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},
101 #define TZ_UTC0 "TZ=UTC0"
104 # define TZSET tzset ()
106 # define TZSET /* empty */
109 #define MAYBE_SET_TZ_UTC0 \
110 do { if (universal_time) set_tz (TZ_UTC0); } while (0)
113 # define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
115 # define DATE_FMT_LANGINFO() ""
122 fprintf (stderr, _("Try `%s --help' for more information.\n"),
127 Usage: %s [OPTION]... [+FORMAT]\n\
128 or: %s [OPTION] [MMDDhhmm[[CC]YY][.ss]]\n\
130 program_name, program_name);
132 Display the current time in the given FORMAT, or set the system date.\n\
134 -d, --date=STRING display time described by STRING, not `now'\n\
135 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
136 -I, --iso-8601[=TIMESPEC] output an ISO-8601 compliant date/time string.\n\
137 TIMESPEC=`date' (or missing) for date only,\n\
138 `hours', `minutes', or `seconds' for date and\n\
139 time to the indicated precision.\n\
140 -r, --reference=FILE display the last modification time of FILE\n\
141 -R, --rfc-822 output RFC-822 compliant date string\n\
142 -s, --set=STRING set time described by STRING\n\
143 -u, --utc, --universal print or set Coordinated Universal Time\n\
144 --help display this help and exit\n\
145 --version output version information and exit\n\
149 FORMAT controls the output. The only valid option for the second form\n\
150 specifies Coordinated Universal Time. Interpreted sequences are:\n\
153 %%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\
158 %%d day of month (01..31)\n\
159 %%D date (mm/dd/yy)\n\
160 %%e day of month, blank padded ( 1..31)\n\
164 %%j day of year (001..366)\n\
167 %%m month (01..12)\n\
168 %%M minute (00..59)\n\
170 %%p locale's AM or PM\n\
171 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
172 %%s seconds since 00:00:00, Jan 1, 1970 (a GNU extension)\n\
173 %%S second (00..60)\n\
174 %%t a horizontal tab\n\
175 %%T time, 24-hour (hh:mm:ss)\n\
176 %%U week number of year with Sunday as first day of week (00..53)\n\
177 %%V week number of year with Monday as first day of week (01..53)\n\
178 %%w day of week (0..6); 0 represents Sunday\n\
179 %%W week number of year with Monday as first day of week (00..53)\n\
180 %%x locale's date representation (mm/dd/yy)\n\
181 %%X locale's time representation (%%H:%%M:%%S)\n\
182 %%y last two digits of year (00..99)\n\
183 %%Y year (1970...)\n\
184 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
185 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
187 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
188 the following modifiers between `%%' and a numeric directive.\n\
190 `-' (hyphen) do not pad the field\n\
191 `_' (underscore) pad the field with spaces\n\
193 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
194 close_stdout_status (2);
199 /* Set the TZ environment variable. */
202 set_tz (const char *tz_eq_zone)
204 if (putenv (tz_eq_zone) != 0)
205 error (1, 0, "memory exhausted");
209 /* Parse each line in INPUT_FILENAME as with --date and display each
210 resulting time and date. If the file cannot be opened, tell why
211 then exit. Issue a diagnostic for any lines that cannot be parsed.
