xref: /freebsd/usr.bin/calendar/calendar.c (revision e796cc77c586c2955b2f3940dbf4991b31e8d289)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1989, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)calendar.c	8.3 (Berkeley) 3/25/94";
41 #endif
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <err.h>
48 #include <errno.h>
49 #include <locale.h>
50 #include <pwd.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <time.h>
55 #include <unistd.h>
56 
57 #include "calendar.h"
58 
59 #define	UTCOFFSET_NOTSET	100	/* Expected between -24 and +24 */
60 #define	LONGITUDE_NOTSET	1000	/* Expected between -360 and +360 */
61 
62 struct passwd	*pw;
63 int		doall = 0;
64 int		debug = 0;
65 static char	*DEBUG = NULL;
66 static time_t	f_time = 0;
67 double		UTCOffset = UTCOFFSET_NOTSET;
68 int		EastLongitude = LONGITUDE_NOTSET;
69 
70 static void	usage(void) __dead2;
71 
72 int
73 main(int argc, char *argv[])
74 {
75 	int	f_dayAfter = 0;		/* days after current date */
76 	int	f_dayBefore = 0;	/* days before current date */
77 	int	Friday = 5;		/* day before weekend */
78 
79 	int ch;
80 	struct tm tp1, tp2;
81 
82 	(void)setlocale(LC_ALL, "");
83 
84 	while ((ch = getopt(argc, argv, "-A:aB:D:dF:f:l:t:U:W:?")) != -1)
85 		switch (ch) {
86 		case '-':		/* backward contemptible */
87 		case 'a':
88 			if (getuid()) {
89 				errno = EPERM;
90 				err(1, NULL);
91 			}
92 			doall = 1;
93 			break;
94 
95 		case 'W': /* we don't need no steenking Fridays */
96 			Friday = -1;
97 			/* FALLTHROUGH */
98 
99 		case 'A': /* days after current date */
100 			f_dayAfter = atoi(optarg);
101 			if (f_dayAfter < 0)
102 				errx(1, "number of days must be positive");
103 			break;
104 
105 		case 'B': /* days before current date */
106 			f_dayBefore = atoi(optarg);
107 			if (f_dayBefore < 0)
108 				errx(1, "number of days must be positive");
109 			break;
110 
111 		case 'D': /* debug output of sun and moon info */
112 			DEBUG = optarg;
113 			break;
114 
115 		case 'd': /* debug output of current date */
116 			debug = 1;
117 			break;
118 
119 		case 'F': /* Change the time: When does weekend start? */
120 			Friday = atoi(optarg);
121 			break;
122 
123 		case 'f': /* other calendar file */
124 			calendarFile = optarg;
125 			break;
126 
127 		case 'l': /* Change longitudal position */
128 			EastLongitude = strtol(optarg, NULL, 10);
129 			break;
130 
131 		case 't': /* other date, for tests */
132 			f_time = Mktime(optarg);
133 			break;
134 
135 		case 'U': /* Change UTC offset */
136 			UTCOffset = strtod(optarg, NULL);
137 			break;
138 
139 		case '?':
140 		default:
141 			usage();
142 		}
143 
144 	argc -= optind;
145 	argv += optind;
146 
147 	if (argc)
148 		usage();
149 
150 	/* use current time */
151 	if (f_time <= 0)
152 		(void)time(&f_time);
153 
154 	/* if not set, determine where I could be */
155 	{
156 		if (UTCOffset == UTCOFFSET_NOTSET &&
157 		    EastLongitude == LONGITUDE_NOTSET) {
158 			/* Calculate on difference between here and UTC */
159 			time_t t;
160 			struct tm tm;
161 			long utcoffset, hh, mm, ss;
162 			double uo;
163 
164 			time(&t);
165 			localtime_r(&t, &tm);
166 			utcoffset = tm.tm_gmtoff;
167 			/* seconds -> hh:mm:ss */
168 			hh = utcoffset / SECSPERHOUR;
169 			utcoffset %= SECSPERHOUR;
170 			mm = utcoffset / SECSPERMINUTE;
171 			utcoffset %= SECSPERMINUTE;
172 			ss = utcoffset;
173 
174 			/* hh:mm:ss -> hh.mmss */
175 			uo = mm + (100.0 * (ss / 60.0));
176 			uo /=  60.0 / 100.0;
177 			uo = hh + uo / 100;
178 
179 			UTCOffset = uo;
180 			EastLongitude = UTCOffset * 15;
181 		} else if (UTCOffset == UTCOFFSET_NOTSET) {
182 			/* Base on information given */
183 			UTCOffset = EastLongitude / 15;
184 		} else if (EastLongitude == LONGITUDE_NOTSET) {
185 			/* Base on information given */
186 			EastLongitude = UTCOffset * 15;
187 		}
188 	}
189 
190 	settimes(f_time, f_dayBefore, f_dayAfter, Friday, &tp1, &tp2);
191 	generatedates(&tp1, &tp2);
192 
193 	/*
194 	 * FROM now on, we are working in UTC.
195 	 * This will only affect moon and sun related events anyway.
196 	 */
197 	if (setenv("TZ", "UTC", 1) != 0)
198 		errx(1, "setenv: %s", strerror(errno));
199 	tzset();
200 
201 	if (debug)
202 		dumpdates();
203 
204 	if (DEBUG != NULL) {
205 		dodebug(DEBUG);
206 		exit(0);
207 	}
208 
209 	if (doall)
210 		while ((pw = getpwent()) != NULL) {
211 			(void)setegid(pw->pw_gid);
212 			(void)initgroups(pw->pw_name, pw->pw_gid);
213 			(void)seteuid(pw->pw_uid);
214 			if (!chdir(pw->pw_dir))
215 				cal();
216 			(void)seteuid(0);
217 		}
218 	else
219 		cal();
220 	exit(0);
221 }
222 
223 
224 static void __dead2
225 usage(void)
226 {
227 
228 	fprintf(stderr, "%s\n%s\n%s\n",
229 	    "usage: calendar [-A days] [-a] [-B days] [-D sun|moon] [-d]",
230 	    "		     [-F friday] [-f calendarfile] [-l longitude]",
231 	    "		     [-t dd[.mm[.year]]] [-U utcoffset] [-W days]"
232 	    );
233 	exit(1);
234 }
235