Hi,

In message "Re: [ ruby-Bugs-1504 ] Open3.popen() doesn't set $?"
    on Thu, 17 Feb 2005 01:44:36 +0900, noreply / rubyforge.org writes:

|Initial Comment:
|$ ruby -e 'require "open3"; stdin,stdout,stderr = Open3.popen3("/bin/true"); stdin.close; puts $?' # prints 256
|256

open3 uses the "double fork" technique, so that you cannot take the
exit status of the command.  But it doesn't have to be 256.

							matz.