1/* date - print or set the system date and time
2   Copyright (C) 1989-2010 Free Software Foundation, Inc.
3
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.
8
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.
13
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/>.
16
17   David MacKenzie <djm@gnu.ai.mit.edu> */
18
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
26
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"
35
36/* The official name of this program (e.g., no `g' prefix).  */
37#define PROGRAM_NAME "date"
38
39#define AUTHORS proper_name ("David MacKenzie")
40
41static bool show_date (const char *format, struct timespec when);
42
43enum Time_spec
44{
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,
51
52  /* Put these last, since they aren't valid for --rfc-3339.  */
53
54  /* Display date and hour.  */
55  TIME_SPEC_HOURS,
56  /* Display date, hours, and minutes.  */
57  TIME_SPEC_MINUTES
58};
59
60static char const *const time_spec_string[] =
61{
62  /* Put "hours" and "minutes" first, since they aren't valid for
63     --rfc-3339.  */
64  "hours", "minutes",
65  "date", "seconds", "ns", NULL
66};
67static enum Time_spec const time_spec[] =
68{
69  TIME_SPEC_HOURS, TIME_SPEC_MINUTES,
70  TIME_SPEC_DATE, TIME_SPEC_SECONDS, TIME_SPEC_NS
71};
72ARGMATCH_VERIFY (time_spec_string, time_spec);
73
74/* A format suitable for Internet RFC 2822.  */
75static char const rfc_2822_format[] = "%a, %d %b %Y %H:%M:%S %z";
76
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.  */
79enum
80{
81  RFC_3339_OPTION = CHAR_MAX + 1
82};
83
84static char const short_options[] = "d:f:I::r:Rs:u";
85
86static struct option const long_options[] =
87{
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}
102};
103
104#if LOCALTIME_CACHE
105# define TZSET tzset ()
106#else
107# define TZSET /* empty */
108#endif
109
110#ifdef _DATE_FMT
111# define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
112#else
113# define DATE_FMT_LANGINFO() ""
114#endif
115
116void
117usage (int status)
118{
119  if (status != EXIT_SUCCESS)
120    fprintf (stderr, _("Try `%s --help' for more information.\n"),
121             program_name);
122  else
123    {
124      printf (_("\
125Usage: %s [OPTION]... [+FORMAT]\n\
126  or:  %s [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]\n\
127"),
128              program_name, program_name);
129      fputs (_("\
130Display the current time in the given FORMAT, or set the system date.\n\
131\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 (_("\
152\n\
153FORMAT controls the output.  Interpreted sequences are:\n\
154\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\
220\n\
221By default, date pads numeric fields with zeroes.\n\
222"), stdout);
223      fputs (_("\
224The following optional flags may follow `%':\n\
225\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 (_("\
233\n\
234After any flags comes an optional field width, as a decimal number;\n\
235then an optional modifier, which is either\n\
236E to use the locale's alternate representations if available, or\n\
237O to use the locale's alternate numeric symbols if available.\n\
238"), stdout);
239      emit_ancillary_info ();
240    }
241  exit (status);
242}
243
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.  */
248
249static bool
250batch_convert (const char *input_filename, const char *format)
251{
252  bool ok;
253  FILE *in_stream;
254  char *line;
255  size_t buflen;
256  struct timespec when;
257
258  if (STREQ (input_filename, "-"))
259    {
260      input_filename = _("standard input");
261      in_stream = stdin;
262    }
263  else
264    {
265      in_stream = fopen (input_filename, "r");
266      if (in_stream == NULL)
267        {
268          error (EXIT_FAILURE, errno, "%s", quote (input_filename));
269        }
270    }
271
272  line = NULL;
273  buflen = 0;
274  ok = true;
275  while (1)
276    {
277      ssize_t line_length = getline (&line, &buflen, in_stream);
278      if (line_length < 0)
279        {
280          /* FIXME: detect/handle error here.  */
281          break;
282        }
283
284      if (! get_date (&when, line, NULL))
285        {
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;
290        }
291      else
292        {
293          ok &= show_date (format, when);
294        }
295    }
296
297  if (fclose (in_stream) == EOF)
298    error (EXIT_FAILURE, errno, "%s", quote (input_filename));
299
300  free (line);
301
302  return ok;
303}
304
305int
306main (int argc, char **argv)
307{
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;
