1 /* date - print or set the system date and time
2 Copyright (C) 1989-2002 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 David MacKenzie <djm@gnu.ai.mit.edu> */
23 #include <sys/types.h>
25 # include <langinfo.h>
36 /* The official name of this program (e.g., no `g' prefix). */
37 #define PROGRAM_NAME "date"
39 #define AUTHORS "David MacKenzie"
49 static void show_date PARAMS ((const char *format, time_t when));
53 /* display only the date: 1999-03-25 */
55 /* display date and hour: 1999-03-25T03-0500 */
57 /* display date, hours, and minutes: 1999-03-25T03:23-0500 */
59 /* display date, hours, minutes, and seconds: 1999-03-25T03:23:14-0500 */
63 static char const *const time_spec_string[] =
65 "date", "hours", "minutes", "seconds", 0
68 static enum Time_spec const time_spec[] =
70 TIME_SPEC_DATE, TIME_SPEC_HOURS, TIME_SPEC_MINUTES, TIME_SPEC_SECONDS
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 non-zero, display time in RFC-(2)822 format for mail or news. */
80 static int rfc_format = 0;
82 #define COMMON_SHORT_OPTIONS "Rd:f:r:s: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 {"set", required_argument, NULL, 's'},
92 {"uct", no_argument, NULL, 'u'},
93 {"utc", no_argument, NULL, 'u'},
94 {"universal", no_argument, NULL, 'u'},
95 {GETOPT_HELP_OPTION_DECL},
96 {GETOPT_VERSION_OPTION_DECL},
101 # define TZSET tzset ()
103 # define TZSET /* empty */
107 # define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
109 # define DATE_FMT_LANGINFO() ""
116 fprintf (stderr, _("Try `%s --help' for more information.\n"),
121 Usage: %s [OPTION]... [+FORMAT]\n\
122 or: %s [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]\n\
124 program_name, program_name);
126 Display the current time in the given FORMAT, or set the system date.\n\
128 -d, --date=STRING display time described by STRING, not `now'\n\
129 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
130 -ITIMESPEC, --iso-8601[=TIMESPEC] output date/time in ISO 8601 format.\n\
131 TIMESPEC=`date' for date only,\n\
132 `hours', `minutes', or `seconds' for date and\n\
133 time to the indicated precision.\n\
134 --iso-8601 without TIMESPEC defaults to `date'.\n\
137 -r, --reference=FILE display the last modification time of FILE\n\
138 -R, --rfc-822 output RFC-822 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 (Sun..Sat)\n\
153 %A locale's full weekday name, variable length (Sunday..Saturday)\n\
154 %b locale's abbreviated month name (Jan..Dec)\n\
155 %B locale's full month name, variable length (January..December)\n\
156 %c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
159 %C century (year divided by 100 and truncated to an integer) [00-99]\n\
160 %d day of month (01..31)\n\
161 %D date (mm/dd/yy)\n\
162 %e day of month, blank padded ( 1..31)\n\
165 %F same as %Y-%m-%d\n\
166 %g the 2-digit year corresponding to the %V week number\n\
167 %G the 4-digit year corresponding to the %V week number\n\
173 %j day of year (001..366)\n\
179 %M minute (00..59)\n\
183 %p locale's upper case AM or PM indicator\n\
184 %P locale's lower case am or pm indicator\n\
185 %r time, 12-hour (hh:mm:ss [AP]M)\n\
186 %R time, 24-hour (hh:mm)\n\
187 %s seconds since `00:00:00 1970-01-01 UTC' (a GNU extension)\n\
190 %S second (00..60)\n\
191 %t a horizontal tab\n\
192 %T time, 24-hour (hh:mm:ss)\n\
193 %u day of week (1..7); 1 represents Monday\n\
196 %U week number of year with Sunday as first day of week (00..53)\n\
197 %V week number of year with Monday as first day of week (01..53)\n\
198 %w day of week (0..6); 0 represents Sunday\n\
199 %W week number of year with Monday as first day of week (00..53)\n\
202 %x locale's date representation (mm/dd/yy)\n\
203 %X locale's time representation (%H:%M:%S)\n\
204 %y last two digits of year (00..99)\n\
208 %z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
209 %Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
211 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
212 the following modifiers between `%' and a numeric directive.\n\
214 `-' (hyphen) do not pad the field\n\
215 `_' (underscore) pad the field with spaces\n\
217 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
222 /* Parse each line in INPUT_FILENAME as with --date and display each
223 resulting time and date. If the file cannot be opened, tell why
224 then exit. Issue a diagnostic for any lines that cannot be parsed.
