1 /* date - print or set the system date and time
2 Copyright (C) 1989-2005 Free Software Foundation, Inc.
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)
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.
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.
18 David MacKenzie <djm@gnu.ai.mit.edu> */
23 #include <sys/types.h>
24 #if HAVE_LANGINFO_CODESET
25 # include <langinfo.h>
37 #include "xanstrftime.h"
39 /* The official name of this program (e.g., no `g' prefix). */
40 #define PROGRAM_NAME "date"
42 #define AUTHORS "David MacKenzie"
46 static bool show_date (const char *format, struct timespec when);
50 /* display only the date: 1999-03-25 */
52 /* display date and hour: 1999-03-25T03-0500 */
54 /* display date, hours, and minutes: 1999-03-25T03:23-0500 */
56 /* display date, hours, minutes, and seconds: 1999-03-25T03:23:14-0500 */
58 /* similar, but display nanoseconds: 1999-03-25T03:23:14,123456789-0500 */
62 static char const *const time_spec_string[] =
64 "date", "hours", "minutes", "seconds", "ns", NULL
66 static enum Time_spec const time_spec[] =
68 TIME_SPEC_DATE, TIME_SPEC_HOURS, TIME_SPEC_MINUTES, TIME_SPEC_SECONDS,
71 ARGMATCH_VERIFY (time_spec_string, time_spec);
73 /* The name this program was run with, for error messages. */
76 /* If nonzero, display an ISO 8601 format date/time string */
77 static int iso_8601_format = 0;
79 /* If true, display time in RFC-(2)822 format for mail or news. */
80 static bool rfc_format = false;
82 static char const short_options[] = "d:f:I::r:Rs:u";
84 static struct option const long_options[] =
86 {"date", required_argument, NULL, 'd'},
87 {"file", required_argument, NULL, 'f'},
88 {"iso-8601", optional_argument, NULL, 'I'},
89 {"reference", required_argument, NULL, 'r'},
90 {"rfc-822", no_argument, NULL, 'R'},
91 {"rfc-2822", no_argument, NULL, 'R'},
92 {"set", required_argument, NULL, 's'},
93 {"uct", no_argument, NULL, 'u'},
94 {"utc", no_argument, NULL, 'u'},
95 {"universal", no_argument, NULL, 'u'},
96 {GETOPT_HELP_OPTION_DECL},
97 {GETOPT_VERSION_OPTION_DECL},
102 # define TZSET tzset ()
104 # define TZSET /* empty */
108 # define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
110 # define DATE_FMT_LANGINFO() ""
116 if (status != EXIT_SUCCESS)
117 fprintf (stderr, _("Try `%s --help' for more information.\n"),
122 Usage: %s [OPTION]... [+FORMAT]\n\
123 or: %s [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]\n\
125 program_name, program_name);
127 Display the current time in the given FORMAT, or set the system date.\n\
129 -d, --date=STRING display time described by STRING, not `now'\n\
130 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
131 -I[TIMESPEC], --iso-8601[=TIMESPEC] output date/time in ISO 8601 format.\n\
132 TIMESPEC=`date' for date only (the default),\n\
133 `hours', `minutes', `seconds', or `ns' for date and\n\
134 time to the indicated precision.\n\
137 -r, --reference=FILE display the last modification time of FILE\n\
138 -R, --rfc-2822 output RFC-2822 compliant date string\n\
139 -s, --set=STRING set time described by STRING\n\
140 -u, --utc, --universal print or set Coordinated Universal Time\n\
142 fputs (HELP_OPTION_DESCRIPTION, stdout);
143 fputs (VERSION_OPTION_DESCRIPTION, stdout);
146 FORMAT controls the output. The only valid option for the second form\n\
147 specifies Coordinated Universal Time. Interpreted sequences are:\n\
150 %a locale's abbreviated weekday name (e.g., Sun)\n\
153 %A locale's full weekday name (e.g., Sunday)\n\
154 %b locale's abbreviated month name (e.g., Jan)\n\
155 %B locale's full month name (e.g., January)\n\
156 %c locale's date and time (e.g., Thu Mar 3 23:05:25 2005)\n\
159 %C century; like %Y, except omit last two digits (e.g., 21)\n\
160 %d day of month (e.g, 01)\n\
161 %D date; same as %m/%d/%y\n\
