What's the best-practice way to find out the platform ruby is running on?

https://stackoverflow.com/questions/15895047

02-04-2022
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题

I am using colored gem for coloured printing in the terminal and ruby logger. I need to run this code on linux and on windows.

On windows, I must first require 'win32console' or else coloured printing doesn't work (I just see ANSI escape characters instead). But if I require win32console on linux it breaks, obviously.

What's the usual way to handle a situation like this in ruby? I noticed the RUBY_PLATFORM variable, but on a windows VM I tried it was "i386-mingw32" or something strange. Using that plus a conditional seems like a pretty flakey way to go about what I need, so I was hoping this problem has a better solution.

解决方案 2

There's always:

begin
  require 'win32console'
rescue LoadError
end

I find this easier to write and reason about that trying to decide for myself which OS I'm on and whether or not to load it.

Update: I was thinking win32console was built-in rather than a gem. I believe Win32API is available on all Windows installs, so it's a good proxy to test "Is this Windows?" (rather than "What OS is this, and is that Windows?").

begin
  require 'Win32API'
  windowsOS = true
rescue LoadError
  windowsOS = false
end

if windowsOS
  begin
    require 'win32console'
  rescue LoadError
    # Prompt user to install win32console gem
  end
end

其他提示

Nothing wrong with using RUBY_PLATFORM, it is its purpose. You could also ask it the OS itself, for windows that would be

ENV['OS']

Which gives "Windows_NT" on a Vista.

Don't know the counterpart for the other OS.