(PHP 4 >= 4.3.0, PHP 5)
msg_send — Send a message to a message queue
$queue
   , int $msgtype
   , mixed $message
   [, bool $serialize = true
   [, bool $blocking = true
   [, int &$errorcode
  ]]] )
   msg_send() sends a message of type
   msgtype (which MUST be greater than 0) to
   the message queue specified by queue.
  
queue
msgtype
message
serialize
       The optional serialize controls how the
       message is sent.  serialize
       defaults to TRUE which means that the message is
       serialized using the same mechanism as the session module before being
       sent to the queue.  This allows complex arrays and objects to be sent to
       other PHP scripts, or if you are using the WDDX serializer, to any WDDX
       compatible client.
      
blocking
       If the message is too large to fit in the queue, your script will wait
       until another process reads messages from the queue and frees enough
       space for your message to be sent.
       This is called blocking; you can prevent blocking by setting the
       optional blocking parameter to FALSE, in which
       case msg_send() will immediately return FALSE if the
       message is too big for the queue, and set the optional
       errorcode to MSG_EAGAIN,
       indicating that you should try to send your message again a little
       later on.
      
errorcode
   Returns TRUE on success or FALSE on failure.
  
   Upon successful completion the message queue data structure is updated as
   follows: msg_lspid is set to the process-ID of the
   calling process, msg_qnum is incremented by 1 and
   msg_stime is set to the current time.