File: [local] / src / usr.bin / cal / cal.c (download)
Revision 1.24, Thu Jan 1 21:07:17 2009 UTC (15 years, 5 months ago) by otto
Branch: MAIN
CVS Tags: OPENBSD_4_6_BASE, OPENBSD_4_6, OPENBSD_4_5_BASE, OPENBSD_4_5 Changes since 1.23: +38 -25 lines
Fix iso weekno calculation by using a different algorithm. Still hard
to follow, but this one has a documented origin at least; ok pyr@
jasper@
|
/* $OpenBSD: cal.c,v 1.24 2009/01/01 21:07:17 otto Exp $ */
/* $NetBSD: cal.c,v 1.6 1995/03/26 03:10:24 glass Exp $ */
/*
* Copyright (c) 1989, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kim Letkeman.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1989, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#if 0
static char sccsid[] = "@(#)cal.c 8.4 (Berkeley) 4/2/94";
#else
static const char rcsid[] = "$OpenBSD: cal.c,v 1.24 2009/01/01 21:07:17 otto Exp $";
#endif
#endif /* not lint */
#include <sys/types.h>
#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tzfile.h>
#include <unistd.h>
#define THURSDAY 4 /* for reformation */
#define SATURDAY 6 /* 1 Jan 1 was a Saturday */
#define FIRST_MISSING_DAY 639799 /* 3 Sep 1752 */
#define NUMBER_MISSING_DAYS 11 /* 11 day correction */
#define MAXDAYS 42 /* max slots in a month array */
#define SPACE -1 /* used in day array */
static const int days_in_month[2][13] = {
{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
{0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
};
const int sep1752s[MAXDAYS] = {
SPACE, SPACE, 1, 2, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23,
24, 25, 26, 27, 28, 29, 30,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
}, sep1752m[MAXDAYS] = {
SPACE, 1, 2, 14, 15, 16, 17,
18, 19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
}, sep1752js[MAXDAYS] = {
SPACE, SPACE, 245, 246, 258, 259, 260,
261, 262, 263, 264, 265, 266, 267,
268, 269, 270, 271, 272, 273, 274,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
}, sep1752jm[MAXDAYS] = {
SPACE, 245, 246, 258, 259, 260, 261,
262, 263, 264, 265, 266, 267, 268,
269, 270, 271, 272, 273, 274, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
}, empty[MAXDAYS] = {
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
};
const char *month_names[12] = {
"January", "February", "March", "April", "May", "June",
"July", "August", "September", "October", "November", "December",
};
#define DAY_HEADINGS_S "Su Mo Tu We Th Fr Sa"
#define DAY_HEADINGS_M "Mo Tu We Th Fr Sa Su"
#define DAY_HEADINGS_JS " Su Mo Tu We Th Fr Sa"
#define DAY_HEADINGS_JM " Mo Tu We Th Fr Sa Su"
const int *sep1752 = NULL;
const char *day_headings = NULL;
/* leap year -- account for gregorian reformation in 1752 */
#define leap_year(yr) \
((yr) <= 1752 ? !((yr) % 4) : \
(!((yr) % 4) && ((yr) % 100)) || !((yr) % 400))
/* number of centuries since 1700, not inclusive */
#define centuries_since_1700(yr) \
((yr) > 1700 ? (yr) / 100 - 17 : 0)
/* number of centuries since 1700 whose modulo of 400 is 0 */
#define quad_centuries_since_1700(yr) \
((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
/* number of leap years between year 1 and this year, not inclusive */
#define leap_years_since_year_1(yr) \
((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
int julian;
int mflag = 0;
int wflag = 0;
void ascii_day(char *, int);
void center(const char *, int, int);
void day_array(int, int, int *);
int day_in_week(int, int, int);
int day_in_year(int, int, int);
int week(int, int, int);
int isoweek(int, int, int);
void j_yearly(int);
void monthly(int, int);
void trim_trailing_spaces(char *);
void usage(void);
void yearly(int);
int parsemonth(const char *);
int
main(int argc, char *argv[])
{
struct tm *local_time;
time_t now;
int ch, month, year, yflag;
const char *errstr;
yflag = year = 0;
while ((ch = getopt(argc, argv, "jmwy")) != -1)
switch(ch) {
case 'j':
julian = 1;
break;
case 'm':
mflag = 1;
break;
case 'w':
wflag = 1;
break;
case 'y':
yflag = 1;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (julian && wflag)
usage();
day_headings = DAY_HEADINGS_S;
sep1752 = sep1752s;
if (mflag && julian) {
sep1752 = sep1752jm;
