environ

cd/__init__.py

@@ -1,7 +1,14 @@
 import os
 
+COMMANDS_PREFIX = 'cd-'
+
+
+def cd_list_environment:
+    for variable, value in os.environ:
+        print(variable, value)
+
 
 def install_commands(path):
     user = '/usr/local/bin'
     for command in ['list-environment']:
-        os.symlink(path, os.path.join(user, f'cd-{command}'))
+        os.symlink(path, os.path.join(user, f'{COMMANDS_PREFIX}{command}'))

cd/__main__.py

@@ -7,9 +7,11 @@ import cd
 
 
 if __name__ == '__main__':
-    command, *_ = sys.argv
+    command, *arguments = sys.argv
     command = os.path.basename(command)
     if command == '__main__.py':
         cd.install_commands(__file__)
     else:
-        print(command)
+        command = command.replace('-', '_')
+        function = getattr(cd, command)
+        function(*arguments)