====== PHP中打开URL地址的几种方法总结 ======

===== file_get_contents get =====
示例代码1: 用file_get_contents 以get方式获取内容

<code php>

<?php

 $url='http://www.baidu.com/';

  $html = file_get_contents($url);
   //print_r($http_response_header);
   ec($html);
   printhr();

   printarr($http_response_header);

   printhr();
 ?>
</code>

===== fopen get =====

示例代码2: 用fopen打开url, 以get方式获取内容
<code php>

<?

   $fp = fopen($url, 'r');
   
   printarr(stream_get_meta_data($fp));

  printhr();
   while(!feof($fp)) {
       $result .= fgets($fp, 1024);
  }
  echo "url body:    $result";
   printhr();

   fclose($fp);
 ?>
</code>

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

<code php>

<?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;
?>
</code>

===== fsockopen get =====

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
<code php>

<?
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;

}


?>
</code>


===== fsockopen post  =====
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
<code php>

<?
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();
?>
</code>

===== curl =====

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
<code php>

<?
$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;
?>
</code>

==== 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

<code php>

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


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:

<code php>

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


换成curl函数的使用示例:
<code php>

< ?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;
?>
</code>

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

<code php>

< ?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;
}
?>
</code>

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。