1 /* date - print or set the system date and time
2 Copyright (C) 1989-2001 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 static struct option const long_options[] =
84 {"date", required_argument, NULL, 'd'},
85 {"file", required_argument, NULL, 'f'},
86 {"iso-8601", optional_argument, NULL, 'I'},
87 {"reference", required_argument, NULL, 'r'},
88 {"rfc-822", no_argument, NULL, 'R'},
89 {"set", required_argument, NULL, 's'},
90 {"uct", no_argument, NULL, 'u'},
91 {"utc", no_argument, NULL, 'u'},
92 {"universal", no_argument, NULL, 'u'},
93 {GETOPT_HELP_OPTION_DECL},
94 {GETOPT_VERSION_OPTION_DECL},
99 # define TZSET tzset ()
101 # define TZSET /* empty */
105 # define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
107 # define DATE_FMT_LANGINFO() ""
114 fprintf (stderr, _("Try `%s --help' for more information.\n"),
119 Usage: %s [OPTION]... [+FORMAT]\n\
120 or: %s [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]\n\
122 program_name, program_name);
124 Display the current time in the given FORMAT, or set the system date.\n\
126 -d, --date=STRING display time described by STRING, not `now'\n\
127 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
128 -I, --iso-8601[=TIMESPEC] output an ISO-8601 compliant date/time string.\n\
129 TIMESPEC=`date' (or missing) for date only,\n\
130 `hours', `minutes', or `seconds' for date and\n\
131 time to the indicated precision.\n\
132 -r, --reference=FILE display the last modification time of FILE\n\
133 -R, --rfc-822 output RFC-822 compliant date string\n\
134 -s, --set=STRING set time described by STRING\n\
135 -u, --utc, --universal print or set Coordinated Universal Time\n\
136 --help display this help and exit\n\
137 --version output version information and exit\n\
141 FORMAT controls the output. The only valid option for the second form\n\
142 specifies Coordinated Universal Time. Interpreted sequences are:\n\
145 %%a locale's abbreviated weekday name (Sun..Sat)\n\
146 %%A locale's full weekday name, variable length (Sunday..Saturday)\n\
147 %%b locale's abbreviated month name (Jan..Dec)\n\
148 %%B locale's full month name, variable length (January..December)\n\
149 %%c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
150 %%C century (year divided by 100 and truncated to an integer) [00-99]\n\
151 %%d day of month (01..31)\n\
152 %%D date (mm/dd/yy)\n\
153 %%e day of month, blank padded ( 1..31)\n\
157 %%j day of year (001..366)\n\
160 %%m month (01..12)\n\
161 %%M minute (00..59)\n\
163 %%p locale's AM or PM\n\
164 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
165 %%s seconds since `00:00:00 1970-01-01 UTC' (a GNU extension)\n\
166 %%S second (00..60)\n\
167 %%t a horizontal tab\n\
168 %%T time, 24-hour (hh:mm:ss)\n\
169 %%u day of week (1..7); 1 represents Monday\n\
170 %%U week number of year with Sunday as first day of week (00..53)\n\
171 %%V week number of year with Monday as first day of week (01..53)\n\
172 %%w day of week (0..6); 0 represents Sunday\n\
173 %%W week number of year with Monday as first day of week (00..53)\n\
174 %%x locale's date representation (mm/dd/yy)\n\
175 %%X locale's time representation (%%H:%%M:%%S)\n\
176 %%y last two digits of year (00..99)\n\
177 %%Y year (1970...)\n\
178 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
179 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
181 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
182 the following modifiers between `%%' and a numeric directive.\n\
184 `-' (hyphen) do not pad the field\n\
185 `_' (underscore) pad the field with spaces\n\
187 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
192 /* Parse each line in INPUT_FILENAME as with --date and display each
193 resulting time and date. If the file cannot be opened, tell why
194 then exit. Issue a diagnostic for any lines that cannot be parsed.
