oxidefetch/src/terminal.rs

/*

Copyright 2023 shibedrill & Namedneon

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the “Software”), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

*/

use lazy_static::lazy_static;
use std::collections::HashMap;
use std::env;
use sysinfo::{Pid, PidExt, ProcessExt, System, SystemExt};

lazy_static! {
    static ref PRETTY_NAMES: HashMap<&'static str, &'static str> = {
        let mut m = HashMap::new();
        m.insert("cmd", "Command Prompt");
        m.insert("powershell", "PowerShell");
        m.insert("konsole", "Konsole");
        m.insert("gnome-terminal", "GNOME Terminal");
        m.insert("xterm", "XTerm");
        m.insert("xfce4-terminal", "XFCE Terminal");
        m.insert("kitty", "KiTTY");
        m.insert("alacritty", "Alacritty");
        m
    };
}

// Allows detection of shells that host themselves (i.e. Command Prompt).
const SELF_HOSTED_SHELLS: [&str; 2] = ["cmd.exe", "powershell.exe"];

macro_rules! match_env_to_terminal {
    ($env: expr, $name: expr) => {
        match env::var($env) {
            Ok(_) => return Some($name.to_string()),
            Err(_) => (),
        };
    };
}

pub fn get_terminal() -> Option<String> {
    // Match Apple terminals.
    if let Ok(f) = env::var("TERM_PROGRAM") {
        return match f.as_str() {
            "iTerm.app" => Some("iTerm2".to_string()),
            "Terminal.app" => Some("Apple Terminal".to_string()),
            "Hyper.app" => Some("Hyper".to_string()),
            _ => None,
        };
    };

    match_env_to_terminal!("ConEmuPID", "ConEmu");
    match_env_to_terminal!("WT_SESSION", "Windows Terminal");
    match_env_to_terminal!("SSH_CONNECTION", "SSH");
    match_env_to_terminal!("tw52", "TosWin2");
    match_env_to_terminal!("tw100", "TosWin2");

    let mut pid = Pid::from_u32(std::process::id());
    let shell = match env::var("SHELL") {
        Ok(f) => f,
        Err(_) => "".to_string(),
    };
    let shell_name = shell.split('/').last().unwrap();

    #[allow(unused_assignments)]
    let mut name: Option<String> = None;

    let mut self_hosted = false;

    // Get to the shell PID.
    'find_shell: loop {
        let ppid = pid_to_ppid(pid);

        if ppid.is_none() {
            // We ran out of parents.
            return None;
        } else if ppid.unwrap().as_u32() == 1 {
            // We have reached the daemon.
            return None;
        }

        pid = ppid.unwrap(); // It should be safe to unwrap the PPID now.

        let pid_name = pid_to_name(pid);

        if pid_name.is_none() {
            continue;
        }

        let name_unwrapped = pid_name.unwrap();

        // Detect self-hosted shells.
        for shell in SELF_HOSTED_SHELLS {
            if name_unwrapped == shell {
                self_hosted = true;
                name = Some(name_unwrapped);
                break 'find_shell;
            }
        }

        if name_unwrapped == shell.as_str() || name_unwrapped == shell_name {
            name = Some(name_unwrapped);
            break; // We found the shell.
        }
    }

    if !self_hosted {
        // Try to get parent once more.
        match pid_to_ppid(pid) {
            None => return None,
            Some(f) => {
                // Try to get name.
                name = pid_to_name(f);
            }
        };
    }

    return match name {
        Some(f) => {
            // Remove the file extension.
            let mut res = f.split('.').next().unwrap().to_string();

            // Try to get a "prettier name".
            if PRETTY_NAMES.contains_key(res.as_str()) {
                res = PRETTY_NAMES.get(res.as_str()).unwrap().to_string();
            }

            Some(res)
        }
        None => None,
    };
}

fn pid_to_name(pid: Pid) -> Option<String> {
    let mut system = System::new();
    system.refresh_processes();

    for process in system.processes() {
        if *process.0 == pid {
            return Some(process.1.name().to_string());
        }
    }

    None
}

fn pid_to_ppid(pid: Pid) -> Option<Pid> {
    let mut system = System::new();
    system.refresh_processes();

    for process in system.processes() {
        // Check if the process in question is ours.
        if *process.0 != pid {
            continue;
        }

        // Check if it has a parent.
        if process.1.parent().is_none() {
            continue;
        }

        // Get the parent PID.
        return Some(process.1.parent().unwrap());
    }

    None
}