Cryptic Unix Arcana (was: Re: APPLEVISION Monitor, Anything !Windows = Cryptic ?)

From: Sean 'Captain Napalm' Conner <spc_at_conman.org>
Date: Mon May 6 21:02:51 2002

It was thus said that the Great Christopher Smith once stated:
>
> > From: Raymond Moyers [mailto:rmoyers_at_nop.org]
>
> > Unix, for years, shipped with a editor nobody could use
> > and backspace key that did not work, and seemed rigged
>
> Hmm -- the backspace key has always worked for me, and the
> editor, while being not incredibly nice, was useable.

  Maybe now, but not always (and I still come across the occasional
problem). The problem lies with what do you use to back the cursor up one
position and delete the character that is there? BS (ASCII 8)? The proper
definition is to move the cursor left one position; nothing at all about
removing the character there. DEL (ASCII 127)? Again, the proper
definition is a character that is to be ignored (comes from paper tape I
believe, to erase or ignore a character on tape, you punch out all the
holes---thus it being defined as 127).

  DEC decided to use DEL to back up one space and delete the character, and
this was carried over by the BSD guys. SysV (from AT&T) seemed to settle on
using BS for this function (as did Microsoft). All through college I was
always having to redefine what my terminal emulation program sent when I hit
the Backspace key or tell Unix what the backspace key is, depending on what
I could and couldn't do at the time.

  Heck, even Linux isn't consistent about this---I think the console has
Backspace sending a DEL character, while under X Windows, the Backspace key
is remapped back to BS, while Linux still things DEL is the backspace
character. It might be fixed now in the latest distributions, but I'm not
about to upgrade from RedHat 5.2 for a variety of reasons.

  For even more weirdness, I remember using HP-UX 9.x ('96 or '97) and it
using the ``_at_'' character to erase a line! And here I thought that died out
by Version 6 or 7.

  -spc (ASCII has a similar problem with CR and LF ... )
Received on Mon May 06 2002 - 21:02:51 BST