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>
37 /* The official name of this program (e.g., no `g' prefix). */
38 #define PROGRAM_NAME "date"
40 #define AUTHORS "David MacKenzie"
50 static void show_date PARAMS ((const char *format, time_t when));
54 /* display only the date: 1999-03-25 */
56 /* display date and hour: 1999-03-25T03-0500 */
58 /* display date, hours, and minutes: 1999-03-25T03:23-0500 */
60 /* display date, hours, minutes, and seconds: 1999-03-25T03:23:14-0500 */
64 static char const *const time_spec_string[] =
66 "date", "hours", "minutes", "seconds", 0
69 static enum Time_spec const time_spec[] =
71 TIME_SPEC_DATE, TIME_SPEC_HOURS, TIME_SPEC_MINUTES, TIME_SPEC_SECONDS
74 /* The name this program was run with, for error messages. */
77 /* If nonzero, display an ISO 8601 format date/time string */
78 static int iso_8601_format = 0;
80 /* If non-zero, display time in RFC-(2)822 format for mail or news. */
81 static int rfc_format = 0;
83 #define COMMON_SHORT_OPTIONS "Rd:f:r:s:u"
85 static struct option const long_options[] =
87 {"date", required_argument, NULL, 'd'},
88 {"file", required_argument, NULL, 'f'},
89 {"iso-8601", optional_argument, NULL, 'I'},
90 {"reference", required_argument, NULL, 'r'},
91 {"rfc-822", 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() ""
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 -ITIMESPEC, --iso-8601[=TIMESPEC] output date/time in ISO 8601 format.\n\
132 TIMESPEC=`date' for date only,\n\
133 `hours', `minutes', or `seconds' for date and\n\
134 time to the indicated precision.\n\
135 --iso-8601 without TIMESPEC defaults to `date'.\n\
138 -r, --reference=FILE display the last modification time of FILE\n\
139 -R, --rfc-822 output RFC-822 compliant date string\n\
140 -s, --set=STRING set time described by STRING\n\
141 -u, --utc, --universal print or set Coordinated Universal Time\n\
143 fputs (HELP_OPTION_DESCRIPTION, stdout);
144 fputs (VERSION_OPTION_DESCRIPTION, stdout);
147 FORMAT controls the output. The only valid option for the second form\n\
148 specifies Coordinated Universal Time. Interpreted sequences are:\n\
151 %a locale's abbreviated weekday name (Sun..Sat)\n\
154 %A locale's full weekday name, variable length (Sunday..Saturday)\n\
155 %b locale's abbreviated month name (Jan..Dec)\n\
156 %B locale's full month name, variable length (January..December)\n\
157 %c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
160 %C century (year divided by 100 and truncated to an integer) [00-99]\n\
161 %d day of month (01..31)\n\
162 %D date (mm/dd/yy)\n\
163 %e day of month, blank padded ( 1..31)\n\
166 %F same as %Y-%m-%d\n\
167 %g the 2-digit year corresponding to the %V week number\n\
168 %G the 4-digit year corresponding to the %V week number\n\
174 %j day of year (001..366)\n\
180 %M minute (00..59)\n\
184 %p locale's upper case AM or PM indicator\n\
185 %P locale's lower case am or pm indicator\n\
186 %r time, 12-hour (hh:mm:ss [AP]M)\n\
187 %R time, 24-hour (hh:mm)\n\
188 %s seconds since `00:00:00 1970-01-01 UTC' (a GNU extension)\n\
191 %S second (00..60)\n\
192 %t a horizontal tab\n\
193 %T time, 24-hour (hh:mm:ss)\n\
194 %u day of week (1..7); 1 represents 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 represents Sunday\n\
200 %W week number of year with Monday as first day of week (00..53)\n\
203 %x locale's date representation (mm/dd/yy)\n\
204 %X locale's time representation (%H:%M:%S)\n\
205 %y last two digits of year (00..99)\n\
209 %z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
210 %Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
212 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
213 the following modifiers between `%' and a numeric directive.\n\
215 `-' (hyphen) do not pad the field\n\
216 `_' (underscore) pad the field with spaces\n\
218 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
223 /* Parse each line in INPUT_FILENAME as with --date and display each
224 resulting time and date. If the file cannot be opened, tell why
225 then exit. Issue a diagnostic for any lines that cannot be parsed.
