27 Feb
2022
27 Feb
'22
2:39 a.m.
Login commands question:
I'm sure it's simple, but I can't figure it out. How do I get something
to run at login in v6? Right now, I use ed to create a file 'setprof'
that contains:
stty erase[space][backspace][return]
stty nl0 cr0
Then after logging in:
sh setprof
It works, but, it is pretty clunky.
stty question:
So, I looked at stty.c and it looks like the following should work, if
the terminal is sending ^H for backspace:
#define BS0 0
#define BS1 0100000
modes[]
...
"bs0",
BS0, BS1,
"bs1",
BS1, BS1,
but:
stty bs0
or
stty bs1
don't result in proper backspace handling..
but:
stty[space][^h][return]
works...
Thoughts?
27 Feb
27 Feb
3:03 a.m.
On 26 Feb 2022 14:39 -0600, from will.senn(a)gmail.com (Will Senn):
I'm sure it's simple, but I can't
figure it out. How do I get something to
run at login in v6?
From a very quick perusal of
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/source/s2/sh.c it
doesn't look like you can, at least not in the way we're used to today
of having the shell execute a magic file (such as ~/.bashrc) during
startup. I also don't see anything in
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/etc/passwd that
suggests that the shell can be specified on a per-user basis the way
we're used to being able to do today, so the hack of making that point
to a program that does some initial setup and then launches the shell
proper also might not be readily available.
On the other hand,
https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/cmd/sh/main.c
looks like it includes such support; see the section surrounding the
pathopen(nullstr, profile) call toward the bottom of main(). (Beware:
it's written in Bourne C.)
I won't say "you can't do it in V6", because I don't know things
anywhere near well enough to say that, but it doesn't look entirely
trivial at least, and it seems to have been added in V7's sh.
--
Michael Kjörling • https://michael.kjorling.se • michael(a)kjorling.se
“Remember when, on the Internet, nobody cared that you were a dog?”
4:49 a.m.
Some thoughts ..
1.) the precursor to the csh is the newshell in {1}BSD. It's Joy's hack to
the Thompson shell and you might find it more usable.
2.) PWB 1.0 is based on a V6 kernel and has the Mashey Shell, which is in C
and predates Bourne's It might also be easier for you to use.
3.) srb wrote his shell during the transition between V6, TS and V7. At
least one version ran on the V6++ system we had at CMU, but of course as
pointed out, it is written in Bourne-Gol. And I'm pretty sure his CPP
definitions will need at least a gen2 /lib/cpp implementation*** However,
Steve was also doing it at the time when the compiler was being updated.
FWIW: We also had the 'Typesetter C' running on our V6 system in those
days. So my >>guess<< is that v6 + Typesetter C - will compile the V7
shell.
Clem
*** Rob or Steve Johnson - maybe remembers when cpp first appeared. I
don't remember if it was part of V5 or not - those bits have faded from my
brain. What I do remember is there were a couple of different cpp's early
on. The first one was pretty crude by today's standards, albeit it was a
cool idea and it was the one thing I really liked about C over BLISS early
on [BLISS had Macros, which was cool aalso, but cpp could do things Bliss
could not].
5:12 a.m.
Cpp was definitely in v6, and I'm pretty sure it was in earlier editions.
The first pass of the C compiler would invoke it if the first byte of the
source file was a '#'. However, the early version only did #define and
#include. It was rewritten for v7, I believe, introducing the catastrophe
of #ifdef, while the existential horror of #if was later still, foisted on
us by someone not in Research.
-rob
On Sun, Feb 27, 2022 at 9:53 AM Clem Cole <clemc(a)ccc.com> wrote:
Some thoughts ..
1.) the precursor to the csh is the newshell in {1}BSD. It's Joy's hack
to the Thompson shell and you might find it more usable.
2.) PWB 1.0 is based on a V6 kernel and has the Mashey Shell, which is in
C and predates Bourne's It might also be easier for you to use.
3.) srb wrote his shell during the transition between V6, TS and V7. At
least one version ran on the V6++ system we had at CMU, but of course as
pointed out, it is written in Bourne-Gol. And I'm pretty sure his CPP
definitions will need at least a gen2 /lib/cpp implementation*** However,
Steve was also doing it at the time when the compiler was being updated.
FWIW: We also had the 'Typesetter C' running on our V6 system in those
days. So my >>guess<< is that v6 + Typesetter C - will compile the V7
shell.
Clem
*** Rob or Steve Johnson - maybe remembers when cpp first appeared. I
don't remember if it was part of V5 or not - those bits have faded from my
brain. What I do remember is there were a couple of different cpp's early
on. The first one was pretty crude by today's standards, albeit it was a
cool idea and it was the one thing I really liked about C over BLISS early
on [BLISS had Macros, which was cool aalso, but cpp could do things Bliss
could not].
