Fix use

r2env/core.py

@@ -35,7 +35,8 @@ class R2Env:
         print_console(" [*] {0} ({1})".format(r2_version, r2_path))
 
     def show_config(self):
-        return json.dumps(self._config)
+        print_console("[*] Current r2env config:")
+        print_console(json.dumps(self._config))
 
     def list_available_packages(self):
         print_console("[*] List of available Radare packages")
@@ -70,8 +71,12 @@ class R2Env:
             return
         self._package_manager.uninstall_package(package)
 
-    def use(self, package):
+    def use(self, package=None):
         self.exit_if_r2env_not_initialized()
+        if not package:
+            print_console("[x] Package not defined. Please use 'r2env use' with one installed package. ", ERROR)
+            self.list_installed_packages()
+            return
         cur_ver = self._get_current_version()
         new_dst_dir = self._package_manager.get_package_path(package)
         if cur_ver:

r2env/repl.py

@@ -47,7 +47,7 @@ def run_action(action, args, use_meson):
         print_console("[X] Action not found", ERROR)
         return
     if action in actions_with_argument:
-        exit_if_not_argument_is_set(args)
+        exit_if_not_argument_is_set(args, action)
         if action == "install":
             actions[action](args[0], use_meson=use_meson)
         else:
@@ -56,9 +56,14 @@ def run_action(action, args, use_meson):
         actions[action]()
 
 
-def exit_if_not_argument_is_set(args):
+def exit_if_not_argument_is_set(args, action):
     if len(args) < 1:
-        print_console("[x] Missing package argument.", ERROR)
+        if action == "use":
+            print_console("[x] Package not defined. Please use 'r2env use' with one installed package. ", ERROR)
+            actions["versions"]()
+        else:
+            print_console("[x] Missing package argument. ( as for example: radare2@latest)", ERROR)
+        print_console("[x] Missing package argument. ( as for example: radare2@latest)", ERROR)
         sys.exit(-1)