一般在做网站系统的时候，出于优化等因素的考虑需要再添加文章的时候删除掉不是本站的链接，对于这一要求可以通过让PHP处理下文章内容，来达到文章外部链接的自动删除的效果。
代码如下:
* 删除非站内链接
*
* @access public
* @param string $body 内容
* @param array $allow_urls 允许的超链接
* @return string
*/
function Replace_Links( &$body,$allow_urls=array() )
{
$host_rule = join('|',$allow_urls);
$host_rule = preg_replace("#[\n\r]#",'',$host_rule);
$host_rule = str_replace('.',"\\.",$host_rule);
$host_rule = str_replace('/',"\\/",$host_rule);
$arr = '';
preg_match_all("#]*)>(.*)<\/a>#iU",$body,$arr);
if( is_array($arr[0]) )
{
$rparr = array();
$tgarr = array();
foreach($arr[0] as $i=>$v)
{
if( $host_rule != '' && preg_match('#'.$host_rule.'#i',$arr[1][$i]) )
{
continue;
} else {
$rparr[] = $v;
$tgarr[] = $arr[2][$i];
}
}
if( !empty($rparr) )
{
$body = str_replace($rparr,$tgarr,$body);
}
}
$arr = $rparr = $tgarr = '';
return $body;
}
*
* @access public
* @param string $body 内容
* @param array $allow_urls 允许的超链接
* @return string
*/
function Replace_Links( &$body,$allow_urls=array() )
{
$host_rule = join('|',$allow_urls);
$host_rule = preg_replace("#[\n\r]#",'',$host_rule);
$host_rule = str_replace('.',"\\.",$host_rule);
$host_rule = str_replace('/',"\\/",$host_rule);
$arr = '';
preg_match_all("#
if( is_array($arr[0]) )
{
$rparr = array();
$tgarr = array();
foreach($arr[0] as $i=>$v)
{
if( $host_rule != '' && preg_match('#'.$host_rule.'#i',$arr[1][$i]) )
{
continue;
} else {
$rparr[] = $v;
$tgarr[] = $arr[2][$i];
}
}
if( !empty($rparr) )
{
$body = str_replace($rparr,$tgarr,$body);
}
}
$arr = $rparr = $tgarr = '';
return $body;
}
