Need ability to specify which file descriptor should be used for input?

[n1000]

I believe the ability to swap out what FD to use for input is needed in cases where the program using rustyline is having its stdin redirected from a file. In these cases, rustyreadline needs to use a FD still connected to the terminal to read input from, instead of using FD=0...

I was looking at this issue: PaulJuliusMartinez/jless#7 (note that I have no affiliation with this project)

And noticed that src/tty/unix.rs directly refered to STDIN_FILENO, without support for passing in / using another FD (such as a fd pointing to /dev/tty).

This seems to sort of be related to #542 (but this would be a simpler change).

A hacked up version of what this might look like is here: https://github.com/kkawakam/rustyline/compare/master...n1000:configurable_input?expand=1

I'm a Rust beginner, so I mostly worked on this to try and further my learning... The changes above are a hack, but demonstrate the concept. I've realized it's time to go back and reread some parts of "Programming Rust"... :)

It may also be the case that some much simpler solution to this exists, and no change in rustyline is needed...

[gwenn]

For reference:

• https://github.com/wez/wezterm/blob/main/termwiz/src/terminal/unix.rs#L248-L253
• https://github.com/wez/wezterm/blob/main/termwiz/src/terminal/windows.rs#L630-L635

[PaulJuliusMartinez]

I had considered filing a bug for this, but I believe it can be handled on the user's side by using freopen, based on this StackOverflow post. I haven't had a chance to test this out yet though.

Even if this does work, I think allowing for some configuration of the input file descriptor, or just supporting a toggle to read from /dev/tty makes sense.

[n1000]

For reference:

* https://github.com/wez/wezterm/blob/main/termwiz/src/terminal/unix.rs#L248-L253

* https://github.com/wez/wezterm/blob/main/termwiz/src/terminal/windows.rs#L630-L635

Thanks, updated src/tty/windows.rs to use "CONIN$" instead of "CON:", and also opened it with both read and write permissions (otherwise was getting a access denied when attempting to call SetConsoleMode()). Did a quick test in a Windows VM, and seems to work.

I had considered filing a bug for this, but I believe it can be handled on the user's side by using freopen, based on this StackOverflow post. I haven't had a chance to test this out yet though.

Agree on this, but unfortunately there also may be some difficulty using freopen, based on this PR: rust-lang/libc#7 . I think that issue is still unresolved based on my searching so far (but I may have missed something also).

[PaulJuliusMartinez]

I was able to use freopen to get around this, but, as mentioned by @n1000, had to bring in an external crate to get a reference to the FILE * associated with stdin.

[gwenn]

https://github.com/judah/haskeline/blob/master/System/Console/Haskeline/InputT.hs#L140-L152
https://github.com/judah/haskeline/blob/master/System/Console/Haskeline/InputT.hs#L192-L199
https://github.com/judah/haskeline/blob/master/System/Console/Haskeline/InputT.hs#L212-L217

[gwenn]

Could you please give a try to this branch ?

let config = Config::builder()
        .behavior(Behavior::PreferTerm)
        .build();
let mut rl = Editor::with_config(config);

echo x | cargo run --example example > debug.log
1> ...

Like Haskeline, with PreferTerm behavior, /dev/tty is used both for input and output on unix platform.
By default, rustyline keeps using stdin / stdout: default Behavior is Stdio.
Thanks.

I still need to fix: https://github.com/gwenn/rustyline/blob/dev_tty/src/tty/windows.rs#L495-L515 (see https://github.com/judah/haskeline/blob/c03e7029b2d9c3d16da5480306b42b8d4ebe03cf/System/Console/Haskeline/Backend/Win32.hsc#L238-L240 or https://github.com/rust-lang/rust/blob/master/library/std/src/sys/windows/stdio.rs#L53-L60)

[n1000]

Works fine for me on Linux (did not try out Windows).

[gwenn]

Version 10.0.0 released.