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

$methodstring

远程服务器支持的GET，POST或其它 HTTP 方法。

默认值是GET。

$headerstring

请求期间发送的额外 header 。在此选项的值将覆盖其他值（诸如User-agent:，Host:和Authentication:）。

$user_agentstring

要发送的 headerUser-Agent:的值。如果在上面的headercontext 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。

$contentstring

在 header 后面要发送的额外数据。通常使用POST或PUT请求。

$proxystring

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

$request_fulluriboolean

当设置为TRUE时，在构建请求时将使用整个 URI 。(i.e.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_locationinteger

跟随Locationheader 的重定向。设置为0以禁用。

默认值是1。

$max_redirectsinteger

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_versionfloat

HTTP 协议版本。

默认值是1.0。

Note:

PHP 5.3.0 以前的版本没有实现分块传输解码。如果此值设置为1.1，与1.1的兼容将是你的责任。

$timeoutfloat

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_errorsboolean

即使是故障状态码依然获取内容。

默认值为FALSE.

更新日志

范例

Example #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);
?>

Example #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, $context);
// header information as well as meta data
// about the stream
var_dump(stream_get_meta_data($stream));
// actual data at $url
var_dump(stream_get_contents($stream));
fclose($stream);
?>

注释

Note:Underlying socket stream context options
Additional context options may be supported by the underlying transport Forhttp://streams, refer to context options for thetcp://transport. Forhttps://streams, refer to context options for thessl://transport.

Note:HTTP status line
When this stream wrapper follows a redirect, thewrapper_datareturned by stream_get_meta_data() might not necessarily contain the HTTP status line that actually applies to the content data at index0. array ( 'wrapper_data' => array ( 0 => 'HTTP/1.0 301 Moved Permantenly', 1 => 'Cache-Control: no-cache', 2 => 'Connection: close', 3 => 'Location: http://example.com/foo.jpg', 4 => 'HTTP/1.1 200 OK', ... The first request returned a301(permanent redirect), so the stream wrapper automatically followed the redirect to get a200response(index =4).

参见

• http://
• 套接字上下文选项
• SSL 上下文选项

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',
    ],
  ],
]));
?>

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(...))));

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.

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(...))));

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.
  )
);
. . .
?>

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

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 );
?>

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).

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);