PHP preg_replace与perl风格正则表达式

问题

Need to remove "&page-X" from a string if its there.X being a number of course

答案

Actually the basic syntax for regular expressions, as supported by preg_replace and friends, is pretty easy to learn. Think of it as a string describing a pattern with certain characters having special meaning.

In your very simple case, a possible pattern is:

&page-\d+
With \d meaning a digit (numeric characters 0-9) and + meaning: Repeat the expression right before + (here: \d) one or more times. All other characters just represent themselves.

Therefore, the pattern above matches any of the following strings:

&page-0
&page-665
&page-1234567890
Since the preg functions use a Perl-compatible syntax and regular expressions are denoted between slashes (/) in Perl, you have to surround the pattern in slashes:

$after = preg_replace('/&page-\d+/', '', $before);
Actually, you can use other characters as well:

$after = preg_replace('#&page-\d+#', '', $before);
For a full reference of supported syntax, see the PHP manual.

参考：



另外一个例子：

$content=preg_replace('#'.$v_config['tmall_url'].'?#i',$v_config['web_url'],$content);
$content=preg_replace('#/\?spm=([^\&]+)\&#i','/?',$content);
$content=preg_replace('#[^"]+(["\']?)#i',$v_config['web_url'].'\\1',$content);
$content=preg_replace('#[^"]+["\']?#i',$v_config['web_url'],$content);
$content=preg_replace('#http://[^/]+/item.htm#i',$v_config['web_url'].'item.php',$content);
$content=preg_replace('#http://\w+\.mall\.taobao\.com#i',$v_config['web_url'],$content);
$content=preg_replace('#\d+\.taobao\.com#i',$v_config['web_url'],$content);
$content=preg_replace('#shop/view_shop.htm#i','',$content);
$content=preg_replace('#/\?search=y#i','/search.php?search=y',$content);
//$content=preg_replace('#shop/viewShop.htm\?#i','search.php?',$content);
$content=preg_replace('#search.htm#i','search.php',$content);
$content=preg_replace('#search.php\?spm=[^&]+\&#i','search.php?',$content);
$content=preg_replace('#item.php\?spm=[^&]+\&#i','item.php?',$content);
$content=preg_replace('#/view_page-(\d+).htm\??#i','/view.php?id=\\1&',$content);