PHP 8.4.2 Released!

socket_write

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

socket_writeソケットに書き込む

説明

socket_write(Socket $socket, string $data, ?int $length = null): int|false

関数 socket_write() は、 data の内容をソケット socket に書き込みます。

パラメータ

socket

data

書き込まれるバッファ。

length

オプションのパラメータ length で、 ソケットに書き込むバイト数を指定することが可能です。 この値がバッファの長さより大きい場合、自動的にバッファのサイズに切り詰められます。

戻り値

ソケットへの書き込みに成功したデータのバイト数を返します。失敗した場合に false を返します。 エラーコードは socket_last_error() を用いて取得することができ、この値を socket_strerror() に渡すことでエラー情報を文字列で取得可能です。

注意:

socket_write() がゼロを返すことも十分ありえます。 これは、書き込むデータが存在しなかったことを意味します。 エラーをチェックするために false かどうかを調べる際には、必ず === 演算子を使用しましょう。

変更履歴

バージョン 説明
8.0.0 socket は、Socket クラスのインスタンスになりました。 これより前のバージョンでは、リソース型でした。
8.0.0 length は、nullable になりました。

注意

注意:

socket_write() は、バッファの内容を必ずしもすべて 書き込むとは限りません。ネットワークバッファの状態にもよりますが、 たとえ 1 バイトだけ書き込まれたのであったとしても、それはエラーではなく正常な動作です。 そのため、データがすべて書き込まれたのかどうかに注意する必要があります。

参考

add a note

User Contributed Notes 5 notes

up
8
revelable at hotmail dot com
14 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
1
anonymous
3 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";
}
up
2
gtk at linux dot online dot no
22 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
php at deguest dot asia
9 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 );
}
}
up
-3
webmaster at you-are-infected dot com
18 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 ;)
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