socket_write

(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

socket_write — Scrive su un socket.

Descrizione

socket_write(resource $socket, string $buffer, int $lunghezza = ?): int

Avviso

Questa funzione è SPERIMENTALE. Ovvero, il comportamento di questa funzione, il nome di questa funzione, in definitiva tutto ciò che è documentato qui può cambiare nei futuri rilasci del PHP senza preavviso. Siete avvisati, l'uso di questa funzione è a vostro rischio.

La funzione socket_write() scrive sul socket socket i dati tratti dal campo buffer.

Il parametro opzionale lunghezza può specificare un numero alternativo di bytes da scrivere nel socket. Se questa dimensione è maggiore della lunghezza di buffer, questa viene, in modo silenzioso, ridotta alla lunghezza di buffer.

La funzione restituisce il numero di bytes scritti con successo nel socket, oppure false se si verifica un errore. Il codice di errore può essere rilevato con socket_last_error(). Passando questo codice alla funzione socket_strerror() si ottiene una spiegazione dell'errore.

Nota:
socket_write() non scrive necessariamente tutti i byte da un dato buffer. E' ammesso che, in base alle dimensioni dei buffer della rete ecc., soltanto un certo ammontare di dati, anche un solo byte, sia scritto nel socket, nonostante il buffer sia di dimensioni maggiori. Si deve prestare attenzione a ciò per evitare di non inviare il resto dei dati.

Nota:
E' regolare per la funzione socket_write() restituire zero, ciò significa che non è stato scritto alcun byte. Si utilizzi l'operatore === per testare il caso di false nelle situazioni di errore.

Vedere anche socket_accept(), socket_bind(), socket_connect(), socket_listen(), socket_read() e socket_strerror().

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User Contributed Notes 8 notes

down

revelable at hotmail dot com ¶

13 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;
        }
            
    }
?>

down

anonymous ¶

2 years ago

sending a few mbs or more results in incomplete transfers, send data in a loop and chunks instead, socket_write reports complete write even though it is only a partial transfer, possibly because of buffer overrun somewhere.

$strlen=strlen($msg);
$totaltransferred=0;

$blocksize=10000;
for ($a=0;$a<$strlen;$a+=$blocksize){
    $part=substr($msg,$a,$blocksize);
    $transferred=socket_write($socket,$part,strlen($part));
    $totaltransferred+=$transferred;
}
    
if ($totaltransferred<$strlen){
    echo "incomplete transfer";
}

down

php at deguest dot asia ¶

8 years ago

I often read in php docs users not checking for the php function returned value, and in the case of socket_write, I could not see here in the comment anyone botering to read on the socket the server reply.

Then one user thought it would be a good idea to use usleep after a socket_write on a smtp connection.

Actually, if you check the server reply, not only will it give time for the server to reply before you write again on the socket, but also this is a great opportunity to check what the server replied you.

For instance, for smtp connection :

In this example MAIL_SERVER, MAIL_PORT and DEBUG are constants I defined.

<?php

function sendmail( $param )

{

    $from    = &$param[ 'from' ];

    $to      = &$param[ 'to' ];

    $message = &$param[ 'data' ];

    

    $isError = function( $string )

    {

        if( preg_match( '/^((\d)(\d{2}))/', $string, $matches ) )

        {

            if( $matches[ 2 ] == 4 || $matches[ 2 ] == 5 ) return( $matches[ 1 ] );

        }

        else

        {

            return( false );

        }

    };

    

    try

    {

        $socket = null;

        if( ( $socket = socket_create( AF_INET, SOCK_STREAM, SOL_TCP ) ) == false )

        {

            throw new Exception( sprintf( "Unable to create a socket: %s", socket_strerror( socket_last_error() ) ) );

        }

        if( !socket_connect( $socket, MAIL_SERVER, MAIL_PORT ) ) 

        {

            throw new Exception( sprintf( "Unable to connect to server %s: %s", MAIL_SERVER, socket_strerror( socket_last_error() ) ) );

        }

        $read = socket_read( $socket, 1024 );

        if( $read == false )

        {

            throw new Exception( sprintf( "Unable to read from socket: %s", socket_strerror( socket_last_error() ) ) );

        }

        

        if( socket_write( $socket, sprintf( "HELO %s\r\n", gethostname() ) ) === false )

        {

            throw new Exception( sprintf( "Unable to write to socket: %s", socket_strerror( socket_last_error() ) ) );

        }

        $read = socket_read( $socket, 1024 );

        if( $read == false )

        {

            throw new Exception( sprintf( "Unable to read from socket: %s", socket_strerror( socket_last_error() ) ) );

        }

        else

        {

            if( ( $errCode = $isError( $read ) ) ) throw new Exception( "Server responded with an error code $errCode" );

        }

        

        if( socket_write( $socket, sprintf( "MAIL FROM: %s\r\n", $from ) ) === false )

        {

            throw new Exception( sprintf( "Unable to write to socket: %s", socket_strerror( socket_last_error() ) ) );

        }

        $read = socket_read( $socket, 1024 );

        if( $read == false )

        {

            throw new Exception( sprintf( "Unable to read from socket: %s", socket_strerror( socket_last_error() ) ) );

        }

        else

        {

            if( ( $errCode = $isError( $read ) ) ) throw new Exception( "Server responded with an error code $errCode" );

        }

        /* And some more code, but not enough place in comment */

        return( $totalWriten );

    }

    catch( Exception $e )

    {

        $ERROR = sprintf( "Error sending mail message at line %d. ", $e->getLine() ) . $e->getMessage();

        return( false );

    }

}

down

gtk at linux dot online dot no ¶

21 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.

down

-3

webmaster at you-are-infected dot com ¶

17 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 ;)

down

-5

jean at briskula dot si ¶

13 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;

    }

?>

down

-6

masterwaster at gmail dot com ¶

15 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.

down

-8

divinity76 at gmail dot com ¶

9 years ago

function AddTCPChecksum(&$data){
//feel free to add some error handling for strlen($data)>65535...
$data=pack("v",strlen($data)).$data;
}

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