wget http://get.sensiolabs.org/php-cs-fixer.phar -O php-cs-fixer sudo chmod a+x php-cs-fixer sudo mv php-cs-fixer /usr/local/bin/php-cs-fixer
Second have a project-specific php-cs config file. As an example take a look here.
In PHPStorm click "File" -> "Settings" -> "Tools" -> "File Watchers"
Fill out the provided view:
Name: PHP CS Fixer
Description: fixes php code style
Show console: Error
File type: PHP
Scope: Project Files
Program: /usr/local/bin/php-cs-fixer
Arguments: --config-file=$ProjectFileDir$/.php_cs fix $FileDir$/$FileName$ -v --diff --dry-run
Working directory: $ProjectFileDir$
It should look like this:
Hint: You can also ommit the --dry-run option, to let PHP-CS-Fixer automatically fix your code.