How can I find which operating system my Ruby program is running on?

Question

I want my Ruby program to do different things on a Mac than on Windows. How can I find out on which system my program is running?

Related: [Detecting Linux distribution/platform in Ruby](https://stackoverflow.com/q/25970280/5389585) — sondra.kinsey, Mar 14 '19 at 16:10

score 157 · Answer 1 · edited Dec 17 '18 at 04:57

157

Use the RUBY_PLATFORM constant, and optionally wrap it in a module to make it more friendly:

module OS
  def OS.windows?
    (/cygwin|mswin|mingw|bccwin|wince|emx/ =~ RUBY_PLATFORM) != nil
  end

  def OS.mac?
   (/darwin/ =~ RUBY_PLATFORM) != nil
  end

  def OS.unix?
    !OS.windows?
  end

  def OS.linux?
    OS.unix? and not OS.mac?
  end

  def OS.jruby?
    RUBY_ENGINE == 'jruby'
  end
end

It is not perfect, but works well for the platforms that I do development on, and it's easy enough to extend.

edited Dec 17 '18 at 04:57

Chloe

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answered Oct 04 '08 at 21:17

Aaron Hinni

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for jruby, you're better off using `RbConfig::CONFIG["host_os"]` to get your OS. – FilBot3 Dec 02 '13 at 19:48
2

Is there anywhere where something like this is packaged up into a gem, that one could use, instead of copy/pasting or such? If so, where? :) – lindes Dec 21 '13 at 21:48
2

I prefer this over any gem. – C.J. May 03 '16 at 15:29
Is there any way I can check for a specific version of windows, for example Windows 8.1? – Sajid Sep 30 '16 at 11:06
That windows variant regex is off btw, each name should be in parentheses for "|" or to work as expected. – Epigene Sep 03 '17 at 20:01
How can I get this to identify freebsd vs linux? – Michael Dorst Oct 01 '19 at 15:04
How can I get the exact OS name and its version? For example, centos 7.5 or redhat 7.8? Please suggest. – NN796 Jul 01 '20 at 06:17

score 28 · Answer 2 · edited May 19 '23 at 09:33

28

I like this, most people use rubygems, its reliable, is cross platform

irb(main):001:0> Gem::Platform.local
=> #<Gem::Platform:0x151ea14 @cpu="x86", @os="mingw32", @version=nil>
irb(main):002:0> Gem::Platform.local.os
=> "mingw32"

update use in conjunction with "Update! Addition! Rubygems nowadays..." to mitigate when Gem::Platform.local.os == 'java'

edited May 19 '23 at 09:33

sandstrom

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answered Oct 16 '13 at 18:29

jtzero

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On jruby it just reports "java" so it's not sufficient if you expect to have anyone running jruby. – Peter Wagenet Nov 13 '13 at 23:51

Vinko Vrsalovic · Answer 3 · 2013-05-16T08:38:26.537

18

Either

irb(main):002:0> require 'rbconfig'
=> true
irb(main):003:0> Config::CONFIG["arch"]
=> "i686-linux"

or

irb(main):004:0> RUBY_PLATFORM
=> "i686-linux"

edited May 16 '13 at 08:38

answered Oct 04 '08 at 20:41

Vinko Vrsalovic

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Don't you mean `Config::CONFIG[‘host_os’]`? – Andrew Grimm Apr 23 '10 at 13:45
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"Use RbConfig instead of obsolete and deprecated Config" => ```RbConfig::CONFIG["arch"]``` – jtzero Oct 16 '13 at 18:19
1

@jtzero If you provide a more complete answer in the comments I'l update the answer written in 2008 – Vinko Vrsalovic Oct 16 '13 at 20:19
in ruby 1.9.3 (p327) its just that line, ruby has it by default `irb(main):002:0> require 'rbconfig' => false` – jtzero Oct 18 '13 at 14:09
When I did it, I got a statement saying that was depreciated. `(irb):10:in `irb_binding': Use RbConfig instead of obsolete and deprecated Config.` So I used that, `RbConfig::CONFIG.each` and listed all the different values. Maybe you can find something in there to help you find what you're looking for. – FilBot3 Dec 02 '13 at 18:34
`RUBY_PLATFORM` is fine. From `Config::CONFIG` though only `target_os` and `host_os` work reliably. As with jruby only they indicate linux. – akostadinov Jun 13 '15 at 18:53

jtzero · Answer 4 · 2019-04-20T22:03:40.277

I have a second answer, to add more options to the fray. The os rubygem, and their github page has a related projects list.

require 'os'

>> OS.windows?
=> true   # or OS.doze?

>> OS.bits
=> 32

>> OS.java?
=> true # if you're running in jruby.  Also OS.jruby?

>> OS.ruby_bin
=> "c:\ruby18\bin\ruby.exe" # or "/usr/local/bin/ruby" or what not

>> OS.posix?
=> false # true for linux, os x, cygwin

>> OS.mac? # or OS.osx? or OS.x?
=> false

Ryan McGeary · Answer 5 · 2013-03-31T23:53:05.140

7

Try the Launchy gem (gem install launchy):

require 'launchy'
Launchy::Application.new.host_os_family # => :windows, :darwin, :nix, or :cygwin

edited Mar 31 '13 at 23:53

answered Oct 05 '08 at 00:18

Ryan McGeary

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That's Launchy::Application.new.host_os_family in 2.1.0. – fakeleft Jan 18 '13 at 15:10
3

FYI -- Launchy uses rbconfig: https://github.com/copiousfreetime/launchy/blob/master/lib/launchy/detect/host_os.rb – codecraig Feb 27 '13 at 13:52

score 6 · Answer 6 · answered Dec 03 '16 at 09:31

6

Update! Addition! Rubygems nowadays ships with Gem.win_platform?.

