You can simply install it through PEAR: `pear install PHP_CodeSniffer`
Once it is installed and available in your PATH, here's the command to run before committing your work:
- $> phpcs --standard=PSR2 <file or directory>
+ $> phpcs --standard=ruleset.xml <file or directory>
The output is a list of all the coding standards violations that you should fix before committing your work.
Additionally, `phpcs` integrates with a few IDEs (Eclipse, Netbeans, PHPStorm...) so that you don't have to fiddle with the command line.
Thankfully, PHP Code Sniffer is shipped with an automatic code fixer that can take care of the tedious task for you.
Here's the command to automatically fix the files you created/modified:
- $> phpcbf --standard=PSR2 <file or directory>
+ $> phpcbf --standard=ruleset.xml <file or directory>
If the command-line tools `diff` and `patch` are unavailabe for you, `phpcbf` can use slightly slower PHP equivalents by using the `--no-patch` argument.