<?php
/*PHP正则提取图片img标记中的任意属性*/
$str = '<center><img src="/uploads/images/20100516000.jpg" height="120" width="120"><br />PHP正则提取或更改图片img标记中的任意属性</center>';

//1、取整个图片代码
preg_match('/</s*img/s+[^>]*?src/s*=/s*(/'|/")(.*?)//1[^>]*?//?/s*>/i',$str,$match);
echo $match[0];

//2、取width
preg_match('/<img.+(width=/"?/d*/"?).+>/i',$str,$match);
echo $match[1];

//3、取height
preg_match('/<img.+(height=/"?/d*/"?).+>/i',$str,$match);
echo $match[1];

//4、取src
preg_match('/<img.+src=/"?(.+/.(jpg|gif|bmp|bnp|png))/"?.+>/i',$str,$match);
echo $match[1];

/*PHP正则替换图片img标记中的任意属性*/
//1、将src="/uploads/images/20100516000.jpg"替换为src="/uploads/uc/images/20100516000.jpg")
print preg_replace('/(<img.+src=/"?.+)(images//)(.+/.(jpg|gif|bmp|bnp|png)/"?.+>)/i',"/${1}uc/images//${3}",$str);
echo "<hr/>";

//2、将src="/uploads/images/20100516000.jpg"替换为src="/uploads/uc/images/20100516000.jpg",并省去宽和高
print preg_replace('/(<img).+(src=/"?.+)images//(.+/.(jpg|gif|bmp|bnp|png)/"?).+>/i',"/${1} /${2}uc/images//${3}>",$str);
?>