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-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 week number of year with Sunday as first day of week (00..53)\n\
170 %%V week number of year with Monday as first day of week (01..53)\n\
171 %%w day of week (0..6); 0 represents Sunday\n\
172 %%W week number of year with Monday as first day of week (00..53)\n\
173 %%x locale's date representation (mm/dd/yy)\n\
174 %%X locale's time representation (%%H:%%M:%%S)\n\
175 %%y last two digits of year (00..99)\n\
176 %%Y year (1970...)\n\
177 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
178 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
180 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
181 the following modifiers between `%%' and a numeric directive.\n\
183 `-' (hyphen) do not pad the field\n\
184 `_' (underscore) pad the field with spaces\n\
186 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
191 /* Parse each line in INPUT_FILENAME as with --date and display each
192 resulting time and date. If the file cannot be opened, tell why
193 then exit. Issue a diagnostic for any lines that cannot be parsed.
194 If any line cannot be parsed, return nonzero; otherwise return zero. */
197 batch_convert (const char *input_filename, const char *format)
206 if (strcmp (input_filename, "-") == 0)
208 input_filename = _("standard input");
213 in_stream = fopen (input_filename, "r");
214 if (in_stream == NULL)
216 error (1, errno, "`%s'", input_filename);
225 line_length = getline (&line, &buflen, in_stream);
228 /* FIXME: detect/handle error here. */
232 when = get_date (line, NULL);
236 if (line[line_length - 1] == '\n')
237 line[line_length - 1] = '\0';
238 error (0, 0, _("invalid date `%s'"), line);
243 show_date (format, when);
247 if (fclose (in_stream) == EOF)
248 error (2, errno, "`%s'", input_filename);
257 main (int argc, char **argv)
260 const char *datestr = NULL;
261 const char *set_datestr = NULL;
265 char *batch_file = NULL;
266 char *reference = NULL;
267 struct stat refstats;
270 int option_specified_date;
272 program_name = argv[0];
273 setlocale (LC_ALL, "");
274 bindtextdomain (PACKAGE, LOCALEDIR);
275 textdomain (PACKAGE);
277 close_stdout_set_status (2);
278 atexit (close_stdout);
280 while ((optc = getopt_long (argc, argv, "d:f:I::r:Rs:u", long_options, NULL))
293 iso_8601_format = (optarg
294 ? XARGMATCH ("--iso-8601", optarg,
295 time_spec_string, time_spec)
305 set_datestr = optarg;
309 /* POSIX.2 says that `date -u' is equivalent to setting the TZ
310 environment variable, so this option should do nothing other
312 if (putenv ("TZ=UTC0") != 0)
316 case_GETOPT_HELP_CHAR;
317 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
322 n_args = argc - optind;
324 option_specified_date = ((datestr ? 1 : 0)
325 + (batch_file ? 1 : 0)
326 + (reference ? 1 : 0));
328 if (option_specified_date > 1)
331 _("the options to specify dates for printing are mutually exclusive"));
335 if (set_date && option_specified_date)
338 _("the options to print and set the time may not be used together"));
344 error (0, 0, _("too many non-option arguments: %s%s"),
345 argv[optind + 1], n_args == 2 ? "" : " ...");
349 if ((set_date || option_specified_date)
350 && n_args == 1 && argv[optind][0] != '+')
353 the argument `%s' lacks a leading `+';\n\
354 When using an option to specify date(s), any non-option\n\
355 argument must be a format string beginning with `+'."),
360 /* Simply ignore --rfc-822 if specified when setting the date. */
361 if (rfc_format && !set_date && n_args > 0)
364 _("a format string may not be specified when using\
365 the --rfc-822 (-R) option"));
370 datestr = set_datestr;
372 if (batch_file != NULL)
374 status = batch_convert (batch_file,
375 (n_args == 1 ? argv[optind] + 1 : NULL));
381 if (!option_specified_date && !set_date)
383 if (n_args == 1 && argv[optind][0] != '+')
385 /* Prepare to set system clock to the specified date/time
386 given in the POSIX-format. */
388 datestr = argv[optind];
389 when = posixtime (datestr,
390 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
395 /* Prepare to print the current date/time. */
396 datestr = _("undefined");
398 format = (n_args == 1 ? argv[optind] + 1 : NULL);
403 /* (option_specified_date || set_date) */
404 if (reference != NULL)
406 if (stat (reference, &refstats))
407 error (1, errno, "%s", reference);
408 when = refstats.st_mtime;
412 when = get_date (datestr, NULL);
415 format = (n_args == 1 ? argv[optind] + 1 : NULL);
419 error (1, 0, _("invalid date `%s'"), datestr);
423 /* Set the system clock to the specified date, then regardless of
424 the success of that operation, format and print that date. */
425 if (stime (&when) == -1)
427 error (0, errno, _("cannot set date"));
432 show_date (format, when);
438 /* Display the date and/or time in WHEN according to the format specified
439 in FORMAT, followed by a newline. If FORMAT is NULL, use the
440 standard output format (ctime style but with a timezone inserted). */
443 show_date (const char *format, time_t when)
447 size_t out_length = 0;
448 /* ISO 8601 formats. See below regarding %z */
449 static char const * const iso_format_string[] =
454 "%Y-%m-%dT%H:%M:%S%z"
457 tm = localtime (&when);
461 /* Print the date in the default format. Vanilla ANSI C strftime
462 doesn't support %e, but POSIX requires it. If you don't use
463 a GNU strftime, make sure yours supports %e.
464 If you are not using GNU strftime, you want to change %z
465 in the RFC format to %Z; this gives, however, an invalid
466 RFC time format outside the continental United States and GMT. */
469 format = "%a, %_d %b %Y %H:%M:%S %z";
470 else if (iso_8601_format)
471 format = iso_format_string[iso_8601_format - 1];
474 char *date_fmt = DATE_FMT_LANGINFO ();
475 /* Do not wrap the following literal format string with _(...).
476 For example, suppose LC_ALL is unset, LC_TIME="POSIX",
477 and LANG="ko_KR". In that case, POSIX.2 says that LC_TIME
478 determines the format and contents of date and time strings
479 written by date, which means "date" must generate output
480 using the POSIX locale; but adding _() would cause "date"
481 to use a Korean translation of the format. */
482 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
485 else if (*format == '\0')
492 setlocale (LC_ALL, "C");
497 out = (char *) xrealloc (out, out_length);
499 /* Mark the first byte of the buffer so we can detect the case
500 of strftime producing an empty string. Otherwise, this loop
501 would not terminate when date was invoked like this
502 `LANG=de date +%p' on a system with good language support. */
505 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
507 printf ("%s\n", out);