day_headings = DAY_HEADINGS_JM;
} else if (mflag) {
sep1752 = sep1752m;
day_headings = DAY_HEADINGS_M;
} else if (julian) {
sep1752 = sep1752js;
day_headings = DAY_HEADINGS_JS;
}
month = 0;
switch(argc) {
case 2:
month = parsemonth(*argv++);
if (!month)
errx(1, "Unable to parse month");
/* FALLTHROUGH */
case 1:
if (argc == 1 && !isdigit(*argv[0])) {
month = parsemonth(*argv);
if (!month)
errx(1, "illegal year value: use 1-9999");
(void)time(&now);
local_time = localtime(&now);
year = local_time->tm_year + TM_YEAR_BASE;
} else {
year = strtonum(*argv, 1, 9999, &errstr);
if (errstr)
errx(1, "illegal year value: use 1-9999");
}
break;
case 0:
(void)time(&now);
local_time = localtime(&now);
year = local_time->tm_year + TM_YEAR_BASE;
if (!yflag)
month = local_time->tm_mon + 1;
break;
default:
usage();
}
if (month)
monthly(month, year);
else if (julian)
j_yearly(year);
else
yearly(year);
exit(0);
}
#define DAY_LEN 3 /* 3 spaces per day */
#define J_DAY_LEN 4 /* 4 spaces per day */
#define WEEK_LEN 20 /* 7 * 3 - one space at the end */
#define WEEKNUMBER_LEN 5 /* 5 spaces per week number */
#define J_WEEK_LEN 27 /* 7 * 4 - one space at the end */
#define HEAD_SEP 2 /* spaces between day headings */
#define J_HEAD_SEP 2
int
week(int day, int month, int year)
{
int yearday;
int firstweekday;
int weekday;
int firstday;
int firstsunday;
int shift;
if (mflag)
return isoweek(day, month, year);
yearday = day_in_year(day, month, year);
firstweekday = day_in_week(1, 1, year) + 1;
weekday = day_in_week(day, month, year) + 1;
firstday = day_in_year(1, 1, year);
firstsunday = firstday + (8 - firstweekday);
shift = 1;
if (yearday < firstsunday)
return (1);
if (firstweekday > THURSDAY - 1)
shift = 2;
return ((((yearday + 1) - (weekday - 1)) / 7) + shift);
}
int
isoweek(int day, int month, int year)
{
/* http://www.tondering.dk/claus/cal/node8.html */
int a, b, c, s, e, f, g, d, n;
a = month <= 2 ? year - 1 : year;
b = a/4 - a/100 + a/400;
c = (a-1)/4 - (a-1)/100 + (a-1)/400;
s = b - c;
if (month <= 2) {
e = 0;
f = day - 1 + 31 * (month-1);
} else {
e = s + 1;
f = day + ((153 * (month-3) + 2) / 5) + 58 + s;
}
g = (a + b) % 7;
d = (f + g - e) % 7;
n = f + 3 - d;
if (n < 0)
return 53 - (g - s) / 5;
else if (n > 364 + s)
return 1;
else
return n/7 + 1;
}
void
monthly(int month, int year)
{
int col, row, len, days[MAXDAYS], firstday;
char *p, lineout[30];
day_array(month, year, days);
(void)snprintf(lineout, sizeof(lineout), "%s %d",
month_names[month - 1], year);
len = strlen(lineout);
(void)printf("%*s%s\n%s\n",
((julian ? J_WEEK_LEN : WEEK_LEN) - len) / 2, "",
lineout, day_headings);
for (row = 0; row < 6; row++) {
firstday = SPACE;
for (col = 0, p = lineout; col < 7; col++,
p += julian ? J_DAY_LEN : DAY_LEN) {
if (firstday == SPACE && days[row * 7 + col] != SPACE)
firstday = days[row * 7 + col];
ascii_day(p, days[row * 7 + col]);
}
*p = '\0';
trim_trailing_spaces(lineout);
(void)printf("%-20s", lineout);
if (wflag && firstday != SPACE)
printf(" [%2d]", week(firstday, month, year));
printf("\n");
}
}
void
j_yearly(int year)
{
int col, *dp, i, month, row, which_cal;
int days[12][MAXDAYS];
char *p, lineout[80];
(void)snprintf(lineout, sizeof(lineout), "%d", year);
center(lineout, J_WEEK_LEN * 2 + J_HEAD_SEP, 0);
(void)printf("\n\n");
for (i = 0; i < 12; i++)
day_array(i + 1, year, days[i]);
(void)memset(lineout, ' ', sizeof(lineout) - 1);
lineout[sizeof(lineout) - 1] = '\0';
for (month = 0; month < 12; month += 2) {
center(month_names[month], J_WEEK_LEN, J_HEAD_SEP);
center(month_names[month + 1], J_WEEK_LEN, 0);
(void)printf("\n%s%*s%s\n", day_headings,
J_HEAD_SEP, "", day_headings);
for (row = 0; row < 6; row++) {
for (which_cal = 0; which_cal < 2; which_cal++) {
p = lineout + which_cal * (J_WEEK_LEN + 2);
dp = &days[month + which_cal][row * 7];
for (col = 0; col < 7; col++, p += J_DAY_LEN)
ascii_day(p, *dp++);
}
*p = '\0';
trim_trailing_spaces(lineout);
(void)printf("%s\n", lineout);
}
}
(void)printf("\n");
}
void
yearly(int year)
{
int col, *dp, i, month, row, which_cal, week_len, wn, firstday;
int days[12][MAXDAYS];
