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[coreutils.git] / src / date.c
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1 /* date - print or set the system date and time
2 Copyright (C) 1989-2009 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 3 of the License, or
7 (at your option) any later version.
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, see <http://www.gnu.org/licenses/>.
17 David MacKenzie <djm@gnu.ai.mit.edu> */
19 #include <config.h>
20 #include <stdio.h>
21 #include <getopt.h>
22 #include <sys/types.h>
23 #if HAVE_LANGINFO_CODESET
24 # include <langinfo.h>
25 #endif
27 #include "system.h"
28 #include "argmatch.h"
29 #include "error.h"
30 #include "getdate.h"
31 #include "posixtm.h"
32 #include "quote.h"
33 #include "stat-time.h"
34 #include "fprintftime.h"
36 /* The official name of this program (e.g., no `g' prefix). */
37 #define PROGRAM_NAME "date"
39 #define AUTHORS proper_name ("David MacKenzie")
41 static bool show_date (const char *format, struct timespec when);
43 enum Time_spec
45 /* Display only the date. */
46 TIME_SPEC_DATE,
47 /* Display date, hours, minutes, and seconds. */
48 TIME_SPEC_SECONDS,
49 /* Similar, but display nanoseconds. */
50 TIME_SPEC_NS,
52 /* Put these last, since they aren't valid for --rfc-3339. */
54 /* Display date and hour. */
55 TIME_SPEC_HOURS,
56 /* Display date, hours, and minutes. */
57 TIME_SPEC_MINUTES
60 static char const *const time_spec_string[] =
62 /* Put "hours" and "minutes" first, since they aren't valid for
63 --rfc-3339. */
64 "hours", "minutes",
65 "date", "seconds", "ns", NULL
67 static enum Time_spec const time_spec[] =
69 TIME_SPEC_HOURS, TIME_SPEC_MINUTES,
70 TIME_SPEC_DATE, TIME_SPEC_SECONDS, TIME_SPEC_NS
72 ARGMATCH_VERIFY (time_spec_string, time_spec);
74 /* A format suitable for Internet RFC 2822. */
75 static char const rfc_2822_format[] = "%a, %d %b %Y %H:%M:%S %z";
77 /* For long options that have no equivalent short option, use a
78 non-character as a pseudo short option, starting with CHAR_MAX + 1. */
79 enum
81 RFC_3339_OPTION = CHAR_MAX + 1
84 static char const short_options[] = "d:f:I::r:Rs:u";
86 static struct option const long_options[] =
88 {"date", required_argument, NULL, 'd'},
89 {"file", required_argument, NULL, 'f'},
90 {"iso-8601", optional_argument, NULL, 'I'}, /* Deprecated. */
91 {"reference", required_argument, NULL, 'r'},
92 {"rfc-822", no_argument, NULL, 'R'},
93 {"rfc-2822", no_argument, NULL, 'R'},
94 {"rfc-3339", required_argument, NULL, RFC_3339_OPTION},
95 {"set", required_argument, NULL, 's'},
96 {"uct", no_argument, NULL, 'u'},
97 {"utc", no_argument, NULL, 'u'},
98 {"universal", no_argument, NULL, 'u'},
99 {GETOPT_HELP_OPTION_DECL},
100 {GETOPT_VERSION_OPTION_DECL},
101 {NULL, 0, NULL, 0}
104 #if LOCALTIME_CACHE
105 # define TZSET tzset ()
106 #else
107 # define TZSET /* empty */
108 #endif
110 #ifdef _DATE_FMT
111 # define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
112 #else
113 # define DATE_FMT_LANGINFO() ""
114 #endif
116 void
117 usage (int status)
119 if (status != EXIT_SUCCESS)
120 fprintf (stderr, _("Try `%s --help' for more information.\n"),
121 program_name);
122 else
124 printf (_("\
125 Usage: %s [OPTION]... [+FORMAT]\n\
126 or: %s [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]\n\
128 program_name, program_name);
129 fputs (_("\
130 Display the current time in the given FORMAT, or set the system date.\n\
132 -d, --date=STRING display time described by STRING, not `now'\n\
133 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
134 "), stdout);
135 fputs (_("\
136 -r, --reference=FILE display the last modification time of FILE\n\
137 -R, --rfc-2822 output date and time in RFC 2822 format.\n\
138 Example: Mon, 07 Aug 2006 12:34:56 -0600\n\
139 "), stdout);
140 fputs (_("\
