git pre-commit hook to block commits on matches of regular expressions

pre-commit

#!/usr/bin/env php

<?php

	$unallowed = array(
	
	);

	exec('git diff --cached --', $output);
	
	$file;
	foreach($output as $line)
	{
		// match this type of thing: +++ b/filename
		if (preg_match('/^\+\+\+ b\/(.+)$/', $line, $match))
		{
			$file = $match[1];
			continue;
		}
		
		// match diff --git a/filename b/filename so we know we're done with prev file
		if (preg_match('/^diff --git/', $line))
		{
			$file = null;
			continue;
		}
		
		// match added lines
		if ($file && !empty($line) && $line[0] == '+')
		{
			// search line for all unallowed content, exit if found
			foreach($unallowed as $search)
			{
				if (preg_match($search, $line))
				{
					echo "Aborting commit! Found '$search' in '$file'\n";
					exit(1);
				}
			}
		}
	}