No Bytes Written to Reply Buffer of Send()

QNX Newsgroups (Archives) qdn.public.qnx4
1

Does anyone know how to obtain the number of bytes in the message
returned to a Send() call?

I can get the no. of bytes in the message sent to the Receive() by
calling Readmsg().
I am putting a bridge between Qnx2 and Qnx4 using the serial ports
created by Dev.net (Qnx4) and netdev(Qnx2). I have various processes on
the Qnx4 system. Each has a different message structure. If I can get
the no of bytes returned to the Send() in the reply buffer - everything
is straight forward.


ie
Send(pid,RqstMsg,RplyMsg,RqstSize,MaxRplySize);

The no. of bytes of data returned by the pid is generally less than
MaxRplySize.

Padraig Furlong

2

Padraig Furlong <Padraig.Furlong@rte.ie> wrote:

Does anyone know how to obtain the number of bytes in the message
returned to a Send() call?

I can get the no. of bytes in the message sent to the Receive() by
calling Readmsg().
I am putting a bridge between Qnx2 and Qnx4 using the serial ports
created by Dev.net (Qnx4) and netdev(Qnx2). I have various processes on
the Qnx4 system. Each has a different message structure. If I can get
the no of bytes returned to the Send() in the reply buffer - everything
is straight forward.

Unfortunately, there is no way to get this information. The usual way
we’ve done it (for things like read()) is to put a header at the start
of the reply message that includes a length field specifying how many
bytes have been replied with.

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.

3

David.
Thanks for your reply. I thought that was the case.

Many thanks

David Gibbs wrote:

Padraig Furlong <> Padraig.Furlong@rte.ie> > wrote:
Does anyone know how to obtain the number of bytes in the message
returned to a Send() call?

I can get the no. of bytes in the message sent to the Receive() by
calling Readmsg().
I am putting a bridge between Qnx2 and Qnx4 using the serial ports
created by Dev.net (Qnx4) and netdev(Qnx2). I have various processes on
the Qnx4 system. Each has a different message structure. If I can get
the no of bytes returned to the Send() in the reply buffer - everything
is straight forward.

Unfortunately, there is no way to get this information. The usual way
we’ve done it (for things like read()) is to put a header at the start
of the reply message that includes a length field specifying how many
bytes have been replied with.

-David

QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.