141 --rfc-3339=TIMESPEC output date and time in RFC 3339 format.\n\
142 TIMESPEC=`date', `seconds', or `ns' for\n\
143 date and time to the indicated precision.\n\
144 Date and time components are separated by\n\
145 a single space: 2006-08-07 12:34:56-06:00\n\
146 -s, --set=STRING set time described by STRING\n\
147 -u, --utc, --universal print or set Coordinated Universal Time\n\
148 "), stdout);
149 fputs (HELP_OPTION_DESCRIPTION, stdout);
150 fputs (VERSION_OPTION_DESCRIPTION, stdout);
151 fputs (_("\
153 FORMAT controls the output. Interpreted sequences are:\n\
155 %% a literal %\n\
156 %a locale's abbreviated weekday name (e.g., Sun)\n\
157 "), stdout);
158 fputs (_("\
159 %A locale's full weekday name (e.g., Sunday)\n\
160 %b locale's abbreviated month name (e.g., Jan)\n\
161 %B locale's full month name (e.g., January)\n\
162 %c locale's date and time (e.g., Thu Mar 3 23:05:25 2005)\n\
163 "), stdout);
164 fputs (_("\
165 %C century; like %Y, except omit last two digits (e.g., 20)\n\
166 %d day of month (e.g, 01)\n\
167 %D date; same as %m/%d/%y\n\
168 %e day of month, space padded; same as %_d\n\
169 "), stdout);
170 fputs (_("\
171 %F full date; same as %Y-%m-%d\n\
172 %g last two digits of year of ISO week number (see %G)\n\
173 %G year of ISO week number (see %V); normally useful only with %V\n\
174 "), stdout);
175 fputs (_("\
176 %h same as %b\n\
177 %H hour (00..23)\n\
178 %I hour (01..12)\n\
179 %j day of year (001..366)\n\
180 "), stdout);
181 fputs (_("\
182 %k hour ( 0..23)\n\
183 %l hour ( 1..12)\n\
184 %m month (01..12)\n\
185 %M minute (00..59)\n\
186 "), stdout);
187 fputs (_("\
188 %n a newline\n\
189 %N nanoseconds (000000000..999999999)\n\
190 %p locale's equivalent of either AM or PM; blank if not known\n\
191 %P like %p, but lower case\n\
192 %r locale's 12-hour clock time (e.g., 11:11:04 PM)\n\
193 %R 24-hour hour and minute; same as %H:%M\n\
194 %s seconds since 1970-01-01 00:00:00 UTC\n\
195 "), stdout);
196 fputs (_("\
197 %S second (00..60)\n\
198 %t a tab\n\
199 %T time; same as %H:%M:%S\n\
200 %u day of week (1..7); 1 is Monday\n\
201 "), stdout);
202 fputs (_("\
203 %U week number of year, with Sunday as first day of week (00..53)\n\
204 %V ISO week number, with Monday as first day of week (01..53)\n\
205 %w day of week (0..6); 0 is Sunday\n\
206 %W week number of year, with Monday as first day of week (00..53)\n\
207 "), stdout);
208 fputs (_("\
209 %x locale's date representation (e.g., 12/31/99)\n\
210 %X locale's time representation (e.g., 23:13:48)\n\
211 %y last two digits of year (00..99)\n\
212 %Y year\n\
213 "), stdout);
214 fputs (_("\
215 %z +hhmm numeric timezone (e.g., -0400)\n\
216 %:z +hh:mm numeric timezone (e.g., -04:00)\n\
217 %::z +hh:mm:ss numeric time zone (e.g., -04:00:00)\n\
218 %:::z numeric time zone with : to necessary precision (e.g., -04, +05:30)\n\
219 %Z alphabetic time zone abbreviation (e.g., EDT)\n\
221 By default, date pads numeric fields with zeroes.\n\
222 "), stdout);
223 fputs (_("\
224 The following optional flags may follow `%':\n\
226 - (hyphen) do not pad the field\n\
227 _ (underscore) pad with spaces\n\
228 0 (zero) pad with zeros\n\
229 ^ use upper case if possible\n\
230 # use opposite case if possible\n\
231 "), stdout);
232 fputs (_("\
234 After any flags comes an optional field width, as a decimal number;\n\
235 then an optional modifier, which is either\n\
236 E to use the locale's alternate representations if available, or\n\
237 O to use the locale's alternate numeric symbols if available.\n\
238 "), stdout);
239 emit_bug_reporting_address ();
241 exit (status);
244 /* Parse each line in INPUT_FILENAME as with --date and display each
245 resulting time and date. If the file cannot be opened, tell why
246 then exit. Issue a diagnostic for any lines that cannot be parsed.
