apply PHP-CS-Fixer on all changed files in the staging area

.gitconfig

 [alias]
    fix-staged = "!git diff-index --cached --name-status HEAD | grep -ve '^D' | cut -f2 | xargs -n1 php-cs-fixer fix"

Sure, but that would reformat the entire file. Legacy projects often come with large controller classes, if you know what I mean ;-)

The first one would be useful for a pre-commit hook, right? The second as an after commit script.

Good suggestion though! Certainly useful! A pre-commit hook is also an option.

I'm using them in conjunction with those two:

[alias]
    ls-staged = diff-index --cached --name-only HEAD

    co-staged = !git ls-staged | xargs git co
    up-staged = "!f() { git ls-staged; }; git add -p `f`"

I apply the fixer on the staged, use the update patch workflow to only stage the fixes on my work. Afterwards I can use cs-head to apply all other fixes to the files I just change.