1 /* date - print or set the system date and time
2 Copyright (C) 1989-2000 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 /* If nonzero, print or set Coordinated Universal Time. */
83 static int universal_time = 0;
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 -I, --iso-8601[=TIMESPEC] output an ISO-8601 compliant date/time string.\n\
132 TIMESPEC=`date' (or missing) for date only,\n\
133 `hours', `minutes', or `seconds' for date and\n\
134 time to the indicated precision.\n\
135 -r, --reference=FILE display the last modification time of FILE\n\
136 -R, --rfc-822 output RFC-822 compliant date string\n\
137 -s, --set=STRING set time described by STRING\n\
138 -u, --utc, --universal print or set Coordinated Universal Time\n\
139 --help display this help and exit\n\
140 --version output version information and exit\n\
144 FORMAT controls the output. The only valid option for the second form\n\
145 specifies Coordinated Universal Time. Interpreted sequences are:\n\
148 %%a locale's abbreviated weekday name (Sun..Sat)\n\
149 %%A locale's full weekday name, variable length (Sunday..Saturday)\n\
150 %%b locale's abbreviated month name (Jan..Dec)\n\
151 %%B locale's full month name, variable length (January..December)\n\
152 %%c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
153 %%d day of month (01..31)\n\
154 %%D date (mm/dd/yy)\n\
155 %%e day of month, blank padded ( 1..31)\n\
159 %%j day of year (001..366)\n\
162 %%m month (01..12)\n\
163 %%M minute (00..59)\n\
165 %%p locale's AM or PM\n\
166 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
167 %%s seconds since 00:00:00, Jan 1, 1970 (a GNU extension)\n\
168 %%S second (00..60)\n\
169 %%t a horizontal tab\n\
170 %%T time, 24-hour (hh:mm:ss)\n\
171 %%U week number of year with Sunday as first day of week (00..53)\n\
172 %%V week number of year with Monday as first day of week (01..53)\n\
173 %%w day of week (0..6); 0 represents Sunday\n\
174 %%W week number of year with Monday as first day of week (00..53)\n\
175 %%x locale's date representation (mm/dd/yy)\n\
176 %%X locale's time representation (%%H:%%M:%%S)\n\
177 %%y last two digits of year (00..99)\n\
178 %%Y year (1970...)\n\
179 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
180 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
182 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
183 the following modifiers between `%%' and a numeric directive.\n\
185 `-' (hyphen) do not pad the field\n\
186 `_' (underscore) pad the field with spaces\n\
188 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
193 /* Parse each line in INPUT_FILENAME as with --date and display each
194 resulting time and date. If the file cannot be opened, tell why
195 then exit. Issue a diagnostic for any lines that cannot be parsed.
196 If any line cannot be parsed, return nonzero; otherwise return zero. */
199 batch_convert (const char *input_filename, const char *format)
208 if (strcmp (input_filename, "-") == 0)
210 input_filename = _("standard input");
215 in_stream = fopen (input_filename, "r");
216 if (in_stream == NULL)
218 error (1, errno, "`%s'", input_filename);
227 line_length = getline (&line, &buflen, in_stream);
230 /* FIXME: detect/handle error here. */
234 when = get_date (line, NULL);
238 if (line[line_length - 1] == '\n')
239 line[line_length - 1] = '\0';
240 error (0, 0, _("invalid date `%s'"), line);
245 show_date (format, when);
249 if (fclose (in_stream) == EOF)
250 error (2, errno, "`%s'", input_filename);
259 main (int argc, char **argv)
262 const char *datestr = NULL;
263 const char *set_datestr = NULL;
267 char *batch_file = NULL;
268 char *reference = NULL;
269 struct stat refstats;
272 int option_specified_date;
274 program_name = argv[0];
275 setlocale (LC_ALL, "");
276 bindtextdomain (PACKAGE, LOCALEDIR);
277 textdomain (PACKAGE);
279 close_stdout_set_status (2);
