This library provides analogues of the :getpriority, :setpriority, :getrlimit,
:setrlimit and :uid methods for MS Windows. It also adds the new methods :job?,
:get_affinity, and :create, and redefines the :kill method.


* ffi
* sys-proctable (dev only)
* test-unit 2 (dev only)

Supported Platforms

This library is supported on Windows 2000 or later.


gem install win32-process


require 'win32/process'

p Process.job? # => true or false

info = Process.create(
  :app_name         => "notepad.exe",
  :creation_flags   => Process::DETACHED_PROCESS,
  :process_inherit  => false,
  :thread_inherit   => true,
  :cwd              => "C:\\"

p info.process_id

Developer's Notes

Removal of Process.fork in release 0.7.0

The Process.fork method was originally experimental but it has never
been particularly useful in practice. On top of that, it required special
implementations of the Process.waitXXX methods, so it was a maintenance
issue as well.

With Ruby 1.9 now becoming standard and its addition of Process.spawn
and friends (and concomitant support for the Process.waitXXX methods) I
felt it was time to remove it.

You can still simulate Process.fork if you like using Process.create, which
is how it was implemented internally anyway. A better solution might be
to follow in the footsteps of ActiveState Perl, which uses native threads
to simulate fork on Windows.

Changes in the custom Process.kill method for 0.7.0

The Process.kill method in 0.7.0 more closely matches the spec now, but
the internal method for killing processes is still nicer for most signals.
With the release of 0.7.0 users can now specify options that provide finer
control over how a process is killed. See the documentation for details.

The removal of the custom Process.ppid method

This was added at some point in the Ruby 1.9 dev cycle so it was removed
from this library.

Known Issues

JRuby doesn't seem to like SIGBRK for Process.kill.

Any issues or bugs should be reported on the project page at


Artistic 2.0


(C) 2003-2015 Daniel J. Berger
All Rights Reserved


This library is provided "as is" and without any express or
implied warranties, including, without limitation, the implied
warranties of merchantability and fitness for a particular purpose.


Park Heesob	
Daniel J. Berger