src/date.c

   1 /* date - print or set the system date and time
   2    Copyright (C) 1989-2006 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  17
  18    David MacKenzie <djm@gnu.ai.mit.edu> */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22 #include <getopt.h>
  23 #include <sys/types.h>
  24 #if HAVE_LANGINFO_CODESET
  25 # include <langinfo.h>
  26 #endif
  27
  28 #include "system.h"
  29 #include "argmatch.h"
  30 #include "error.h"
  31 #include "getdate.h"
  32 #include "getline.h"
  33 #include "inttostr.h"
  34 #include "posixtm.h"
  35 #include "quote.h"
  36 #include "stat-time.h"
  37 #include "fprintftime.h"
  38
  39 /* The official name of this program (e.g., no `g' prefix).  */
  40 #define PROGRAM_NAME "date"
  41
  42 #define AUTHORS "David MacKenzie"
  43
  44 int putenv ();
  45
  46 static bool show_date (const char *format, struct timespec when);
  47
  48 enum Time_spec
  49 {
  50   /* Display only the date.  */
  51   TIME_SPEC_DATE,
  52   /* Display date, hours, minutes, and seconds.  */
  53   TIME_SPEC_SECONDS,
  54   /* Similar, but display nanoseconds. */
  55   TIME_SPEC_NS,
  56
  57   /* Put these last, since they aren't valid for --rfc-3339.  */
  58
  59   /* Display date and hour.  */
  60   TIME_SPEC_HOURS,
  61   /* Display date, hours, and minutes.  */
  62   TIME_SPEC_MINUTES
  63 };
  64
  65 static char const *const time_spec_string[] =
  66 {
  67   /* Put "hours" and "minutes" first, since they aren't valid for
  68      --rfc-3339.  */
  69   "hours", "minutes",
  70   "date", "seconds", "ns", NULL
  71 };
  72 static enum Time_spec const time_spec[] =
  73 {
  74   TIME_SPEC_HOURS, TIME_SPEC_MINUTES,
  75   TIME_SPEC_DATE, TIME_SPEC_SECONDS, TIME_SPEC_NS
  76 };
  77 ARGMATCH_VERIFY (time_spec_string, time_spec);
  78
  79 /* A format suitable for Internet RFC 2822.  */
  80 static char const rfc_2822_format[] = "%a, %d %b %Y %H:%M:%S %z";
  81
  82 /* The name this program was run with, for error messages. */
  83 char *program_name;
  84
  85 /* For long options that have no equivalent short option, use a
  86    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  87 enum
  88 {
  89   RFC_3339_OPTION = CHAR_MAX + 1
  90 };
  91
  92 static char const short_options[] = "d:f:I::r:Rs:u";
  93
  94 static struct option const long_options[] =
  95 {
  96   {"date", required_argument, NULL, 'd'},
  97   {"file", required_argument, NULL, 'f'},
  98   {"iso-8601", optional_argument, NULL, 'I'}, /* Deprecated.  */
  99   {"reference", required_argument, NULL, 'r'},
 100   {"rfc-822", no_argument, NULL, 'R'},
 101   {"rfc-2822", no_argument, NULL, 'R'},
 102   {"rfc-3339", required_argument, NULL, RFC_3339_OPTION},
 103   {"set", required_argument, NULL, 's'},
 104   {"uct", no_argument, NULL, 'u'},
 105   {"utc", no_argument, NULL, 'u'},
 106   {"universal", no_argument, NULL, 'u'},
 107   {GETOPT_HELP_OPTION_DECL},
 108   {GETOPT_VERSION_OPTION_DECL},
 109   {NULL, 0, NULL, 0}
 110 };
 111
 112 #if LOCALTIME_CACHE
 113 # define TZSET tzset ()
 114 #else
 115 # define TZSET /* empty */
 116 #endif
 117
 118 #ifdef _DATE_FMT
 119 # define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
 120 #else
 121 # define DATE_FMT_LANGINFO() ""
 122 #endif
 123
 124 void
 125 usage (int status)
 126 {
 127   if (status != EXIT_SUCCESS)
 128     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 129              program_name);
 130   else
 131     {
 132       printf (_("\
 133 Usage: %s [OPTION]... [+FORMAT]\n\
 134   or:  %s [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]\n\
 135 "),
 136               program_name, program_name);
 137       fputs (_("\
