[net.unix-wizards] \"UC.C\" command problem

lblock@almsa-1.arpa (Laurie A. Block) (01/29/86)

We have recently installed the "uc" command on a VAX 11/780 running
BRL VAX UNIX.  We have encountered several tranmission errors. When
trying to send a file it hangs up always on the 18th block. When
trying to receive a file, it does not appear to start. 

We were told that there were certain compilation flags that need to be
set for it to compile correctly. In looking at the source code,
and reading the "cc" man page, I have not been able to identify 
these flags. I have only been using the optimizer option. 

Any help you can give us would be much appreciated. We have acquired 
the source code from simtel20.


Thank you
Laurie

egray@fthood (01/31/86)

> We have recently installed the "uc" command on a VAX 11/780 running
> BRL VAX UNIX.  We have encountered several tranmission errors. When
> trying to send a file it hangs up always on the 18th block. When
> trying to receive a file, it does not appear to start. 
> ... 
> Thank you
> Laurie

I have never heard of the 'uc' command and don't even know what it is...
But becuase of your excellent observations, I know what the problem is!

The transmission block numbers are being sent allong with each block of
data.  These would probably start at 1 (or perhaps 0) and increase as
the blocks are sent.  After the 18th block is sent, character 19 is sent
as the block number.  This character is the XOFF character that would
instruct the listener to wait until a XON character is sent.

This is more than likely what is happening...  Now, to solve the problem:

Find the part of the code that resets the communication line.  This would
either be a 'ioctl' call or a 'setty' call.  Change the communication
protocol to the 'raw' mode (the mode that ignores XOFF and XON).  There are
several ways of doing this depending on which flavor of unix you are using.
You will find a write-up in the manual sections tty(4) or termio(7) depending
again on the flavor of unix.

PS: If you have a uucp address, indicate it in your note.  That way other
uucp domain sites can respond directly to you by mail.

Emmet P. Gray				US Army, HQ III Corps & Ft. Hood
..!ihnp4!uiucdcs!uiucuxc!fthood!egray	Attn: AFZF-DE-EMO
					DEH, Environmental Management Office
					Fort Hood, TX 76544-5057