returns the current git branch, remote name, hash and timestamp for a git repository dir or git submodule dir

git_status.php

<?php

function git_status($dir) {
    $git_line = 'Unable to determine git hash';
    $git_dir = $dir . '/.git';

    $repo = null;
    $submodule = null;
    if (is_file($git_dir) && preg_match('@gitdir: (.*)@', trim(file_get_contents($git_dir)), $m)) {
        $repo = basename($m[1]);
        $git_dir = $m[1];
        $submodule = true;
    } else {
        // detect repo for root git...
        $config = parse_ini_file($git_dir . '/config', true);
        if (isset($config['remote origin'], $config['remote origin']['url'])) {
            $repo = pathinfo(parse_url($config['remote origin']['url'], PHP_URL_PATH), PATHINFO_FILENAME);
        }
    }
    $head_file = $git_dir . '/HEAD';
    if (!is_file($head_file)) {
        return $git_line;
    }

    if (!preg_match('@ref:\s*(.*)@', file_get_contents($head_file), $m)) {
        return $git_line;
    }
    $head_file = $git_dir . '/' . $m[1];

    $hash = trim(file_get_contents($head_file));

    $mtime = filemtime($head_file);
    $branch = basename($head_file);

    return sprintf('<strong>%s</strong>@<em>%s</em>:<code>%s</code> <datetime>%s</datetime>',
        $repo, $branch, $hash, date(DATE_COOKIE, $mtime));
}