system/helpers/string_helper.php

<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 4.3.2 or newer
 *
 * @package		CodeIgniter
 * @author		Rick Ellis
 * @copyright	Copyright (c) 2006, EllisLab, Inc.
 * @license		http://www.codeignitor.com/user_guide/license.html
 * @link		http://www.codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * CodeIgniter String Helpers
 *
 * @package		CodeIgniter
 * @subpackage	Helpers
 * @category	Helpers
 * @author		Rick Ellis
 * @link		http://www.codeigniter.com/user_guide/helpers/string_helper.html
 */

// ------------------------------------------------------------------------

/**
 * Trim Slashes
 *
 * Removes any leading/traling slashes from a string:
 *
 * /this/that/theother/
 *
 * becomes:
 *
 * this/that/theother
 *
 * @access	public
 * @param	string
 * @return	string
 */	
function trim_slashes($str)
{
    return trim($str, '/');
} 
	
// ------------------------------------------------------------------------

/**
 * Reduce Double Slashes
 *
 * Converts double slashes in a string to a single slash,
 * except those found in http://
 *
 * http://www.some-site.com//index.php
 *
 * becomes:
 *
 * http://www.some-site.com/index.php
 *
 * @access	public
 * @param	string
 * @return	string
 */	
function reduce_double_slashes($str)
{
	return preg_replace("#([^:])//+#", "\\1/", $str);
}
	
// ------------------------------------------------------------------------

/**
 * Create a Random String
 *
 * Useful for generating passwords or hashes.
 *
 * @access	public
 * @param	string 	type of random string.  Options: alunum, numeric, nozero, unique
 * @param	integer	number of characters
 * @return	string
 */	
function random_string($type = 'alnum', $len = 8)
{					
	switch($type)
	{
		case 'alnum'	:
		case 'numeric'	:
		case 'nozero'	:
		
				switch ($type)
				{
					case 'alnum'	:	$pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
						break;
					case 'numeric'	:	$pool = '0123456789';
						break;
					case 'nozero'	:	$pool = '123456789';
						break;
				}

				$str = '';
				for ($i=0; $i < $len; $i++)
				{
					$str .= substr($pool, mt_rand(0, strlen($pool) -1), 1);
				}
				return $str;
		  break;
		case 'unique' : return md5(uniqid(mt_rand()));
		  break;
	}
}
// ------------------------------------------------------------------------

/**
 * Alternator
 *
 * Allows strings to be alternated.  See docs...
 *
 * @access	public
 * @param	string (as many parameters as needed)
 * @return	string
 */		
function alternator()
{
	static $i;	

	if (func_num_args() == 0)
	{
		$i = 0;
		return '';
	}
	$args = func_get_args();
	return $args[($i++ % count($args))];
}

// ------------------------------------------------------------------------

/**
 * Repeater function
 *
 * @access	public
 * @param	string
 * @param	integer	number of repeats
 * @return	string
 */	
function repeater($data, $num = 1)
{
	return (($num > 0) ? str_repeat($data, $num) : '');
} 


?>