Get registry string from ruby 2.0

Al Hart

There are a lot of threads about this, but I am getting confused.

I took a look at Win32Api.rb in SketchUp 2014, and it says:

"Win32API is deprecated after Ruby 1.9.1; use dl directly instead"

Do I took a look at DL, and it says:

"DL is deprecated, please use Fiddle"

So I took a look at Fiddle, which does have some Win32 stuff, but I couldn't find an example on how to get a string from the registry using Fiddle.

Can someone post, or point me to a Ruby 2.0 example which will run in SketchUp and read a Windows Registry String?

Dan Rathbun

The standard library has a Registry class BUT it is currently bugged with regard to string encodings.

If you wish to be backward compatible you can still use the Win32API class, which in Ruby 1.9.1+, becomes a wrapper to the DL class (which is more C-like,) which in Ruby 2.x, becomes a wrapper to Fiddle.

There should be examples in the CHM or embedded in the ruby scripts that load them (the CHM help docs are generated from inline documentation.)

Dan Rathbun

If you wish to do this from a C/C++ extension, you can:

include "Winreg.h" (include "Windows.h"),
load the "Advapi32.dll" library,
and use the registry functions.

The pages on individual functions have examples.

http://msdn.microsoft.com/en-us/library/ms724875(v=VS.85).aspx

These are the functions you'd call using DL, Win32API or Fiddle if you go that route.

Add: These ways are more complicated, as you must first open a handle to the registry key before a calling read, and be sure to call close on the key when done (like in an ensure clause! )

Al Hart

Thanks Dan, this looks great.

Let me try it out

Al Hart

Thanks Dan - that works!

Is there anything similar for Ruby 1.8, or do I need to continue to use Win32API.so to read the registry?

Dan Rathbun

@al hart said:

Thanks Dan - that works!

Is there anything similar for Ruby 1.8, or do I need to continue to use Win32API.so to read the registry?

WHAT works ?

(I talked about at least 3 ways.)

IF you went with the low level system calls, via Win32API class then you use the "Win32API.rb" wrapper script that comes with Ruby 1.9.x and higher.

As I said, ... for Ruby 1.8.6, you use the "Win32API.so" (and/or "win32ole.so",) files ("lifted from the Windows Installer package",) that I posted in the "Plugins" forum. (Use the Author Index Sticky post to find it.)

Dan Rathbun

You can ALSO instead use the WIN32OLE class ("win32ole.rb" all lowercase,) and instantiate a ref to a Windows Scripting Host object, which has SAFE functions to access the registry.
http://msdn.microsoft.com/en-us/library/x05fawxd(v=vs.84).aspx

Something like this (tested):

module MyCode

  def self.sketchup_install_location()

    require "win32ole"

    wsh = WIN32OLE.new("WScript.Shell")
    begin
      val = wsh.RegRead("HKLM\\Software\\Wow6432Node\\SketchUp\\SketchUp 2014\\InstallLocation\\")
    rescue WIN32OLERuntimeError
      val = wsh.RegRead("HKLM\\Software\\SketchUp\\SketchUp 2014\\InstallLocation\\")
    end

    wsh.ole_free

    return val

  end

end

Add: The value returned (in my test.) is "UTF-8" encoded, which is a good thing.

FYI: The path to the key for SketchUp < 2013 is under:
"HKLM\Software\Google\Google SketchUp 8\InstallLocation\"
etc. for older versions.
But "win32ole.so" does not come with older version of SketchUp. You will need to provide a 1.8.6 compiled versions of the so file. [url=http://sketchucation.com/forums/viewtopic.php?t=42732:27osqac0]It is posted (by me,) in the "Plugins" forum[/url:27osqac0].

Al Hart

@dan rathbun said:

@al hart said:

Thanks Dan - that works!

WHAT works ?

(I talked about at least 3 ways.)

We wound up using win32ole and RegRead

However we ran into problems with an uncaught exception when the Registry Key we passed did not exist, so we added a second rescue for the second registry key.

Like this (I added XX to the key to intentionally make it fail)


require "win32ole"

wsh = WIN32OLE.new("WScript.Shell")
begin
	val = wsh.RegRead("HKLM\\Software\\Wow6432Node\\SketchUpXX\\SketchUp 2014\\InstallLocation\\")
rescue WIN32OLERuntimeError
	val = ""
end#begin/rescue

if (val == "")
	begin
		val = wsh.RegRead("HKLM\\Software\\SketchUpXX\\SketchUp 2014\\InstallLocation\\")
	rescue WIN32OLERuntimeError
		val = ""
	end#begin/rescue
end#if

wsh.ole_free

puts "VAL; " + val