 138 Display the current time in the given FORMAT, or set the system date.\n\
 139 \n\
 140   -d, --date=STRING         display time described by STRING, not `now'\n\
 141   -f, --file=DATEFILE       like --date once for each line of DATEFILE\n\
 142 "), stdout);
 143       fputs (_("\
 144   -r, --reference=FILE      display the last modification time of FILE\n\
 145   -R, --rfc-2822            output date and time in RFC 2822 format\n\
 146       --rfc-3339=TIMESPEC   output date and time in RFC 3339 format.\n\
 147                             TIMESPEC=`date', `seconds', or `ns' for\n\
 148                             date and time to the indicated precision.\n\
 149   -s, --set=STRING          set time described by STRING\n\
 150   -u, --utc, --universal    print or set Coordinated Universal Time\n\
 151 "), stdout);
 152       fputs (HELP_OPTION_DESCRIPTION, stdout);
 153       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 154       fputs (_("\
 155 \n\
 156 FORMAT controls the output.  The only valid option for the second form\n\
 157 specifies Coordinated Universal Time.  Interpreted sequences are:\n\
 158 \n\
 159   %%   a literal %\n\
 160   %a   locale's abbreviated weekday name (e.g., Sun)\n\
 161 "), stdout);
 162       fputs (_("\
 163   %A   locale's full weekday name (e.g., Sunday)\n\
 164   %b   locale's abbreviated month name (e.g., Jan)\n\
 165   %B   locale's full month name (e.g., January)\n\
 166   %c   locale's date and time (e.g., Thu Mar  3 23:05:25 2005)\n\
 167 "), stdout);
 168       fputs (_("\
 169   %C   century; like %Y, except omit last two digits (e.g., 21)\n\
 170   %d   day of month (e.g, 01)\n\
 171   %D   date; same as %m/%d/%y\n\
 172   %e   day of month, space padded; same as %_d\n\
 173 "), stdout);
 174       fputs (_("\
 175   %F   full date; same as %Y-%m-%d\n\
 176   %g   last two digits of year of ISO week number (see %G)\n\
 177   %G   year of ISO week number (see %V); normally useful only with %V\n\
 178 "), stdout);
 179       fputs (_("\
 180   %h   same as %b\n\
 181   %H   hour (00..23)\n\
 182   %I   hour (01..12)\n\
 183   %j   day of year (001..366)\n\
 184 "), stdout);
 185       fputs (_("\
 186   %k   hour ( 0..23)\n\
 187   %l   hour ( 1..12)\n\
 188   %m   month (01..12)\n\
 189   %M   minute (00..59)\n\
 190 "), stdout);
 191       fputs (_("\
 192   %n   a newline\n\
 193   %N   nanoseconds (000000000..999999999)\n\
 194   %p   locale's equivalent of either AM or PM; blank if not known\n\
 195   %P   like %p, but lower case\n\
 196   %r   locale's 12-hour clock time (e.g., 11:11:04 PM)\n\
 197   %R   24-hour hour and minute; same as %H:%M\n\
 198   %s   seconds since 1970-01-01 00:00:00 UTC\n\
 199 "), stdout);
 200       fputs (_("\
 201   %S   second (00..60)\n\
 202   %t   a tab\n\
 203   %T   time; same as %H:%M:%S\n\
 204   %u   day of week (1..7); 1 is Monday\n\
 205 "), stdout);
 206       fputs (_("\
 207   %U   week number of year, with Sunday as first day of week (00..53)\n\
 208   %V   ISO week number, with Monday as first day of week (01..53)\n\
 209   %w   day of week (0..6); 0 is Sunday\n\
 210   %W   week number of year, with Monday as first day of week (00..53)\n\
 211 "), stdout);
 212       fputs (_("\
 213   %x   locale's date representation (e.g., 12/31/99)\n\
 214   %X   locale's time representation (e.g., 23:13:48)\n\
 215   %y   last two digits of year (00..99)\n\
 216   %Y   year\n\
 217 "), stdout);
 218       fputs (_("\
 219   %z   +hhmm numeric timezone (e.g., -0400)\n\
 220   %:z  +hh:mm numeric timezone (e.g., -04:00)\n\
 221   %::z  +hh:mm:ss numeric time zone (e.g., -04:00:00)\n\
