/**
 *base64編碼方法、本方法只是做base64轉換過程代碼舉例說明，通過該例子可以任意改造不同語言版
 *@author 程默
 *@copyright http://blog.chacuo.net
 *@param $src 原字符串
 *@return string base64字符串*
 */
function c_base64_encode($src)
{
	static $base="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	
	////將原始的3個字節轉換為4個字節
	$slen=strlen($src);
	$smod = ($slen%3);
	$snum = floor($slen/3);
	
	
	$desc = array();
	
	for($i=0;$i$snum;$i++)
	{
		////讀取3個字節
		$_arr = array_map('ord',str_split(substr($src,$i*3,3)));
		
		///計算每一個base64值
		$_dec0= $_arr[0]>>2;
		$_dec1= (($_arr[0]3)4)|($_arr[1]>>4);
		$_dec2= (($_arr[1]0xF)2)|($_arr[2]>>6);	
		$_dec3= $_arr[2]63;

		$desc = array_merge($desc,array($base[$_dec0],$base[$_dec1],$base[$_dec2],$base[$_dec3]));
	}
	
	if($smod==0) return implode('',$desc);
	
	///計算非3倍數字節
	$_arr = array_map('ord',str_split(substr($src,$snum*3,3)));
	$_dec0= $_arr[0]>>2;
	///只有一個字節
	if(!isset($_arr[1]))
	{
		$_dec1= (($_arr[0]3)4);
		$_dec2=$_dec3="=";
	}
	else 
	{
		///2個字節
		$_dec1= (($_arr[0]3)4)|($_arr[1]>>4);
		$_dec2= $base[($_arr[1]7)2];
		$_dec3="=";
	}
	$desc = array_merge($desc,array($base[$_dec0],$base[$_dec1],$_dec2,$_dec3));
	return implode('',$desc);
}