Magento Image Optimisation Script

img_optimiser.bash

#!/usr/bin/env bash
readonly DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )";
cd $DIR;
set -e
set -u
set -o pipefail
standardIFS="$IFS"
IFS=$'\n\t'

# To use this script you'll need to install:
#  - jpegoptim
#  - optipng
#
# As well as set the mediaDir and skinDir below.

function echoTopLevelMsg()
{
    echo "[ $(date +%Y.%m.%dT%H:%M:%S) ] ===== $1 =====";
}

echoTopLevelMsg "Running optimisation script";

function usage()
{
    echo "
    $0 <period>

        - period: number of minutes since the script last ran (defaults to all images)
";
}

function checkDependency()
{
    local dependency=$1;

    command -v ${dependency} >/dev/null 2>&1 || {
        echo >&2 "Please install '${dependency}' and then rerun this script.";
        exit 1;
    }
}

function processImages()
{
    local baseDir="$1";
    local match="$2";
    local tool="$3";
    shift 3;

    echo "Processing images using: baseDir=${baseDir} period=-${period} match=${match} tool=${tool} toolArgs=$@";

    # Used \; in place of + because jpegoptim isn't able to handle large numbers of files in one go.
    local periodFilter=""
    if [[ "${period}" != "0" ]]
    then
        find ${baseDir} -type f -mmin -${period} -iregex ${match} -exec ${tool} "$@" {} \;
    else
        find ${baseDir} -type f -iregex ${match} -exec ${tool} "$@" {} \;
    fi

    echo "Processing complete";
}

function optimiseJpeg()
{
    local match='.*\.jpg\|.*\.jpeg';
    local tool='jpegoptim';

    checkDependency ${tool};

    processImages ${mediaDir} ${match} ${tool} --strip-all -o;
    processImages ${skinDir} ${match} ${tool} --strip-all -o;
}

function optimisePng()
{
    local match='.*\.png';
    local tool='optipng';

    checkDependency ${tool};

    processImages ${mediaDir} ${match} ${tool} -o2 -strip all;
    processImages ${skinDir} ${match} ${tool} -o2 -strip all;
}

#defaults to processing all
readonly period=${1:-0};

readonly mediaDir="${DIR}/path/to/media";
readonly skinDir="${DIR}/path/to/skin";


if [ ! -d "${mediaDir}" ]; then
    echo "${mediaDir} does not exist";
    exit 1;
fi

if [ ! -d "${skinDir}" ]; then
    echo "${skinDir} does not exist";
    exit 1;
fi

echoTopLevelMsg "Optimising JPG's";
optimiseJpeg;

echoTopLevelMsg "Optimising PNG's";
optimisePng;