Simple Child Process

Spawn a child process with piped stdout/stderr for output capture.

Overview

This is the most basic usage of ProcessManager: spawn a process, let it run, and stop it when done. The Piped stdio configuration causes ProcessManager to spawn reader threads that forward stdout to tracing::debug! and stderr to tracing::error!, preventing pipe buffer deadlocks.

Example

#![allow(unused)]
fn main() {
use process_manager::{ProcessConfig, ProcessManager, StdioConfig};

let manager = ProcessManager::new();
let config = ProcessConfig::builder()
    .command("echo".to_string())
    .args(vec!["hello world".to_string()])
    .stdout(StdioConfig::Piped)
    .stderr(StdioConfig::Piped)
    .build();

let id = manager.start("echo-app", &config)?;
// Reader threads capture stdout/stderr and forward to tracing

// Check if the process is still running
println!("Running: {}", manager.is_running(id).unwrap_or(false));
println!("State: {}", manager.state(id).unwrap_or(process_manager::ProcessState::Failed));

// Stop when done
manager.stop(id)?;
}

What Happens Internally

1. ProcessManager::start() resolves echo via which (since it’s not an absolute path)
2. A std::process::Command is built with the piped stdio configuration
3. The child is spawned and stored in the DashMap under the label "echo-app"
4. Reader threads are spawned for stdout and stderr, forwarding lines to tracing
5. manager.stop(id) sends SIGTERM, waits up to 5 seconds, then escalates to SIGKILL if needed