gno/usr.bin/cal/cal.c
1998-03-09 15:30:26 +00:00

224 lines
3.1 KiB
C

/* static char rcsid[] = "$Header: /nobackup/gdr/copy-of-cvs-from-tekarra/gno/usr.bin/cal/cal.c,v 1.1 1998/03/09 15:29:53 gdr-ftp Exp $";
#ifdef __ORCAC__
#pragma stacksize 1024
#pragma optimize 8
#endif
#ifndef lint
static char sccsid[] = "@(#)cal.c 4.3 (Berkeley) 83/08/11";
#endif */
#include <stdio.h>
char dayw[] = {
" S M Tu W Th F S"
};
char *smon[]= {
"January", "February", "March", "April",
"May", "June", "July", "August",
"September", "October", "November", "December",
};
char string[432];
char *progname;
main(argc, argv)
char *argv[];
{
register y, i, j;
int m;
extern int _INITGNOSTDIO(void);
_INITGNOSTDIO();
/* setvbuf(stdout, NULL,_IOFBF, 1024l); */
progname = argv[0];
if(argc < 2) {
fprintf(stderr, "usage: %s [month] year\n",progname);
exit(0);
}
if(argc == 2)
goto xlong;
/*
* print out just month
*/
m = number(argv[1]);
if(m<1 || m>12)
goto badarg;
y = number(argv[2]);
if(y<1 || y>9999)
goto badarg;
printf(" %s %u\n", smon[m-1], y);
printf("%s\n", dayw);
cal(m, y, string, 24);
for(i=0; i<6*24; i+=24)
pstr(string+i, 24);
exit(0);
/*
* print out complete year
*/
xlong:
y = number(argv[1]);
if(y<1 || y>9999)
goto badarg;
printf("\n\n\n");
printf(" %u\n", y);
printf("\n");
for(i=0; i<12; i+=3) {
for(j=0; j<6*72; j++)
string[j] = '\0';
printf(" %.3s", smon[i]);
printf(" %.3s", smon[i+1]);
printf(" %.3s\n", smon[i+2]);
printf("%s %s %s\n", dayw, dayw, dayw);
cal(i+1, y, string, 72);
cal(i+2, y, string+23, 72);
cal(i+3, y, string+46, 72);
for(j=0; j<6*72; j+=72)
pstr(string+j, 72);
}
printf("\n\n\n");
exit(0);
badarg:
printf("Bad argument\n");
}
number(str)
char *str;
{
register n, c;
register char *s;
n = 0;
s = str;
while(c = *s++) {
if(c<'0' || c>'9')
return(0);
n = n*10 + c-'0';
}
return(n);
}
pstr(str, n)
char *str;
{
register i;
register char *s;
s = str;
i = n;
while(i--)
if(*s++ == '\0')
s[-1] = ' ';
i = n+1;
while(i--)
if(*--s != ' ')
break;
s[1] = '\0';
printf("%s\n", str);
}
char mon[] = {
0,
31, 29, 31, 30,
31, 30, 31, 31,
30, 31, 30, 31,
};
cal(m, y, p, w)
char *p;
{
register d, i;
register char *s;
s = p;
d = jan1(y);
mon[2] = 29;
mon[9] = 30;
switch((jan1(y+1)+7-d)%7) {
/*
* non-leap year
*/
case 1:
mon[2] = 28;
break;
/*
* 1752
*/
default:
mon[9] = 19;
break;
/*
* leap year
*/
case 2:
;
}
for(i=1; i<m; i++)
d += mon[i];
d %= 7;
s += 3*d;
for(i=1; i<=mon[m]; i++) {
if(i==3 && mon[m]==19) {
i += 11;
mon[m] += 11;
}
if(i > 9)
*s = i/10+'0';
s++;
*s++ = i%10+'0';
s++;
if(++d == 7) {
d = 0;
s = p+w;
p = s;
}
}
}
/*
* return day of the week
* of jan 1 of given year
*/
jan1(yr)
{
register y, d;
/*
* normal gregorian calendar
* one extra day per four years
*/
y = yr;
d = 4+y+(y+3)/4;
/*
* julian calendar
* regular gregorian
* less three days per 400
*/
if(y > 1800) {
d -= (y-1701)/100;
d += (y-1601)/400;
}
/*
* great calendar changeover instant
*/
if(y > 1752)
d += 3;
return(d%7);
}