char *p, lineout[81];
week_len = WEEK_LEN;
if (wflag)
week_len += WEEKNUMBER_LEN;
(void)snprintf(lineout, sizeof(lineout), "%d", year);
center(lineout, week_len * 3 + HEAD_SEP * 2, 0);
(void)printf("\n\n");
for (i = 0; i < 12; i++)
day_array(i + 1, year, days[i]);
(void)memset(lineout, ' ', sizeof(lineout) - 1);
lineout[sizeof(lineout) - 1] = '\0';
for (month = 0; month < 12; month += 3) {
center(month_names[month], week_len, HEAD_SEP);
center(month_names[month + 1], week_len, HEAD_SEP);
center(month_names[month + 2], week_len, 0);
(void)printf("\n%s%*s%s%*s%s\n", day_headings,
HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings,
HEAD_SEP + (wflag ? WEEKNUMBER_LEN : 0), "", day_headings);
for (row = 0; row < 6; row++) {
for (which_cal = 0; which_cal < 3; which_cal++) {
p = lineout + which_cal * (week_len + 2);
dp = &days[month + which_cal][row * 7];
firstday = SPACE;
for (col = 0; col < 7; col++, p += DAY_LEN) {
if (firstday == SPACE && *dp != SPACE)
firstday = *dp;
ascii_day(p, *dp++);
}
if (wflag && firstday != SPACE) {
wn = week(firstday,
month + which_cal + 1, year);
(void)snprintf(p, 5, "[%2d]", wn);
p += strlen(p);
*p = ' ';
} else
memset(p, ' ', 4);
}
*p = '\0';
trim_trailing_spaces(lineout);
(void)printf("%s\n", lineout);
}
}
(void)printf("\n");
}
/*
* day_array --
* Fill in an array of 42 integers with a calendar. Assume for a moment
* that you took the (maximum) 6 rows in a calendar and stretched them
* out end to end. You would have 42 numbers or spaces. This routine
* builds that array for any month from Jan. 1 through Dec. 9999.
*/
void
day_array(int month, int year, int *days)
{
int day, dw, dm;
if (month == 9 && year == 1752) {
memmove(days, sep1752, MAXDAYS * sizeof(int));
return;
}
memmove(days, empty, MAXDAYS * sizeof(int));
dm = days_in_month[leap_year(year)][month];
dw = day_in_week(mflag?0:1, month, year);
day = julian ? day_in_year(1, month, year) : 1;
while (dm--)
days[dw++] = day++;
}
/*
* day_in_year --
* return the 1 based day number within the year
*/
int
day_in_year(int day, int month, int year)
{
int i, leap;
leap = leap_year(year);
for (i = 1; i < month; i++)
day += days_in_month[leap][i];
return (day);
}
/*
* day_in_week
* return the 0 based day number for any date from 1 Jan. 1 to
* 31 Dec. 9999. Assumes the Gregorian reformation eliminates
* 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
* missing days.
*/
int
day_in_week(int day, int month, int year)
{
long temp;
temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
+ day_in_year(day, month, year);
if (temp < FIRST_MISSING_DAY)
return ((temp - 1 + SATURDAY) % 7);
if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
return (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
return (THURSDAY);
}
void
ascii_day(char *p, int day)
{
int display, val;
static const char *aday[] = {
"",
" 1", " 2", " 3", " 4", " 5", " 6", " 7",
" 8", " 9", "10", "11", "12", "13", "14",
"15", "16", "17", "18", "19", "20", "21",
"22", "23", "24", "25", "26", "27", "28",
"29", "30", "31",
};
if (day == SPACE) {
memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
return;
}
if (julian) {
val = day / 100;
if (val) {
day %= 100;
*p++ = val + '0';
display = 1;
} else {
*p++ = ' ';
display = 0;
}
val = day / 10;
if (val || display)
*p++ = val + '0';
else
*p++ = ' ';
*p++ = day % 10 + '0';
} else {
*p++ = aday[day][0];
*p++ = aday[day][1];
}
*p = ' ';
}
void
trim_trailing_spaces(char *s)
{
char *p;
for (p = s; *p; ++p)
continue;
while (p > s && isspace(*--p))
continue;
if (p > s)
++p;
*p = '\0';
}
void
center(const char *str, int len, int separate)
{
len -= strlen(str);
(void)printf("%*s%s%*s", len / 2, "", str,
len / 2 + len % 2 + separate, "");
}
void
usage(void)
{
(void)fprintf(stderr, "usage: cal [-jmwy] [month] [year]\n");
exit(1);
}
int
parsemonth(const char *s)
{
struct tm tm;
char *cp;
int v;
v = (int)strtol(s, &cp, 10);
if (*cp != '\0') { /* s wasn't purely numeric */
v = 0;
if ((cp = strptime(s, "%b", &tm)) != NULL && *cp == '\0')
v = tm.tm_mon + 1;
}
if (v <= 0 || v > 12)
errx(1, "invalid month: use 1-12 or a name");
return (v);
}