#!/bin/csh -f
#
# [Here it is... the original shell script and PostScript boilerplate that
# would eventually become "pcal".  Modified slightly by A. W. Rogers to
# correct bug in leap year algorithm, suppress the illegible weekday names
# in the small calendars, use the more common "-d" flag (instead of "-P") to
# specify line printer destination, default to the current month/year, and
# add the current century to years between 0 and 99.]
#
# Original From: patwood@unirot.UUCP (Patrick Wood)
# 
# The following is a PostScript program to print calendars.  It doesn't
# work on or before 1752.
# 
# Shell stuff added 3/9/87 by King Ables
# 
# Made pretty by tjt 1988
#
# Tim Tessin - Lawrence Livermore National Laboratory 
# tjt@tis.llnl.gov
# Phone: (415) 423-4560 / 422-8971
# Run like the following: pscalendar -Pstrudel 4 1988     - for April 1988
#
set printer="cat"

top:
if ($#argv > 0) then
	switch ("$argv[1]")
		case -d*:
		case -P*:
			set printer="lp "`echo $argv[1] | sed s/-P/-d/`
			shift argv
			goto top
		case *:
			if ($?month) then
				set year="$argv[1]"
			else if ($?year) then
				echo "usage: $0 [-dprinter] month year"
				exit 1
			else
				set month="$argv[1]"
			endif
			shift argv
			goto top
	endsw
endif

if ($?year) then
else 
	@ month = `date +%m`
	@ year = `date +%Y`
endif

if ($year >= 0 && $year < 100) then
	@ year += 100 * (`date +%Y` / 100)
endif

cat <<END-OF-CALENDAR | $printer
%!PS-Adobe-1.0
%%BoundingBox: 0 0 612 792
%%Orientation: Landscape

% PostScript program to draw calendar
% Copyright (C) 1987 by Pipeline Associates, Inc.
% Permission is granted to modify and distribute this free of charge.

% /month should be set to a number from 1 to 12
% /year should be set to the year you want
% you can change the title and date fonts, if you want
% we figure out the rest
% won't produce valid calendars before 1800 (weird stuff happened
% in September of 1752)

/month $month def
/year $year def
/titlefont /Times-Bold def
/dayfont /Helvetica-Bold def

/month_names [ (January) (February) (March) (April) (May) (June) (July)
		(August) (September) (October) (November) (December) ] def

/prtnum { 3 string cvs show} def

/drawgrid {		% draw calendar boxes
	dayfont findfont 10 scalefont setfont
	0 1 6 {
		dup dup 100 mul 40 moveto
		submonth 0 eq {
			[ (Sunday) (Monday) (Tuesday) (Wednesday)
			  (Thursday) (Friday) (Saturday) ] exch get
			100 center
		} if
		100 mul 35 moveto
		1.0 setlinewidth
		0 1 5 {
			gsave
			100 0 rlineto 
			0 -80 rlineto
			-100 0 rlineto
			closepath stroke
			grestore
			0 -80 rmoveto
		} for
	} for
} def

/drawnums {		% place day numbers on calendar
	dayfont findfont 30 scalefont setfont
	/start startday def
	/days ndays def
	start 100 mul 5 add 10 rmoveto
	1 1 days {
		/day exch def
		gsave
		day start add 7 mod 0 eq
		{
			submonth 0 eq
			{
				.8 setgray
			} if
		} if
		day start add 7 mod 1 eq
		{
			submonth 0 eq
			{
				.8 setgray
			} if
		} if
		day prtnum
		grestore
		day start add 7 mod 0 eq
		{
			currentpoint exch pop 80 sub 5 exch moveto
		}
		{
			100 0 rmoveto
		} ifelse
	} for
} def

/drawfill {		% place fill squares on calendar
	/start startday def
	/days ndays def
	0 35 rmoveto
	1.0 setlinewidth
	0 1 start 1 sub {
		gsave
		.9 setgray
		100 0 rlineto 
		0 -80 rlineto
		-100 0 rlineto
		closepath fill
		grestore
		100 0 rmoveto
	} for
	submonth 1 eq
	{
		/lastday 42 def
		600 -365 moveto
	}
	{
		/lastday 40 def
		400 -365 moveto
	} ifelse
	lastday -1 ndays start 1 add add
	{
		/day exch def
		gsave
		.9 setgray
		100 0 rlineto 
		0 -80 rlineto
		-100 0 rlineto
		closepath fill
		grestore
		day 7 mod 1 eq
		{
			600 -365 80 add moveto
		}
		{
			-100 0 rmoveto
		} ifelse
	} for
} def

/isleap {		% is this a leap year?
	year 4 mod 0 eq			% multiple of 4
	year 100 mod 0 ne 		% not century
	year 400 mod 0 eq or and	% unless it's divisible by 400
} def

/days_month [ 31 28 31 30 31 30 31 31 30 31 30 31 ] def

/ndays {		% number of days in this month
	days_month month 1 sub get
	month 2 eq	% Feb
	isleap and
	{
		1 add
	} if
} def

/startday {		% starting day-of-week for this month
	/off year 1 sub def	% offset from start of "epoch"
	year
	off 4 idiv add		% number of leap years
	off 100 idiv sub	% number of centuries
	off 400 idiv add	% number of 400-year intervals
	/off exch def
	1 1 month 1 sub {	% add days in previous months
		/idx exch def
		days_month idx 1 sub get
		idx 2 eq
		isleap and
		{
			1 add
		} if
		/off exch off add def
	} for
	off 7 mod		% 0--Sunday, 1--monday, etc.
} def

/center {		% center string in given width
	/width exch def
	/str exch def width str 
	stringwidth pop sub 2 div 0 rmoveto str show
} def

/calendar
{
	titlefont findfont 48 scalefont setfont
	0 60 moveto
	/month_name month_names month 1 sub get def
	month_name show
	/yearstring year 10 string cvs def
	700 yearstring stringwidth pop sub 60 moveto
	yearstring show

	0 0 moveto
	drawnums

	0 0 moveto
	drawfill

	0 0 moveto
	drawgrid
} def

90 rotate
50 -120 translate
/submonth 0 def
calendar
month 1 sub 0 eq
{
	/lmonth 12 def
	/lyear year 1 sub def
}
{
	/lmonth month 1 sub def
	/lyear year def
} ifelse
month 1 add 13 eq
{
	/nmonth 1 def
	/nyear year 1 add def
} 
{
	/nmonth month 1 add def
	/nyear year def
} ifelse
/submonth 1 def
/year lyear def
/month lmonth def
500 -365 translate
gsave
.138 .138 scale
10 -120 translate
calendar
grestore
/submonth 1 def
/year nyear def
/month nmonth def
100 0 translate
gsave
.138 .138 scale
10 -120 translate
calendar
grestore

showpage

END-OF-CALENDAR

exit 0