B. The Sockmap Protocol

Sockmap is a simple request/reply protocol over TCP or UNIX domain sockets. Both requests and replies are encoded in the following manner:

 
 len:text,

where text is the actual payload, and len is its length in bytes, as a decimal number in ASCII representation. The colon and comma are transmitted verbatim. For example, if text is the string ‘hello there’, then the socket map packet for transmitting it is:

 
11:hello there,

Sockmap requests consist of the map name and the actual lookup key, separated by a single space character.

Replies consist of the status code and optional data, separated by a single space character.

Below we describe status codes implemented by various programs. The bracketed parts in the ‘code’ field of the tables below indicate optional values. The brackets themselves are not required by the protocol.