 222   %:::z  numeric time zone with : to necessary precision (e.g., -04, +05:30)\n\
 223   %Z   alphabetic time zone abbreviation (e.g., EDT)\n\
 224 \n\
 225 By default, date pads numeric fields with zeroes.\n\
 226 The following optional flags may follow `%':\n\
 227 \n\
 228   - (hyphen) do not pad the field\n\
 229   _ (underscore) pad with spaces\n\
 230   0 (zero) pad with zeros\n\
 231   ^ use upper case if possible\n\
 232   # use opposite case if possible\n\
 233 "), stdout);
 234       fputs (_("\
 235 \n\
 236 After any flags comes an optional field width, as a decimal number;\n\
 237 then an optional modifier, which is either\n\
 238 E to use the locale's alternate representations if available, or\n\
 239 O to use the locale's alternate numeric symbols if available.\n\
 240 "), stdout);
 241       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 242     }
 243   exit (status);
 244 }
 245
 246 /* Parse each line in INPUT_FILENAME as with --date and display each
 247    resulting time and date.  If the file cannot be opened, tell why
 248    then exit.  Issue a diagnostic for any lines that cannot be parsed.
 249    Return true if successful.  */
 250
 251 static bool
 252 batch_convert (const char *input_filename, const char *format)
 253 {
 254   bool ok;
 255   FILE *in_stream;
 256   char *line;
 257   size_t buflen;
 258   struct timespec when;
 259
 260   if (STREQ (input_filename, "-"))
 261     {
 262       input_filename = _("standard input");
 263       in_stream = stdin;
 264     }
 265   else
 266     {
 267       in_stream = fopen (input_filename, "r");
 268       if (in_stream == NULL)
 269         {
 270           error (EXIT_FAILURE, errno, "%s", quote (input_filename));
 271         }
 272     }
 273
 274   line = NULL;
 275   buflen = 0;
 276   ok = true;
 277   while (1)
 278     {
 279       ssize_t line_length = getline (&line, &buflen, in_stream);
 280       if (line_length < 0)
 281         {
 282           /* FIXME: detect/handle error here.  */
 283           break;
 284         }
 285
 286       if (! get_date (&when, line, NULL))
 287         {
 288           if (line[line_length - 1] == '\n')
 289             line[line_length - 1] = '\0';
 290           error (0, 0, _("invalid date %s"), quote (line));
 291           ok = false;
 292         }
 293       else
 294         {
 295           ok &= show_date (format, when);
 296         }
 297     }
 298
 299   if (fclose (in_stream) == EOF)
 300     error (EXIT_FAILURE, errno, "%s", quote (input_filename));
 301
 302   free (line);
 303
 304   return ok;
 305 }
 306
 307 int
 308 main (int argc, char **argv)
 309 {
 310   int optc;
 311   const char *datestr = NULL;
 312   const char *set_datestr = NULL;
 313   struct timespec when;
 314   bool set_date = false;
 315   char const *format = NULL;
 316   char *batch_file = NULL;
 317   char *reference = NULL;
 318   struct stat refstats;
 319   bool ok;
 320   int option_specified_date;
 321
 322   initialize_main (&argc, &argv);
 323   program_name = argv[0];
 324   setlocale (LC_ALL, "");
 325   bindtextdomain (PACKAGE, LOCALEDIR);
 326   textdomain (PACKAGE);
 327
 328   atexit (close_stdout);
 329
 330   while ((optc = getopt_long (argc, argv, short_options, long_options, NULL))
 331          != -1)
 332     {
 333       char const *new_format = NULL;
 334
 335       switch (optc)
 336         {
 337         case 'd':
 338           datestr = optarg;
 339           break;
 340         case 'f':
 341           batch_file = optarg;
 342           break;
 343         case RFC_3339_OPTION:
 344           {
 345             static char const rfc_3339_format[][32] =
 346               {
 347                 "%Y-%m-%d",
