The plugin says I’m missing something
The EWWW Image Optimizer uses jpegtran, optipng, gifsicle, pngout, pngquant, and cwebp. Odds are, most of these won’t be installed on your server, so EWWW I.O. comes bundled with binaries (executables) that work on most platforms. But sometimes they don’t because the Linux landscape is quite diverse, and some webhosts will even build their own custom distributions of Linux. The source code for Pngout is not available, so that requires a different installation process. For everything else, keep reading.
So what do you do?
Can I build it?
ldconfig -p | grep libjpeg gcc -v make -v
Yes I Can!
1. Download the source package from the project’s website:
webp: http://downloads.webmproject.org/releases/webp/index.html (latest source tarball is usually at the bottom)
wget <a href="http://www.lcdf.org/gifsicle/gifsicle-1.88.tar.gz">http://www.lcdf.org/gifsicle/gifsicle-1.88.tar.gz</a>
2. Unpack/extract the tarball:
tar xvzf gifsicle-1.88.tar.gz tar xvzf optipng-0.7.6.tar.gz tar xvjf pngquant-2.5.2-src.tar.bz
v = verbose (you can skip this, but I like to see what the command did)
z = gzip compression, usually when the extension is .tar.gz or .tgz
j = bzip2 compression, when the extension is .bz or .bzip2
f = file, or in other words “use the file listed after this option”
3. Configure the build
cd optipng-0.7.6/ ./configure
4. Build it
5. Install the binary
sudo make install
cp src/optipng/optipng /path-to-your-wordpress-folder/wp-content/ewww/optipng-custom