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" );
}
return( $totalWriten );
}
catch( Exception $e )
{
$ERROR = sprintf( "Error sending mail message at line %d. ", $e->getLine() ) . $e->getMessage();
return( false );
}
}