195 If any line cannot be parsed, return nonzero; otherwise return zero. */
198 batch_convert (const char *input_filename, const char *format)
207 if (strcmp (input_filename, "-") == 0)
209 input_filename = _("standard input");
214 in_stream = fopen (input_filename, "r");
215 if (in_stream == NULL)
217 error (1, errno, "`%s'", input_filename);
226 line_length = getline (&line, &buflen, in_stream);
229 /* FIXME: detect/handle error here. */
233 when = get_date (line, NULL);
237 if (line[line_length - 1] == '\n')
238 line[line_length - 1] = '\0';
239 error (0, 0, _("invalid date `%s'"), line);
244 show_date (format, when);
248 if (fclose (in_stream) == EOF)
249 error (2, errno, "`%s'", input_filename);
258 main (int argc, char **argv)
261 const char *datestr = NULL;
262 const char *set_datestr = NULL;
266 char *batch_file = NULL;
267 char *reference = NULL;
268 struct stat refstats;
271 int option_specified_date;
273 program_name = argv[0];
274 setlocale (LC_ALL, "");
275 bindtextdomain (PACKAGE, LOCALEDIR);
276 textdomain (PACKAGE);
278 close_stdout_set_status (2);
279 atexit (close_stdout);
281 while ((optc = getopt_long (argc, argv, "d:f:I::r:Rs:u", long_options, NULL))
294 iso_8601_format = (optarg
295 ? XARGMATCH ("--iso-8601", optarg,
296 time_spec_string, time_spec)
306 set_datestr = optarg;
310 /* POSIX.2 says that `date -u' is equivalent to setting the TZ
311 environment variable, so this option should do nothing other
313 if (putenv ("TZ=UTC0") != 0)
317 case_GETOPT_HELP_CHAR;
318 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
323 n_args = argc - optind;
325 option_specified_date = ((datestr ? 1 : 0)
326 + (batch_file ? 1 : 0)
327 + (reference ? 1 : 0));
329 if (option_specified_date > 1)
332 _("the options to specify dates for printing are mutually exclusive"));
336 if (set_date && option_specified_date)
339 _("the options to print and set the time may not be used together"));
345 error (0, 0, _("too many non-option arguments: %s%s"),
346 argv[optind + 1], n_args == 2 ? "" : " ...");
350 if ((set_date || option_specified_date)
351 && n_args == 1 && argv[optind][0] != '+')
354 the argument `%s' lacks a leading `+';\n\
355 When using an option to specify date(s), any non-option\n\
356 argument must be a format string beginning with `+'."),
361 /* Simply ignore --rfc-822 if specified when setting the date. */
362 if (rfc_format && !set_date && n_args > 0)
365 _("a format string may not be specified when using\
366 the --rfc-822 (-R) option"));
371 datestr = set_datestr;
373 if (batch_file != NULL)
375 status = batch_convert (batch_file,
376 (n_args == 1 ? argv[optind] + 1 : NULL));
382 if (!option_specified_date && !set_date)
384 if (n_args == 1 && argv[optind][0] != '+')
386 /* Prepare to set system clock to the specified date/time
387 given in the POSIX-format. */
389 datestr = argv[optind];
390 when = posixtime (datestr,
391 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
396 /* Prepare to print the current date/time. */
397 datestr = _("undefined");
399 format = (n_args == 1 ? argv[optind] + 1 : NULL);
404 /* (option_specified_date || set_date) */
405 if (reference != NULL)
407 if (stat (reference, &refstats))
408 error (1, errno, "%s", reference);
409 when = refstats.st_mtime;
413 when = get_date (datestr, NULL);
416 format = (n_args == 1 ? argv[optind] + 1 : NULL);
420 error (1, 0, _("invalid date `%s'"), datestr);
424 /* Set the system clock to the specified date, then regardless of
425 the success of that operation, format and print that date. */
426 if (stime (&when) == -1)
428 error (0, errno, _("cannot set date"));
433 show_date (format, when);
439 /* Display the date and/or time in WHEN according to the format specified
440 in FORMAT, followed by a newline. If FORMAT is NULL, use the
441 standard output format (ctime style but with a timezone inserted). */
444 show_date (const char *format, time_t when)
448 size_t out_length = 0;
449 /* ISO 8601 formats. See below regarding %z */
450 static char const * const iso_format_string[] =
455 "%Y-%m-%dT%H:%M:%S%z"
458 tm = localtime (&when);
462 /* Print the date in the default format. Vanilla ANSI C strftime
463 doesn't support %e, but POSIX requires it. If you don't use
464 a GNU strftime, make sure yours supports %e.
465 If you are not using GNU strftime, you want to change %z
466 in the RFC format to %Z; this gives, however, an invalid
467 RFC time format outside the continental United States and GMT. */
470 format = "%a, %d %b %Y %H:%M:%S %z";
471 else if (iso_8601_format)
472 format = iso_format_string[iso_8601_format - 1];
475 char *date_fmt = DATE_FMT_LANGINFO ();
476 /* Do not wrap the following literal format string with _(...).
477 For example, suppose LC_ALL is unset, LC_TIME="POSIX",
478 and LANG="ko_KR". In that case, POSIX.2 says that LC_TIME
479 determines the format and contents of date and time strings
480 written by date, which means "date" must generate output
481 using the POSIX locale; but adding _() would cause "date"
482 to use a Korean translation of the format. */
483 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
486 else if (*format == '\0')
496 out = (char *) xrealloc (out, out_length);
498 /* Mark the first byte of the buffer so we can detect the case
499 of strftime producing an empty string. Otherwise, this loop
500 would not terminate when date was invoked like this
501 `LANG=de date +%p' on a system with good language support. */
505 setlocale (LC_ALL, "C");
507 done = (strftime (out, out_length, format, tm) || out[0] == '\0');
510 setlocale (LC_ALL, "");
516 printf ("%s\n", out);