include "sys.m";
sys := load Sys Sys->PATH;

fversion: fn(fd: ref FD, bufsize: int, version: string): (int, string);

The bufsize determines the size of the I/O buffer used to stage Styx requests to the server, subject to the constraints of the server itself. The version is a text string that represents the highest version level the protocol will support.

Fversion returns a tuple (n,useversion) where n is -1 if the request was rejected, and otherwise n is bufsize and useversion is a string representing the negotiated, possibly lower, version of the protocol.

Default values of zero for bufsize and the empty string for version will negotiate sensible defaults for the connection.

The interpretation of the version strings is defined in version(5).

It is rare to use fversion directly; usually the default negotiation performed by the kernel during mount (see sys-bind(2)) is sufficient.