Re: how-to get commit content with pre-receive hook ?

From: Igor Djordjevic <igor.d.djordjevic@gmail.com>
Date: Apr 6, 2017, 20:13 UTC
Message-ID: <0dec12a8-b3d2-41e5-4563-4bec2a6df7be@gmail.com>
In-Reply-To: <955c152a-b278-ecfd-8bc7-671c3aa81dc6@ricozome.net>

Hello Eric,

On 06/04/2017 16:03, Eric Belhomme wrote:

Show 15 quoted lines

> Until now I ever had a quite "basic" Git usage, but now I'm working 
> on a project based on Git hooks feature.. and I'm a very beginner 
> with Git hooks !
> 
> My need consist doing a syntax check on submitted files before a 'git 
> push'. So the right hook is 'pre-receive' and I'm already able to 
> identify the files I want to check using 'git show'.
> 
> But I don't know how to get the *content* of the file being submitted 
> to run my syntax check rules against it !
> 
> I googled but most examples using pre-receive I found are doing 
> sanity check on enveloppe but never on actual content of the file !
> 
> Could someone here put me on the rails ?

I`m yet another beginner with both Git hooks and Bash scripting, but I`ve managed to patch something up that might give you an idea, just drop it inside your "pre-receive" hook file:

	while read oldrev newrev
	do
		for commit in $(git rev-list --reverse $oldrev..$newrev)
		do
			for file in $(git diff-tree --no-commit-id --name-only -r $commit)
			do
				echo "$(git show $commit:$file)" >&1
			done
		done
	done
	exit 1

This should reject any push attempt, returning back *content* of each changed file for each new commit.

Feel free to adapt as needed, like processing/checking file content instead of sending it over, allowing or rejecting the push accordingly, and also handling corner cases (for example, "oldrev" value of 0000... in case of a new ref creation).

I guess there might be better ways (comments welcome), but this should at least get you going... and I`ve learned something new as well ;)

Regards, Buga