This commit uses the new virtual terminal processing feature in Windows 10
to enable the use of ANSI escape codes to color ripgrep's output. This
technique is preferred over the console APIs because it seems like where
the future is heading, but also because it avoids needing to use an
intermediate buffer to deal with the Windows console in a multithreaded
environment.
This commit adds a new method to the Console type which permits toggling
the VIRTUAL_TERMINAL_PROCESSING mode on a console. Specifically, this
enables the use of ANSI escape sequences for color in Windows terminals.
The primary motivation for this commit was rust-lang/cargo#4189 where dropping a
`wincolor::Console` would call `CloseHandle` to close the console handle. Cargo
creates a few `Console` instances so it ended up closing stdout a little
earlier as intended!
The `GetStdHandle` function returns handles I believe aren't intended to be
closed (as there's no refcounting). I believe libstd doesn't close these
handles.
This commit also moves to calling `GetStdHandle` on demand which libstd changed
to doing so recently as well, preventing caching of stale handles that change
over time with calls to `SetStdHandle`.
This commit completely guts all of the color handling code and replaces
most of it with two new crates: wincolor and termcolor. wincolor
provides a simple API to coloring using the Windows console and
termcolor provides a platform independent coloring API tuned for
multithreaded command line programs. This required a lot more
flexibility than what the `term` crate provided, so it was dropped.
We instead switch to writing ANSI escape sequences directly and ignore
the TERMINFO database.
In addition to fixing several bugs, this commit also permits end users
to customize colors to a certain extent. For example, this command will
set the match color to magenta and the line number background to yellow:
rg --colors 'match:fg:magenta' --colors 'line:bg:yellow' foo
For tty handling, we've adopted a hack from `git` to do tty detection in
MSYS/mintty terminals. As a result, ripgrep should get both color
detection and piping correct on Windows regardless of which terminal you
use.
Finally, switch to line buffering. Performance doesn't seem to be
impacted and it's an otherwise more user friendly option.
Fixes#37, Fixes#51, Fixes#94, Fixes#117, Fixes#182, Fixes#231
