1.代碼如下:

1. //自動提取摘要   
2.         if(isset($_POST['add_introduce']) && $systeminfo['description'] == '' && isset($modelinfo['content'])) {   
3.             $content = stripslashes($modelinfo['content']);   
4.             $introcude_length = intval($_POST['introcude_length']);   
5.             $systeminfo['description'] = str_cut(str_replace(array("/r/n","/t",'[page]','[/page]','“','”',' '), '', strip_tags($content)),$introcude_length);   
6.             $inputinfo['system']['description'] = $systeminfo['description'] = addslashes($systeminfo['description']);   
7.         }   
8.         //自動提取縮略圖   
9.         if(isset($_POST['auto_thumb']) && $systeminfo['thumb'] == '' && isset($modelinfo['content'])) {   
10.             $content = $content ? $content : stripslashes($modelinfo['content']);   
11.             $auto_thumb_no = intval($_POST['auto_thumb_no'])-1;   
12.             if(preg_match_all("/(src)=([/"|']?)([^ /"'>]+/.(gif|jpg|jpeg|bmp|png))//2/i", $content, $matches)) {   
13.                 $systeminfo['thumb'] = $matches[3][$auto_thumb_no];   
14.             }   
15.         } 

2.案例:

1. <?php   
2. $str='<a href="http://www.49028c.com/"><img src="http://www.49028c.com/uploadfile/2012/1205/20121205112558940.jpg"></a><a href="http://www.baidu.com/"><img src="http://www.49028c.com/uploadfile/2012/1205/20121205112558940.jpg"></a>';  
3. preg_match_all("/(src)=([/"|']?)([^ /"'>]+/.(gif|jpg|jpeg|bmp|png))//2/i", $str, $out);   
4. echo "<pre>";   
5. print_r($out);   
6. ?> 

3.結果:

1. <pre>Array   
2. (   
3.     [0] => Array   
4.         (   
5.             [0] => src="http://www.49028c.com/uploadfile/2012/1205/20121205112558940.jpg"   
6.             [1] => src="http://www.49028c.com/uploadfile/2012/1205/20121205112558940.jpg"   
7.         )   
8.    
9.     [1] => Array   
10.         (   
11.             [0] => src   
12.             [1] => src   
13.         )   
14.    
15.     [2] => Array   
16.         (   
17.             [0] => "   
18.             [1] => "   
19.         )   
20.    
21.     [3] => Array   
22.         (   
23.             [0] => http://www.49028c.com/uploadfile/2012/1205/20121205112558940.jpg   
24.             [1] => http://www.49028c.com/uploadfile/2012/1205/20121205112558940.jpg   
25.         )   
26.    
27.     [4] => Array   
28.         (   
29.             [0] => jpg   
30.             [1] => jpg   
31.         )   
32.    
33. )