6:46 a.m.
Yes. Thanks. I do remember it in 6 and the hack in cc to run it or not(it
took years for me to break the habit of starting a C program with a #) but
what I don’t remember was it in v5 - which we only ran briefly (I
personally never saw V4 either although I know Columbia and I believe
Harvard had it)
Clem
On Sat, Feb 26, 2022 at 6:12 PM Rob Pike <robpike(a)gmail.com> wrote:
Cpp was definitely in v6, and I'm pretty sure it
was in earlier editions.
The first pass of the C compiler would invoke it if the first byte of the
source file was a '#'. However, the early version only did #define and
#include. It was rewritten for v7, I believe, introducing the catastrophe
of #ifdef, while the existential horror of #if was later still, foisted on
us by someone not in Research.
-rob
On Sun, Feb 27, 2022 at 9:53 AM Clem Cole <clemc(a)ccc.com> wrote:
Sent from a handheld expect more typos than usual
Some thoughts ..
1.) the precursor to the csh is the newshell in {1}BSD. It's Joy's hack
to the Thompson shell and you might find it more usable.
2.) PWB 1.0 is based on a V6 kernel and has the Mashey Shell, which is in
C and predates Bourne's It might also be easier for you to use.
3.) srb wrote his shell during the transition between V6, TS and V7. At
least one version ran on the V6++ system we had at CMU, but of course as
pointed out, it is written in Bourne-Gol. And I'm pretty sure his CPP
definitions will need at least a gen2 /lib/cpp implementation*** However,
Steve was also doing it at the time when the compiler was being updated.
FWIW: We also had the 'Typesetter C' running on our V6 system in those
days. So my >>guess<< is that v6 + Typesetter C - will compile the V7
shell.
Clem
*** Rob or Steve Johnson - maybe remembers when cpp first appeared. I
don't remember if it was part of V5 or not - those bits have faded from my
brain. What I do remember is there were a couple of different cpp's early
on. The first one was pretty crude by today's standards, albeit it was a
cool idea and it was the one thing I really liked about C over BLISS early
on [BLISS had Macros, which was cool aalso, but cpp could do things Bliss
could not].
-- 
9:01 p.m.
On Sun, Feb 27, 2022 at 10:12:39AM +1100, Rob Pike wrote:
Cpp was definitely in v6, and I'm pretty sure it
was in earlier editions.
The first pass of the C compiler would invoke it if the first byte of the
source file was a '#'. However, the early version only did #define and
#include. It was rewritten for v7, I believe, introducing the catastrophe
of #ifdef, while the existential horror of #if was later still, foisted on
us by someone not in Research.
-rob
As someone who has lived through a lot of #if / #ifdef et al, I've got
mixed feelings. SGI definitely abused it, Dave Cutler was asked to
make NT work on MIPS and was given the IRIX kernel source as a guide.
That source was riddled with #ifdef <something>WAR where "WAR" stood for
"work around" (I might have the details wrong but definitely have the
idea correct). All of those work arounds were kernel code that had to
be different because various MIPS chips had bugs.
Cutler's response was "Send me the kernel code when you have MIPS chips
that actually work". He was disgusted and I don't blame him.
On the other hand, I grew up in the era that X11 was sort of new, all the
vendors had their own windowing system (Sunview comes to mind), and while
they all had something to be said for them (the Sunview API was really
nice), they all were different. So people like me carried around an X11
source tree and built it on whatever platform I happened to be running
on today (I was a contractor early on, worked on lots of different boxes).
The X11 tree was a heavily ifdef-ed. And it needed to be, I don't have
an answer as to how you would reuse all that code on different hardware
in a better way. Yep, ugly, but having N copies of the same code,
all almost the same but a little different, yeah, that's a formula for
having bugs fixed in one of those copies but not the others.
So while I understand (I think) Rob's distaste for #ifdef, I've been
very grateful for it when I needed it. I ran ctwm on X11 for decades
and everything "just worked" on Suns, SGIs, PowerPC, PARISC, etc.
--lm
11:10 p.m.
On Sun, Feb 27, 2022 at 10:01 AM Larry McVoy <lm(a)mcvoy.com> wrote:
So while I understand (I think) Rob's distaste
for #ifdef, I've been very
grateful for it when I needed it.
Yep - like symlinks -- useful feature when appropriately used in specific
moderation where they really do help. But both are like giving whiskey to
teenagers, so don't be surprised when the result is catastrophic.
1029
days inactive
1030
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6 comments
5 participants
participants (5)
-
Clem Cole -
Larry McVoy -
Michael Kjörling -
Rob Pike -
Will Senn