bin/date/date.c

   1 /* $NetBSD: date.c,v 1.51 2008/02/24 04:49:45 dholland 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 1.51 2008/02/24 04:49:45 dholland 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 <locale.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <syslog.h>
  58 #include <time.h>
  59 #include <tzfile.h>
  60 #include <unistd.h>
  61 #include <util.h>
  62
  63 #include "extern.h"
  64
  65 static time_t tval;
  66 static int aflag, jflag, rflag, nflag;
  67 int retval;
  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);
  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
  83         setprogname(argv[0]);
  84         (void)setlocale(LC_ALL, "");
  85
  86         while ((ch = getopt(argc, argv, "ad:jnr:u")) != -1) {
  87                 switch (ch) {
  88                 case 'a':               /* adjust time slowly */
  89                         aflag = 1;
  90                         nflag = 1;
  91                         break;
  92                 case 'd':
  93                         rflag = 1;
  94                         tval = parsedate(optarg, NULL, NULL);
  95                         if (tval == -1)
  96                                 errx(1, "Cannot parse `%s'", optarg);
  97                         break;
  98                 case 'j':               /* don't set time */
  99                         jflag = 1;
 100                         break;
 101                 case 'n':               /* don't set network */
 102                         nflag = 1;
 103                         break;
 104                 case 'r':               /* user specified seconds */
 105                         rflag = 1;
 106                         tval = strtoll(optarg, NULL, 0);
 107                         break;
 108                 case 'u':               /* do everything in UTC */
 109                         (void)putenv("TZ=UTC0");
 110                         break;
 111                 default:
 112                         usage();
 113                 }
 114         }
 115         argc -= optind;
 116         argv += optind;
 117
 118         if (!rflag && time(&tval) == -1)
 119                 err(EXIT_FAILURE, "time");
 120
 121         format = "%a %b %e %H:%M:%S %Z %Y";
 122
 123         /* allow the operands in any order */
 124         if (*argv && **argv == '+') {
 125                 format = *argv + 1;
 126                 ++argv;
 127         }
 128
 129         if (*argv) {
 130                 setthetime(*argv);
 131                 ++argv;
 132         }
 133
 134         if (*argv && **argv == '+')
 135                 format = *argv + 1;
 136
 137         if ((buf = malloc(bufsiz = 1024)) == NULL)
 138                 goto bad;
 139         while (strftime(buf, bufsiz, format, localtime(&tval)) == 0)
 140                 if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
 141                         goto bad;
 142         (void)printf("%s\n", buf);
 143         free(buf);
 144         return 0;
 145 bad:
 146         err(1, "Cannot allocate format buffer");
 147 }
 148
 149 static void
 150 badformat(void)
 151 {
 152         warnx("illegal time format");
 153         usage();
 154 }
 155
 156 static void
 157 badtime(void)
 158 {
 159         errx(EXIT_FAILURE, "illegal time");
 160         /* NOTREACHED */
 161 }
 162
 163 static void
 164 badvalue(const char *param)
 165 {
 166         warnx("invalid %s supplied", param);
 167         usage();
 168 }
 169
 170 #define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
 171
 172 static void
 173 setthetime(const char *p)
 174 {
 175         struct timeval tv;
 176         time_t new_time;
 177         struct tm *lt;
 178         const char *dot, *t;
 179         size_t len;
 180         int yearset;
 181
 182         for (t = p, dot = NULL; *t; ++t) {
 183                 if (isdigit((unsigned char)*t))
 184                         continue;
 185                 if (*t == '.' && dot == NULL) {
 186                         dot = t;
 187                         continue;
 188                 }
 189                 badformat();
 190         }
 191
 192         lt = localtime(&tval);
 193
 194         lt->tm_isdst = -1;                      /* Divine correct DST */
 195
 196         if (dot != NULL) {                      /* .ss */
 197                 len = strlen(dot);
 198                 if (len != 3)
 199                         badformat();
 200                 ++dot;
 201                 lt->tm_sec = ATOI2(dot);
 202                 if (lt->tm_sec > 61)
 203                         badvalue("seconds");
 204         } else {
 205                 len = 0;
 206                 lt->tm_sec = 0;
 207         }
 208
 209         yearset = 0;
 210         switch (strlen(p) - len) {
