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date.c revision 1.59
      1 /* $NetBSD: date.c,v 1.59 2011/01/29 02:16:52 christos Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1985, 1987, 1988, 1993
      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 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT(
     35 "@(#) Copyright (c) 1985, 1987, 1988, 1993\
     36  The Regents of the University of California.  All rights reserved.");
     37 #endif /* not lint */
     38 
     39 #ifndef lint
     40 #if 0
     41 static char sccsid[] = "@(#)date.c	8.2 (Berkeley) 4/28/95";
     42 #else
     43 __RCSID("$NetBSD: date.c,v 1.59 2011/01/29 02:16:52 christos Exp $");
     44 #endif
     45 #endif /* not lint */
     46 
     47 #include <sys/param.h>
     48 #include <sys/time.h>
     49 
     50 #include <ctype.h>
     51 #include <err.h>
     52 #include <fcntl.h>
     53 #include <errno.h>
     54 #include <locale.h>
     55 #include <stdio.h>
     56 #include <stdlib.h>
     57 #include <string.h>
     58 #include <syslog.h>
     59 #include <time.h>
     60 #include <tzfile.h>
     61 #include <unistd.h>
     62 #include <util.h>
     63 
     64 #include "extern.h"
     65 
     66 static time_t tval;
     67 static int aflag, jflag, rflag, nflag;
     68 
     69 static void badformat(void);
     70 static void badtime(void);
     71 static void badvalue(const char *);
     72 static void setthetime(const char *);
     73 static void usage(void) __attribute__((__noreturn__));
     74 
     75 int
     76 main(int argc, char *argv[])
     77 {
     78 	char *buf;
     79 	size_t bufsiz;
     80 	const char *format;
     81 	int ch;
     82 	long long val;
     83 	struct tm *tm;
     84 
     85 	setprogname(argv[0]);
     86 	(void)setlocale(LC_ALL, "");
     87 
     88 	while ((ch = getopt(argc, argv, "ad:jnr:u")) != -1) {
     89 		switch (ch) {
     90 		case 'a':		/* adjust time slowly */
     91 			aflag = 1;
     92 			nflag = 1;
     93 			break;
     94 		case 'd':
     95 			rflag = 1;
     96 			tval = parsedate(optarg, NULL, NULL);
     97 			if (tval == -1)
     98 badarg:				 errx(EXIT_FAILURE,
     99 				    "Cannot parse `%s'", optarg);
    100 			break;
    101 		case 'j':		/* don't set time */
    102 			jflag = 1;
    103 			break;
    104 		case 'n':		/* don't set network */
    105 			nflag = 1;
    106 			break;
    107 		case 'r':		/* user specified seconds */
    108 			errno = 0;
    109 			val = strtoll(optarg, &buf, 0);
    110 			if (optarg[0] == '\0' || *buf != '\0')
    111 				goto badarg;
    112 			if (errno == ERANGE && (val == LLONG_MAX ||
    113 			    val == LLONG_MIN))
    114 				err(EXIT_FAILURE, "Bad number `%s'", optarg);
    115 			rflag = 1;
    116 			tval = (time_t)val;
    117 			break;
    118 		case 'u':		/* do everything in UTC */
    119 			(void)setenv("TZ", "UTC0", 1);
    120 			break;
    121 		default:
    122 			usage();
    123 		}
    124 	}
    125 	argc -= optind;
    126 	argv += optind;
    127 
    128 	if (!rflag && time(&tval) == -1)
    129 		err(EXIT_FAILURE, "time");
    130 
    131 
    132 	/* allow the operands in any order */
    133 	if (*argv && **argv == '+') {
    134 		format = *argv;
    135 		++argv;
    136 	} else
    137 		format = "+%a %b %e %H:%M:%S %Z %Y";
    138 
    139 	if (*argv) {
    140 		setthetime(*argv);
    141 		++argv;
    142 	}
    143 
    144 	if (*argv && **argv == '+')
    145 		format = *argv;
    146 
    147 	if ((buf = malloc(bufsiz = 1024)) == NULL)
    148 		goto bad;
    149 
    150 	if ((tm = localtime(&tval)) == NULL)
    151 		err(EXIT_FAILURE, "localtime %lld failed", (long long)tval);
    152 
    153 	while (strftime(buf, bufsiz, format, tm) == 0)
    154 		if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
    155 			goto bad;
    156 
    157 	(void)printf("%s\n", buf + 1);
    158 	free(buf);
    159 	return 0;
    160 bad:
    161 	err(EXIT_FAILURE, "Cannot allocate format buffer");
    162 }
    163 
    164 static void
    165 badformat(void)
    166 {
    167 	warnx("illegal time format");
    168 	usage();
    169 }
    170 
    171 static void
    172 badtime(void)
    173 {
    174 	errx(EXIT_FAILURE, "illegal time");
    175 	/* NOTREACHED */
    176 }
    177 
    178 static void
    179 badvalue(const char *param)
    180 {
    181 	warnx("invalid %s supplied", param);
    182 	usage();
    183 }
    184 