319
320  initialize_main (&argc, &argv);
321  set_program_name (argv[0]);
322  setlocale (LC_ALL, "");
323  bindtextdomain (PACKAGE, LOCALEDIR);
324  textdomain (PACKAGE);
325
326  atexit (close_stdout);
327
328  while ((optc = getopt_long (argc, argv, short_options, long_options, NULL))
329         != -1)
330    {
331      char const *new_format = NULL;
332
333      switch (optc)
334        {
335        case 'd':
336          datestr = optarg;
337          break;
338        case 'f':
339          batch_file = optarg;
340          break;
341        case RFC_3339_OPTION:
342          {
343            static char const rfc_3339_format[][32] =
344              {
345                "%Y-%m-%d",
346                "%Y-%m-%d %H:%M:%S%:z",
347                "%Y-%m-%d %H:%M:%S.%N%:z"
348              };
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;
354          }
355        case 'I':
356          {
357            static char const iso_8601_format[][32] =
358              {
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"
364              };
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;
371          }
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);
394        }
395
396      if (new_format)
397        {
398          if (format)
399            error (EXIT_FAILURE, 0, _("multiple output formats specified"));
400          format = new_format;
401        }
402    }
403
404  option_specified_date = ((datestr ? 1 : 0)
405                           + (batch_file ? 1 : 0)
406                           + (reference ? 1 : 0));
407
408  if (option_specified_date > 1)
409    {
410      error (0, 0,
411        _("the options to specify dates for printing are mutually exclusive"));
412      usage (EXIT_FAILURE);
413    }
414
415  if (set_date && option_specified_date)
416    {
417      error (0, 0,
418          _("the options to print and set the time may not be used together"));
419      usage (EXIT_FAILURE);
420    }
421
422  if (optind < argc)
423    {
424      if (optind + 1 < argc)
425        {
426          error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
427          usage (EXIT_FAILURE);
428        }
429
430      if (argv[optind][0] == '+')
431        {
432          if (format)
433            error (EXIT_FAILURE, 0, _("multiple output formats specified"));
434          format = argv[optind++] + 1;
435        }
436      else if (set_date || option_specified_date)
437        {
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);
444        }
445    }
446
447  if (!format)
448    {
449      format = DATE_FMT_LANGINFO ();
450      if (! *format)
451        {
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";
460        }
461    }
462
463  if (batch_file != NULL)
464    ok = batch_convert (batch_file, format);
465  else
466    {
467      bool valid_date = true;
468      ok = true;
469
470      if (!option_specified_date && !set_date)
471        {
472          if (optind < argc)
473            {
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.  */
483            }
484          else
485            {
486              /* Prepare to print the current date/time.  */
487              gettime (&when);
488            }
489        }
490      else
491        {
492          /* (option_specified_date || set_date) */
493          if (reference != NULL)
494            {
495              if (stat (reference, &refstats) != 0)
496                error (EXIT_FAILURE, errno, "%s", reference);
497              when = get_stat_mtime (&refstats);
498            }
499          else
500            {
501              if (set_datestr)
502                datestr = set_datestr;
503              valid_date = get_date (&when, datestr, NULL);
504            }
505        }
506
507      if (! valid_date)
508        error (EXIT_FAILURE, 0, _("invalid date %s"), quote (datestr));
509
510      if (set_date)
511        {
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)
515            {
516              error (0, errno, _("cannot set date"));
517              ok = false;
518            }
519        }
520
521      ok &= show_date (format, when);
522    }
523
524  exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
525}
526
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.  */
529
530static bool
531show_date (const char *format, struct timespec when)
532{
533  struct tm *tm;
534
535  tm = localtime (&when.tv_sec);
536  if (! tm)
537    {
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;
541    }
542
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, "");
549
550  return true;
551}
552