xref: /freebsd/bin/date/date.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
1 /*
2  * Copyright (c) 1985, 1987, 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static char copyright[] =
36 "@(#) Copyright (c) 1985, 1987, 1988, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 static char sccsid[] = "@(#)date.c	8.1 (Berkeley) 5/31/93";
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/time.h>
46 
47 #include <ctype.h>
48 #include <err.h>
49 #include <fcntl.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <syslog.h>
54 #include <unistd.h>
55 
56 #include "extern.h"
57 
58 time_t tval;
59 int retval, nflag;
60 
61 static void setthetime __P((char *));
62 static void badformat __P((void));
63 static void usage __P((void));
64 
65 int logwtmp __P((char *, char *, char *));
66 
67 int
68 main(argc, argv)
69 	int argc;
70 	char **argv;
71 {
72 	extern int optind;
73 	extern char *optarg;
74 	struct timezone tz;
75 	int ch, rflag;
76 	char *format, buf[1024];
77 
78 	tz.tz_dsttime = tz.tz_minuteswest = 0;
79 	rflag = 0;
80 	while ((ch = getopt(argc, argv, "d:nr:ut:")) != EOF)
81 		switch((char)ch) {
82 		case 'd':		/* daylight savings time */
83 			tz.tz_dsttime = atoi(optarg) ? 1 : 0;
84 			break;
85 		case 'n':		/* don't set network */
86 			nflag = 1;
87 			break;
88 		case 'r':		/* user specified seconds */
89 			rflag = 1;
90 			tval = atol(optarg);
91 			break;
92 		case 'u':		/* do everything in GMT */
93 			(void)setenv("TZ", "GMT0", 1);
94 			break;
95 		case 't':		/* minutes west of GMT */
96 					/* error check; don't allow "PST" */
97 			if (isdigit(*optarg)) {
98 				tz.tz_minuteswest = atoi(optarg);
99 				break;
100 			}
101 			/* FALLTHROUGH */
102 		default:
103 			usage();
104 		}
105 	argc -= optind;
106 	argv += optind;
107 
108 	/*
109 	 * If -d or -t, set the timezone or daylight savings time; this
110 	 * doesn't belong here, there kernel should not know about either.
111 	 */
112 	if ((tz.tz_minuteswest || tz.tz_dsttime) &&
113 	    settimeofday(NULL, &tz))
114 		err(1, "settimeofday");
115 
116 	if (!rflag && time(&tval) == -1)
117 		err(1, "time");
118 
119 	format = "%a %b %e %H:%M:%S %Z %Y\n";
120 
121 	/* allow the operands in any order */
122 	if (*argv && **argv == '+') {
123 		format = *argv + 1;
124 		++argv;
125 	}
126 
127 	if (*argv) {
128 		setthetime(*argv);
129 		++argv;
130 	}
131 
132 	if (*argv && **argv == '+')
133 		format = *argv + 1;
134 
135 	(void)strftime(buf, sizeof(buf), format, localtime(&tval));
136 	(void)printf("%s", buf);
137 	exit(retval);
138 }
139 
140 #define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
141 void
142 setthetime(p)
143 	register char *p;
144 {
145 	register struct tm *lt;
146 	struct timeval tv;
147 	char *dot, *t;
148 
149 	for (t = p, dot = NULL; *t; ++t) {
150 		if (isdigit(*t))
151 			continue;
152 		if (*t == '.' && dot == NULL) {
153 			dot = t;
154 			continue;
155 		}
156 		badformat();
157 	}
158 
159 	lt = localtime(&tval);
160 
161 	if (dot != NULL) {			/* .ss */
162 		*dot++ = '\0';
163 		if (strlen(dot) != 2)
164 			badformat();
165 		lt->tm_sec = ATOI2(dot);
166 		if (lt->tm_sec > 61)
167 			badformat();
168 	} else
169 		lt->tm_sec = 0;
170 
171 	switch (strlen(p)) {
172 	case 10:				/* yy */
173 		lt->tm_year = ATOI2(p);
174 		if (lt->tm_year < 69)		/* hack for 2000 ;-} */
175 			lt->tm_year += 100;
176 		/* FALLTHROUGH */
177 	case 8:					/* mm */
178 		lt->tm_mon = ATOI2(p);
179 		if (lt->tm_mon > 12)
180 			badformat();
181 		--lt->tm_mon;			/* time struct is 0 - 11 */
182 		/* FALLTHROUGH */
183 	case 6:					/* dd */
184 		lt->tm_mday = ATOI2(p);
185 		if (lt->tm_mday > 31)
186 			badformat();
187 		/* FALLTHROUGH */
188 	case 4:					/* hh */
189 		lt->tm_hour = ATOI2(p);
190 		if (lt->tm_hour > 23)
191 			badformat();
192 		/* FALLTHROUGH */
193 	case 2:					/* mm */
194 		lt->tm_min = ATOI2(p);
195 		if (lt->tm_min > 59)
196 			badformat();
197 		break;
198 	default:
199 		badformat();
200 	}
201 
202 	/* convert broken-down time to GMT clock time */
203 	if ((tval = mktime(lt)) == -1)
204 		badformat();
205 
206 	/* set the time */
207 	if (nflag || netsettime(tval)) {
208 		logwtmp("|", "date", "");
209 		tv.tv_sec = tval;
210 		tv.tv_usec = 0;
211 		if (settimeofday(&tv, NULL)) {
212 			perror("date: settimeofday");
213 			exit(1);
214 		}
215 		logwtmp("{", "date", "");
216 	}
217 
218 	if ((p = getlogin()) == NULL)
219 		p = "???";
220 	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
221 }
222 
223 static void
224 badformat()
225 {
226 	warnx("illegal time format");
227 	usage();
228 }
229 
230 static void
231 usage()
232 {
233 	(void)fprintf(stderr,
234 	    "usage: date [-nu] [-d dst] [-r seconds] [-t west] [+format]\n");
235 	(void)fprintf(stderr, "            [yy[mm[dd[hh]]]]mm[.ss]]\n");
236 	exit(1);
237 }
238