From: "Iñaki Baz Castillo" <ibc@...>
Date: 2009-12-13T08:51:02+09:00
Subject: Re: Is it possible to force a Ruby program to run as a proc name different than "ruby"?

El Sábado, 12 de Diciembre de 2009, Robert Klemme escribió:
> This is what I would do:
> 
> VAR='/var/run'
> 
> pid_file = File.join(VAR, File.basename($0) + '.pid')
> 
> begin
>    old_pid = File.read(pid_file).to_i
>    Process.kill 0, old_pid
>    $stderr.puts "ERROR: already running with PID #{old_pid}"
>    exit 1
> rescue Errno::ENOENT
>    # no pid file
> rescue Errno::ESRCH
>    # process not running
>    $stderr.puts 'WARNING: stale pid file'
> end
> 
> # open file with EXCL in order to catch race conditions where two
> # processes were started almost at the same time and both thought
> # they would be a new instance.  Uncomment sleep to simulate:
> # sleep 2
> File.open(pid_file, File::EXCL | File::WRONLY | File::CREAT) {|io| 
> io.write($$)}
> trap(0) {File.delete pid_file}
> 
> puts "OK, here we go."


Let me a question: is the above a fragment of a Linux init script written in 
Ruby (rather than bash/sh as usual)?

If so, according to LSB specifications it should return 0 (success) in case of 
"start" action when the daemon is already running.

Thanks a lot.


-- 
Iñaki Baz Castillo <ibc@aliax.net>