Ripgrep: Color doesn't work in windows mintty (git bash)

[auxym]

I can't get rg to output color in mintty, ie the default term that comes with git for windows and MSYS2. Tried --color always and -p, to no avail. Color works fine (by default) in standard cmd.exe.

Color (--color=auto) works with standard grep in mintty, or at least the grep build that comes with git for windows.

[BurntSushi]

Do you know if mintty uses the Windows console for coloring? Or does it use something else? I wonder if ripgrep is supposed to be using ANSI escape sequences here and is instead trying to use the Windows console.

[auxym]

Here is the raw output from echo "AAAaaa" | grep --color=always aa > grepcolor.txt in mintty:

b'AAA\x1b[01;31m\x1b[Kaa\x1b[m\x1b[Ka\n'

I tried the same exercise with rg, but couldn't get it to output the escape codes, both in mintty and cmd.exe. It looks like rg doesn't detect terminal output and ignores the color=always options.

[BurntSushi]

It does detect terminal output, just apparently not on Windows. :-) I think the issue is that I baked an assumption into ripgrep that if it's on Windows, then it should do coloring with the Windows console. It looks like in the case of mintty, it should use ANSI escape codes? Is that right?

For cmd.exe, I don't think it should be printing escape codes.

cc @retep998 Would you be able to add any insight here? Thanks so much. :-)

[retep998]

@BurntSushi Basically with mintty you have a pipe instead of a console. Because of this there is no API you can call to determine whether a pipe is actually a terminal that accepts ansi escape codes. The best you can do is that if you're not talking to a console, then check whether TERM is set, if it is then you're _probably_ in a terminal emulator (or being redirected to a file while inside a terminal emulator).

Conhost (which is what cmd.exe uses) doesn't support escape codes in older Windows, and in Windows 10 it only supports them if a certain mode is enabled.

[leafgarland]

Perhaps the --color flag could support extra options such as ansi and wincon, which would behave the same as always but also force one or the other color output method. There are enough command line options in Windows that it seems unlikely a cmdline tool can guess the exact requirements (e.g. Windows 10 can support ansi, or when using something like Maximus5/ConEmu).

[BurntSushi]

@leafgarland That's plausible. Good idea.

[retep998]

I don't think you really need the user's help deciding which to use. If you're in a Windows console, then the Windows console API will work all the time. If you're not in a Windows console, then the Windows console API will work none of time and the only other option is ansi escape codes. So I'd probably enable color by default in the Windows console, and elsewhere support color using ansi escape codes only if enabled via --color=always.

[thierryvolpiatto]

We have the same problem in emacs where ripgrep is apparently not recognizing pseudo emacs terminal (pty) as a terminal, see https://github.com/emacs-helm/helm/issues/1624.

[BurntSushi]

@thierryvolpiatto Is that on Windows? If not, it sounds like an entirely distinct issue.

[thierryvolpiatto]

Andrew Gallant [email protected] writes:

@thierryvolpiatto Is that on Windows?

No, on GNU/Linux.

If not, it sounds like an entire distinct issue.

Ok, should I open an other issue ?

Thierry

[BurntSushi]

@thierryvolpiatto I think #182 might be relevant.

[thierryvolpiatto]

Ok, yes I just see @chunyang have opened another issue, thanks.

[BurntSushi]

@retep998 I'm in the process of fixing this issue, and it actually looks like I can successfully get a handle to the Windows console when using mintty. Namely, no error occurs. Actually using the console has no effect, so it appears that we do indeed need a way to force ANSI escape sequences.

[retep998]

@BurntSushi GetStdHandle succeeding does not necessarily mean it is a Windows console. You have to call GetConsoleMode on that handle to determine whether it is actually a Windows console. If GetConsoleMode succeeds, then always use the console API. If GetConsoleMode fails, then you _might_ be able to use ANSI escape codes, or you might be redirected to a file.

[BurntSushi]

@retep998 This is the code I'm using to get a console, and it doesn't appear to return an error in mintty:

    pub fn new() -> io::Result<Console> {
        let name = b"CONOUT$\0";
        let handle = unsafe {
            kernel32::CreateFileA(
                name.as_ptr() as *const i8,
                winapi::GENERIC_READ | winapi::GENERIC_WRITE,
                winapi::FILE_SHARE_WRITE,
                ptr::null_mut(),
                winapi::OPEN_EXISTING,
                0,
                ptr::null_mut(),
            )
        };
        if handle == winapi::INVALID_HANDLE_VALUE {
            return Err(io::Error::last_os_error());
        }
        let mut info = unsafe { mem::zeroed() };
        let res = unsafe {
            kernel32::GetConsoleScreenBufferInfo(handle, &mut info)
        };
        if res == 0 {
            return Err(io::Error::last_os_error());
        }
        let attr = TextAttributes::from_word(info.wAttributes);
        Ok(Console {
            handle: handle,
            start_attr: attr,
            cur_attr: attr,
        })
    }

So I'm not using GetConsoleMode but I am using GetConsoleScreenBufferInfo. Should that call fail if there's no console available? The docs don't seem to say, but do seem to imply that it at least _can_ fail.

[BurntSushi]

Hmm, I guess the difference here is that in that code above, I am opening CONOUT$, where as I do believe it fails if I do it on, say, stdout.

[retep998]

@BurntSushi Getting CONOUT$ is usually the wrong thing to do, because it ignores what stdout is set to, completely bypassing any redirection, and just gets whatever the active framebuffer is. Stick with GetStdHandle as the way to obtain the handle.

[BurntSushi]

@retep998 Ah I see now, OK that works! Thanks! My only problem now is figuring out how to detect whether stdout is tty or not inside of mintty. From searching, it seems like the problem is basically unsolveable, although I will note that grep from cygwin seems to get it right. git itself seems to have hacked around it and the mintty project doesn't have a good answer either.

_sigh_

[BurntSushi]

For those following this issue but not #94, this will be fixed in the next ripgrep release!

[lilianmoraru]

Colors stopped working in one of the releases, on an ARM target I tested ripgrep on.
I'll test again and see if this fixed the issue.

[lilianmoraru]

Yey, colors work again on that ARM target.