xref: /dragonfly/bin/date/date.c (revision a9783bc6)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#) Copyright (c) 1985, 1987, 1988, 1993 The Regents of the University of California.  All rights reserved.
30  * @(#)date.c	8.2 (Berkeley) 4/28/95
31  * $FreeBSD: src/bin/date/date.c,v 1.47 2005/01/10 08:39:21 imp Exp $
32  */
33 
34 #include <sys/param.h>
35 #include <sys/time.h>
36 
37 #include <ctype.h>
38 #include <err.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 #include <locale.h>
45 #include <libutil.h>
46 #include <utmpx.h>
47 
48 #include "vary.h"
49 
50 #ifndef	TM_YEAR_BASE
51 #define	TM_YEAR_BASE	1900
52 #endif
53 
54 static time_t tval;
55 
56 static void setthetime(const char *, const char *, int);
57 static void badformat(void);
58 static void usage(void);
59 
60 static const char *rfc2822_format ="%a, %d %b %Y %T %z";
61 
62 int
63 main(int argc, char **argv)
64 {
65 	int ch, rflag;
66 	int jflag, Rflag;
67 	const char *format;
68 	char buf[1024];
69 	char *fmt;
70 	char *tmp;
71 	struct vary *v;
72 	const struct vary *badv;
73 	struct tm lt;
74 
75 	v = NULL;
76 	fmt = NULL;
77 	setlocale(LC_TIME, "");
78 	rflag = 0;
79 	jflag = Rflag = 0;
80 	while ((ch = getopt(argc, argv, "f:jnRr:uv:")) != -1)
81 		switch(ch) {
82 		case 'f':
83 			fmt = optarg;
84 			break;
85 		case 'j':
86 			jflag = 1;	/* don't set time */
87 			break;
88 		case 'n':		/* don't set network */
89 			break;
90 		case 'R':
91 			Rflag = 1;	/*RFC 2822 datetime format */
92 			break;
93 		case 'r':		/* user specified seconds */
94 			rflag = 1;
95 			tval = strtoll(optarg, &tmp, 0);
96 			if (*tmp != 0)
97 				usage();
98 			break;
99 		case 'u':		/* do everything in UTC */
100 			if (setenv("TZ", "UTC0", 1) != 0)
101 				err(1, "setenv: cannot set TZ=UTC0");
102 			break;
103 		case 'v':
104 			v = vary_append(v, optarg);
105 			break;
106 		default:
107 			usage();
108 		}
109 	argc -= optind;
110 	argv += optind;
111 
112 	if (!rflag && time(&tval) == -1)
113 		err(1, "time");
114 
115 	format = "%+";
116 
117 	if (Rflag)
118 		format = rfc2822_format;
119 
120 	/* allow the operands in any order */
121 	if (*argv && **argv == '+') {
122 		format = *argv + 1;
123 		++argv;
124 	}
125 
126 	if (*argv) {
127 		setthetime(fmt, *argv, jflag);
128 		++argv;
129 	} else if (fmt != NULL)
130 		usage();
131 
132 	if (*argv && **argv == '+')
133 		format = *argv + 1;
134 
135 	lt = *localtime(&tval);
136 	badv = vary_apply(v, &lt);
137 	if (badv) {
138 		fprintf(stderr, "%s: Cannot apply date adjustment\n",
139 			badv->arg);
140 		vary_destroy(v);
141 		usage();
142 	}
143 	vary_destroy(v);
144 
145 	if (format == rfc2822_format) {
146 		/*
147 		 * When using RFC 2822 datetime format, don't honor the
148 		 * locale.