 348                 "%Y-%m-%d %H:%M:%S%:z",
 349                 "%Y-%m-%d %H:%M:%S.%N%:z"
 350               };
 351             enum Time_spec i =
 352               XARGMATCH ("--rfc-3339", optarg,
 353                          time_spec_string + 2, time_spec + 2);
 354             new_format = rfc_3339_format[i];
 355             break;
 356           }
 357         case 'I':
 358           {
 359             static char const iso_8601_format[][32] =
 360               {
 361                 "%Y-%m-%d",
 362                 "%Y-%m-%dT%H:%M:%S%z",
 363                 "%Y-%m-%dT%H:%M:%S,%N%z",
 364                 "%Y-%m-%dT%H%z",
 365                 "%Y-%m-%dT%H:%M%z"
 366               };
 367             enum Time_spec i =
 368               (optarg
 369                ? XARGMATCH ("--iso-8601", optarg, time_spec_string, time_spec)
 370                : TIME_SPEC_DATE);
 371             new_format = iso_8601_format[i];
 372             break;
 373           }
 374         case 'r':
 375           reference = optarg;
 376           break;
 377         case 'R':
 378           new_format = rfc_2822_format;
 379           break;
 380         case 's':
 381           set_datestr = optarg;
 382           set_date = true;
 383           break;
 384         case 'u':
 385           /* POSIX says that `date -u' is equivalent to setting the TZ
 386              environment variable, so this option should do nothing other
 387              than setting TZ.  */
 388           if (putenv ("TZ=UTC0") != 0)
 389             xalloc_die ();
 390           TZSET;
 391           break;
 392         case_GETOPT_HELP_CHAR;
 393         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 394         default:
 395           usage (EXIT_FAILURE);
 396         }
 397
 398       if (new_format)
 399         {
 400           if (format)
 401             error (EXIT_FAILURE, 0, _("multiple output formats specified"));
 402           format = new_format;
 403         }
 404     }
 405
 406   option_specified_date = ((datestr ? 1 : 0)
 407                            + (batch_file ? 1 : 0)
 408                            + (reference ? 1 : 0));
 409
 410   if (option_specified_date > 1)
 411     {
 412       error (0, 0,
 413         _("the options to specify dates for printing are mutually exclusive"));
 414       usage (EXIT_FAILURE);
 415     }
 416
 417   if (set_date && option_specified_date)
 418     {
 419       error (0, 0,
 420           _("the options to print and set the time may not be used together"));
 421       usage (EXIT_FAILURE);
 422     }
 423
 424   if (optind < argc)
 425     {
 426       if (optind + 1 < argc)
 427         {
 428           error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
 429           usage (EXIT_FAILURE);
 430         }
 431
 432       if (argv[optind][0] == '+')
 433         {
 434           if (format)
 435             error (EXIT_FAILURE, 0, _("multiple output formats specified"));
 436           format = argv[optind++] + 1;
 437         }
 438       else if (set_date || option_specified_date)
 439         {
 440           error (0, 0,
 441                  _("the argument %s lacks a leading `+';\n"
 442                    "When using an option to specify date(s), any non-option\n"
 443                    "argument must be a format string beginning with `+'."),
 444                  quote (argv[optind]));
 445           usage (EXIT_FAILURE);
 446         }
 447     }
 448
 449   if (!format)
 450     {
 451       format = DATE_FMT_LANGINFO ();
 452       if (! *format)
 453         {
 454           /* Do not wrap the following literal format string with _(...).