 211         case 12:                                /* cc */
 212                 lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
 213                 if (lt->tm_year < 0)
 214                         badtime();
 215                 yearset = 1;
 216                 /* FALLTHROUGH */
 217         case 10:                                /* yy */
 218                 if (yearset) {
 219                         lt->tm_year += ATOI2(p);
 220                 } else {
 221                         yearset = ATOI2(p);
 222                         if (yearset < 69)
 223                                 lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
 224                         else
 225                                 lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
 226                 }
 227                 /* FALLTHROUGH */
 228         case 8:                                 /* mm */
 229                 lt->tm_mon = ATOI2(p);
 230                 if (lt->tm_mon > 12 || lt->tm_mon == 0)
 231                         badvalue("month");
 232                 --lt->tm_mon;                   /* time struct is 0 - 11 */
 233                 /* FALLTHROUGH */
 234         case 6:                                 /* dd */
 235                 lt->tm_mday = ATOI2(p);
 236                 switch (lt->tm_mon) {
 237                 case 0:
 238                 case 2:
 239                 case 4:
 240                 case 6:
 241                 case 7:
 242                 case 9:
 243                 case 11:
 244                         if (lt->tm_mday > 31 || lt->tm_mday == 0)
 245                                 badvalue("day of month");
 246                         break;
 247                 case 3:
 248                 case 5:
 249                 case 8:
 250                 case 10:
 251                         if (lt->tm_mday > 30 || lt->tm_mday == 0)
 252                                 badvalue("day of month");
 253                         break;
 254                 case 1:
 255                         if (lt->tm_mday > 29 || lt->tm_mday == 0 ||
 256                             (lt->tm_mday == 29 &&
 257                              !isleap(lt->tm_year + TM_YEAR_BASE)))
 258                                 badvalue("day of month");
 259                         break;
 260                 default:
 261                         badvalue("month");
 262                         break;
 263                 }
 264                 /* FALLTHROUGH */
 265         case 4:                                 /* hh */
 266                 lt->tm_hour = ATOI2(p);
 267                 if (lt->tm_hour > 23)
 268                         badvalue("hour");
 269                 /* FALLTHROUGH */
 270         case 2:                                 /* mm */
 271                 lt->tm_min = ATOI2(p);
 272                 if (lt->tm_min > 59)
 273                         badvalue("minute");
 274                 break;
 275         case 0:                                 /* was just .sss */
 276                 if (len != 0)
 277                         break;
 278                 /* FALLTHROUGH */
 279         default:
 280                 badformat();
 281         }
 282
 283         /* convert broken-down time to UTC clock time */
 284         if ((new_time = mktime(lt)) == -1)
 285                 badtime();
 286
 287         /* if jflag is set, don't actually change the time, just return */
 288         if (jflag) {
 289                 tval = new_time;
 290                 return;
 291         }
 292
 293         /* set the time */
 294         if (nflag || netsettime(new_time)) {
 295                 logwtmp("|", "date", "");
 296                 if (aflag) {
 297                         tv.tv_sec = new_time - tval;
 298                         tv.tv_usec = 0;
 299                         if (adjtime(&tv, NULL))
 300                                 err(EXIT_FAILURE, "adjtime");
 301                 } else {
 302                         tval = new_time;
 303                         tv.tv_sec = tval;
 304                         tv.tv_usec = 0;
 305                         if (settimeofday(&tv, NULL))
 306                                 err(EXIT_FAILURE, "settimeofday");
 307                 }
 308                 logwtmp("{", "date", "");
 309         }
 310
 311         if ((p = getlogin()) == NULL)
 312                 p = "???";
 313         syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
 314 }
 315
 316 static void
 317 usage(void)
 318 {
 319         (void)fprintf(stderr,
 320             "usage: %s [-ajnu] [-d date] [-r seconds] [+format]", getprogname());
 321         (void)fprintf(stderr, " [[[[[[CC]yy]mm]dd]HH]MM[.SS]]\n");
 322         exit(EXIT_FAILURE);
 323         /* NOTREACHED */
 324 }