This is your disclaimer.
#
# Uses jpegtran (http://jpegclub.org/jpegtran/), part of libjpeg, 
# and zopflipng (https://github.com/google/zopfli).

# Ubuntu install: sudo apt install libjpeg-turbo-progs zopfli -y

# Set to WordPress upload directory or any folder with images.
base_path=~/Downloads/images/

# Find files with a JPG extension recursively and process with jpegtran by
# - stripping comments
# - optimize image table
# - making the JPEG progressive
if type -P jpegtran &>/dev/null; then
	echo 'Running jpegtran';
	find $base_path -iname "*.jpg" -type f -exec jpegtran -outfile '{}' -copy none -optimize -progressive '{}' \;
else
	echo 'jpegtran not found';
fi

# Find files with a PNG extension recursively and process with ZopfliPNG
if type -P zopflipng &>/dev/null; then
	echo 'Running ZopfliPNG';
	find $base_path -iname "*.png" -type f -exec zopflipng -y --lossy_transparent '{}' '{}' \;
else
	echo 'zopflipng not found';
fi