HTTP context 选项

HTTP context 选项 — HTTP context 的选项列表

说明

提供给 http:// 和 https:// 传输协议的 context 选项。 transports.

可选项

method string

远程服务器支持的 GET，POST 或其它 HTTP 方法。

默认值是 GET。

header array 或 string

请求期间发送的附加 header 。此选项中的值将覆盖其他值 （如 User-agent:， Host: 和 Authentication:)， 即使在执行 Location: 重定向时也是如此。 所以，如果启用了 follow_location 就不建议设置 Host: header。

user_agent string

要发送的 header User-Agent: 的值。如果在上面的 header context 选项中没有指定 user-agent，此值将被使用。

默认使用 php.ini 中设置的 user_agent。

content string

在 header 后面要发送的额外数据。通常使用POST或PUT请求。

proxy string

URI 指定的代理服务器的地址。(e.g. tcp://proxy.example.com:5100).

request_fulluri bool

当设置为 true 时，在构建请求时将使用整个 URI 。(例如： GET http://www.example.com/path/to/file.html HTTP/1.0)。 虽然这是一个非标准的请求格式，但某些代理服务器需要它。

默认值是 false.

follow_location int

跟随 Location header 的重定向。设置为 0 以禁用。

默认值是 1。

max_redirects int

跟随重定向的最大次数。值为 1 或更少则意味不跟随重定向。

默认值是 20。

protocol_version float

HTTP 协议版本。

PHP 8.0.0 起默认值是 1.1。在此之前默认值是 1.0。

timeout float

读取超时时间，单位为秒（s），用 float 指定(e.g. 10.5)。

默认使用 php.ini 中设置的 default_socket_timeout。

ignore_errors bool

即使是故障状态码依然获取内容。

默认值为 false.

范例

示例 #1 获取一个页面并发送 POST 数据

<?php

$postdata = http_build_query(
    array(
        'var1' => 'some content',
        'var2' => 'doh'
    )
);

$opts = array('http' =>
    array(
        'method'  => 'POST',
        'header'  => 'Content-type: application/x-www-form-urlencoded',
        'content' => $postdata
    )
);

$context = stream_context_create($opts);

$result = file_get_contents('http://example.com/submit.php', false, $context);

?>

示例 #2 忽略重定向并获取 header 和内容

<?php

$url = "http://www.example.org/header.php";

$opts = array('http' =>
    array(
        'method' => 'GET',
        'max_redirects' => '0',
        'ignore_errors' => '1'
    )
);

$context = stream_context_create($opts);
$stream = fopen($url, 'r', false, $context);

// header 信息和 stream 的元数据一样
var_dump(stream_get_meta_data($stream));

// $url 的实际数据
var_dump(stream_get_contents($stream));
fclose($stream);
?>

注释

注意: 底层 socket stream 上下文选项
Additional context options may be supported by the underlying transport For http:// streams, refer to context options for the tcp:// transport. For https:// streams, refer to context options for the ssl:// transport.

注意: HTTP 状态行
When this stream wrapper follows a redirect, the wrapper_data returned by stream_get_meta_data() might not necessarily contain the HTTP status line that actually applies to the content data at index 0. 

array (
  'wrapper_data' =>
  array (
    0 => 'HTTP/1.0 301 Moved Permanently',
    1 => 'Cache-Control: no-cache',
    2 => 'Connection: close',
    3 => 'Location: http://example.com/foo.jpg',
    4 => 'HTTP/1.1 200 OK',
    ...
第一个请求返回 301 （永久重定向）， 因此 stream 包装器自动跟随重定向到获得 200 响应（index = 4）。
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User Contributed Notes 10 notes

up
23
nate
8 years ago
Note that if you set the protocol_version option to 1.1 and the server you are requesting from is configured to use keep-alive connections, the function (fopen, file_get_contents, etc.) will "be slow" and take a long time to complete. This is a feature of the HTTP 1.1 protocol you are unlikely to use with stream contexts in PHP.

