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.NET is a cross-platform runtime for cloud, mobile, desktop, and IoT apps.
https://docs.microsoft.com/dotnet/core/
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.net 8 Console ReadKey - how to set back to 'echo mode' before child process launch? #91710

Open kjpgit opened 1 year ago

kjpgit commented 1 year ago

I have a full-screen, interactive console app in C#, started by bash. There is a background thread constantly polling ReadKey(interept=True). Those key events, plus posix signal events, go into an input queue that is consumed by the main thread.

The main thread consumes a keypress event like 'enter' and knows it needs to launch a process like 'vim' and then exit (ideally it would just use execve, but that's another issue I opened). But vim needs to start with a 'clean' (i.e. echo mode) tty settings, because that's what it will restore to when it exits back to bash.

"When Vim exits the terminal will be put back into the mode it was before Vim started."

Right now, what's happening is when vim exits, bash is using no-echo mode, because that's how c#'s last state was. And that's annoying, not being able to see what you type 😀

I don't see a good way to force the .Net Console back to 'normal/echo' mode before calling Tmds.Libc.execve() or Mono.Posix Syscall.execve().

It seems the only controls on this are Read/ReadKey, but the user is done pressing keys at this point. There won't be any more.

I think conflating tty mode setting with readkey was not a good design. Those should be orthogonal settings. And even mono.unix doesn't seem to have an ioctl to override this.

ghost commented 1 year ago

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Issue Details
I have a console app in C#, started by bash. There is a background thread constantly polling ReadKey(interept=True). Those key events, plus posix signal events, go into an input queue that is consumed by the main thread. The main thread sees it needs to launch a process like 'vim' and then exit (ideally it would just use execve, but that's another issue). But vim needs to start with a 'clean' (i.e. echo mode) tty settings, because that's what it will restore to when it exits back to bash. I don't see a good way to force the .Net Console back to 'normal/echo' mode before calling Tmds.Libc.execve(). It seems the only controls on this are Read/ReadKey, but the user is done pressing keys at this point. There won't be any more.
Author: kjpgit
Assignees: -
Labels: `area-System.Console`, `untriaged`
Milestone: -
adamsitnik commented 12 months ago

I think conflating tty mode setting with readkey was not a good design.

I agree, but how can we implement Console.ReadKey(interept: true) without it?