Function nix::unistd::daemon [−] [src]

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

Daemonize this process by detaching from the controlling terminal (see daemon(3)).

When a process is launched it is typically associated with a parent and it, in turn, by its controlling terminal/process. In order for a process to run in the "background" it must daemonize itself by detaching itself. Under posix, this is done by doing the following:

  1. Parent process (this one) forks
  2. Parent process exits
  3. Child process continues to run.

nochdir:

  • nochdir = true: The current working directory after daemonizing will be the current working directory.
  • nochdir = false: The current working directory after daemonizing will be the root direcory, /.

noclose:

  • noclose = true: The process' current stdin, stdout, and stderr file descriptors will remain identical after daemonizing.
  • noclose = false: The process' stdin, stdout, and stderr will point to /dev/null after daemonizing.

The underlying implementation (in libc) calls both fork(2) and setsid(2) and, as such, error that could be returned by either of those functions could also show up as errors here.