正则表达式提取img的src

<?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); 
 
?>

/正则表达式
<script language="javascript">
var a='<P><IMG src="http://bbs.cn.yimg.com/user_img/200701/31/jisuanji986_117025184198149.jpg" mce_src="http://bbs.cn.yimg.com/user_img/200701/31/jisuanji986_117025184198149.jpg"></P>'
var b=/<IMG src=\"([^\"]*?)\">/gi
var s=a.match(b)
for(var i= 0;i<s.length;i++)
{
alert(s[i]);
alert(RegExp.$1)
}
</script>

<script language="javascript">
var a='<P><IMG src="http://bbs.cn.yimg.com/user_img/200701/31/jisuanji986_117025184198149.jpg" mce_src="http://bbs.cn.yimg.com/user_img/200701/31/jisuanji986_117025184198149.jpg"></P>'
var b=/<IMG src=\"([^\"]*?)\">/gi
var s=a.match(b)
for(var i= 0;i<s.length;i++)
{
alert(s[i]);
alert(s[i].replace(b,"$1"))
}
</script>