php访问url的四种方式

//访问指定URL函数
function access_url($url) { 
 if ($url=='') return false; 
 $fp = fopen($url, 'r') or exit('Open url faild!'); 
 if($fp){ 
 while(!feof($fp)) { 
 $file.=fgets($fp).""; 
 } 
 fclose($fp); 
 } 
 return $file; 
}

$content = file_get_contents("http://www.google.com");

function curl_file_get_contents($durl){ 
 $ch = curl_init(); 
 curl_setopt($ch, CURLOPT_URL, $durl); 
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true) ; // 获取数据返回 
 curl_setopt($ch, CURLOPT_BINARYTRANSFER, true) ; // 在启用 CURLOPT_RETURNTRANSFER 时候将获取数据返回 
 $r = curl_exec($ch); 
 curl_close($ch); 
 return $r; 
}

$fp = fsockopen("www.example.com", 80, $errno, $errstr, 30); 
if (!$fp) { 
 echo "$errstr ($errno)<br />
"; 
} else { 
 $out="GET / HTTP/1.1
"; 
 $out.="Host: www.example.com
"; 
 $out.="Connection: Close

"; 
 fwrite($fp, $out); 
 while (!feof($fp)) { 
 echo fgets($fp, 128); 
 } 
 fclose($fp); 
}