* PATCH: Allow using STTY= to save terminal state
@ 2022-01-18 22:24 Mikael Magnusson
2022-01-18 22:27 ` Bart Schaefer
0 siblings, 1 reply; 9+ messages in thread
From: Mikael Magnusson @ 2022-01-18 22:24 UTC (permalink / raw)
To: zsh-workers
A person in IRC had issues with a command (fastlane) changing some random
stty settings, which broke some stuff (prompt printed twice sometimes
etc). I suggested aliasing fastlane to "STTY=-echonl fastlane" which
causes zsh to restore stty settings after the command returns. However,
it would be nice to be able to do this without having to specify a random
stty setting to actually change when starting the command, this patch
does that.
---
Src/exec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Src/exec.c b/Src/exec.c
index 63feb6cff6..85e2f8d992 100644
--- a/Src/exec.c
+++ b/Src/exec.c
@@ -684,8 +684,10 @@ execute(LinkList args, int flags, int defpath)
/* If the parameter STTY is set in the command's environment, *
* we first run the stty command with the value of this *
- * parameter as it arguments. */
- if ((s = STTYval) && isatty(0) && (GETPGRP() == getpid())) {
+ * parameter as it arguments. If the parameter is empty, we *
+ * do nothing, but this causes the terminal settings to be *
+ * restored later which can be useful. */
+ if ((s = STTYval) && *s && isatty(0) && (GETPGRP() == getpid())) {
char *t = tricat("stty", " ", s);
STTYval = 0; /* this prevents infinite recursion */
--
2.15.1
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-18 22:24 PATCH: Allow using STTY= to save terminal state Mikael Magnusson
@ 2022-01-18 22:27 ` Bart Schaefer
2022-01-18 23:17 ` Mikael Magnusson
0 siblings, 1 reply; 9+ messages in thread
From: Bart Schaefer @ 2022-01-18 22:27 UTC (permalink / raw)
To: Mikael Magnusson; +Cc: Zsh hackers list
On Tue, Jan 18, 2022 at 2:25 PM Mikael Magnusson <mikachu@gmail.com> wrote:
>
> A person in IRC had issues with a command (fastlane) changing some random
> stty settings [...]
> it would be nice to be able to do this without having to specify a random
> stty setting to actually change when starting the command
Umm, isn't this what "ttyctl -f" is for? What have I missed?
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-18 22:27 ` Bart Schaefer
@ 2022-01-18 23:17 ` Mikael Magnusson
2022-01-19 1:10 ` Bart Schaefer
2022-01-19 14:06 ` Daniel Shahaf
0 siblings, 2 replies; 9+ messages in thread
From: Mikael Magnusson @ 2022-01-18 23:17 UTC (permalink / raw)
To: Bart Schaefer; +Cc: Zsh hackers list
On 1/18/22, Bart Schaefer <schaefer@brasslantern.com> wrote:
> On Tue, Jan 18, 2022 at 2:25 PM Mikael Magnusson <mikachu@gmail.com> wrote:
>>
>> A person in IRC had issues with a command (fastlane) changing some random
>> stty settings [...]
>> it would be nice to be able to do this without having to specify a random
>> stty setting to actually change when starting the command
>
> Umm, isn't this what "ttyctl -f" is for? What have I missed?
I remembered about STTY= existing, and its documentation does not
reference ttyctl (in fact nothing references ttyctl except for the
ttyctl entry). That said, running ttyctl -f and ttyctl -u around a
command is a bit more work than simply prepending STTY= (which
currently just causes the stty help text to be printed, which doesn't
seem very useful).
--
Mikael Magnusson
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-18 23:17 ` Mikael Magnusson
@ 2022-01-19 1:10 ` Bart Schaefer
2022-01-19 14:06 ` Daniel Shahaf
1 sibling, 0 replies; 9+ messages in thread
From: Bart Schaefer @ 2022-01-19 1:10 UTC (permalink / raw)
To: Mikael Magnusson; +Cc: Zsh hackers list
On Tue, Jan 18, 2022 at 3:17 PM Mikael Magnusson <mikachu@gmail.com> wrote:
>
> [...] running ttyctl -f and ttyctl -u around a
> command is a bit more work than simply prepending STTY=
The point of ttyctl -f is to run it from .zshrc and only use ttyctl -u
when absolutely necessary. You're not supposed to need to switch it
on and off.
(I wonder, though, if the thread from users/27471 might get tangled up
here. Something about the startup sequence seems to have got wonky.)
> ([STTY=]
> currently just causes the stty help text to be printed, which doesn't
> seem very useful).
