CAL  -  display a calendar
(substitute unix "cal" command)

by Alex Matulich, Unicorn Research Corporation
Version 4.0


Contents:



NAME

cal - displays a calendar

SYNOPSIS

cal [options] [[num_month] year]
cal [options] [word_month] [year]

DESCRIPTION

By default, cal will display a calendar for the current month with the current day marked. By specifing certain arguments, cal will display a calendar for a whole year or a specified month and year.

The transition from the Julian to Gregorian calendar is assumed to have occured in 1752 on the 3rd of September. Ten days following that date were eliminated by the reformation, so the calendar for that month is a bit unusual.

If displaying a calendar in the single-month format, cal will look for a date file. If found, cal will read the file, looking for special date descriptions for that month which will be displayed to the right of the calendar. By default, up to 24 appointments may be displayed per month. If the current date happens to fall on one of these special dates, it will be flagged by an asterisk. If there is room, appointments for the next month may also be displayed with some limitations (currently, special dates such as the 3rd Thursday of will not be calculated for next month).

cal can also optionally use colors when displaying the calendar. It will not display colors any time the calendar is not directly displaying on the console. This is generally the desired behavior when your redirecting cal's output to another program or a file.

ARGUMENTS

A verbally-specified month may be entered without specifying a year in the argument list; however, a single numerical argument will be interpreted as a year. Only the first 3 characters of the month name are significant for a verbally-specified month. NOTE: The command "cal 10" refers to 10 AD, not October, and not 1910.

The available options are:

--3[months]
Display previous/current/next month together. This option will be ignored when displaying a full year.
--a[ppts]
Maximum number of appointments to display. Minimum is 8, maximum is 50, default is 24.
--col[or-file]=filename
Read color definitions from `filename' (default color filename depends on operating system).
--con[tinue]=n
Display the next n successive months starting with the month specified.
--d[ata-file]=filename
Read appointments from `filename' (default appointment data filename depends on operating system). You may use -d up to 8 times in a commandline to specify multiple data file names.
--e[urope]
Use European format (first weekday is Monday).
--f[uture]
If current month is displayed, then show only future appointments from the date file, not appointments that are past. This allows room for other descriptions with future dates to be displayed. As time progresses through the month, old descriptions are discarded and newer ones are used. The --future switch affects only the display for the current month, and not other months.
--j[ulian]
Display Julian dates (days one-based, numbered from January 1.
--m[onday]
Display Monday as the first day of the week (same as --europe)
--noc[olor]
Inhibit the use of colors.
--nod[ata]
Do not try to read any appointment data file.
--p[ause]
Pause before exiting and prompt for a keystroke.
--th[ismonth]
Disable display of next month appointments; show only current month's.
--to[day]
Show only today's appointments.
--u[se-color]
Allow the use of colors.
--y[ear]
Display a calendar for the current year.

There is an optional environment variable that can be used by cal if found. If CALOPT is set then cal will read it and use any valid command line options found. This allows any commonly used switches to be set in your environment and always used (e.g. --europe). Cal will produce its usage screen when run if any invalid options are set in this variable.

COMMAND EXAMPLES

cal -f -d=my_dates
display the current month and future appointments defined in file 'my_dates'
cal 1996
display the entire year of 1996
cal 9 1752
display the month of September 1752
cal sep 1752
same as above
cal January
display January of the current year
cal help
help message displayed for unrecognized arguments

DATE FILES

cal will search for a date file called cal.dat in the directory it was executed from. If not found it will search in the users $HOME directory for a file called .cal.dat. If still not found, it will look for a global cal.dat in a system wide directory. To find out where this location is you can run cal --help which will display the location.

The special date descriptions specified in the date file are single lines, formatted as follows:

YYYY MM DD NW xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

where

YYYY is the year,
MM is the month (01 - 12),
DD is the day (00 if the NW field is used),
NW is the weekday-of-month code (00 if the DD field is used)
xxxx is the description; it will be truncated as necessary to fit

The data MUST occupy the character fields as shown. If YYYY is specified as -999, the month and day are assumed to be annual events such as holidays, and the description will be displayed for any year. If MM is specified as -9, the day is assumed to be a monthly event for the specified year. In the weekday-of-month code NW, N signifies on which weekday W the special date occurs. For example, 31 indicates the third sunday. Values of W range from 1 to 7, for Sunday to Saturday, respectively. A value of 9 for N indicates "last" as in 95 for "last thursday."

