1.Dd January 15, 2023
2.Dt GRDC 6
3.Os
4.Sh NAME
5.Nm grdc
6.Nd grand digital clock (curses)
7.Sh SYNOPSIS
8.Nm
9.Op Fl st
10.Op Ar n
11.Nm
12.Fl c
13.Ar n
14.Sh DESCRIPTION
15.Nm
16runs a digital clock made of reverse-video blanks on a curses
17compatible VDU screen.
18With an optional numeric argument
19.Ar n
20it stops after
21.Ar n
22seconds (default never).
23The clock can act as a countdown timer with the
24.Fl c
25flag,
26.Ar n
27specifies the number of seconds to time for.
28The optional
29.Fl s
30flag makes digits scroll as they change.
31The optional
32.Fl t
33flag tells grdc to output the time in a 12-hour format.
34In this curses mode implementation,
35the scrolling option has trouble keeping up.
36.Sh ENVIRONMENT
37.Bl -tag -width Ds
38.It Ev TZ
39The time zone to use for displaying the time.
40It is normally specified as a pathname relative to
41.Pa /usr/share/zoneinfo ,
42though see
43.Xr tzset 3
44for more information.
45If this variable is not set, the time zone is determined based on
46.Pa /etc/localtime .
47.El
48.Sh NOTES
49In countdown timer mode, the specifying of
50.Fl n
51> 360000 seconds (100 hours) will lead to the counter displaying
52incorrect remaining time, however it will time correctly, and
53display correctly when the remaining time becomes less than
54100 hours.
55.Sh AUTHORS
56.An -nosplit
57.An Amos Shapir ,
58modified for curses by
59.An John Lupien .
60Countdown timer mode by
61.An Gavin Atkinson .
62