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$", ...)` to retrieve the console handle works correctly even if STDOUT and/or STDERR are redirected
28 let console_out_name: Vec<u16> = OsStr::new("CONOUT$").encode_wide().chain(once(0)).collect();
29 let console_handle = CreateFileW(
30 console_out_name.as_ptr(),
31 GENERIC_READ | GENERIC_WRITE,
32 FILE_SHARE_WRITE,
33 null_mut(),
34 OPEN_EXISTING,
35 0,
36 null_mut(),
37 );
38 if console_handle == INVALID_HANDLE_VALUE
39 {
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 {
47 return Err(GetLastError());
48 }
49
50 // VT processing not already enabled?
51 if console_mode & ENABLE_VIRTUAL_TERMINAL_PROCESSING == 0 {
52 // https://docs.microsoft.com/en-us/windows/console/setconsolemode
53 if 0 == SetConsoleMode(console_handle, console_mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING)
54 {
55 return Err(GetLastError());
56 }
57 }
58 }
59
60 return Ok(());
61}
62