stream_context_get_default()

(PHP 5 >= 5.1.0, PHP 7)

Retrieve the default stream context

说明

stream_context_get_default([array $options]): resource

Returns the default stream context which is used whenever file operations (fopen(),file_get_contents(), etc...) are called without a context parameter. Options for the default context can optionally be specified with this function using the same syntax asstream_context_create().

参数

$options

$optionsmust be an associative array of associative arrays in the format$arr['wrapper']['option']=$value.

Note:

As of PHP 5.3.0,thestream_context_set_default()function can be used to set the default context.

返回值

A stream contextresource.

范例

Usingstream_context_get_default()

<?php
$default_opts = array(
  'http'=>array(
    'method'=>"GET",
    'header'=>"Accept-language: en\r\n" .
              "Cookie: foo=bar",
    'proxy'=>"tcp://10.54.1.39:8000"
  )
);
$alternate_opts = array(
  'http'=>array(
    'method'=>"POST",
    'header'=>"Content-type: application/x-www-form-urlencoded\r\n" .
              "Content-length: " . strlen("baz=bomb"),
    'content'=>"baz=bomb"
  )
);
$default = stream_context_get_default($default_opts);
$alternate = stream_context_create($alternate_opts);
/* Sends a regular GET request to proxy server at 10.54.1.39
 * For www.example.com using context options specified in $default_opts
 */
readfile('http://www.example.com');
/* Sends a POST request directly to www.example.com
 * Using context options specified in $alternate_opts
 */
readfile('http://www.example.com', false, $alternate);
?>

参见

• stream_context_create() 创建资源流上下文
• Listing of supported wrappers with context options (支持的协议和封装协议).

If you are using stream_context_get_default() and are still finding that some functions do not work, make sure that they are not based upon the libxml functions (DOM, SimpleXML and XSLT). These require their own context.
You can easily set them using the following code ...
<?php
// Define the default, system-wide context.
$r_default_context = stream_context_get_default
  (
  array
    (
    'http' => array
      ( // All HTTP requests are passed through the local NTLM proxy server on port 8080.
      'proxy' => 'tcp://127.0.0.1:8080',
      'request_fulluri' => True,
      ),
    )
  );
// Though we said system wide, some extensions need a little coaxing.
libxml_set_streams_context($r_default_context);
?>