247 Return true if successful. */
249 static bool
250 batch_convert (const char *input_filename, const char *format)
252 bool ok;
253 FILE *in_stream;
254 char *line;
255 size_t buflen;
256 struct timespec when;
258 if (STREQ (input_filename, "-"))
260 input_filename = _("standard input");
261 in_stream = stdin;
263 else
265 in_stream = fopen (input_filename, "r");
266 if (in_stream == NULL)
268 error (EXIT_FAILURE, errno, "%s", quote (input_filename));
272 line = NULL;
273 buflen = 0;
274 ok = true;
275 while (1)
277 ssize_t line_length = getline (&line, &buflen, in_stream);
278 if (line_length < 0)
280 /* FIXME: detect/handle error here. */
281 break;
284 if (! get_date (&when, line, NULL))
286 if (line[line_length - 1] == '\n')
287 line[line_length - 1] = '\0';
288 error (0, 0, _("invalid date %s"), quote (line));
289 ok = false;
291 else
293 ok &= show_date (format, when);
297 if (fclose (in_stream) == EOF)
298 error (EXIT_FAILURE, errno, "%s", quote (input_filename));
300 free (line);
302 return ok;
306 main (int argc, char **argv)
308 int optc;
309 const char *datestr = NULL;
310 const char *set_datestr = NULL;
311 struct timespec when;
312 bool set_date = false;
313 char const *format = NULL;
314 char *batch_file = NULL;
315 char *reference = NULL;
316 struct stat refstats;
317 bool ok;
318 int option_specified_date;
320 initialize_main (&argc, &argv);
321 set_program_name (argv[0]);
322 setlocale (LC_ALL, "");
323 bindtextdomain (PACKAGE, LOCALEDIR);
324 textdomain (PACKAGE);
326 atexit (close_stdout);
328 while ((optc = getopt_long (argc, argv, short_options, long_options, NULL))
329 != -1)
331 char const *new_format = NULL;
333 switch (optc)
335 case 'd':
336 datestr = optarg;
337 break;
338 case 'f':
339 batch_file = optarg;
340 break;
341 case RFC_3339_OPTION:
343 static char const rfc_3339_format[][32] =
345 "%Y-%m-%d",
346 "%Y-%m-%d %H:%M:%S%:z",
347 "%Y-%m-%d %H:%M:%S.%N%:z"
349 enum Time_spec i =
350 XARGMATCH ("--rfc-3339", optarg,
351 time_spec_string + 2, time_spec + 2);
352 new_format = rfc_3339_format[i];
353 break;
355 case 'I':
357 static char const iso_8601_format[][32] =
359 "%Y-%m-%d",
360 "%Y-%m-%dT%H:%M:%S%z",
361 "%Y-%m-%dT%H:%M:%S,%N%z",
362 "%Y-%m-%dT%H%z",
363 "%Y-%m-%dT%H:%M%z"
365 enum Time_spec i =
366 (optarg
367 ? XARGMATCH ("--iso-8601", optarg, time_spec_string, time_spec)
368 : TIME_SPEC_DATE);
369 new_format = iso_8601_format[i];
370 break;
372 case 'r':
373 reference = optarg;
374 break;
375 case 'R':
376 new_format = rfc_2822_format;
377 break;
378 case 's':
379 set_datestr = optarg;
380 set_date = true;
381 break;
382 case 'u':
383 /* POSIX says that `date -u' is equivalent to setting the TZ
384 environment variable, so this option should do nothing other
385 than setting TZ. */
386 if (putenv (bad_cast ("TZ=UTC0")) != 0)
387 xalloc_die ();
388 TZSET;
389 break;
390 case_GETOPT_HELP_CHAR;
391 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
392 default:
393 usage (EXIT_FAILURE);
396 if (new_format)
398 if (format)
399 error (EXIT_FAILURE, 0, _("multiple output formats specified"));
400 format = new_format;
404 option_specified_date = ((datestr ? 1 : 0)
405 + (batch_file ? 1 : 0)
406 + (reference ? 1 : 0));
408 if (option_specified_date > 1)
410 error (0, 0,
411 _("the options to specify dates for printing are mutually exclusive"));
