GoHUP

GoHup allows you to run a long running command in a detached background process. It is not a daemon runner which monitors the status of the process restarting when necessary, GoHup only starts the process and returns the process id.

GoHup is similar to the Unix command nohup, except GoHup automatically creates a PID file and redirects log output to a file. You can use GoHup in your own applications, commands started with GoHup will continue to run after the application using the library has exited.

Usage

To create and start a new process create a new instance of gohup.LocalProcess and call the Start method with the process options.

The following exanple will start the command tail in the background and return the pid and the pidfile containing the pid.

lp := &gohup.LocalProcess{}
o := gohup.Options{
	Path: "/usr/bin/tail",
	Args: []string{
		"-f",
		"/dev/null",
	},
  Logfile: "./process.log",
}

pid, pidfile, err := lp.Start(o)
if err != nil {
	panic(err)
}

fmt.Printf("Started PID: %d, PID file: %s\n", pid, pidfile)

To query the status of a process, you can use the QueryStatus method passing the location of the pidfile. QueryStatus will return a string, gohup.StatusRunning or gohup.StatusStopped depending on the state of the process.

s, err := lp.QueryStatus(pidfile)
if err != nil {
	panic(err)
}

fmt.Println("Status:", s)

To stop a backgrounded process you can call the Stop method passing the location of a pidfile.

GoHup removes the pidfile if Stop is successful.

fmt.Println("Stopping process")
err = lp.Stop(pidfile)
if err != nil {
	panic(err)
}