Function daemon 

pub fn daemon(nochdir: bool, noclose: bool) -> Result<Fork>

The daemon function is for programs wishing to detach themselves from the controlling terminal and run in the background as system daemons.

• nochdir = false, changes the current working directory to the root (/).
• noclose = false, redirects stdin, stdout, and stderr to /dev/null

Behavior Change in v0.4.0

Previously, noclose = false would close stdio file descriptors. Now it redirects them to /dev/null instead, which is safer and prevents file descriptor reuse bugs. This matches industry standard implementations (libuv, systemd, BSD daemon(3)).

Errors

Returns an io::Error if any of the underlying system calls fail:

• fork fails (e.g., resource limits)
• setsid fails (e.g., already a session leader)
• chdir fails (when nochdir is false)
• redirect_stdio fails (when noclose is false)

Example:

use fork::{daemon, Fork};
use std::process::Command;

if let Ok(Fork::Child) = daemon(false, false) {
    Command::new("sleep")
        .arg("3")
        .output()
        .expect("failed to execute process");
}