280 atexit (close_stdout);
282 while ((optc = getopt_long (argc, argv, "d:f:I::r:Rs:u", long_options, NULL))
295 iso_8601_format = (optarg
296 ? XARGMATCH ("--iso-8601", optarg,
297 time_spec_string, time_spec)
307 set_datestr = optarg;
313 case_GETOPT_HELP_CHAR;
314 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
319 n_args = argc - optind;
321 option_specified_date = ((datestr ? 1 : 0)
322 + (batch_file ? 1 : 0)
323 + (reference ? 1 : 0));
325 if (option_specified_date > 1)
328 _("the options to specify dates for printing are mutually exclusive"));
332 if (set_date && option_specified_date)
335 _("the options to print and set the time may not be used together"));
341 error (0, 0, _("too many non-option arguments"));
345 if ((set_date || option_specified_date)
346 && n_args == 1 && argv[optind][0] != '+')
349 the argument `%s' lacks a leading `+';\n\
350 When using an option to specify date(s), any non-option\n\
351 argument must be a format string beginning with `+'."),
357 datestr = set_datestr;
361 if (putenv ("TZ=UTC0") != 0)
366 if (batch_file != NULL)
368 status = batch_convert (batch_file,
369 (n_args == 1 ? argv[optind] + 1 : NULL));
375 if (!option_specified_date && !set_date)
377 if (n_args == 1 && argv[optind][0] != '+')
379 /* Prepare to set system clock to the specified date/time
380 given in the POSIX-format. */
382 datestr = argv[optind];
383 when = posixtime (datestr,
384 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
389 /* Prepare to print the current date/time. */
390 datestr = _("undefined");
392 format = (n_args == 1 ? argv[optind] + 1 : NULL);
397 /* (option_specified_date || set_date) */
398 if (reference != NULL)
400 if (stat (reference, &refstats))
401 error (1, errno, "%s", reference);
402 when = refstats.st_mtime;
406 when = get_date (datestr, NULL);
409 format = (n_args == 1 ? argv[optind] + 1 : NULL);
413 error (1, 0, _("invalid date `%s'"), datestr);
417 /* Set the system clock to the specified date, then regardless of
418 the success of that operation, format and print that date. */
419 if (stime (&when) == -1)
421 error (0, errno, _("cannot set date"));
426 show_date (format, when);
432 /* Display the date and/or time in WHEN according to the format specified
433 in FORMAT, followed by a newline. If FORMAT is NULL, use the
434 standard output format (ctime style but with a timezone inserted). */
437 show_date (const char *format, time_t when)
441 size_t out_length = 0;
442 /* ISO 8601 formats, in local and UTC. See below regarding %z */
443 static char *iso_format_string[5][2] =
446 {"%Y-%m-%d", "%Y-%m-%d"},
447 {"%Y-%m-%dT%H%z", "%Y-%m-%dT%HZ"},
448 {"%Y-%m-%dT%H:%M%z", "%Y-%m-%dT%H:%MZ"},
449 {"%Y-%m-%dT%H:%M:%S%z", "%Y-%m-%dT%H:%M:%SZ"}
452 tm = localtime (&when);
456 /* Print the date in the default format. Vanilla ANSI C strftime
457 doesn't support %e, but POSIX requires it. If you don't use
458 a GNU strftime, make sure yours supports %e.
459 If you are not using GNU strftime, you want to change %z
460 in the RFC format to %Z; this gives, however, an invalid
461 RFC time format outside the continental United States and GMT. */
464 format = (universal_time
465 ? "%a, %_d %b %Y %H:%M:%S GMT"
466 : "%a, %_d %b %Y %H:%M:%S %z");
467 else if (iso_8601_format)
468 format = iso_format_string[iso_8601_format][universal_time];
471 char *date_fmt = DATE_FMT_LANGINFO ();
472 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
475 else if (*format == '\0')
482 setlocale (LC_ALL, "C");
487 out = (char *) xrealloc (out, out_length);
489 /* Mark the first byte of the buffer so we can detect the case
490 of strftime producing an empty string. Otherwise, this loop
491 would not terminate when date was invoked like this
492 `LANG=de date +%p' on a system with good language support. */
495 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
497 printf ("%s\n", out);