img lazy load php 正则替换

今天看到有人提问，觉得自己会用到，写了一个

html内容中的

<img src="images/1.jpg" imgtype="upload" /> <img src="images/2.jpg" imgtype="upload" /> 

   替换成  

<img src="load.jpg" imgtype="upload" url="images/1.jpg" /> <img src="load.jpg" imgtype="upload"  url="images/2.jpg" />

 

<?php
$loadimg = 'load.jpg';
$str = '<img src="images/1.jpg" imgtype="upload" />';
$pattern = '/^(<img.*)src=([\'|\"])(.*)([\'|\"])(.*)$/i';
$replacement = '$1src=$2'.$loadimg.'$4 url=$2$3$4$5';
$str1 = preg_replace($pattern, $replacement, $str);
echo( $str1 );
?>