How do you display the active git tag with php without exec / shell_exec

Question

Assuming a tag is currently checked out, and the .git folder sits in the root of the site's codebase, I'd like to include the tag in the rendered html of a page using php.

I've seen solutions which make use of shell_exec / shell, but assuming I'm unable to use those two functions, how can I get the label of the currently checked out tag. For example v1.2.3 using php alone?

Answer 1

You can get the current HEAD commit hash from .git/HEAD . You can then loop all tag refs to find a matching commit hash. We reverse the array first as you're more likely to be on a recent tag than an old one.

Obviously replacing the exit s with variabled and spitting it to the page will give you a better result.

So if your php file sits in a public_html or www folder one level down from the .git folder...

<?php

$HEAD_hash = file_get_contents('../.git/refs/heads/master'); // or branch x

$files = glob('../.git/refs/tags/*');
foreach(array_reverse($files) as $file) {
    $contents = file_get_contents($file);

    if($HEAD_hash === $contents)
    {
        exit('Current tag is ' . basename($file));
    }
}

exit('No matching tag');