Windows Process Manager

Manage Windows-specific process isolation and stdio handling for LibrAgent.

Key Challenges

1. ANSI Code Page Handling

Windows uses ANSI code pages by default. Stdio output from MCP servers may contain non-UTF-8 characters.

// Convert ANSI to UTF-8
use std::os::windows::prelude::*;
use winapi::um::consoleapi::GetConsoleOutputCP;

2. Stdio Pipe Reading

Windows pipes require special handling for async reading:

use tokio::io::{AsyncReadExt, BufReader};
use tokio::process::Command;

let mut child = Command::new("cmd")
    .args(&["/C", "server.exe"])
    .stdout(Stdio::piped())
    .spawn()?;

let mut stdout = BufReader::new(child.stdout.take().unwrap());
let mut buffer = Vec::new();
stdout.read_to_end(&mut buffer).await?;

3. Path Discovery

Windows paths require normalization:

use std::path::{Path, PathBuf};

fn normalize_windows_path(path: &str) -> PathBuf {
    let path = Path::new(path);
    if path.is_absolute() {
        path.to_path_buf()
    } else {
        std::env::current_dir().unwrap().join(path)
    }
}

4. Process Spawning

use std::process::Stdio;

let mut cmd = Command::new(program);
cmd.args(args)
    .stdin(Stdio::piped())
    .stdout(Stdio::piped())
    .stderr(Stdio::piped())
    .creation_flags(CREATE_NO_WINDOW); // Hide console window

Audit Checklist

• Stdio pipes use Stdio::piped() not Stdio::inherit()
• Process spawning uses CREATE_NO_WINDOW flag on Windows
• Output decoding handles ANSI code pages
• Path handling uses PathBuf and normalization
• No hardcoded Unix paths (/usr/bin, /tmp)
• Environment variables use Windows format (%VAR% vs $VAR)

Platform Detection

#[cfg(target_os = "windows")]
{
    // Windows-specific code
}

#[cfg(not(target_os = "windows"))]
{
    // Unix-specific code
}