412 usage (EXIT_FAILURE);
415 if (set_date && option_specified_date)
417 error (0, 0,
418 _("the options to print and set the time may not be used together"));
419 usage (EXIT_FAILURE);
422 if (optind < argc)
424 if (optind + 1 < argc)
426 error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
427 usage (EXIT_FAILURE);
430 if (argv[optind][0] == '+')
432 if (format)
433 error (EXIT_FAILURE, 0, _("multiple output formats specified"));
434 format = argv[optind++] + 1;
436 else if (set_date || option_specified_date)
438 error (0, 0,
439 _("the argument %s lacks a leading `+';\n"
440 "when using an option to specify date(s), any non-option\n"
441 "argument must be a format string beginning with `+'"),
442 quote (argv[optind]));
443 usage (EXIT_FAILURE);
447 if (!format)
449 format = DATE_FMT_LANGINFO ();
450 if (! *format)
452 /* Do not wrap the following literal format string with _(...).
453 For example, suppose LC_ALL is unset, LC_TIME="POSIX",
454 and LANG="ko_KR". In that case, POSIX says that LC_TIME
455 determines the format and contents of date and time strings
456 written by date, which means "date" must generate output
457 using the POSIX locale; but adding _() would cause "date"
458 to use a Korean translation of the format. */
459 format = "%a %b %e %H:%M:%S %Z %Y";
463 if (batch_file != NULL)
464 ok = batch_convert (batch_file, format);
465 else
467 bool valid_date = true;
468 ok = true;
470 if (!option_specified_date && !set_date)
472 if (optind < argc)
474 /* Prepare to set system clock to the specified date/time
475 given in the POSIX-format. */
476 set_date = true;
477 datestr = argv[optind];
478 valid_date = posixtime (&when.tv_sec,
479 datestr,
480 (PDS_TRAILING_YEAR
481 | PDS_CENTURY | PDS_SECONDS));
482 when.tv_nsec = 0; /* FIXME: posixtime should set this. */
484 else
486 /* Prepare to print the current date/time. */
487 gettime (&when);
490 else
492 /* (option_specified_date || set_date) */
493 if (reference != NULL)
495 if (stat (reference, &refstats) != 0)
496 error (EXIT_FAILURE, errno, "%s", reference);
497 when = get_stat_mtime (&refstats);
499 else
501 if (set_datestr)
502 datestr = set_datestr;
503 valid_date = get_date (&when, datestr, NULL);
507 if (! valid_date)
508 error (EXIT_FAILURE, 0, _("invalid date %s"), quote (datestr));
510 if (set_date)
512 /* Set the system clock to the specified date, then regardless of
513 the success of that operation, format and print that date. */
514 if (settime (&when) != 0)
516 error (0, errno, _("cannot set date"));
517 ok = false;
521 ok &= show_date (format, when);
524 exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
527 /* Display the date and/or time in WHEN according to the format specified
528 in FORMAT, followed by a newline. Return true if successful. */
530 static bool
531 show_date (const char *format, struct timespec when)
533 struct tm *tm;
535 tm = localtime (&when.tv_sec);
536 if (! tm)
538 char buf[INT_BUFSIZE_BOUND (intmax_t)];
539 error (0, 0, _("time %s is out of range"), timetostr (when.tv_sec, buf));
540 return false;
543 if (format == rfc_2822_format)
544 setlocale (LC_TIME, "C");
545 fprintftime (stdout, format, tm, 0, when.tv_nsec);
546 fputc ('\n', stdout);
547 if (format == rfc_2822_format)
548 setlocale (LC_TIME, "");
550 return true;