PHP301跳转不带www域名的网址

//如果域名是不带www的网址那么进行下面的301跳转
$the_host = $_SERVER[‘HTTP_HOST’];
t h e u r l = i s s e t ( the_url = isset(the 
u
​
 rl=isset(_SERVER[‘REQUEST_URI’]) ? S E R V E R [ ′ R E Q U E S T U R I ′ ] : ′ ′ ; i f ( s t r p o s ( _SERVER['REQUEST_URI'] : ''; if(strpos( 
S
​
 ERVER[ 
′
 REQUEST 
U
​
 RI 
′
 ]: 
′′
 ;if(strpos(the_host,‘www.’)===false)
{
header(‘HTTP/1.1 301 Moved Permanently’);
header(‘Location:http://www.’.t h e h o s t . the_host.the 
h
​
 ost.the_url);
exit();
}
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