supports_unicode/
lib.rs

1#![doc = include_str!("../README.md")]
2
3/// possible stream sources
4#[derive(Clone, Copy, Debug)]
5pub enum Stream {
6    Stdout,
7    Stderr,
8}
9
10fn is_a_tty(stream: Stream) -> bool {
11    use std::io::IsTerminal;
12    match stream {
13        Stream::Stdout => std::io::stdout().is_terminal(),
14        Stream::Stderr => std::io::stderr().is_terminal(),
15    }
16}
17
18/// Returns true if `stream` is a TTY or the current terminal
19/// [supports_unicode].
20pub fn on(stream: Stream) -> bool {
21    if !is_a_tty(stream) {
22        // If we're just piping out, it's fine to spit out unicode! :)
23        true
24    } else {
25        supports_unicode()
26    }
27}
28
29/// Returns true if the current terminal, detected through various environment
30/// variables, is known to support unicode rendering.
31pub fn supports_unicode() -> bool {
32    if std::env::consts::OS == "windows" {
33        // Just a handful of things!
34        std::env::var("CI").is_ok()
35        || std::env::var("WT_SESSION").is_ok() // Windows Terminal
36        || std::env::var("ConEmuTask") == Ok("{cmd:Cmder}".into()) // ConEmu and cmder
37        || std::env::var("TERM_PROGRAM") == Ok("vscode".into())
38        || std::env::var("TERM") == Ok("xterm-256color".into())
39        || std::env::var("TERM") == Ok("alacritty".into())
40    } else if std::env::var("TERM") == Ok("linux".into()) {
41        // Linux kernel console. Maybe redundant with the below?...
42        false
43    } else {
44        // From https://github.com/iarna/has-unicode/blob/master/index.js
45        let ctype = std::env::var("LC_ALL")
46            .or_else(|_| std::env::var("LC_CTYPE"))
47            .or_else(|_| std::env::var("LANG"))
48            .unwrap_or_else(|_| "".into())
49            .to_uppercase();
50        ctype.ends_with("UTF8") || ctype.ends_with("UTF-8")
51    }
52}
supports_unicode/lib.rs

supports_unicode/
lib.rs
