php下载远程文件

这段代码允许你通过php内置方法下载其它网站上的文件，无需安装任何扩展

if (!function_exists('fetch_remote_file')) {
 
   function fetch_remote_file($file) {
 
      $path = parse_url($file);
 
      $fs = @fsockopen($path['host'], 80);
 
      if ($fs) {
 
         $header  = 'GET ' . $file . ' HTTP/1.0' . lnbr;
         $header .= 'Host: ' . $path['host'] . str_repeat(lnbr, 2);
 
         fwrite($fs, $header);
 
         $buffer = '';
 
         while ($tmp = fread($fs, 1024)) { $buffer .= $tmp; }
 
         $matches = Array();
 
         preg_match('/Content-Length: ([0-9]+)/', $buffer, $matches);
 
         return substr($buffer, -@$matches[1]);
 
      } else { return false; }
 
   }
 
}