Simply add a "Connection: close" header to the request to eliminate the keep-alive timeout:

<?php
// php 5.4 : array syntax and header option with array value
$data = file_get_contents('http://www.example.com/', null, stream_context_create([
    'http' => [
        'protocol_version' => 1.1,
        'header'           => [
            'Connection: close',
        ],
    ],
]));
?>
up
17
daniel.peder (a) gmail.com
4 years ago
note that both http and https transports require the same context name http

// OK example:
// this will work as expected
// note the url with https but context with http
$correct_data = file_get_contents('https://example.com', false, stream_context_create(array('http' => array(...))));

// INVALID example:
// this will not work, the context will be ignored
// note the url with https also context with https
$correct_data = file_get_contents('https://example.com', false, stream_context_create(array('https' => array(...))));
up
11
daniel dot peder at gmail dot com
4 years ago
note that for both http and https protocols require the same 'http' context keyword:

<?php

// CORRECT example:
// this will work as expected
// note the url with https but context with http
$correct_data = file_get_contents('https://example.com', false, stream_context_create(array('http' => array(...))));

// INVALID example:
// this will not work, the context will be ignored
// note the url with https also context with https
$correct_data = file_get_contents('https://example.com', false, stream_context_create(array('https' => array(...))));
up
12
gourav sarkar
11 years ago
watch your case when using methods (POST and GET)...it must be always uppercase. in case of you write it in lower case it wont work.
up
2
ywarnier at beeznest dot org
4 years ago
Note that setting request_fulluri to true will *change* the value of $_SERVER['REQUEST_URI] on the receiving end (from /abc.php to http://domain.com/abc.php).
up
3
aruntechguy at outlook dot com
4 years ago
If you want to use Basic Auth while using get_headers(), use stream_context options below.

I am using HEAD method here, but please feel free to use GET also.

<?php
$targetUrl = 'http or https target url here';
$basicAuth = base64_encode('username:password');

stream_context_set_default(
    [
        'http' => [
            'method' => 'HEAD',
            'header' => 'Authorization: Basic ' . $basicAuth
        ]
    ]
);
$result = get_headers($targetUrl);

print_r($result);
up
7
vchampion at gmail dot com
9 years ago
If you use the proxy server and encounter an error "fopen(http://example.com): failed to open stream: HTTP request failed! HTTP/1.0 400 Bad Request" note that in many situations you need also set the parameter "request_fulluri" to "true" in your stream options. Without this option the php script sends the empty request to the server as "GET / HTTP/0.0" and the proxy server replies to it with the "HTTP 400" error.

For example (working sample):
<?php
$stream = stream_context_create(Array("http" => Array("method"  => "GET",
                                                      "timeout" => 20,
                                                      "header"  => "User-agent: Myagent",
                                                      "proxy"   => "tcp://my-proxy.localnet:3128",
                                                      'request_fulluri' => True /* without this option we get an HTTP error! */
                                )));

if ( $fp = fopen("http://example.com", 'r', false, $stream) ) {
    print "well done";
}
?>

P>S> PHP 5.3.17
up
6
jay
7 years ago
Remember to match content with Content-type:

<?php

$data = array(
    'var1' => 'some content',
    'var2' => 'doh'
);

$opts = array('http' =>
    array(
        'method'  => 'POST',
        'header'  => 'Content-type: application/json',  // here...
        'content' => json_encode($data)  // and here.
    )
);

. . .

?>
up
3
chris
8 years ago
I had quite a bit of trouble trying to make a request with fopen through a proxy to a secure url.  I kept getting a 400 Bad Request back from the remote host.  It was receiving the proxy url as the SNI host.  In order to get around this I had to explicity set the SNI host to the domain I was trying to reach.  It's apparently the issue outlined in this bug:

https://bugs.php.net/bug.php?id=63519

<?php
$domain = parse_url($file, PHP_URL_HOST);
$proxy_string = "tcp://" . WP_PROXY_HOST  . ":" . WP_PROXY_PORT;
$opts = array(
    'http' => array( 'proxy' => $proxy_string ),
    'ssl' => array( 'SNI_enabled' => true, 'SNI_server_name' => $domain));
$context = stream_context_create($opts);
$handle = fopen( $file, 'r', false, $context );
?>
up
2
ASchmidt at Anamera dot net
1 year ago
With the default of

    'follow_location'   =>  1

be certain NEVER include a "Host:" header in the 'header' array.

If the host is set to "mydomain.com", and that web site has a (quite common) redirect to "www.mydomain.com", then the initial request to "http://mydomain.com" will get the expected response of:

HTTP/1.1 301 Moved Permanently
Location: http://www.mydomain.com/

However, the follow-up request does NOT replace the original "host" header with the new "location" value, as one would expect. Consequently each "follow-location" request will again be served by the original host of "http://mydomain.com", and continue the redirect loop until 'max_redirects' has been exhausted.

(For details: https://bugs.php.net/bug.php?id=77889)
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