Use powershell.exe instead of clip.exe to copy to WSL clipboard

[johnDeSilencio]

Problem

Copying to clipboard in WSL environment using clip.exe leads to garbled data being copied to clipboard for Unicode point characters (e.g. 💯). Using powershell.exe set-clipboard instead copies Unicode point characters to the clipboard correctly.

Evidence

I have a crate that I put together for fun called emojicp. I liked your crate because it gave me the widest number of environments to run emojicp in. However, it seems to fail for WSL environments.

Below are 10 emojis that I tried to copy to my clipboard in WSL alongside what was actually copied to my clipboard:

Emoji Name	Expected Output	Expected Output (Hex)	Actual Output	Actual Output (Hex)
white_check_mark	✅	e2 9c 85	Γ£à	ce 93 c2 a3 c3 a0
santa	🎅	f0 9f 8e 85	≡ƒÄà	e2 89 a1 c6 92 c3 84 c3 a0
monkey	🐒	f0 9f 90 92	≡ƒÉÆ	e2 89 a1 c6 92 c3 89 c3 86
see_no_evil	🙈	f0 9f 99 88	≡ƒÖê	e2 89 a1 c6 92 c3 96 c3 aa
hear_no_evil	🙉	f0 9f 99 89	≡ƒÖë	e2 89 a1 c6 92 c3 96 c3 ab
speak_no_evil	🙊	f0 9f 99 8a	≡ƒÖè	e2 89 a1 c6 92 c3 96 c3 a8
monkey_face	🐵	f0 9f 90 b5	≡ƒÉ╡	e2 89 a1 c6 92 c3 89 e2 95 a1
sunglasses	😎	f0 9f 98 8e	≡ƒÿÄ	e2 89 a1 c6 92 c3 bf c3 84
oncoming_automobile	🚘	f0 9f 9a 98	≡ƒÜÿ	e2 89 a1 c6 92 c3 9c c3 bf
orangutan	🦧	f0 9f a6 a7	≡ƒªº	e2 89 a1 c6 92 c2 aa c2 ba
japanese_goblin	👺	f0 9f 91 ba	ቡƒæ║	e1 89 a1 c6 92 c3 a6 e2 95 91

Solution

After reading a lot of obscure WSL GitHub issues and playing around with encodings, the only solution that actually fixed my use case was replacing clip.exe with powershell.exe set-clipboard altogether. Now, with powershell.exe set-clipboard, I can copy emojis to my clipboard in WSL just fine.

[rgwood]

Thank you for the great PR+description! It might be a few days before I have time to test this on WSL but it looks good.

The only concern I have is that PowerShell can be quite slow to launch. Not the end of the world though, I think correctness is more important than speed here.

[johnDeSilencio]

You're welcome! Thank you for putting together a great crate 😁

I've also observed powershell being slow. I'm open to trying to rework clip.exe. I just wasn't able to get it to work on WSL in the couple of hours I was fiddling with it.

I would also wait on merging the PR. I was testing again this morning and saw that the way Rust is doing escaping, this PR breaks for copying string with double quotes " in them. Gonna try to push another commit today to fix that edge case.

[johnDeSilencio]

The most recent commit should address the quote escaping issue. I use single-quotes ' instead of double-quotes " inside the format!() macro. Run this Rust program in WSL and you should see that strings with single-quotes and strings with double-quotes both get copied to your clipboard successfully:

use std::process::Command;
use std::io::Read;

fn main() {
    for s in &["'🦀'", "\"🦀\""] {
        let mut command = Command::new("powershell.exe");
        command.arg("-NoProfile").arg("-Command").arg(&format!("Set-Clipboard -Value '{}'", s.replace("'", "''")));
        println!("{:?}", command);

        let mut command = command.spawn().unwrap();
        command.wait().unwrap();

        println!("Copied {} to your clipboard. Press ENTER to continue...", s);
        let buffer = &mut [0u8];
        std::io::stdin().read_exact(buffer).unwrap();
    }
}

[rgwood]

Thanks for your patience, finally had a chance to test this.

Timing-wise Powershell is not great but OK; 150-300ms on my 12900K desktop.

I tried adding a test, and it looks like setting emoji content works but getting it from the clipboard does not:

#[test]
fn set_and_get() -> Result<()> {
    let text = "Hello, world! 🌍";
    set_clipboard(text)?;

    let clipboard_contents = get_clipboard()?;
    assert_eq!(clipboard_contents, text);

    Ok(())
}

---- set_and_get stdout ----
Copy finished in 172ms
thread 'set_and_get' panicked at 'assertion failed: `(left == right)`
  left: `"Hello, world! ??"`,
 right: `"Hello, world! 🌍"`', src/lib.rs:94:5

If you have time/energy/interest, it would be nice to get that working. In the meantime, this looks like a strict improvement and I'm happy to merge it.

[rgwood]

Published to Cargo as v0.2.3.