 455              For example, suppose LC_ALL is unset, LC_TIME="POSIX",
 456              and LANG="ko_KR".  In that case, POSIX says that LC_TIME
 457              determines the format and contents of date and time strings
 458              written by date, which means "date" must generate output
 459              using the POSIX locale; but adding _() would cause "date"
 460              to use a Korean translation of the format.  */
 461           format = "%a %b %e %H:%M:%S %Z %Y";
 462         }
 463     }
 464
 465   if (batch_file != NULL)
 466     ok = batch_convert (batch_file, format);
 467   else
 468     {
 469       bool valid_date = true;
 470       ok = true;
 471
 472       if (!option_specified_date && !set_date)
 473         {
 474           if (optind < argc)
 475             {
 476               /* Prepare to set system clock to the specified date/time
 477                  given in the POSIX-format.  */
 478               set_date = true;
 479               datestr = argv[optind];
 480               valid_date = posixtime (&when.tv_sec,
 481                                       datestr,
 482                                       (PDS_TRAILING_YEAR
 483                                        | PDS_CENTURY | PDS_SECONDS));
 484               when.tv_nsec = 0; /* FIXME: posixtime should set this.  */
 485             }
 486           else
 487             {
 488               /* Prepare to print the current date/time.  */
 489               gettime (&when);
 490             }
 491         }
 492       else
 493         {
 494           /* (option_specified_date || set_date) */
 495           if (reference != NULL)
 496             {
 497               if (stat (reference, &refstats) != 0)
 498                 error (EXIT_FAILURE, errno, "%s", reference);
 499               when = get_stat_mtime (&refstats);
 500             }
 501           else
 502             {
 503               if (set_datestr)
 504                 datestr = set_datestr;
 505               valid_date = get_date (&when, datestr, NULL);
 506             }
 507         }
 508
 509       if (! valid_date)
 510         error (EXIT_FAILURE, 0, _("invalid date %s"), quote (datestr));
 511
 512       if (set_date)
 513         {
 514           /* Set the system clock to the specified date, then regardless of
 515              the success of that operation, format and print that date.  */
 516           if (settime (&when) != 0)
 517             {
 518               error (0, errno, _("cannot set date"));
 519               ok = false;
 520             }
 521         }
 522
 523       ok &= show_date (format, when);
 524     }
 525
 526   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 527 }
 528
 529 /* Display the date and/or time in WHEN according to the format specified
 530    in FORMAT, followed by a newline.  Return true if successful.  */
 531
 532 static bool
 533 show_date (const char *format, struct timespec when)
 534 {
 535   struct tm *tm;
 536
 537   tm = localtime (&when.tv_sec);
 538   if (! tm)
 539     {
 540       char buf[INT_BUFSIZE_BOUND (intmax_t)];
 541       error (0, 0, _("time %s is out of range"),
 542              (TYPE_SIGNED (time_t)
 543               ? imaxtostr (when.tv_sec, buf)
 544               : umaxtostr (when.tv_sec, buf)));
 545       return false;
 546     }
 547
 548   if (format == rfc_2822_format)
 549     setlocale (LC_TIME, "C");
 550   fprintftime (stdout, format, tm, 0, when.tv_nsec);
 551   fputc ('\n', stdout);
 552   if (format == rfc_2822_format)
 553     setlocale (LC_TIME, "");
 554
 555   return true;
 556 }