212 If any line cannot be parsed, return nonzero; otherwise return zero. */
215 batch_convert (const char *input_filename, const char *format)
223 char *initial_TZ IF_LINT (= NULL);
225 if (strcmp (input_filename, "-") == 0)
227 input_filename = _("standard input");
232 in_stream = fopen (input_filename, "r");
233 if (in_stream == NULL)
235 error (1, errno, "`%s'", input_filename);
244 initial_TZ = getenv ("TZ");
245 if (initial_TZ == NULL)
247 initial_TZ = xstrdup ("TZ=");
251 size_t tz_len = strlen (initial_TZ);
252 char *buf = xmalloc (3 + tz_len + 1);
253 memcpy (mempcpy (buf, "TZ=", 3), initial_TZ, tz_len + 1);
261 line_length = getline (&line, &buflen, in_stream);
264 /* FIXME: detect/handle error here. */
270 /* When given a universal time option, restore the initial
271 value of TZ before parsing each string. */
275 when = get_date (line, NULL);
279 if (line[line_length - 1] == '\n')
280 line[line_length - 1] = '\0';
281 error (0, 0, _("invalid date `%s'"), line);
287 show_date (format, when);
293 if (fclose (in_stream) == EOF)
294 error (2, errno, "`%s'", input_filename);
303 main (int argc, char **argv)
306 const char *datestr = NULL;
307 const char *set_datestr = NULL;
311 char *batch_file = NULL;
312 char *reference = NULL;
313 struct stat refstats;
316 int option_specified_date;
318 program_name = argv[0];
319 setlocale (LC_ALL, "");
320 bindtextdomain (PACKAGE, LOCALEDIR);
321 textdomain (PACKAGE);
323 while ((optc = getopt_long (argc, argv, "d:f:I::r:Rs:u", long_options, NULL))
336 iso_8601_format = (optarg
337 ? XARGMATCH ("--iso-8601", optarg,
338 time_spec_string, time_spec)
348 set_datestr = optarg;
354 case_GETOPT_HELP_CHAR;
355 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
360 n_args = argc - optind;
362 option_specified_date = ((datestr ? 1 : 0)
363 + (batch_file ? 1 : 0)
364 + (reference ? 1 : 0));
366 if (option_specified_date > 1)
369 _("the options to specify dates for printing are mutually exclusive"));
373 if (set_date && option_specified_date)
376 _("the options to print and set the time may not be used together"));
382 error (0, 0, _("too many non-option arguments"));
386 if ((set_date || option_specified_date)
387 && n_args == 1 && argv[optind][0] != '+')
390 the argument `%s' lacks a leading `+';\n\
391 When using an option to specify date(s), any non-option\n\
392 argument must be a format string beginning with `+'."),
398 datestr = set_datestr;
400 if (batch_file != NULL)
402 status = batch_convert (batch_file,
403 (n_args == 1 ? argv[optind] + 1 : NULL));
409 if (!option_specified_date && !set_date)
411 if (n_args == 1 && argv[optind][0] != '+')
413 /* Prepare to set system clock to the specified date/time
414 given in the POSIX-format. */
416 datestr = argv[optind];
417 when = posixtime (datestr,
418 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
423 /* Prepare to print the current date/time. */
424 datestr = _("undefined");
426 format = (n_args == 1 ? argv[optind] + 1 : NULL);
431 /* (option_specified_date || set_date) */
432 if (reference != NULL)
434 if (stat (reference, &refstats))
435 error (1, errno, "%s", reference);
436 when = refstats.st_mtime;
440 when = get_date (datestr, NULL);
443 format = (n_args == 1 ? argv[optind] + 1 : NULL);
447 error (1, 0, _("invalid date `%s'"), datestr);
451 /* Set the system clock to the specified date, then regardless of
452 the success of that operation, format and print that date. */
453 if (stime (&when) == -1)
455 error (0, errno, _("cannot set date"));
460 /* When given a universal time option, set TZ to UTC0 after
461 parsing the specified date, but before printing it. */
464 show_date (format, when);
467 close_stdout_status (2);
472 /* Display the date and/or time in WHEN according to the format specified
473 in FORMAT, followed by a newline. If FORMAT is NULL, use the
474 standard output format (ctime style but with a timezone inserted). */
477 show_date (const char *format, time_t when)
481 size_t out_length = 0;
482 /* ISO 8601 formats, in local and UTC. See below regarding %z */
483 static char *iso_format_string[5][2] =
486 {"%Y-%m-%d", "%Y-%m-%d"},
487 {"%Y-%m-%dT%H%z", "%Y-%m-%dT%HZ"},
488 {"%Y-%m-%dT%H:%M%z", "%Y-%m-%dT%H:%MZ"},
489 {"%Y-%m-%dT%H:%M:%S%z", "%Y-%m-%dT%H:%M:%SZ"}
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 = (universal_time
505 ? "%a, %_d %b %Y %H:%M:%S GMT"
506 : "%a, %_d %b %Y %H:%M:%S %z");
507 else if (iso_8601_format)
508 format = iso_format_string[iso_8601_format][universal_time];
511 char *date_fmt = DATE_FMT_LANGINFO ();
512 format = *date_fmt ? date_fmt : "%a %b %e %H:%M:%S %Z %Y";
515 else if (*format == '\0')
522 setlocale (LC_ALL, "C");
527 out = (char *) xrealloc (out, out_length);
529 /* Mark the first byte of the buffer so we can detect the case
530 of strftime producing an empty string. Otherwise, this loop
531 would not terminate when date was invoked like this
532 `LANG=de date +%p' on a system with good language support. */
535 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
537 printf ("%s\n", out);