Ruby Programming/Standard Library/Win32::Registry

The source code itself is also pretty useful.

How to do a simple query (values)

With the win32 registry, keys mean “subkey” (like a folder), and values mean “subentry” (like file).

This example shows how to look at values:

require 'win32/registry' keyname= 'SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Environment' # KEY_ALL_ACCESS enables you to write and deleted. # the default access is KEY_READ if you specify nothing access = Win32::Registry::KEY_ALL_ACCESS Win32::Registry::HKEY_LOCAL_MACHINE.open(keyname, access) do |reg| # each is the same as each_value, because #each_key actually means # "each child folder" so #each doesn't list any child folders... # use #keys for that... reg.each{|name, value| puts name, value} end 

or

a = Win32::Registry::HKEY_LOCAL_MACHINE.open \ "SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Environment", Win32::Registry::KEY_READ a.each{|n, v| p n, v} a.close 

which results in:

CLASSPATH 1 ComSpec 2 FP_NO_HOST_CHECK 1 HOME ... 

and this example shows you how to look at keys:

require 'win32/registry' keyname= "SOFTWARE" # this isn't actually case sensitive, but hey access = Win32::Registry::KEY_ALL_ACCESS Win32::Registry::HKEY_LOCAL_MACHINE.open(keyname, access) do |reg|; 
 
 reg.each_key{|k, v| puts k, v} 
 
end 
 

which results in:

... Windows 128883664814843750 Windows 3.1 Migration Status 128783367437500000 WinPcap 
 

Default tutorial

This code is given in the registry.rb file (doesn’t show up in the normal rdocs for some reason)

<code> Win32::Registry::HKEY_CURRENT_USER.open('SOFTWARE\foo') do |reg| value = reg['foo'] # read a value value = reg['foo', Win32::Registry::REG_SZ] # read a value with type type, value = reg.read('foo') # read a value reg['foo'] = 'bar' # write a value reg['foo', Win32::Registry::REG_SZ] = 'bar' # write a value with type reg.write('foo', Win32::Registry::REG_SZ, 'bar') # write a value reg.each_value { |name, type, data| ... } # Enumerate values reg.each_key { |key, wtime| ... } # Enumerate subkeys reg.delete_value(name) # Delete a value reg.delete_key(name) # Delete a subkey reg.delete_key(name, true) # Delete a subkey recursively end </code>

Win32::Registry.create

<code> Win32::Registry::HKEY_LOCAL_MACHINE.create "software\\abc" </code>

Note also that you can do nested creates in a single call, like “software\\classes\\*\\shell\\abc\\subdir\\subdir”

How to write default values:

Write default values ("Default" in regedit) by passing nil as the name, ex:

 a.write_s nil, "a default string" # and read it back a.read_s nil 

More complex example

This code adds an option to the context menu with you right click on any file.

name = Win32::Registry::HKEY_LOCAL_MACHINE.create "Software\\classes\\*\\shell\\open_with_arcadia" name.write_s nil, "play with arcadia" dir = Win32::Registry::HKEY_LOCAL_MACHINE.create "Software\\classes\\*\\shell\\open_with_arcadia\\command" dir.write_s nil, %!"#{ruby}" "#{arcadia}" "%1"! 

Related links

• http://rubyforge.org/snippet/detail.php?type=snippet&id=13