[PHP学习教程 - 网络]002.获取网页内容(URL Content) - PHP

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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

１.file_get_contents＋[请求方式：GET]

<?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";
?>

.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;
?>

.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, $request);
while (!@feof($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;
}
?>

.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;
}
?>

.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;
?>