Not use WrapExcel::Cygwin when ruby platform is not cywgin.

Not run when not install cygwin.

lib/wrap_excel.rb

@@ -3,47 +3,9 @@
 require File.join(File.dirname(__FILE__), 'wrap_excel/sheet')
 require File.join(File.dirname(__FILE__), 'wrap_excel/cell')
 require File.join(File.dirname(__FILE__), 'wrap_excel/range')
+require File.join(File.dirname(__FILE__), 'wrap_excel/cygwin') if RUBY_PLATFORM =~ /cygwin/
 require "wrap_excel/version"
 
 module WrapExcel
 
-  module Cygwin
-    require 'Win32API'
-
-    @conv_to_full_posix_path =
-      Win32API.new('cygwin1.dll', 'cygwin_conv_to_full_posix_path', 'PP', 'I')
-    @conv_to_posix_path =
-      Win32API.new('cygwin1.dll', 'cygwin_conv_to_posix_path', 'PP', 'I')
-    @conv_to_full_win32_path =
-      Win32API.new('cygwin1.dll', 'cygwin_conv_to_full_win32_path', 'PP', 'I')
-    @conv_to_win32_path =
-      Win32API.new('cygwin1.dll', 'cygwin_conv_to_win32_path', 'PP', 'I')
-
-    def cygpath(options, path)
-      absolute = shortname = false
-      func = nil
-      options.delete(" \t-").chars {|opt|
-        case opt
-        when ?u
-          func = [@conv_to_full_posix_path, @conv_to_posix_path]
-        when ?w
-          func = [@conv_to_full_win32_path, @conv_to_win32_path]
-        when ?a
-          absolute = true
-        when ?s
-          shortname = true
-        end
-      }
-      raise "first argument must contain -u or -w" if func.nil?
-      func = absolute ? func[0] : func[1]
-      buf = "\0" * 300
-      if func.Call(path, buf) == -1
-        raise "cannot convert path name"
-      end
-      buf.delete!("\0")
-      buf
-    end
-    module_function :cygpath
-  end
-
 end

lib/wrap_excel/cygwin.rb

@@ -0,0 +1,40 @@
+module WrapExcel
+  module Cygwin
+    require 'Win32API'
+
+    @conv_to_full_posix_path =
+      Win32API.new('cygwin1.dll', 'cygwin_conv_to_full_posix_path', 'PP', 'I')
+    @conv_to_posix_path =
+      Win32API.new('cygwin1.dll', 'cygwin_conv_to_posix_path', 'PP', 'I')
+    @conv_to_full_win32_path =
+      Win32API.new('cygwin1.dll', 'cygwin_conv_to_full_win32_path', 'PP', 'I')
+    @conv_to_win32_path =
+      Win32API.new('cygwin1.dll', 'cygwin_conv_to_win32_path', 'PP', 'I')
+
+    def cygpath(options, path)
+      absolute = shortname = false
+      func = nil
+      options.delete(" \t-").chars {|opt|
+        case opt
+        when ?u
+          func = [@conv_to_full_posix_path, @conv_to_posix_path]
+        when ?w
+          func = [@conv_to_full_win32_path, @conv_to_win32_path]
+        when ?a
+          absolute = true
+        when ?s
+          shortname = true
+        end
+      }
+      raise "first argument must contain -u or -w" if func.nil?
+      func = absolute ? func[0] : func[1]
+      buf = "\0" * 300
+      if func.Call(path, buf) == -1
+        raise "cannot convert path name"
+      end
+      buf.delete!("\0")
+      buf
+    end
+    module_function :cygpath
+  end
+end

spec/cygwin_spec.rb

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 require File.join(File.dirname(__FILE__), './spec_helper')
 
-describe WrapExcel::Cygwin, :if => RUBY_PLATFORM =~ /cygwin/ do
+describe "on cygwin",  :if => RUBY_PLATFORM =~ /cygwin/ do
   describe ".cygpath" do
     context "cygwin path is '/cygdrive/c/Users'" do
       context "with '-w' options" do