正则表达式删除两个字符串间的字符实例

<user>
      <id>18752</id>
      <name>方方</screen_name>
      <name>方方</name>
      <province>44</province>
      <city>3</city>
</user>

(?is)(?<=<user>).*?(?=</user>)

<?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*imgs+[^>]*?srcs*=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);

$word = '<p height="22" align="cenetr">111 22</p> <img src="/upload/images/aaa.jpg" width="100"><div style="float:left;">中国人</div>';
//取整个图片代码
preg_match('/</s*img/s+[^>]*?src/s*=/s*(/'|/")(.*?)//1[^>]*?//?/s*>/i',$word,$matches);
echo $matches[0];//结果：<img src="/upload/images/aaa.jpg" width="100">

$word = '<p height="22" align="cenetr">111 22</p> <img height="60" src="/upload/images/aaa.jpg" width=100 style=><div style="float:left;">中国人</div>';
//取width
preg_match('/<img.+(width=/"?/d*/"?).+>/i',$word,$matches);
echo $matches[1];

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

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

/*正则替换去掉或改变图片img标记中的任意属性***************************************************************/
$str = '<p height="22" align="cenetr">111 22</p> <img height="60" src="/upload/images/aaa.jpg" width=100 style=><div style="float:left;">中国人</div>
<p height="22" align="cenetr">31313 224344</p> <img src="/upload/images/bbb.jpg" height="60" width=100 style=><div style="float:left;">1212121</div>';

//改变src属性(此处将原来的src="/upload/images/bbb.jpg"改变为src="/upload/_thumbs/Images/bbb.jpg")
print preg_replace('/(<img.+src=/"?.+)(images//)(.+/.(jpg|gif|bmp|bnp|png)/"?.+>)/i',"/${1}_thumbs/Images//${3}",$str);

/*改变src属性,
此处将原来的src="/upload/images/bbb.jpg"改变为src="/upload/_thumbs/Images/bbb.jpg",并舍弃宽和高
(比如你想在前台显示缩略图,但数据库中存储的是原图的路径。为什么要舍弃宽高??你缩略图啊!还是原图的宽高,会怎样???)
*/
print preg_replace('/(<img).+(src=/"?.+)images//(.+/.(jpg|gif|bmp|bnp|png)/"?).+>/i',"/${1} /${2}_thumbs/Images//${3}>",$str);
?>

$str = preg_replace("/(s*?r?ns*?)+/","n",$str);

$str = preg_replace('/($s*$)|(^s*^)/m', '',$str);

$newhtml=preg_replace("/(r?n)\1+/","\1",$newhtml)；

echo preg_replace('/($s*$)|(^s*^)/m', '', $str); 完美解决:victory:

$a = 'gdgdga

gagda
faf

fefe

fefe';
echo preg_replace('/(r?n)\1+/',"nn",$a);

 $a ="/<script[^>]*?>.*?</script>/si";
 $keyword = preg_replace($a,' ',$_POST['searchword']);

<?php
$title="<style>ssss{'float:right'}</style>";
$title = strip_tags($title);
if(preg_match('/<style>(.*)</style>|<script>(.*)</script>|<img src=(.*)>/',$title,$info)){
 $title=$info['1'];
}else{
 $title = $title;
}
echo $title;