/python-server

A simple client-server system written in Python.

Primary LanguagePython

Python Server

Communication between two python scripts via sockets.

Usage

You then have to set the ("IP", port) of the server in client.py (line 14) and in server.py (line 14).

It uses the Curses module for the UI (See Terminal).

You can then run the server.py or client.py with python 3 (doesn't work in IDLE with curses).

The client/server can be used without installing the curses module by changing the logging handler at the end of client.py and server.py and replacing references to the term object in the same files:

In client.py:

  • (line 32) In the Client class, commandInput(self, term, text), term.appendHistory.
  • (line 62) In the main(term) function, term.callback.

In server.py:

  • (line 43) In the commandInput(term, text) function, term.appendHistory.

An alternative method of calling the commandInput functions must then be used.

Default states

Inspired by https://wiki.vg/Protocol

Default server commands:

  • stop - Stops the server.
  • list [state] - Lists the clients connected and their state.
    • Set state option to filter by state.
  • ping [payload (Long)] - Sends a ping to every client in state 0.
    • Set payload option to send a custom signed 64-bit integer.

State 0 (default)

The Client waits for:

  • User command:

    • exit - Stops the client.
    • ping [payload (Long)] - Sends a ping to the server (changes state to 1).
      • Set payload option to send a custom signed 64-bit integer.

  • packet 0x00 - Request from the server.

    • Empty packet. No actions required.

  • packet 0x01 - Ping from the server.

    • Sends same data back to the server.

      Field Name Field Type
      Payload Long

The Server waits for:

  • packet 0x00 - Handshake from the client.

    • Changes the state of the server-side client.

      Field Name Field Type
      Protocol Version VarInt
      Server Address String (255)
      Server Port Unsigned Short
      Next State VarInt Enum

  • packet 0x01 - Pong from the client.

    • Should be the same as sent by the server.

      Field Name Field Type
      Payload Long

State 1 (status)

The Client waits for:

  • User command:

    • exit - Stops the client.
    • stop - Stops the status request (changes state to 0).

  • packet 0x00 - Response from the server.

    • JSON string containing informations about the server.

      Field Name Field Type
      JSON Response String (32767)

  • packet 0x01 - Pong from the server.

    • Should be the same as sent by the client.

      Field Name Field Type
      Payload Long

The Server waits for:

  • packet 0x00 - Request from the client.

    • Empty packet. Requests the server properties.

  • packet 0x01 - Ping from the client.

    • Epoch time in ms by default. Sends same data back to the client.

      Field Name Field Type
      Payload Long

Terminal

Simple curses terminal emulation. Can be used independently of the client/server.

MAX_HISTORY_SIZE (line 7) can be used to set the command history size.

To install curses it on a UNIX system:

pip install curses

To install curses it on a Windows system: https://pypi.org/project/windows-curses/

pip install windows-curses