.\" Public domain - 1999/7/21 - Steven Schultz
.\"	@(#)gt307.8	1.0 (2.11BSD) 1999/7/21
.\"
.TH GT307 8 "July 21, 1999"
.UC 4
.SH NAME
gt307 \- read and set GT307 clock board
.SH SYNOPSIS
.B gt307
[
\fB\-d\fP n
]
[
\fB\-l\fP
]
[
\fByymmddhhmm.ss\fP
]
.SH DESCRIPTION
The
.B gt307
is used to read and/or set a Computer Products Inc GT307
clock calendar board.  If the date argument is not given
the board is read but not written.
.PP
The options are:
.TP 20
\fB\-d\fP n
sets Daylight Savings Time (DST) on if \fBn\fP is 1, off if \fBn\fP if 0.
.TP 20
\fB\-l\fP
switches output between long and short formats.  The short format is
suitable for input to the 
.IR date (8) 
command.
.PP
.B gt307
is a user mode program only (not a standalone/bootable program like
.B toyset
).  The kernel does not know how to read a GT307 clock.  Thus the
recommended use of
.B gt307
is to set the system time from within the
.IR rc (8)
file:
.sp
.in +1.0i
date `/sbin/gt307 -l`
.br
.in -1.0i
.SH FILES
None.
.SH SEE ALSO
date(8),
phys(2),
rc(8)
.SH BUGS
.B gt307
uses the 
.BR phys (2)
syscall to access the I/O page and thus can only be run by the superuser.  
Making
this program
setuid (so that users can read the GT307 board) could be a large threat
to system integrity in the event of bugs in the program.  It is \fBNOT\fP
recommended that 
.B gt307
be made setuid.
.SH HISTORY
The
.B gt307
command first appeared in 2.11BSD.   It was contributed by Robin
Birch 
.br
(robin@falstaf.demon.co.uk).
.PP
The Makefile, manpage and integration into
2.11BSD were done by Steven Schultz (sms@moe.2bsd.com).