Implement os.isWindows

doc/api/os.markdown

@@ -14,6 +14,10 @@ Returns the operating system name.
 
 Returns the operating system release.
 
+### os.isWindows
+
+True on windows, false otherwise.
+
 ### os.uptime()
 
 Returns the system uptime in seconds.

lib/os.js

@@ -8,3 +8,4 @@ exports.totalmem = binding.getTotalMem;
 exports.cpus = binding.getCPUs;
 exports.type = binding.getOSType;
 exports.release = binding.getOSRelease;
+exports.isWindows = binding.isWindows;

src/node_os.cc

@@ -145,6 +145,12 @@ void OS::Initialize(v8::Handle<v8::Object> target) {
   NODE_SET_METHOD(target, "getCPUs", GetCPUInfo);
   NODE_SET_METHOD(target, "getOSType", GetOSType);
   NODE_SET_METHOD(target, "getOSRelease", GetOSRelease);
+
+#ifdef __POSIX__
+  target->Set(String::New("isWindows"), False());
+#else // __MINGW32__
+  target->Set(String::New("isWindows"), True());
+#endif
 }