stream_context

Description

resource stream_context_create ( [array options] )

Creates and returns a stream context with any options supplied in options preset.

options must be an associative array of associative arrays in the format $arr['wrapper']['option'] = $value. It defaults to an empty array.

例子 1. Using stream_context_create()


<?php
$opts = array(
  'http'=>array(
    'method'=>"GET",
    'header'=>"Accept-language: en\r\n" . 
              "Cookie: foo=bar\r\n"
  )
);

$context = stream_context_create($opts);

/* Sends an http request to www.example.com
   with additional headers shown above */
$fp = fopen('http://www.example.com', 'r', false, $context);
fpassthru($fp);
fclose($fp);
?>

See also stream_context_set_option(), and Listing of supported wrappers with context options (附录 L).

add a note User Contributed Notes

dev at zayso dot org
06-Mar-2006 09:31


Example of a stream for reading a string passed 

via a context object.

<?php

/* ----------------------------------------

 * Designed to read from a string

 */

class sfStreamStringRead

{

    const PROTOCOL = 'stringread'; /* Underscore not allowed */

        

    protected $dataPos  = NULL;

    protected $dataBuf  = NULL;

    protected $dataLen  = NULL;

    

    function stream_open($path, $mode, $options, &$opened_path)

    {

        /* Verify context has data */ 

        $contextOptions = stream_context_get_options($this->context);

        if (!isset($contextOptions[self::PROTOCOL]['data'])) {

            return FALSE;

        }

        $this->dataBuf = $contextOptions[self::PROTOCOL]['data'];

        $this->dataLen = strlen($this->dataBuf);

        $this->dataPos = 0;

        return TRUE;

    }

    function stream_read($count){ 

        $ret = substr($this->dataBuf, $this->dataPos, $count); 

        $this->dataPos += strlen($ret); 

        return $ret; 

    }

    function stream_eof(){ 

        return $this->dataPos >= $this->dataLen; 

    } 

    function stream_tell(){ 

        return $this->dataPos; 

    }

    /* ------------------------------------------

     * A few helper functions

     */ 

    static function genURL()

    {

        return self::PROTOCOL . '://';

    }

    static function genContext($dataBuf)

    {

        return stream_context_create(array(

            self::PROTOCOL => array(

                'data' => $dataBuf,

            ),

        ));

    }

    static function open($dataBuf)

    {

        return fopen(self::genURL(),'r',FALSE,self::genContext($dataBuf)); 

    }  

}

stream_wrapper_register(

    sfStreamStringRead::PROTOCOL,

   'sfStreamStringRead'

);



$sp = sfStreamStringRead::open("Some String Data\n");

echo fgets($sp);

fclose($sp);        



?>

net_navard at yahoo dot com
10-Dec-2005 02:38


Hi,you can create an array of parameters(what it's called a stream context),which can be transmitted each time you read or write a stream through a socket.In the below example:



$opts =array('http'=>arra('method'=>"GET",

'header'=>"Accept-language:en\r\n"."Cookie: foo=bar\r\n");



What you're actually doing is create a set of parameters(the protocol to be used,the request method,additional http headers and a cookie) which will be used each time you open a socket connection to request www.example.com.This saves a lot of time if you want to use these parameters (called a stream context) whenever you include them when making a request to www.example.com,instead of having to specify them over and over again.

Using the previous example,say you want to create a stream context,which sends a "Content-Type" http header and utilize it when making a request to www.example.com.Take a look:



$opts = array('http'=>array('method'=>"GET",

'header'=>"Content-Type: text/xml; charset=utf-8");



$context = stream_context_create($opts);

$fp = fopen('http://www.example.com','r',false,$context);

fpassthru($fp);

fclose($fp);



Now,when you make a request to www.example.com,the above http header will be included within the socket and transmitted to the server.Best of luck for you friends,Hossein

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