nu_ansi_term/
windows.rs

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1/// Enables ANSI code support on Windows 10.
2///
3/// This uses Windows API calls to alter the properties of the console that
4/// the program is running in.
5///
6/// https://msdn.microsoft.com/en-us/library/windows/desktop/mt638032(v=vs.85).aspx
7///
8/// Returns a `Result` with the Windows error code if unsuccessful.
9#[cfg(windows)]
10pub fn enable_ansi_support() -> Result<(), u32> {
11    // ref: https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences#EXAMPLE_OF_ENABLING_VIRTUAL_TERMINAL_PROCESSING @@ https://archive.is/L7wRJ#76%
12
13    use std::ffi::OsStr;
14    use std::iter::once;
15    use std::os::windows::ffi::OsStrExt;
16    use std::ptr::null_mut;
17    use winapi::um::consoleapi::{GetConsoleMode, SetConsoleMode};
18    use winapi::um::errhandlingapi::GetLastError;
19    use winapi::um::fileapi::{CreateFileW, OPEN_EXISTING};
20    use winapi::um::handleapi::INVALID_HANDLE_VALUE;
21    use winapi::um::winnt::{FILE_SHARE_WRITE, GENERIC_READ, GENERIC_WRITE};
22
23    const ENABLE_VIRTUAL_TERMINAL_PROCESSING: u32 = 0x0004;
24
25    unsafe {
26        // ref: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew
27        // Using `CreateFileW("CONOUT$", ...)` to retrieve the console handle works correctly even if STDOUT and/or STDERR are redirected
28        let console_out_name: Vec<u16> =
29            OsStr::new("CONOUT$").encode_wide().chain(once(0)).collect();
30        let console_handle = CreateFileW(
31            console_out_name.as_ptr(),
32            GENERIC_READ | GENERIC_WRITE,
33            FILE_SHARE_WRITE,
34            null_mut(),
35            OPEN_EXISTING,
36            0,
37            null_mut(),
38        );
39        if console_handle == INVALID_HANDLE_VALUE {
40            return Err(GetLastError());
41        }
42
43        // ref: https://docs.microsoft.com/en-us/windows/console/getconsolemode
44        let mut console_mode: u32 = 0;
45        if 0 == GetConsoleMode(console_handle, &mut console_mode) {
46            return Err(GetLastError());
47        }
48
49        // VT processing not already enabled?
50        if console_mode & ENABLE_VIRTUAL_TERMINAL_PROCESSING == 0 {
51            // https://docs.microsoft.com/en-us/windows/console/setconsolemode
52            if 0 == SetConsoleMode(
53                console_handle,
54                console_mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING,
55            ) {
56                return Err(GetLastError());
57            }
58        }
59    }
60
61    Ok(())
62}
nu_ansi_term/windows.rs

nu_ansi_term/
windows.rs