225 If any line cannot be parsed, return nonzero; otherwise return zero. */
228 batch_convert (const char *input_filename, const char *format)
237 if (strcmp (input_filename, "-") == 0)
239 input_filename = _("standard input");
244 in_stream = fopen (input_filename, "r");
245 if (in_stream == NULL)
247 error (1, errno, "`%s'", input_filename);
256 line_length = getline (&line, &buflen, in_stream);
259 /* FIXME: detect/handle error here. */
263 when = get_date (line, NULL);
267 if (line[line_length - 1] == '\n')
268 line[line_length - 1] = '\0';
269 error (0, 0, _("invalid date `%s'"), line);
274 show_date (format, when);
278 if (fclose (in_stream) == EOF)
279 error (2, errno, "`%s'", input_filename);
288 main (int argc, char **argv)
291 const char *datestr = NULL;
292 const char *set_datestr = NULL;
296 char *batch_file = NULL;
297 char *reference = NULL;
298 struct stat refstats;
301 int option_specified_date;
302 char const *short_options = (posix2_version () < 200112
303 ? COMMON_SHORT_OPTIONS "I::"
304 : COMMON_SHORT_OPTIONS "I:");
306 program_name = argv[0];
307 setlocale (LC_ALL, "");
308 bindtextdomain (PACKAGE, LOCALEDIR);
309 textdomain (PACKAGE);
311 close_stdout_set_status (2);
312 atexit (close_stdout);
314 while ((optc = getopt_long (argc, argv, short_options, long_options, NULL))
327 iso_8601_format = (optarg
328 ? XARGMATCH ("--iso-8601", optarg,
329 time_spec_string, time_spec)
339 set_datestr = optarg;
343 /* POSIX says that `date -u' is equivalent to setting the TZ
344 environment variable, so this option should do nothing other
346 if (putenv ("TZ=UTC0") != 0)
350 case_GETOPT_HELP_CHAR;
351 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
356 n_args = argc - optind;
358 option_specified_date = ((datestr ? 1 : 0)
359 + (batch_file ? 1 : 0)
360 + (reference ? 1 : 0));
362 if (option_specified_date > 1)
365 _("the options to specify dates for printing are mutually exclusive"));
369 if (set_date && option_specified_date)
372 _("the options to print and set the time may not be used together"));
378 error (0, 0, _("too many non-option arguments: %s%s"),
379 argv[optind + 1], n_args == 2 ? "" : " ...");
383 if ((set_date || option_specified_date)
384 && n_args == 1 && argv[optind][0] != '+')
387 the argument `%s' lacks a leading `+';\n\
388 When using an option to specify date(s), any non-option\n\
389 argument must be a format string beginning with `+'."),
394 /* Simply ignore --rfc-822 if specified when setting the date. */
395 if (rfc_format && !set_date && n_args > 0)
398 _("a format string may not be specified when using\
399 the --rfc-822 (-R) option"));
404 datestr = set_datestr;
406 if (batch_file != NULL)
408 status = batch_convert (batch_file,
409 (n_args == 1 ? argv[optind] + 1 : NULL));
415 if (!option_specified_date && !set_date)
417 if (n_args == 1 && argv[optind][0] != '+')
419 /* Prepare to set system clock to the specified date/time
420 given in the POSIX-format. */
422 datestr = argv[optind];
423 when = posixtime (datestr,
424 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
429 /* Prepare to print the current date/time. */
430 datestr = _("undefined");
432 format = (n_args == 1 ? argv[optind] + 1 : NULL);
437 /* (option_specified_date || set_date) */
438 if (reference != NULL)
440 if (stat (reference, &refstats))
441 error (1, errno, "%s", reference);
442 when = refstats.st_mtime;
446 when = get_date (datestr, NULL);
449 format = (n_args == 1 ? argv[optind] + 1 : NULL);
453 error (1, 0, _("invalid date `%s'"), datestr);
457 /* Set the system clock to the specified date, then regardless of
458 the success of that operation, format and print that date. */
459 if (stime (&when) == -1)
461 error (0, errno, _("cannot set date"));
466 show_date (format, when);
472 /* Display the date and/or time in WHEN according to the format specified
473 in FORMAT, followed by a newline. If FORMAT is NULL, use the
474 standard output format (ctime style but with a timezone inserted). */
477 show_date (const char *format, time_t when)
481 size_t out_length = 0;
482 /* ISO 8601 formats. See below regarding %z */
483 static char const * const iso_format_string[] =
488 "%Y-%m-%dT%H:%M:%S%z"
491 tm = localtime (&when);
495 /* Print the date in the default format. Vanilla ANSI C strftime
496 doesn't support %e, but POSIX requires it. If you don't use
497 a GNU strftime, make sure yours supports %e.
498 If you are not using GNU strftime, you want to change %z
499 in the RFC format to %Z; this gives, however, an invalid
500 RFC time format outside the continental United States and GMT. */
503 format = "%a, %d %b %Y %H:%M:%S %z";
504 else if (iso_8601_format)
505 format = iso_format_string[iso_8601_format - 1];
508 char *date_fmt = DATE_FMT_LANGINFO ();
509 /* Do not wrap the following literal format string with _(...).
510 For example, suppose LC_ALL is unset, LC_TIME="POSIX",
511 and LANG="ko_KR". In that case, POSIX says that LC_TIME
512 determines the format and contents of date and time strings
513 written by date, which means "date" must generate output
514 using the POSIX locale; but adding _() would cause "date"
515 to use a Korean translation of the format. */
516 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
519 else if (*format == '\0')
529 out = (char *) xrealloc (out, out_length);
531 /* Mark the first byte of the buffer so we can detect the case
532 of strftime producing an empty string. Otherwise, this loop
533 would not terminate when date was invoked like this
534 `LANG=de date +%p' on a system with good language support. */
538 setlocale (LC_ALL, "C");
540 done = (strftime (out, out_length, format, tm) || out[0] == '\0');
543 setlocale (LC_ALL, "");
549 printf ("%s\n", out);