# Classic

Prior to version 3, RPyC employed a modus-operandi that’s now referred to as “classic mode”. In this mode, the server was completely under the control of its client – there was no way to restrict what the client could do, and there was no notion of services. A client simply connected to a server and began to manipulate it.

Starting with version 3, RPyC became service-oriented, and now servers expose well-defined services, which define what a client can access. However, since the classic mode proved very useful and powerful, especially in testing environments, and in order to retain backwards compatibility, the classic mode is still exists in current versions – this time implemented as a `service`.

See also the API reference

## Usage

RPyC installs `rpyc_classic.py` to your Python scripts directory (e.g., `C:\PythonXX\Scripts`, `/usr/local/bin`, etc.), which is a ready-to-run classic-mode server. It can be configured with command-line parameters. Once you have it running, you can connect to it like so

    conn = rpyc.classic.connect("hostname")    # use default TCP port (18812)

    proc = conn.modules.subprocess.Popen("ls", stdout = -1, stderr = -1)
    stdout, stderr = proc.communicate()
    print(stdout.split())

    remote_list = conn.builtin.range(7)

    conn.execute("print('foo')")