SYS-FVERSION(2)SYS-FVERSION(2)NAME
fversion - initialize 9P connection and negotiate version
SYNOPSIS
include "sys.m";
sys := load Sys Sys->PATH;
fversion: fn(fd: ref FD, bufsize: int, version: string): (int, string);
DESCRIPTION
Fversion initialises the 9P connection represented by fd and negotiates
the maximum message size and the version of the protocol to be used.
The bufsize determines the size of the I/O buffer used to stage 9P
requests to the server, subject to the constraints of the server
itself. The version is a text string that represents the highest ver‐
sion 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.
SEE ALSOsys-fauth(2), intro(5), version(5).
DIAGNOSTICS
Fversion returns a value of -1 for n on error, including failure to
negotiate acceptable values, and sets the system error string.
BUGS
The returned value of n when no error occurs should be the negotiated
message size but is currently the original bufsize parameter.
SYS-FVERSION(2)