Example usages in the Rubygems repo, and this one, for clarity:

def self.ant_script
  Gem.win_platform? ? 'ant.bat' : 'ant'
end

answered Dec 03 '16 at 09:31

olleolleolle

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score 6 · Answer 7 · answered Mar 14 '19 at 17:54

For something readily accessible in most Ruby installations that is already somewhat processed for you, I recommend these:

Gem::Platform.local.os #=> eg. "mingw32", "java", "linux", "cygwin", "aix", "dalvik" (code)
Gem.win_platform? #=> eg. true, false (code)

Both these and every other platform checking script I know is based on interpreting these underlying variables:

RbConfig::CONFIG["host_os"] #=> eg. "linux-gnu" (code 1, 2)
RbConfig::CONFIG["arch"] #=> eg. "i686-linux", "i386-linux-gnu" (passed as parameter when the Ruby interpreter is compiled)
RUBY_PLATFORM #=> eg. "i386-linux-gnu", "darwin" - Note that this returns "java" in JRuby! (code)
- These are all Windows variants: /cygwin|mswin|mingw|bccwin|wince|emx/
RUBY_ENGINE #=> eg. "ruby", "jruby"

Libraries are available if you don't mind the dependency and want something a little more user-friendly. Specifically, OS offers methods like OS.mac? or OS.posix?. Platform can distinguish well between a variety of Unix platforms. Platform::IMPL will return, eg. :linux, :freebsd, :netbsd, :hpux. sys-uname and sysinfo are similar. utilinfo is extremely basic, and will fail on any systems beyond Windows, Mac, and Linux.

If you want more advanced libraries with specific system details, like different Linux distributions, see my answer for Detecting Linux distribution in Ruby.

I'd welcome more precise explanations or links to how `RUBY_PLATFORM` or `RbConfig::CONFIG["host_os"]` are populated. Looking at the code, it's still not clear to me. — sondra.kinsey, Mar 14 '19 at 18:02

score 4 · Answer 8 · answered Oct 17 '12 at 15:22

4

require 'rbconfig'
include Config

case CONFIG['host_os']
  when /mswin|windows/i
    # Windows
  when /linux|arch/i
    # Linux
  when /sunos|solaris/i
    # Solaris
  when /darwin/i
    #MAC OS X
  else
    # whatever
end

answered Oct 17 '12 at 15:22

Pikachu

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I guess this should be `case Config::CONFIG['host_os']` ? – equivalent8 Mar 05 '15 at 17:40
actually in ruby 2 it should be `RbConfig::Obsolete::CONFIG['host_os']` ...+no need to include the `Config` – equivalent8 Mar 05 '15 at 17:45
Change the `include` or both types of Modules, and then this is the best answer IMO. Notice how he `include`'d the Module, so no need for RbConfig or Config. – FilBot3 May 31 '16 at 20:35

score 2 · Answer 9 · answered Jan 19 '16 at 16:09

We have been doing pretty good so far with the following code

  def self.windows?
    return File.exist? "c:/WINDOWS" if RUBY_PLATFORM == 'java'
    RUBY_PLATFORM =~ /mingw32/ || RUBY_PLATFORM =~ /mswin32/
  end

  def self.linux?
    return File.exist? "/usr" if RUBY_PLATFORM == 'java'
    RUBY_PLATFORM =~ /linux/
  end

  def self.os
    return :linux if self.linux?
    return :windows if self.windows?
    nil
  end

score 0 · Answer 10 · answered Feb 11 '22 at 17:44

Using the os gem, when loading different binaries for IMGKit

# frozen_string_literal: true
IMGKit.configure do |config|
  if OS.linux? && OS.host_cpu == "x86_64"
    config.wkhtmltoimage =
      Rails.root.join("bin", "wkhtmltoimage-linux-amd64").to_s
  elsif OS.mac? && OS.host_cpu == "x86_64"
    config.wkhtmltoimage =
      Rails.root.join("bin", "wkhtmltoimage-macos-amd64").to_s
  else
    puts OS.report
    abort "You need to add a binary for wkhtmltoimage for your OS and CPU"
  end
end

score -7 · Answer 11 · answered Sep 27 '13 at 09:40

-7

When I just need to know if it is a Windows or Unix-like OS it is often enough to

is_unix = is_win = false
File::SEPARATOR == '/' ? is_unix = true : is_win = true

answered Sep 27 '13 at 09:40

dimus

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File::SEPARATOR gives / in windows, so this doesn't work – peter Apr 12 '14 at 13:09
3

Bad practice all around. If you want to know what the file separator is, use `File::SEPARATOR`. It's best to duck-type the platform just like developing in Ruby. But if you have to know whether the platform is Windows, ask the question instead of trying to infer it. – Robin Daugherty Jul 20 '14 at 17:03

How can I find which operating system my Ruby program is running on?

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