stream_context_get_default
(PHP 5 >= 5.1.0)
stream_context_get_default — Retreive the default streams context
Description
      resource stream_context_get_default
       ([ array $options
     ] )
    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 as stream_context_create().
options must be an associative array of associative arrays in the format $arr['wrapper']['option'] = $value.
Example#1 Using stream_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('https://www.example.com');
/* Sends a POST request directly to www.example.com
 * Using context options specified in $alternate_opts
 */
readfile('https://www.example.com', false, $alternate);
?>
See also stream_context_create(), and Listing of supported wrappers with context options (List of Supported Protocols/Wrappers).