162 %e day of month, space padded; same as %_d\n\
165 %F full date; same as %Y-%m-%d\n\
166 %g the last two digits of the year corresponding to the %V week number\n\
167 %G the year corresponding to the %V week number\n\
173 %j day of year (001..366)\n\
179 %M minute (00..59)\n\
183 %N nanoseconds (000000000..999999999)\n\
184 %p locale's equivalent of either AM or PM; blank if not known\n\
185 %P like %p, but lower case\n\
186 %r locale's 12-hour clock time (e.g., 11:11:04 PM)\n\
187 %R 24-hour hour and minute; same as %H:%M\n\
188 %s seconds since 1970-01-01 00:00:00 UTC\n\
191 %S second (00..60)\n\
193 %T time; same as %H:%M:%S\n\
194 %u day of week (1..7); 1 is Monday\n\
197 %U week number of year with Sunday as first day of week (00..53)\n\
198 %V week number of year with Monday as first day of week (01..53)\n\
199 %w day of week (0..6); 0 is Sunday\n\
200 %W week number of year with Monday as first day of week (00..53)\n\
203 %x locale's date representation (e.g., 12/31/99)\n\
204 %X locale's time representation (e.g., 23:13:48)\n\
205 %y last two digits of year (00..99)\n\
209 %z numeric timezone (e.g., -0400)\n\
210 %Z alphabetic time zone abbreviation (e.g., EDT)\n\
212 By default, date pads numeric fields with zeroes.\n\
213 The following optional flags may follow `%':\n\
215 - (hyphen) do not pad the field\n\
216 _ (underscore) pad with spaces\n\
217 0 (zero) pad with zeros\n\
218 ^ use upper case if possible\n\
219 # use opposite case if possible\n\
223 After any flags comes an optional field width, as a decimal number;\n\
224 then an optional modifier, which is either\n\
225 E to use the locale's alternate representations if available, or\n\
226 O to use the locale's alternate numeric symbols if available.\n\
228 printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
233 /* Parse each line in INPUT_FILENAME as with --date and display each
234 resulting time and date. If the file cannot be opened, tell why
235 then exit. Issue a diagnostic for any lines that cannot be parsed.
236 Return true if successful. */
239 batch_convert (const char *input_filename, const char *format)
245 struct timespec when;
247 if (STREQ (input_filename, "-"))
249 input_filename = _("standard input");
254 in_stream = fopen (input_filename, "r");
255 if (in_stream == NULL)
257 error (EXIT_FAILURE, errno, "%s", quote (input_filename));
266 ssize_t line_length = getline (&line, &buflen, in_stream);
269 /* FIXME: detect/handle error here. */
273 if (! get_date (&when, line, NULL))
275 if (line[line_length - 1] == '\n')
276 line[line_length - 1] = '\0';
277 error (0, 0, _("invalid date %s"), quote (line));
282 ok &= show_date (format, when);
286 if (fclose (in_stream) == EOF)
287 error (EXIT_FAILURE, errno, "%s", quote (input_filename));
295 main (int argc, char **argv)
298 const char *datestr = NULL;
299 const char *set_datestr = NULL;
300 struct timespec when;
301 bool set_date = false;
303 char *batch_file = NULL;
304 char *reference = NULL;
305 struct stat refstats;
308 int option_specified_date;
310 initialize_main (&argc, &argv);
311 program_name = argv[0];
312 setlocale (LC_ALL, "");
313 bindtextdomain (PACKAGE, LOCALEDIR);
314 textdomain (PACKAGE);
316 atexit (close_stdout);
318 while ((optc = getopt_long (argc, argv, short_options, long_options, NULL))
329 iso_8601_format = (optarg
330 ? XARGMATCH ("--iso-8601", optarg,
331 time_spec_string, time_spec)
341 set_datestr = optarg;
345 /* POSIX says that `date -u' is equivalent to setting the TZ
346 environment variable, so this option should do nothing other
348 if (putenv ("TZ=UTC0") != 0)
352 case_GETOPT_HELP_CHAR;
353 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
355 usage (EXIT_FAILURE);
358 n_args = argc - optind;
360 option_specified_date = ((datestr ? 1 : 0)
