[PHP学习教程]006.获取网页内容(URL Content)

引言：获取网页内容是我们实现网页操作的基本之基本，今天这一讲，我们和大家讲一下基本请求网页内容的几种方法。

我们似乎每天都要做这样一件事情，打开一个浏览器，输入网址，回车，一个空白的页面顿时有了东西，它可能是百度之类的搜索页面，或是一个挤满了文字和图片的门户网站。

我们可以从三个方面理解这个过程，一个是浏览器，二个是服务器，第三个是浏览器和服务器之间通信的协议。

当然，我们今天不讲<网页请求过程 >

这一次，我们说一下如何用PHP代码请求网页内容。

获取网页内容方法

<?php
$url  = ‘http://do.org.cn‘;
$html = file_get_contents($url);
echo $html;
?> 

２.file_get_contents＋[请求方式：POST]

无需Cookie操作，则使用以下方式：

<?php
$url    = ‘http://do.org.cn/upload.php‘;
$data   = http_build_query(array(‘foo‘ => ‘bar‘));
$params = array(
    ‘http‘ => array(
        ‘method‘  => ‘POST‘,
        ‘content‘ => $data,
        ‘header‘  =>
            "Content-type: application/x-www-form-urlencoded\r\n" .
            "Content-Length: " . strlen($data) . "\r\n"
    )
);
$context = stream_context_create($params);
$html    = @file_get_contents($url, ‘‘, $context); 

有需Cookie操作，则在$params里的‘header‘添加下一行(类似如下文)：

"cookie:cookie1=c1;cookie2=c2\r\n" ;

３.fopen＋[请求方式：GET]

<?php
// 尝试打开网页
$fp = fopen($url, ‘r‘);
// 获取报头信息
$header = stream_get_meta_data($fp);
while (!feof($fp)) {
    $result .= fgets($fp, 1024);
}
fclose($fp);
// 输出结果
echo "url header: {$header} <br/>";
echo "url body: $result";
?> 

4.fopen＋[请求方式：POST]

<?php
$data   = http_build_query(array(‘foo1‘ => ‘bar1‘, ‘foo2‘ => ‘bar2‘));
$params = array(
    ‘http‘ => array(
        ‘method‘  => ‘POST‘,
        ‘content‘ => $data,
        ‘header‘  => "Content-type: application/x-www-form-urlencoded\r\nCookie:cook1=c3;cook2=c4\r\n" .
        "Content-Length: " . strlen($data) . "\r\n"
    )
); 

$context = stream_context_create($params);
$fp      = fopen(‘http://do.org.cn/upload.php‘, ‘rb‘, false, $context);
$content = fread($fp, 1024);
fclose($fp);
echo $content;
?>

5.fsockopen＋[请求方式：GET]

用fsockopen函数打开网址URL，以GET方式请求完整的数据，包括header和body．

<?php
function get_url($url, $cookie=false) {
    $url   = parse_url($url);
    $query = $url[path]. "?" .$url[query];
    echo "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\r\n";
        $request .= "Host: $url[host]\r\n";
        $request .= "Connection: Close\r\n";
        if ($cookie) {
            $request.="Cookie: $cookie\r\n";
        }
        $request .= "\r\n";
        fwrite($fp, $request);
        while ([email protected]feof($fp)) {
            $result .= @fgets($fp, 1024);
        }
        fclose($fp);
        return $result;
    }
}
// 获取url的html部分，去掉header
function get_html($url, $cookie=false) {
    $data = get_url($url, $cookie);
    if ($data) {
        $body = stristr($data, "\r\n\r\n");
        $body = substr($body, 4, strlen($body));
        return $body;
    }
    return false;
}
?> 

6.fsockopen＋[请求方式：POST]

用fsockopen函数打开网址URL，以POST方式请求完整的数据，包括header和body．

<?php
function post_url($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;
}
?>

7.curl库

注意：使用curl库之前，需要查看一下php.ini是否已经打开了curl扩展．

<?php
$ch = curl_init();
$timeout = 5;
curl_setopt($ch, CURLOPT_URL, ‘http://do.org.cn/‘);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
$content = curl_exec($ch);
curl_close($ch); 

echo $content;
?>

本站文章为宝宝巴士 SD.Team原创，转载务必在明显处注明：（作者官方网站：宝宝巴士) 
转载自【宝宝巴士SuperDo团队】 原文链接: http://www.cnblogs.com/superdo/p/4805187.html