fix system() func

Author: glaukiol1

os/os.module.go

@@ -244,13 +244,15 @@ func system(self py.Object, args py.Tuple) (py.Object, error) {
 		return nil, py.ExceptionNewf(py.TypeError, "missing one required argument: 'command:str'")
 	}
 	arg, ok := args[0].(py.String)
-	if !ok { ... }
+	if !ok {
+		return nil, py.ExceptionNewf(py.TypeError, "str expected (pos 1), not "+args[0].Type().Name)
+	}
 
 	var command *exec.Cmd
 	if runtime.GOOS != "windows" {
-		command = exec.Command("/bin/sh", "-c", carg)
+		command = exec.Command("/bin/sh", "-c", string(arg))
 	} else {
-		command = exec.Command(cargs[0], cargs[1:]...)
+		command = exec.Command("cmd.exe", string(arg))
 	}
 	outb, err := command.CombinedOutput() // - commbinedoutput to get both stderr and stdout -
 	if err != nil {