If ALL of the fields contain a positive number and the year is at least 1970, then the description is assumed to be periodic, starting at the given date, with the period in days specified in NW (e.g. 1995 01 06 14 will display the description every 2nd Friday using 6 January 1995 as the base date). The base date does not get displayed.

You can display birthdays and anniversaries by putting the year of birth (or other special event) inside brackets or braces, in the description. This number is converted to the number of years since the year you indicate and the brackets or braces are removed from the output. If braces {} are used the number will have an ordinal suffix, as in 21st, 32nd, 43rd, 54th, etc. If the number in brackets or braces is greater than the current year, the number will be displayed unchanged. Example: "Alex's {1961} birthday" will display as "Alex's 34th birthday" (if the current year is 1995). If you need to include brackets or braces in your output then you can escape them by prefixing it with a '\'. Example: "Alex's \{1961\} birthday" will be displayed as "Alex's {1961} birthday".

NOTE: If cal is invoked with the --europe or --monday switch, then the W values 1-7 denote Monday(1) to Sunday(7) rather than Sunday(1) to Saturday(7).

A line in cal.dat must start with -999 or a 4-digit number to be considered as data. The data lines may be in any order. All these appointments will be displayed in chronological order, regardless of the ordering in the appointment data file.

If cal was compiled with the reminder support then call will also search for the files dates and .dates in the same places as for the caldat equivalents. The dates file is used by the reminder(1) program and is an alternate, less-powerful format for specifying descriptions. A file in this format cannot be specified with the --data-file= option.

The reminder format consists of text lines of length < screen width in the following format:

DDDDDDDD:N:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:yyyyyy:S

where

DDDDDDDD
is the date in one of the following formats:
M/D/Y
an event occurring on a specific day (year can be two or four digits, but must be two for backward compatibility with reminder)
M/D
an event occurring every year
D
an event occurring every month
DDD
an event occurring every week (day of the week is 'Sun', 'Mon', etc.)
N
is the number of days notice of the event to give the user (ignored by cal)
xxxxx
the event description
yyyyy
an optional receptor of the event (e.g. Mr. Jones)
S
status flag, either N for normal event or D for a deleted (not displayed) event

Blank lines are ignored. A line otherwise not in the above format is assume to specify a file name from which to read more events. The file is searched for in the usual places.

COLOR ATTRIBUTES

cal will search for a color definition file called cal.col in the directory it was executed from. If not found it will search in the users $HOME directory for a file called .cal.col. If still not found, it will look for a global cal.col in a system wide directory. To find out where this location is you can run cal --help which will display the location.

Users may override the default colors used when displaying calendars. This may be done by creating a color definition file.

Example of a color definition file:

15 02   video colors for month name
01 03   video colors for weekday header
07 01   video colors for normal calendar days
13 01   video colors for sundays
14 02   video colors for current day
07 06   bkgd for yearly calendar (space between months)
11 00   video colors for special day descriptions
12 08   video colors for * indicating descr.=today

Color definitions must appear as above, as a two-character field for the foreground color, followed by a space, folowed by a two-character field for the background color. The color definitions must start on the first line, and must not contain blank lines. Comments may appear after the second field, provided that the total line length does not exceed 80 characters.

Possible colors:
0   black
1   blue
2   green
3   cyan
4   red
5   violet
6   orange
7   light gray
 
8   dark gray
9   bright blue
10   bright green
11   bright cyan
12   bright red
13   bright violet
14   yellow
15   white

Specifying a background color from 8 to 15 will result in a background color of 0 to 7, with flashing text.

FILES

cal.dat
Date file. Can be located in the current directory or the directory in which cal is run from.
cal.col
Color definition file. Can be located in the current directory or the directory in which cal is run from.
$HOME/.cal.dat
unix local date file.
$HOME/.cal.col
unix local color file.
$HOME/.dates
Date file used with unix reminder program and can be used with cal.

BUGS

All known bugs fixed in version 4.0.

WHERE TO GET CAL

The latest version of cal is available from http://unicorn.us.com/pub/cal40.zip

AUTHOR

Alex Matulich - alex@unicorn.us.com

...with enhancements and modifications by other contributors.

- © 1993-2002 by Unicorn Research Corporation
Inspired by an Amiga program by Gary L. Brant.


SEE ALSO

date(1), reminder(1), rs(1)