zsh (stty speed) question or tmux question?

zsh (stty speed) question or tmux question?

[rj]

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I think this is a zsh question, though it may be a tmux question, or
a question relating to both.

I SSH to a server from a Windows box using PuTTY. In the PuTTY
configuration window, in the Data panel, I have terminal speeds set to
"230400, 230400".

At the server end, in my .zprofile, I have "stty speed 230400". When
I enter "stty -a" at my zsh prompt, it shows "speed 230400 baud;" (among
several other stty settings).

When I log in to the server, I see (below a welcome banner) "230400" on
a line by itself just above the zsh prompt.

I assume (somewhat uncertainly) from this that I am connecting at or close
to that speed.

So why is it that when I open tmux from my zsh prompt, just before the
child zsh prompt appears (inside tmux), I see, on a line just above the
child zsh prompt, "9600"?

Do I need to -export- the "stty speed 230400" command that's in my
.zprofile?  I'm not sure I can do that (not sure I know how to), since
"stty speed 230400" is not an environment variable setting.

Or, can I / do I need to set from within tmux the speed at which the shell
opens tmux?

Or am I better off not trying to set these speeds at all? (The PuTTY manual
says, for example, about its "terminal speeds" setting:

	"This parameter does not affect the actual speed of the connection, which
	is always ‘as fast as possible’; it is just a hint that is sometimes used
	by server software to modify its behaviour. For instance, if a slow speed
	is indicated, the server may switch to a less bandwidth-hungry display
	mode.

	"The value is usually meaningless in a network environment, but PuTTY lets
	you configure it, in case you find the server is reacting badly to the
	default value.

	"The format is a pair of numbers separated by a comma, for instance,
	38400,38400. The first number represents the output speed (from the server)
	in bits per second, and the second is the input speed (to the server)."

In any event, I find the "9600" odd. I also am not really sure if these
supposed connection speeds have any real meaning or if they bear accurately
on my real connection speeds.

So, what is the source of the appearance of the "9600" speed indicator, and
why that speed when all settings are at the higher number, and appear to be
working at that higher number?



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Re: zsh (stty speed) question or tmux question?

[rj]

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On Thu 03 at 12:05 AM -0400, rj <rj@panix.com> wrote:

> So, what is the source of the appearance of the "9600" speed indicator ..

These speeds apparently apply only to serial connections which was how most
terminals used to connect.  (Sorry, has little to do with zsh.)



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Re: zsh (stty speed) question or tmux question?

[Peter Stephenson]

On Fri, 04 Apr 2014 00:13:09 -0400
rj <rj@panix.com> wrote:
> On Thu 03 at 12:05 AM -0400, rj <rj@panix.com> wrote:
> 
> > So, what is the source of the appearance of the "9600" speed indicator ..
> 
> These speeds apparently apply only to serial connections which was how most
> terminals used to connect.  (Sorry, has little to do with zsh.)

There's one remaining effect of this in the shell that I can see (there
used to be more): it appears still to be using it to decide whether it's
worth trying to update the terminal when waiting for a key press.  The
lower the speed, the longer it will wait before performing a refresh if
you don't type anything, up to a maximum of half a second.

I suspect there's more going on, so that it's not that simple --- there
are other occasions when terminal refreshes happen.

pws