361 + (batch_file ? 1 : 0)
362 + (reference ? 1 : 0));
364 if (option_specified_date > 1)
367 _("the options to specify dates for printing are mutually exclusive"));
368 usage (EXIT_FAILURE);
371 if (set_date && option_specified_date)
374 _("the options to print and set the time may not be used together"));
375 usage (EXIT_FAILURE);
380 error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
381 usage (EXIT_FAILURE);
384 if ((set_date || option_specified_date)
385 && n_args == 1 && argv[optind][0] != '+')
388 the argument %s lacks a leading `+';\n\
389 When using an option to specify date(s), any non-option\n\
390 argument must be a format string beginning with `+'."),
391 quote (argv[optind]));
392 usage (EXIT_FAILURE);
395 /* Simply ignore --rfc-2822 if specified when setting the date. */
396 if (rfc_format && !set_date && n_args > 0)
399 _("a format string may not be specified when using\
400 the --rfc-2822 (-R) option"));
401 usage (EXIT_FAILURE);
405 datestr = set_datestr;
407 if (batch_file != NULL)
408 ok = batch_convert (batch_file, (n_args == 1 ? argv[optind] + 1 : NULL));
411 bool valid_date = true;
414 if (!option_specified_date && !set_date)
416 if (n_args == 1 && argv[optind][0] != '+')
418 /* Prepare to set system clock to the specified date/time
419 given in the POSIX-format. */
421 datestr = argv[optind];
422 valid_date = posixtime (&when.tv_sec,
425 | PDS_CENTURY | PDS_SECONDS));
426 when.tv_nsec = 0; /* FIXME: posixtime should set this. */
431 /* Prepare to print the current date/time. */
432 datestr = _("undefined");
434 format = (n_args == 1 ? argv[optind] + 1 : NULL);
439 /* (option_specified_date || set_date) */
440 if (reference != NULL)
442 if (stat (reference, &refstats))
443 error (EXIT_FAILURE, errno, "%s", reference);
444 when.tv_sec = refstats.st_mtime;
445 when.tv_nsec = TIMESPEC_NS (refstats.st_mtim);
449 valid_date = get_date (&when, datestr, NULL);
452 format = (n_args == 1 ? argv[optind] + 1 : NULL);
456 error (EXIT_FAILURE, 0, _("invalid date %s"), quote (datestr));
460 /* Set the system clock to the specified date, then regardless of
461 the success of that operation, format and print that date. */
462 if (settime (&when) != 0)
464 error (0, errno, _("cannot set date"));
469 ok &= show_date (format, when);
472 exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
475 /* Display the date and/or time in WHEN according to the format specified
476 in FORMAT, followed by a newline. If FORMAT is NULL, use the
477 standard output format (ctime style but with a timezone inserted).
478 Return true if successful. */
481 show_date (const char *format, struct timespec when)
484 /* ISO 8601 formats. See below regarding %z */
485 static char const * const iso_format_string[] =
490 "%Y-%m-%dT%H:%M:%S%z",
491 "%Y-%m-%dT%H:%M:%S,%N%z"
497 format = "%a, %d %b %Y %H:%M:%S %z";
498 else if (iso_8601_format)
499 format = iso_format_string[iso_8601_format - 1];
502 char *date_fmt = DATE_FMT_LANGINFO ();
503 /* Do not wrap the following literal format string with _(...).
504 For example, suppose LC_ALL is unset, LC_TIME="POSIX",
505 and LANG="ko_KR". In that case, POSIX says that LC_TIME
506 determines the format and contents of date and time strings
507 written by date, which means "date" must generate output
508 using the POSIX locale; but adding _() would cause "date"
509 to use a Korean translation of the format. */
510 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
514 tm = localtime (&when.tv_sec);
517 char buf[INT_BUFSIZE_BOUND (intmax_t)];
518 error (0, 0, _("time %s is out of range"),
519 (TYPE_SIGNED (time_t)
520 ? imaxtostr (when.tv_sec, buf)
521 : umaxtostr (when.tv_sec, buf)));
529 setlocale (LC_TIME, "C");
530 out = xanstrftime (format, tm, 0, when.tv_nsec);
532 setlocale (LC_TIME, "");