gp <gp / NOSPAM.le.isac.cnr.it> wrote in message news:<b2tjdr$i19$1 / newsfeed.cineca.it>... 
> I need to check if a process is running.

On Linux:

pid = 2212
if FileTest.exist?("/proc/#{pid}")
  puts "process #{pid} is running"
end

Dan's sys-proctable is a more portable version.

Regards,

Tom