Format unix permissions

gistfile1.php

<?php

/**
 * Toggle the formatting of unix permissions between:
 *  - 0644 OR 755
 *  - -rw-r--r--
 *
 * @param string|int $permissions : The permissions string or int that needs to be formatted.
 * @param string $is_dir : if true, the first char of the long permissions format will be 'd'. ie: drw-r--r--
 * @return string: The formatted permissions.
 * @author Aziz Light
 */
function formatPermissions($permissions, $is_dir = false)
{
	$permissions_lookup = array(
		'---', // 0
		'--x', // 1
		'-w-', // 2
		'-wx', // 3
		'r--', // 4
		'r-x', // 5
		'rw-', // 6
		'rwx', // 7
	);
	
	$len = strlen($permissions);
	$new_permissions = '';
	
	if ($len < 5 && $len > 2)
	{ // format: 0644 OR 755
		if ($len == 4)
			$permissions = substr($permissions, 1);
		
		$permissions = str_split($permissions);
		$new_permissions .= ($is_dir) ? 'd':'-';
		
		foreach ($permissions as $permission)
		{
			$new_permissions .= $permissions_lookup[(int) $permission];
		}
	}
	elseif ($len == 10)
	{ // format: -rw-r--r--
		$r    = 4;
		$w    = 2;
		$x    = 1;
		$zero = 0;
		
		$permissions = substr($permissions, 1);
		$permissions = str_split($permissions);
		
		$group = 0;
		for ($i = 0, $j = 0, $max = count($permissions); $i < $max; $i++, $j++)
		{
			if ($permissions[$i] == '-')
				$permissions[$i] = 'zero';
			
			if ($j > 2)
			{
				$new_permissions .= $group;
				
				unset($j, $group);
				$j = 0;
				$group = 0;
			}
			
			$group += ${$permissions[$i]};
		}
		
		// add the last permission digit
		$new_permissions .= $group;
	}
	else
	{
		return $permissions;
	}
	
	return $new_permissions;
} // End of formatPermissions