Agreed that running stty with no arguments in that instance is not helpful.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-18 23:17 ` Mikael Magnusson
2022-01-19 1:10 ` Bart Schaefer
@ 2022-01-19 14:06 ` Daniel Shahaf
2022-01-19 17:29 ` Bart Schaefer
1 sibling, 1 reply; 9+ messages in thread
From: Daniel Shahaf @ 2022-01-19 14:06 UTC (permalink / raw)
To: Zsh hackers list
Mikael Magnusson wrote on Wed, Jan 19, 2022 at 00:17:10 +0100:
> That said, running ttyctl -f and ttyctl -u around a command is a bit
> more work than simply prepending STTY=
So perhaps we need some syntactic sugar for "wrap a command with
a well-known pair of before/after modifiers". I'm thinking of something
similar to Python context managers, where
.
with open("foo.txt") as fd:
...
.
is syntactic sugar for
.
try:
fd = open("foo.txt")
...
finally: # equivalent to «always» in zsh
close(fd)
.
.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-19 14:06 ` Daniel Shahaf
@ 2022-01-19 17:29 ` Bart Schaefer
2022-01-19 20:08 ` Peter Stephenson
0 siblings, 1 reply; 9+ messages in thread
From: Bart Schaefer @ 2022-01-19 17:29 UTC (permalink / raw)
To: Daniel Shahaf; +Cc: Zsh hackers list
On Wed, Jan 19, 2022 at 6:07 AM Daniel Shahaf <d.s@daniel.shahaf.name> wrote:
>
> So perhaps we need some syntactic sugar for "wrap a command with
> a well-known pair of before/after modifiers".
Not every problem deserves a generalized solution. This sort of thing
can already be done with function wrappers, wanders pretty far afield
from shell syntax, and adds keywords in ambiguous contexts.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-19 17:29 ` Bart Schaefer
@ 2022-01-19 20:08 ` Peter Stephenson
2022-01-21 7:11 ` Daniel Shahaf
0 siblings, 1 reply; 9+ messages in thread
From: Peter Stephenson @ 2022-01-19 20:08 UTC (permalink / raw)
To: zsh-workers
On Wed, 2022-01-19 at 09:29 -0800, Bart Schaefer wrote:
> On Wed, Jan 19, 2022 at 6:07 AM Daniel Shahaf <d.s@daniel.shahaf.name> wrote:
> >
> > So perhaps we need some syntactic sugar for "wrap a command with
> > a well-known pair of before/after modifiers".
>
> Not every problem deserves a generalized solution. This sort of thing
> can already be done with function wrappers, wanders pretty far afield
> from shell syntax, and adds keywords in ambiguous contexts.
Yes, I think Mikael's tiny change would be a good addition.
The STTY parameter is not something crying out for generalisation.
pws
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-19 20:08 ` Peter Stephenson
@ 2022-01-21 7:11 ` Daniel Shahaf
2022-01-22 22:44 ` Bart Schaefer
0 siblings, 1 reply; 9+ messages in thread
From: Daniel Shahaf @ 2022-01-21 7:11 UTC (permalink / raw)
To: zsh-workers
Peter Stephenson wrote on Wed, 19 Jan 2022 20:08 +00:00:
> On Wed, 2022-01-19 at 09:29 -0800, Bart Schaefer wrote:
>> On Wed, Jan 19, 2022 at 6:07 AM Daniel Shahaf <d.s@daniel.shahaf.name> wrote:
>> >
>> > So perhaps we need some syntactic sugar for "wrap a command with
>> > a well-known pair of before/after modifiers".
>>
>> Not every problem deserves a generalized solution. This sort of thing
>> can already be done with function wrappers, wanders pretty far afield
>> from shell syntax, and adds keywords in ambiguous contexts.
>
> Yes, I think Mikael's tiny change would be a good addition.
> The STTY parameter is not something crying out for generalisation.
Fair enough.
As to "adds keywords in ambiguous contexts": I haven't proposed any
particular syntax; I only described functionality.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: PATCH: Allow using STTY= to save terminal state
2022-01-21 7:11 ` Daniel Shahaf
@ 2022-01-22 22:44 ` Bart Schaefer
0 siblings, 0 replies; 9+ messages in thread
From: Bart Schaefer @ 2022-01-22 22:44 UTC (permalink / raw)
To: Zsh hackers list
On Thu, Jan 20, 2022 at 11:12 PM Daniel Shahaf <d.s@daniel.shahaf.name> wrote:
>
> As to "adds keywords in ambiguous contexts": I haven't proposed any
> particular syntax; I only described functionality.
Fair enough. :-) I'm not sure how you'd do it without a keyword, though.
As to the original question, zsh runs "stty" without qualification, so
you can do:
stty() {
[[ -n "$*" ]] && command stty "$@"
}
to get the same effect as Mikael's patch.
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2022-01-22 22:44 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-18 22:24 PATCH: Allow using STTY= to save terminal state Mikael Magnusson
2022-01-18 22:27 ` Bart Schaefer
2022-01-18 23:17 ` Mikael Magnusson
2022-01-19 1:10 ` Bart Schaefer
2022-01-19 14:06 ` Daniel Shahaf
2022-01-19 17:29 ` Bart Schaefer
2022-01-19 20:08 ` Peter Stephenson
2022-01-21 7:11 ` Daniel Shahaf
2022-01-22 22:44 ` Bart Schaefer
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