149 		 */
150 		setlocale(LC_TIME, "C");
151 	}
152 
153 	strftime(buf, sizeof(buf), format, &lt);
154 	printf("%s\n", buf);
155 	if (fflush(stdout) != 0)
156 		err(1, "stdout");
157 	exit(EXIT_SUCCESS);
158 }
159 
160 #define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
161 
162 static void
163 setthetime(const char *fmt, const char *p, int jflag)
164 {
165 	struct tm *lt;
166 	struct timeval tv;
167 	const char *dot, *t;
168 	int century;
169 
170 	if (fmt != NULL) {
171 		lt = localtime(&tval);
172 		t = strptime(p, fmt, lt);
173 		if (t == NULL) {
174 			fprintf(stderr, "Failed conversion of ``%s''"
175 				" using format ``%s''\n", p, fmt);
176 			badformat();
177 		} else if (*t != '\0')
178 			fprintf(stderr, "Warning: Ignoring %ld extraneous"
179 				" characters in date string (%s)\n",
180 				(long) strlen(t), t);
181 	} else {
182 		for (t = p, dot = NULL; *t; ++t) {
183 			if (isdigit(*t))
184 				continue;
185 			if (*t == '.' && dot == NULL) {
186 				dot = t;
187 				continue;
188 			}
189 			badformat();
190 		}
191 
192 		lt = localtime(&tval);
193 
194 		if (dot != NULL) {			/* .ss */
195 			dot++; /* *dot++ = '\0'; */
196 			if (strlen(dot) != 2)
197 				badformat();
198 			lt->tm_sec = ATOI2(dot);
199 			if (lt->tm_sec > 61)
200 				badformat();
201 		} else
202 			lt->tm_sec = 0;
203 
204 		century = 0;
205 		/* if p has a ".ss" field then let's pretend it's not there */
206 		switch (strlen(p) - ((dot != NULL) ? 3 : 0)) {
207 		case 12:				/* cc */
208 			lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
209 			century = 1;
210 			/* FALLTHROUGH */
211 		case 10:				/* yy */
212 			if (century)
213 				lt->tm_year += ATOI2(p);
214 			else {				/* hack for 2000 ;-} */
215 				lt->tm_year = ATOI2(p);
216 				if (lt->tm_year < 69)
217 					lt->tm_year += 2000 - TM_YEAR_BASE;
218 				else
219 					lt->tm_year += 1900 - TM_YEAR_BASE;
220 			}
221 			/* FALLTHROUGH */
222 		case 8:					/* mm */
223 			lt->tm_mon = ATOI2(p);
224 			if (lt->tm_mon > 12)
225 				badformat();
226 			--lt->tm_mon;		/* time struct is 0 - 11 */
227 			/* FALLTHROUGH */
228 		case 6:					/* dd */
229 			lt->tm_mday = ATOI2(p);
230 			if (lt->tm_mday > 31)
231 				badformat();
232 			/* FALLTHROUGH */
233 		case 4:					/* HH */
234 			lt->tm_hour = ATOI2(p);
235 			if (lt->tm_hour > 23)
236 				badformat();
237 			/* FALLTHROUGH */
238 		case 2:					/* MM */
239 			lt->tm_min = ATOI2(p);
240 			if (lt->tm_min > 59)
241 				badformat();
242 			break;
243 		default:
244 			badformat();
245 		}
246 	}
247 
248 	/* Let mktime() decide whether summer time is in effect. */
249 	lt->tm_isdst = -1;
250 
251 	/* convert broken-down time to GMT clock time */
252 	if ((tval = mktime(lt)) == -1)
253 		errx(1, "nonexistent time");
254 
255 	if (!jflag) {
256 		logwtmpx("|", "date", "", 0, OLD_TIME);
257 		tv.tv_sec = tval;
258 		tv.tv_usec = 0;
259 		if (settimeofday(&tv, NULL))
260 			err(1, "settimeofday (timeval)");
261 		logwtmpx("{", "date", "", 0, NEW_TIME);
262 
263 		if ((p = getlogin()) == NULL)
264 			p = "???";
265 		syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
266 	}
267 }
268 
269 static void
270 badformat(void)
271 {
272 	warnx("illegal time format");
273 	usage();
274 }
275 
276 static void
277 usage(void)
278 {
279 	fprintf(stderr, "%s\n%s\n",
280 	    "usage: date [-jnRu] [-r seconds] [-v[+|-]val[ymwdHMS]] ... ",
281 	    "            "
282 	    "[-f fmt date | [[[[[cc]yy]mm]dd]HH]MM[.ss]] [+format]");
283 	exit(1);
284 }
285