226 If any line cannot be parsed, return nonzero; otherwise return zero. */
229 batch_convert (const char *input_filename, const char *format)
238 if (strcmp (input_filename, "-") == 0)
240 input_filename = _("standard input");
245 in_stream = fopen (input_filename, "r");
246 if (in_stream == NULL)
248 error (1, errno, "`%s'", input_filename);
257 line_length = getline (&line, &buflen, in_stream);
260 /* FIXME: detect/handle error here. */
264 when = get_date (line, NULL);
268 if (line[line_length - 1] == '\n')
269 line[line_length - 1] = '\0';
270 error (0, 0, _("invalid date `%s'"), line);
275 show_date (format, when);
279 if (fclose (in_stream) == EOF)
280 error (2, errno, "`%s'", input_filename);
289 main (int argc, char **argv)
292 const char *datestr = NULL;
293 const char *set_datestr = NULL;
297 char *batch_file = NULL;
298 char *reference = NULL;
299 struct stat refstats;
302 int option_specified_date;
303 char const *short_options = (posix2_version () < 200112
304 ? COMMON_SHORT_OPTIONS "I::"
305 : COMMON_SHORT_OPTIONS "I:");
307 program_name = argv[0];
308 setlocale (LC_ALL, "");
309 bindtextdomain (PACKAGE, LOCALEDIR);
310 textdomain (PACKAGE);
312 close_stdout_set_status (2);
313 atexit (close_stdout);
315 while ((optc = getopt_long (argc, argv, short_options, long_options, NULL))
328 iso_8601_format = (optarg
329 ? XARGMATCH ("--iso-8601", optarg,
330 time_spec_string, time_spec)
340 set_datestr = optarg;
344 /* POSIX says that `date -u' is equivalent to setting the TZ
345 environment variable, so this option should do nothing other
347 if (putenv ("TZ=UTC0") != 0)
351 case_GETOPT_HELP_CHAR;
352 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
357 n_args = argc - optind;
359 option_specified_date = ((datestr ? 1 : 0)
360 + (batch_file ? 1 : 0)
361 + (reference ? 1 : 0));
363 if (option_specified_date > 1)
366 _("the options to specify dates for printing are mutually exclusive"));
370 if (set_date && option_specified_date)
373 _("the options to print and set the time may not be used together"));
379 error (0, 0, _("too many non-option arguments: %s%s"),
380 argv[optind + 1], n_args == 2 ? "" : " ...");
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 `+'."),
395 /* Simply ignore --rfc-822 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-822 (-R) option"));
405 datestr = set_datestr;
407 if (batch_file != NULL)
409 status = batch_convert (batch_file,
410 (n_args == 1 ? argv[optind] + 1 : NULL));
416 if (!option_specified_date && !set_date)
418 if (n_args == 1 && argv[optind][0] != '+')
420 /* Prepare to set system clock to the specified date/time
421 given in the POSIX-format. */
423 datestr = argv[optind];
424 when = posixtime (datestr,
425 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
430 /* Prepare to print the current date/time. */
431 datestr = _("undefined");
433 format = (n_args == 1 ? argv[optind] + 1 : NULL);
438 /* (option_specified_date || set_date) */
439 if (reference != NULL)
441 if (stat (reference, &refstats))
442 error (1, errno, "%s", reference);
443 when = refstats.st_mtime;
447 when = get_date (datestr, NULL);
450 format = (n_args == 1 ? argv[optind] + 1 : NULL);
454 error (1, 0, _("invalid date `%s'"), datestr);
458 /* Set the system clock to the specified date, then regardless of
459 the success of that operation, format and print that date. */
460 if (stime (&when) == -1)
462 error (0, errno, _("cannot set date"));
467 show_date (format, when);
473 /* Display the date and/or time in WHEN according to the format specified
474 in FORMAT, followed by a newline. If FORMAT is NULL, use the
475 standard output format (ctime style but with a timezone inserted). */
478 show_date (const char *format, time_t when)
482 size_t out_length = 0;
483 /* ISO 8601 formats. See below regarding %z */
484 static char const * const iso_format_string[] =
489 "%Y-%m-%dT%H:%M:%S%z"
492 tm = localtime (&when);
496 /* Print the date in the default format. Vanilla ANSI C strftime
497 doesn't support %e, but POSIX requires it. If you don't use
498 a GNU strftime, make sure yours supports %e.
499 If you are not using GNU strftime, you want to change %z
500 in the RFC format to %Z; this gives, however, an invalid
501 RFC time format outside the continental United States and GMT. */
504 format = "%a, %d %b %Y %H:%M:%S %z";
505 else if (iso_8601_format)
506 format = iso_format_string[iso_8601_format - 1];
509 char *date_fmt = DATE_FMT_LANGINFO ();
510 /* Do not wrap the following literal format string with _(...).
511 For example, suppose LC_ALL is unset, LC_TIME="POSIX",
512 and LANG="ko_KR". In that case, POSIX says that LC_TIME
513 determines the format and contents of date and time strings
514 written by date, which means "date" must generate output
515 using the POSIX locale; but adding _() would cause "date"
516 to use a Korean translation of the format. */
517 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
520 else if (*format == '\0')
530 out = (char *) xrealloc (out, out_length);
532 /* Mark the first byte of the buffer so we can detect the case
533 of strftime producing an empty string. Otherwise, this loop
534 would not terminate when date was invoked like this
535 `LANG=de date +%p' on a system with good language support. */
539 setlocale (LC_ALL, "C");
541 done = (strftime (out, out_length, format, tm) || out[0] == '\0');
544 setlocale (LC_ALL, "");
550 printf ("%s\n", out);