PHP下打开URL地址的几种方法小结

1: 用file_get_contents 以get方式获取内容

<?php 
$url='http://www.baidu.com/'; 
$html = file_get_contents($url); 
//print_r($http_response_header); 
ec($html); 
printhr(); 
printarr($http_response_header); 
printhr(); 
?>

示例代码2: 用fopen打开url, 以get方式获取内容

<? 
$fp = fopen($url, 'r'); 
printarr(stream_get_meta_data($fp)); 
printhr(); 
while(!feof($fp)) { 
$result .= fgets($fp, 1024); 
} 
echo "url body: $result"; 
printhr(); 
fclose($fp); 
?>

示例代码3：用file_get_contents函数,以post方式获取url

<?php 
$data = array ('foo' => 'bar'); 
$data = http_build_query($data); 
$opts = array ( 
'http' => array ( 
'method' => 'POST', 
'header'=> "Content-type: application/x-www-form-urlencoded" . 
"Content-Length: " . strlen($data) . "", 
'content' => $data 
), 
); 
$context = stream_context_create($opts); 
$html = file_get_contents('http://localhost/e/admin/test.html', false, $context); 
echo $html; 
?>

示例代码4：用fsockopen函数打开url，以get方式获取完整的数据，包括header和body

<? 
function get_url ($url,$cookie=false) { 
$url = parse_url($url); 
$query = $url[path]."?".$url[query]; 
ec("Query:".$query); 
$fp = fsockopen( $url[host], $url[port]?$url[port]:80 , $errno, $errstr, 30); 
if (!$fp) { 
return false; 
} else { 
$request = "GET $query HTTP/1.1"; 
$request .= "Host: $url[host]"; 
$request .= "Connection: Close"; 
if($cookie) $request.="Cookie: $cookie\n"; 
$request.=""; 
fwrite($fp,$request); 
while(!@feof($fp)) { 
$result .= @fgets($fp, 1024); 
} 
fclose($fp); 
return $result; 
} 
} 
//获取url的html部分，去掉header 
function GetUrlHTML($url,$cookie=false) { 
$rowdata = get_url($url,$cookie); 
if($rowdata) 
{ 
$body= stristr($rowdata,""); 
$body=substr($body,4,strlen($body)); 
return $body; 
} 
return false; 
} ?>

示例代码5：用fsockopen函数打开url，以POST方式获取完整的数据，包括header和body

<? 
function HTTP_Post($URL,$data,$cookie, $referrer="") { 
// parsing the given URL 
$URL_Info=parse_url($URL); 
// Building referrer 
if($referrer=="") // if not given use this script as referrer 
$referrer="111"; 
// making string from $data 
foreach($data as $key=>$value) 
$values[]="$key=".urlencode($value); 
$data_string=implode("&",$values); 
// Find out which port is needed - if not given use standard (=80) 
if(!isset($URL_Info["port"])) 
$URL_Info["port"]=80; 
// building POST-request: 
$request.="POST ".$URL_Info["path"]." HTTP/1.1\n"; 
$request.="Host: ".$URL_Info["host"]."\n"; 
$request.="Referer: $referer\n"; 
$request.="Content-type: application/x-www-form-urlencoded\n"; 
$request.="Content-length: ".strlen($data_string)."\n"; 
$request.="Connection: close\n"; 
$request.="Cookie: $cookie\n"; 
$request.="\n"; 
$request.=$data_string."\n"; 
$fp = fsockopen($URL_Info["host"],$URL_Info["port"]); 
fputs($fp, $request); 
while(!feof($fp)) { 
$result .= fgets($fp, 1024); 
} 
fclose($fp); 
return $result; 
} 
printhr(); 
?>

示例代码6:使用curl库，使用curl库之前，你可能需要查看一下php.ini，查看是否已经打开了curl扩展

<? 
$ch = curl_init(); 
$timeout = 5; 
curl_setopt ($ch, CURLOPT_URL, 'http://www.baidu.com/'); 
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1); 
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout); 
$file_contents = curl_exec($ch); 
curl_close($ch); 
echo $file_contents; 
?>

关于curl库：
curl官方网站http://curl.haxx.se/
curl 是使用URL语法的传送文件工具，支持FTP、FTPS、HTTP HTPPS SCP SFTP TFTP TELNET DICT FILE和LDAP。curl 支持SSL证书、HTTP POST、HTTP PUT 、FTP 上传，kerberos、基于HTT格式的上传、代理、cookie、用户＋口令证明、文件传送恢复、http代理通道和大量其他有用的技巧

<? 
function printarr(array $arr) 
{ 
echo "<br> Row field count: ".count($arr)."<br>"; 
foreach($arr as $key=>$value) 
{ 
echo "$key=$value <br>"; 
} 
} 
?>

7.
有些主机服务商把php的allow_url_fopen选项是关闭了，就是没法直接使用file_get_contents来获取远程web页面的内容。那就是可以使用另外一个函数curl。
下面是file_get_contents和curl两个函数同样功能的不同写法
file_get_contents函数的使用示例:

< ?php 
$file_contents = file_get_contents('http://www.ccvita.com/'); 
echo $file_contents; 
?>

换成curl函数的使用示例:

< ?php 
$ch = curl_init(); 
$timeout = 5; 
curl_setopt ($ch, CURLOPT_URL, 'http://www.ccvita.com'); 
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1); 
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout); 
$file_contents = curl_exec($ch); 
curl_close($ch); 
echo $file_contents; 
?>

利用function_exists函数来判断php是否支持一个函数可以轻松写出下面函数

< ?php 
function vita_get_url_content($url) { 
if(function_exists('file_get_contents')) { 
$file_contents = file_get_contents($url); 
} else { 
$ch = curl_init(); 
$timeout = 5; 
curl_setopt ($ch, CURLOPT_URL, $url); 
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1); 
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout); 
$file_contents = curl_exec($ch); 
curl_close($ch); 
} 
return $file_contents; 
} 
?>

其实上面的这个函数还有待商榷，如果你的主机服务商把file_get_contents和curl都关闭了，上面的函数就会出现错误。