PHP 5.4.31 Released

socket_write

(PHP 4 >= 4.1.0, PHP 5)

socket_writeWrite to a socket

Description

int socket_write ( resource $socket , string $buffer [, int $length = 0 ] )

The function socket_write() writes to the socket from the given buffer.

Parameters

socket

buffer

The buffer to be written.

length

The optional parameter length can specify an alternate length of bytes written to the socket. If this length is greater then the buffer length, it is silently truncated to the length of the buffer.

Return Values

Returns the number of bytes successfully written to the socket or FALSE on failure. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.

Note:

It is perfectly valid for socket_write() to return zero which means no bytes have been written. Be sure to use the === operator to check for FALSE in case of an error.

Notes

Note:

socket_write() does not necessarily write all bytes from the given buffer. It's valid that, depending on the network buffers etc., only a certain amount of data, even one byte, is written though your buffer is greater. You have to watch out so you don't unintentionally forget to transmit the rest of your data.

See Also

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User Contributed Notes 6 notes

up
1
gtk at linux dot online dot no
11 years ago
from http://www.manualy.sk/sock-faq/unix-socket-faq-2.html
read() is equivalent to recv() with a flags parameter of 0. Other values for the flags parameter change the behaviour of recv(). Similarly, write() is equivalent to send() with flags == 0.
up
1
masterwaster at gmail dot com
5 years ago
Hi,
if you got same problems like i have

<?php
@socket_write($xd, "Good Bye!\n\r");
@
socket_shutdown($xd, 2);
@
socket_close($xd);
?>

wont'tx send "Good Bye!\n\r" to the opened socket.

but if you put a
usleep or something like echo "";
between write and shutdown its working.
up
1
revelable at hotmail dot com
3 years ago
Here we have the same function to write a socket but with improved performance.

If the messager are not larger, they will be written entirely with a single socket_write() call. And is not needed to call the substr() function for the first bucle.

<?php
$st
="Message to sent";
$length = strlen($st);
       
    while (
true) {
       
       
$sent = socket_write($socket, $st, $length);
           
        if (
$sent === false) {
       
            break;
        }
           
       
// Check if the entire message has been sented
       
if ($sent < $length) {
               
           
// If not sent the entire message.
            // Get the part of the message that has not yet been sented as message
           
$st = substr($st, $sent);
               
           
// Get the length of the not sented part
           
$length -= $sent;

        } else {
           
            break;
        }
           
    }
?>
up
0
Anonymous
2 days ago
Watch out for these examples and contributions.

First off, in the official examples you must confirm that socket_write() has written your data, and in most cases that it has written all your data, as the example is usually a "write one thing and then finish" case where the socket is not left open.

I am pretty sure you cannot keep calling socket_write() on data that you already called it upon just because it has not been sent in the first call to socket_write(). If buffering ever occurs, you would end up re-sending fragments of your data.

You should not use a sleep/wait to compensate for the fact that output is buffered.

And finally, you should not be confused as to why separating your data into two separate calls to socket_write() results in receiving data on the far end, and yet one call does not.

All of these problems with the contributed examples show a lack of understanding of Buffering.
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0
webmaster at you-are-infected dot com
7 years ago
If you connect to a Server in a way like you do with telnet or some similar protokoll you may have problems with sending data to the server. I found out that at some servers there is a different between:

<?php
   
    socket_write
($my_socket, $line, strlen ($line));
   
socket_write ($my_socket, "\r\n", strlen ("\r\n"));
   
?>
witch worked at least, and
<?php
    socket_write
($my_socket, $line."\r\n", strlen ($line."\r\n"));
?>
wich made the server stop sending any data.

I hope this helps to save a lot of time. I needed about two days to find out, that this was the problem ;)
up
-3
jean at briskula dot si
3 years ago
Some clients (Flash's XMLSocket for example) won't fire a read event until a new line is recieved.

<?php
   
/*
     * Write to a socket
     * add a newline and null character at the end
     * some clients don't read until new line is recieved
     *
     * try to send the rest of the data if it gets truncated
     */
   
function write(&$sock,$msg) {
       
$msg = "$msg\n\0";
       
$length = strlen($msg);
        while(
true) {
           
$sent = socket_write($sock,$msg,$length);
            if(
$sent === false) {
                return
false;
            }
            if(
$sent < $length) {
               
$msg = substr($msg, $sent);
               
$length -= $sent;
                print(
"Message truncated: Resending: $msg");
            } else {
                return
true;
            }
        }
        return
false;
    }
?>
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