require_login.php

<?php
/**
 *	Requires certain username and password to continue.
 *	
 *	How to use?
 *	Simply add require_login("username", "password", "realm") in your PHP code and it will
 *	require the user to login with given username and password.
 *	
 *	@param string The required username
 *	@param string The required password
 *	@param string The "Basic realm", which is shown to user while asking for username/password
 *	@return boolean Returns TRUE if username and password matches. Otherwise it will exit.
 */
function require_login($username, $password, $realm = ""){
	
	// Set up default variables
	$authed = FALSE;
	
	// Checks if we are authenticating
	if( isset($_SERVER['PHP_AUTH_USER']) ){
		if( $_SERVER['PHP_AUTH_USER'] == $username && $_SERVER['PHP_AUTH_PW'] == $password ){
			$authed = TRUE;
		}
	}
	
	// Are we authenticated
	if( ! $authed ){
	    header('WWW-Authenticate: Basic realm="'.$realm.'"');
	    header('HTTP/1.0 401 Unauthorized');
		exit;
	}
	
	return TRUE;	
}