What's the best way to start a background process, that can get accessed later on

Question

I am currently developing a RubyGem that provides an executable. The executable keeps track of the state of some log files using the FSSM gem.

This executable should get started, do something in background, and get stopped later on.

For example:

$ my_executable start
# do something different...
$ my_executable stop

I would first start a new process, that does the file watching stuff, inside the start method. But I don't know how to address this process for stopping it.

What's the best way to provide such a behavior?

Regards

Answer 1

pid = Process.fork{exec 'gcalctool'} #don't use 'system' or `executable`
1.upto(10) do |n|
  puts "counting #{n}"
  STDOUT.flush
  sleep 1
end
Process.kill( 'HUP', pid )

Answer 2

There is daemons library that'll help you daemonizing your ruby script. It's used by mongrel.

Also there are some other useful gems described on ruby-toolbox.