telnet_suboption

NAME

telnet_suboption - process telnet suboptions

SYNOPSIS

void telnet_suboption( string buffer );

DESCRIPTION

This apply is called on the interactive object when the client sends a
telnet subnegotiation (IAC SB <option> ... IAC SE) for an option the
driver does not handle itself, for mudlib defined processing.

The buffer is the subnegotiation payload only: the option byte has
already been removed, so the first byte is the option's own subcommand.
The option code is not passed, so the apply has to work out which option
sent the payload from its contents. NUL bytes in the payload are replaced
with 'I'. An empty subnegotiation does not call this apply.

These options are handled by the driver and never reach this apply:

    TTYPE                  terminal_type(4)
    ENVIRON, NEW_ENVIRON   receive_environ(4)
    NAWS                   window_size(4)
    GMCP                   gmcp(4)
    MSDP                   msdp(4)
    ZMP                    zmp(4)
    LINEMODE, MSSP, COMPRESS2

EXAMPLE

The driver offers CHARSET and sends REQUEST ";UTF-8". A client that
accepts replies with IAC SB CHARSET ACCEPTED "UTF-8" IAC SE, which
reaches this apply as "\x02UTF-8" (2 is ACCEPTED from RFC 2066):

    void telnet_suboption(string buffer) {
        if (sizeof(buffer) > 1 && buffer[0] == 2 &&
            upper_case(buffer[1..]) == "UTF-8") {
            // client accepted UTF-8
        }
    }

SEE ALSO

terminal_type(4), receive_environ(4), window_size(4), gmcp(4), msdp(4), zmp(4)