[sclug] Exporting a terminal over the network

[John Stumbles]

Roland Turner (SCLUG) wrote:
> John Stumbles wrote:
> 
> 
> 
>>Roland Turner (SCLUG) wrote:
>>
>>>Are you certain? The man page claims a complete set of TERMIOS options
>>>including xon and xoff (which, despite the ridiculous names, relate to
>>>inward and outward flow control characters respectively).
>>
>>IIRC (long time since I plumbed layer 0 :)) Xoff & Xon (sometimes
>>generated from the keyboard by ^S and ^Q) tell the other end of the
>>link  to stop & restart (respectively) transmission. Inward & outward
>>flow  control is acheived by sending Xoff & Xon chars in each
>>direction: the  characters used are the same in each direction. (You
>>could also have  Xoff/Xon aka software flow control in one direction
>>and hardware, or no,  flow control in the other: the two directions of
>>data flow are
>>effectively independent channels.)
> 
> 
> 
> I'm not clear whether you are adding to or contradicting my comments

I wasn't clear myself :-)


> - According to the stty manpage, the 'ixon' option enables/disables
> inbound flow control (that is, it enables/disables the recognition of
> inbound XON/XOFF characters to control the flow of the outbound character
> stream).
> 
> - According to the stty manpage, the 'ixoff' option enables/disables
> outbound flow control (that is, it enables/disables the sending of
> XON/XOFF characters to attempt to control the remote sender of the inbound
> character stream).
> 
> - The names of the options are clearly misleading

Agreed: it makes it sound as if xon and xoff relate to inward and 
outward flow control characters respectively (which is what you said, 
and which caused me to raise my eyebrows and reply with my own 
understanding).

> I've not actually tested this; inband flow control is the work of the
> devil and I avoid it like the plague.

It's OK as long as the data stream doesn't think the channel is 8-bit 
(or even 7-bit) clean.

Getting hardware flow control to work correctly can be fun, too :-)


-- 
John Stumbles                                      mobile 0780 866 8204
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