xref: /dragonfly/bin/date/date.c (revision eb0e7146)
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 
47 #include "vary.h"
48 
49 #ifndef	TM_YEAR_BASE
50 #define	TM_YEAR_BASE	1900
51 #endif
52 
53 static time_t tval;
54 
55 static void setthetime(const char *, const char *, int);
56 static void badformat(void);
57 static void usage(void);
58 
59 static const char *rfc2822_format ="%a, %d %b %Y %T %z";
60 
61 int
62 main(int argc, char **argv)
63 {
64 	int ch, rflag;
65 	int jflag, Rflag;
66 	const char *format;
67 	char buf[1024];
68 	char *fmt;
69 	char *tmp;
70 	struct vary *v;
71 	const struct vary *badv;
72 	struct tm lt;
73 
74 	v = NULL;
75 	fmt = NULL;
76 	setlocale(LC_TIME, "");
77 	rflag = 0;
78 	jflag = Rflag = 0;
79 	while ((ch = getopt(argc, argv, "f:jnRr:uv:")) != -1)
80 		switch(ch) {
81 		case 'f':
82 			fmt = optarg;
83 			break;
84 		case 'j':
85 			jflag = 1;	/* don't set time */
86 			break;
87 		case 'n':		/* don't set network */
88 			break;
89 		case 'R':
90 			Rflag = 1;	/*RFC 2822 datetime format */
91 			break;
92 		case 'r':		/* user specified seconds */
93 			rflag = 1;
94 			tval = strtoll(optarg, &tmp, 0);
95 			if (*tmp != 0)
96 				usage();
97 			break;
98 		case 'u':		/* do everything in UTC */
99 			if (setenv("TZ", "UTC0", 1) != 0)
100 				err(1, "setenv: cannot set TZ=UTC0");
101 			break;
102 		case 'v':
103 			v = vary_append(v, optarg);
104 			break;
105 		default:
106 			usage();
107 		}
108 	argc -= optind;
109 	argv += optind;
110 
111 	if (!rflag && time(&tval) == -1)
112 		err(1, "time");
113 
114 	format = "%+";
115 
116 	if (Rflag)
117 		format = rfc2822_format;
118 
119 	/* allow the operands in any order */
120 	if (*argv && **argv == '+') {
121 		format = *argv + 1;
122 		++argv;
123 	}
124 
125 	if (*argv) {
126 		setthetime(fmt, *argv, jflag);
127 		++argv;
128 	} else if (fmt != NULL)
129 		usage();
130 
131 	if (*argv && **argv == '+')
132 		format = *argv + 1;
133 
134 	lt = *localtime(&tval);
135 	badv = vary_apply(v, &lt);
136 	if (badv) {
137 		fprintf(stderr, "%s: Cannot apply date adjustment\n",
138 			badv->arg);
139 		vary_destroy(v);
140 		usage();
141 	}
142 	vary_destroy(v);
143 
144 	if (format == rfc2822_format) {
145 		/*
146 		 * When using RFC 2822 datetime format, don't honor the
147 		 * locale.
148 		 */
149 		setlocale(LC_TIME, "C");
150 	}
151 
152 	strftime(buf, sizeof(buf), format, &lt);
153 	printf("%s\n", buf);
154 	if (fflush(stdout) != 0)
155 		err(1, "stdout");
156 	exit(EXIT_SUCCESS);
157 }
158 
159 #define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
160 
161 static void
162 setthetime(const char *fmt, const char *p, int jflag)
163 {
164 	struct tm *lt;
165 	struct timeval tv;
166 	const char *dot, *t;
167 	int century;
168 
169 	if (fmt != NULL) {
170 		lt = localtime(&tval);
171 		t = strptime(p, fmt, lt);
172 		if (t == NULL) {
173 			fprintf(stderr, "Failed conversion of ``%s''"
174 				" using format ``%s''\n", p, fmt);
175 			badformat();
176 		} else if (*t != '\0')
177 			fprintf(stderr, "Warning: Ignoring %ld extraneous"
178 				" characters in date string (%s)\n",
179 				(long) strlen(t), t);
180 	} else {
181 		for (t = p, dot = NULL; *t; ++t) {
182 			if (isdigit(*t))
183 				continue;
184 			if (*t == '.' && dot == NULL) {
185 				dot = t;
186 				continue;
187 			}
188 			badformat();
189 		}
190 
191 		lt = localtime(&tval);
192 
193 		if (dot != NULL) {			/* .ss */
194 			dot++; /* *dot++ = '\0'; */
195 			if (strlen(dot) != 2)
196 				badformat();
197 			lt->tm_sec = ATOI2(dot);
198 			if (lt->tm_sec > 61)
199 				badformat();
200 		} else
201 			lt->tm_sec = 0;
202 
203 		century = 0;
204 		/* if p has a ".ss" field then let's pretend it's not there */
205 		switch (strlen(p) - ((dot != NULL) ? 3 : 0)) {
206 		case 12:				/* cc */
207 			lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
208 			century = 1;
209 			/* FALLTHROUGH */
210 		case 10:				/* yy */
211 			if (century)
212 				lt->tm_year += ATOI2(p);
213 			else {				/* hack for 2000 ;-} */
214 				lt->tm_year = ATOI2(p);
215 				if (lt->tm_year < 69)
216 					lt->tm_year += 2000 - TM_YEAR_BASE;
217 				else
218 					lt->tm_year += 1900 - TM_YEAR_BASE;
219 			}
220 			/* FALLTHROUGH */
221 		case 8:					/* mm */
222 			lt->tm_mon = ATOI2(p);
223 			if (lt->tm_mon > 12)
224 				badformat();
225 			--lt->tm_mon;		/* time struct is 0 - 11 */
226 			/* FALLTHROUGH */
227 		case 6:					/* dd */
228 			lt->tm_mday = ATOI2(p);
229 			if (lt->tm_mday > 31)
230 				badformat();
231 			/* FALLTHROUGH */
232 		case 4:					/* HH */
233 			lt->tm_hour = ATOI2(p);
234 			if (lt->tm_hour > 23)
235 				badformat();
236 			/* FALLTHROUGH */
237 		case 2:					/* MM */
238 			lt->tm_min = ATOI2(p);
239 			if (lt->tm_min > 59)
240 				badformat();
241 			break;
242 		default:
243 			badformat();
244 		}
245 	}
246 
247 	/* Let mktime() decide whether summer time is in effect. */
248 	lt->tm_isdst = -1;
249 
250 	/* convert broken-down time to GMT clock time */
251 	if ((tval = mktime(lt)) == -1)
252 		errx(1, "nonexistent time");
253 
254 	if (!jflag) {
255 		logwtmp("|", "date", "");
256 		tv.tv_sec = tval;
257 		tv.tv_usec = 0;
258 		if (settimeofday(&tv, NULL))
259 			err(1, "settimeofday (timeval)");
260 		logwtmp("{", "date", "");
261 
262 		if ((p = getlogin()) == NULL)
263 			p = "???";
264 		syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
265 	}
266 }
267 
268 static void
269 badformat(void)
270 {
271 	warnx("illegal time format");
272 	usage();
273 }
274 
275 static void
276 usage(void)
277 {
278 	fprintf(stderr, "%s\n%s\n",
279 	    "usage: date [-jnRu] [-r seconds] [-v[+|-]val[ymwdHMS]] ... ",
280 	    "            "
281 	    "[-f fmt date | [[[[[cc]yy]mm]dd]HH]MM[.ss]] [+format]");
282 	exit(1);
283 }
284