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Message-ID: <45869F8F.2020009@seclark.us>
Date: Mon, 18 Dec 2006 09:02:55 -0500
From: Stephen Clark <Stephen.Clark@...lark.us>
To: James Cloos <cloos@...loos.com>
CC: Jan Engelhardt <jengelh@...ux01.gwdg.de>,
Pavel Machek <pavel@....cz>, James Lockie <bjlockie@...kie.ca>,
Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [Fwd: escape key]
James Cloos wrote:
>>>>>>"Jan" == Jan Engelhardt <jengelh@...ux01.gwdg.de> writes:
>>>>>>
>>>>>>
>
>Jan> HOWEVER, unix people probably _had a reason_ to make ESC generate
>Jan> part of what function keys do.
>
>You are looking at it backwards. The Escape key generates an ASCII
>escape. The funtion keys (including the cursor keys) generate escape
>sequences because the vt100 won out the title as the most ubiquitous
>async serial terminal, and linux devs chose to have the console be
>(mostly) vt100 compatable. As xterm, et al had done before.
>
>The terminals (the actual hardware) used ASCII, so it was normal to
>use Escape to initiate the sequences used by the function keys.
>
>And that concept goes back a *lot* longer than unix. (Hmm. I can't
>remember. Did TOPS-20 or its predecessor have glass terminals in the
>day? I did get to use a DEC paper terminal a couple of times, but
>that was connected to a VMS box back in the '80s; most of the time it
>sat in the corner collecting dust....)
>
>At any rate, given that Escape was used to initiate sequences sent to
>the terminal for funtions such as moving the cursor around the screen,
>clearing rows or cols, et al it must have only seemed natural to also
>have it initiate sequences /from/ the terminal which did not fit into
>standard ASCII. That was after all Escape's purpose in the ASCII std.
>
>If you do want to change the console's terminal emulation, a good
>first step would be to check whether any existing terminal already
>uses something other than Escape to initiate function key sequences,
>and, if so, promote that as the alternative to vt100-esque emulation.
>
>Finally, note that the reason vt100 was chosen for the console was to
>make it more useful for users who were physically at a linux box, were
>logged in on the console, and from there logged in to remote servers.
>That does remain something which the console *must* support.
>
>-JimC
>
>
Also ansi came along and pretty much put their blessing on what DEC had
done and made the
escape sequences a standard.
Steve
--
"They that give up essential liberty to obtain temporary safety,
deserve neither liberty nor safety." (Ben Franklin)
"The course of history shows that as a government grows, liberty
decreases." (Thomas Jefferson)
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