    185 #define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
    186 
    187 static void
    188 setthetime(const char *p)
    189 {
    190 	struct timeval tv;
    191 	time_t new_time;
    192 	struct tm *lt;
    193 	const char *dot, *t;
    194 	size_t len;
    195 	int yearset;
    196 
    197 	for (t = p, dot = NULL; *t; ++t) {
    198 		if (isdigit((unsigned char)*t))
    199 			continue;
    200 		if (*t == '.' && dot == NULL) {
    201 			dot = t;
    202 			continue;
    203 		}
    204 		badformat();
    205 	}
    206 
    207 	if ((lt = localtime(&tval)) == NULL)
    208 		err(EXIT_FAILURE, "localtime %lld failed", (long long)tval);
    209 
    210 	lt->tm_isdst = -1;			/* Divine correct DST */
    211 
    212 	if (dot != NULL) {			/* .ss */
    213 		len = strlen(dot);
    214 		if (len != 3)
    215 			badformat();
    216 		++dot;
    217 		lt->tm_sec = ATOI2(dot);
    218 		if (lt->tm_sec > 61)
    219 			badvalue("seconds");
    220 	} else {
    221 		len = 0;
    222 		lt->tm_sec = 0;
    223 	}
    224 
    225 	yearset = 0;
    226 	switch (strlen(p) - len) {
    227 	case 12:				/* cc */
    228 		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
    229 		if (lt->tm_year < 0)
    230 			badtime();
    231 		yearset = 1;
    232 		/* FALLTHROUGH */
    233 	case 10:				/* yy */
    234 		if (yearset) {
    235 			lt->tm_year += ATOI2(p);
    236 		} else {
    237 			yearset = ATOI2(p);
    238 			if (yearset < 69)
    239 				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
    240 			else
    241 				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
    242 		}
    243 		/* FALLTHROUGH */
    244 	case 8:					/* mm */
    245 		lt->tm_mon = ATOI2(p);
    246 		if (lt->tm_mon > 12 || lt->tm_mon == 0)
    247 			badvalue("month");
    248 		--lt->tm_mon;			/* time struct is 0 - 11 */
    249 		/* FALLTHROUGH */
    250 	case 6:					/* dd */
    251 		lt->tm_mday = ATOI2(p);
    252 		switch (lt->tm_mon) {
    253 		case 0:
    254 		case 2:
    255 		case 4:
    256 		case 6:
    257 		case 7:
    258 		case 9:
    259 		case 11:
    260 			if (lt->tm_mday > 31 || lt->tm_mday == 0)
    261 				badvalue("day of month");
    262 			break;
    263 		case 3:
    264 		case 5:
    265 		case 8:
    266 		case 10:
    267 			if (lt->tm_mday > 30 || lt->tm_mday == 0)
    268 				badvalue("day of month");
    269 			break;
    270 		case 1:
    271 			if (lt->tm_mday > 29 || lt->tm_mday == 0 ||
    272 			    (lt->tm_mday == 29 &&
    273 			     !isleap(lt->tm_year + TM_YEAR_BASE)))
    274 				badvalue("day of month");
    275 			break;
    276 		default:
    277 			badvalue("month");
    278 			break;
    279 		}
    280 		/* FALLTHROUGH */
    281 	case 4:					/* hh */
    282 		lt->tm_hour = ATOI2(p);
    283 		if (lt->tm_hour > 23)
    284 			badvalue("hour");
    285 		/* FALLTHROUGH */
    286 	case 2:					/* mm */
    287 		lt->tm_min = ATOI2(p);
    288 		if (lt->tm_min > 59)
    289 			badvalue("minute");
    290 		break;
    291 	case 0:					/* was just .sss */
    292 		if (len != 0)
    293 			break;
    294 		/* FALLTHROUGH */
    295 	default:
    296 		badformat();
    297 	}
    298 
    299 	/* convert broken-down time to UTC clock time */
    300 	if ((new_time = mktime(lt)) == -1)
    301 		badtime();
    302 
    303 	/* if jflag is set, don't actually change the time, just return */
    304 	if (jflag) {
    305 		tval = new_time;
    306 		return;
    307 	}
    308 
    309 	/* set the time */
    310 	if (nflag || netsettime(new_time)) {
    311 		logwtmp("|", "date", "");
    312 		if (aflag) {
    313 			tv.tv_sec = new_time - tval;
    314 			tv.tv_usec = 0;
    315 			if (adjtime(&tv, NULL))
    316 				err(EXIT_FAILURE, "adjtime");
    317 		} else {
    318 			tval = new_time;
    319 			tv.tv_sec = tval;
    320 			tv.tv_usec = 0;
    321 			if (settimeofday(&tv, NULL))
    322 				err(EXIT_FAILURE, "settimeofday");
    323 		}
    324 		logwtmp("{", "date", "");
    325 	}
    326 
    327 	if ((p = getlogin()) == NULL)
    328 		p = "???";
    329 	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
    330 }
    331 
    332 static void
    333 usage(void)
    334 {
    335 	(void)fprintf(stderr,
    336 	    "Usage: %s [-ajnu] [-d date] [-r seconds] [+format]",
    337 	    getprogname());
    338 	(void)fprintf(stderr, " [[[[[[CC]yy]mm]dd]HH]MM[.SS]]\n");
    339 	exit(EXIT_FAILURE);
    340 	/* NOTREACHED */
    341 }
    342