(PHP 5)
stream_get_contents — Reads remainder of a stream into a string
Identical to file_get_contents(), except that stream_get_contents() operates on an already open stream resource and returns the remaining contents in a string, up to maxlength bytes and starting at the specified offset.
A stream resource (e.g. returned from fopen())
The maximum bytes to read. Defaults to -1 (read all the remaining buffer).
Seek to the specified offset before reading. If this number is negative, no seeking will occur and reading will start from the current position.
Returns a stringIm Fehlerfall wird FALSE zurückgegeben..
Version | Beschreibung |
---|---|
5.1.0 | The offset was added. |
Beispiel #1 stream_get_contents() example
<?php
if ($stream = fopen('http://www.example.com', 'r')) {
// print all the page starting at the offset 10
echo stream_get_contents($stream, -1, 10);
fclose($stream);
}
if ($stream = fopen('http://www.example.net', 'r')) {
// print the first 5 bytes
echo stream_get_contents($stream, 5);
fclose($stream);
}
?>
Hinweis: Diese Funktion ist binary safe.
some times this functions cause an max execution time time error, Why?
Simple, if you use it the function wait for have the specified byte length into the resource or the end of file, but, several times this not happend, so we need implement an artificial flag like this:
$tmp = stream_get_contents($this->socket, 42);
while($tmp[42] != 'N'){
//Your code...
$tmp = stream_get_contents($this->socket, 42);
}
Per wez (at php.net), "the trick is to tell the recipient how big the packet is, so that it can read the correct length."
In my own experience, when using PHP streams to send data bursts, the "max length" parameter seems to act more as an exact length parameter, as the stream will block indefinitely until max length is reached or until the other side fcloses() the stream. The latter is ok unless you need to keep the stream open to continue communication, in which case you have to let the receiving end know how much data to expect, or it will block indefinitely if the max length of data is not sent. You need to pack() and prepend the length of the outgoing data stream in the first 4 bytes of the packet, as follows:
function send_pkt($stream, $my_data)
{
$len = strlen($my_data);
$send_data = pack('N', $len) . $my_data; //Pack the length in a network-friendly way, then prepend it to the data.
$final_len = strlen($send_data);
if ( fwrite($stream, $send_data) < $final_len ) {
//something went wrong, trigger error
}
}
function recv_pkt($stream)
{
$packed_len = stream_get_contents($stream, 4); //The first 4 bytes contain our N-packed length
$hdr = unpack('Nlen', $packed_len);
$len = $hdr['len'];
$recvd_data = stream_get_contents($stream, $len);
return $recvd_data;
}