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 %%d day of month (01..31)\n\
151 %%D date (mm/dd/yy)\n\
152 %%e day of month, blank padded ( 1..31)\n\
156 %%j day of year (001..366)\n\
159 %%m month (01..12)\n\
160 %%M minute (00..59)\n\
162 %%p locale's AM or PM\n\
163 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
164 %%s seconds since `00:00:00 1970-01-01 UTC' (a GNU extension)\n\
165 %%S second (00..60)\n\
166 %%t a horizontal tab\n\
167 %%T time, 24-hour (hh:mm:ss)\n\
168 %%U week number of year with Sunday as first day of week (00..53)\n\
169 %%V week number of year with Monday as first day of week (01..53)\n\
170 %%w day of week (0..6); 0 represents Sunday\n\
171 %%W week number of year with Monday as first day of week (00..53)\n\
172 %%x locale's date representation (mm/dd/yy)\n\
173 %%X locale's time representation (%%H:%%M:%%S)\n\
174 %%y last two digits of year (00..99)\n\
175 %%Y year (1970...)\n\
176 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
177 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
179 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
180 the following modifiers between `%%' and a numeric directive.\n\
182 `-' (hyphen) do not pad the field\n\
183 `_' (underscore) pad the field with spaces\n\
185 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
190 /* Parse each line in INPUT_FILENAME as with --date and display each
191 resulting time and date. If the file cannot be opened, tell why
192 then exit. Issue a diagnostic for any lines that cannot be parsed.
193 If any line cannot be parsed, return nonzero; otherwise return zero. */
196 batch_convert (const char *input_filename, const char *format)
205 if (strcmp (input_filename, "-") == 0)
207 input_filename = _("standard input");
212 in_stream = fopen (input_filename, "r");
213 if (in_stream == NULL)
215 error (1, errno, "`%s'", input_filename);
224 line_length = getline (&line, &buflen, in_stream);
227 /* FIXME: detect/handle error here. */
231 when = get_date (line, NULL);
235 if (line[line_length - 1] == '\n')
236 line[line_length - 1] = '\0';
237 error (0, 0, _("invalid date `%s'"), line);
242 show_date (format, when);
246 if (fclose (in_stream) == EOF)
247 error (2, errno, "`%s'", input_filename);
256 main (int argc, char **argv)
259 const char *datestr = NULL;
260 const char *set_datestr = NULL;
264 char *batch_file = NULL;
265 char *reference = NULL;
266 struct stat refstats;
269 int option_specified_date;
271 program_name = argv[0];
272 setlocale (LC_ALL, "");
273 bindtextdomain (PACKAGE, LOCALEDIR);
274 textdomain (PACKAGE);
276 close_stdout_set_status (2);
277 atexit (close_stdout);
279 while ((optc = getopt_long (argc, argv, "d:f:I::r:Rs:u", long_options, NULL))
292 iso_8601_format = (optarg
293 ? XARGMATCH ("--iso-8601", optarg,
294 time_spec_string, time_spec)
304 set_datestr = optarg;
308 /* POSIX.2 says that `date -u' is equivalent to setting the TZ
309 environment variable, so this option should do nothing other
311 if (putenv ("TZ=UTC0") != 0)
315 case_GETOPT_HELP_CHAR;
316 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
321 n_args = argc - optind;
323 option_specified_date = ((datestr ? 1 : 0)
324 + (batch_file ? 1 : 0)
325 + (reference ? 1 : 0));
327 if (option_specified_date > 1)
330 _("the options to specify dates for printing are mutually exclusive"));
334 if (set_date && option_specified_date)
337 _("the options to print and set the time may not be used together"));
343 error (0, 0, _("too many non-option arguments"));
347 if ((set_date || option_specified_date)
348 && n_args == 1 && argv[optind][0] != '+')
351 the argument `%s' lacks a leading `+';\n\
352 When using an option to specify date(s), any non-option\n\
353 argument must be a format string beginning with `+'."),
358 /* Simply ignore --rfc-822 if specified when setting the date. */
359 if (rfc_format && !set_date && n_args > 0)
362 _("a format string may not be specified when using\
363 the --rfc-822 (-R) option"));
368 datestr = set_datestr;
370 if (batch_file != NULL)
372 status = batch_convert (batch_file,
373 (n_args == 1 ? argv[optind] + 1 : NULL));
379 if (!option_specified_date && !set_date)
381 if (n_args == 1 && argv[optind][0] != '+')
383 /* Prepare to set system clock to the specified date/time
384 given in the POSIX-format. */
386 datestr = argv[optind];
387 when = posixtime (datestr,
388 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
393 /* Prepare to print the current date/time. */
394 datestr = _("undefined");
396 format = (n_args == 1 ? argv[optind] + 1 : NULL);
401 /* (option_specified_date || set_date) */
402 if (reference != NULL)
404 if (stat (reference, &refstats))
405 error (1, errno, "%s", reference);
406 when = refstats.st_mtime;
410 when = get_date (datestr, NULL);
413 format = (n_args == 1 ? argv[optind] + 1 : NULL);
417 error (1, 0, _("invalid date `%s'"), datestr);
421 /* Set the system clock to the specified date, then regardless of
422 the success of that operation, format and print that date. */
423 if (stime (&when) == -1)
425 error (0, errno, _("cannot set date"));
430 show_date (format, when);
436 /* Display the date and/or time in WHEN according to the format specified
437 in FORMAT, followed by a newline. If FORMAT is NULL, use the
438 standard output format (ctime style but with a timezone inserted). */
441 show_date (const char *format, time_t when)
445 size_t out_length = 0;
446 /* ISO 8601 formats. See below regarding %z */
447 static char const * const iso_format_string[] =
452 "%Y-%m-%dT%H:%M:%S%z"
455 tm = localtime (&when);
459 /* Print the date in the default format. Vanilla ANSI C strftime
460 doesn't support %e, but POSIX requires it. If you don't use
461 a GNU strftime, make sure yours supports %e.
462 If you are not using GNU strftime, you want to change %z
463 in the RFC format to %Z; this gives, however, an invalid
464 RFC time format outside the continental United States and GMT. */
467 format = "%a, %_d %b %Y %H:%M:%S %z";
468 else if (iso_8601_format)
469 format = iso_format_string[iso_8601_format - 1];
472 char *date_fmt = DATE_FMT_LANGINFO ();
473 /* Do not wrap the following literal format string with _(...).
474 For example, suppose LC_ALL is unset, LC_TIME="POSIX",
475 and LANG="ko_KR". In that case, POSIX.2 says that LC_TIME
476 determines the format and contents of date and time strings
477 written by date, which means "date" must generate output
478 using the POSIX locale; but adding _() would cause "date"
479 to use a Korean translation of the format. */
480 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
483 else if (*format == '\0')
490 setlocale (LC_ALL, "C");
495 out = (char *) xrealloc (out, out_length);
497 /* Mark the first byte of the buffer so we can detect the case
498 of strftime producing an empty string. Otherwise, this loop
499 would not terminate when date was invoked like this
500 `LANG=de date +%p' on a system with good language support. */
503 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
505 printf ("%s\n", out);