Base-server

TCP request syntax

A valid request contains a 4-byte (32-bit) big endian unsigned integer denoting the length of the data in bytes, not including the integer itself, a null-byte (00000000), which is also not included in the length, followed by the data. Responses are formed in the same format.

Text-server

Command data syntax

• The server accepts UTF-8/ASCII encoded messages.
• Each message may be formatted like: command,argument 1,argument 2,...
• The arguments are optional, depending on the command.
• Spaces between commas are parsed, so to the server, command , would be "command " and , argument would be " argument".
• Commas may be escaped by use of a \
• Sending a \, without escaping the next character, can be done with \\
• Responses and other client-messages are formed in the same format.
• Responses may include UTF-8.

Default commands

Legend: commands, <required aguments>, [optional arguments]

• req
  Execute a command with an associated request ID. Returns with the same ID, and the command's return value(s).
  Arguments: req,<ID>,<command>,[argument 1],[argument 2],[...]
  Return: req,<ID>,[return value 1],[return value 2],[...]
• register
  Register a new user on the server.
  Arguments: <user>,<password>
• login
  Log into an existing server.
  Arguments: <user>,<password>
• whoami
  Check which user this session is using.
  Return: user,<user>
• send
  Sends command to another user's clients. The command will arrive as-is, with the user switched to be the sender instead of the receiver. So if you are fier, and you execute send,fier2,text,hello, fier2 will get send,fier,text,hello
  Arguments: <user>,<command>,[argument 1],[argument 2],[...]
• nop
  Do (almost) nothing.
  Return: An "empty" response (four bytes denoting the message has a length of 0, the null byte, and no additional data, unless called with req)

If a return is not specified, the command will return ok. If arguments are not specified, the command does not take any arguments. Any command may return an error if malformed or an exception occurs.

The server may add, remove or change commands.

Error responses

• An error returns as error,<fatality>,<type>,[info] or req,<ID>,error,<fatality>,<type>,[info] if req was used.
• <fatality> is either fatal or nonfatal. fatal usually results in the connection being dropped.
• <type> is the programmatic name of the error. These are usually lower-case. The types are listed below.
• [info] is additional info, meant to be read by a human.

Error types

• unhandled
  An error occured on the server.
• request_too_long
  The request sent by the client is too long.
• timeout
  The request did not finish in a timely fashion, or the session timed out.
• command_not_found
  The command is not available on this server.
• syntax
  The command's arguments are wrong in some way.
• name_too_short
  The user name is not long enough.
• invalid_name
  The user name contains invalid characters.
• wrong_user_or_password
  The user does not exist, or the password is incorrect.
• not_logged_in
  Action requires the session to log in.