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>
33 /* The official name of this program (e.g., no `g' prefix). */
34 #define PROGRAM_NAME "date"
36 #define AUTHORS "David MacKenzie"
46 static void show_date PARAMS ((const char *format, time_t when));
50 /* display only the date: 1999-03-25 */
52 /* display date and hour: 1999-03-25T03-0500 */
54 /* display date, hours, and minutes: 1999-03-25T03:23-0500 */
56 /* display date, hours, minutes, and seconds: 1999-03-25T03:23:14-0500 */
60 static char const *const time_spec_string[] =
62 "date", "hours", "minutes", "seconds", 0
65 static enum Time_spec const time_spec[] =
67 TIME_SPEC_DATE, TIME_SPEC_HOURS, TIME_SPEC_MINUTES, TIME_SPEC_SECONDS
70 /* The name this program was run with, for error messages. */
73 /* If nonzero, display an ISO 8601 format date/time string */
74 static int iso_8601_format = 0;
76 /* If non-zero, display time in RFC-822 format for mail or news. */
77 static int rfc_format = 0;
79 /* If nonzero, print or set Coordinated Universal Time. */
80 static int universal_time = 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},
98 #define TZ_UTC0 "TZ=UTC0"
101 # define TZSET tzset ()
103 # define TZSET /* empty */
106 #define MAYBE_SET_TZ_UTC0 \
107 do { if (universal_time) set_tz (TZ_UTC0); } while (0)
113 fprintf (stderr, _("Try `%s --help' for more information.\n"),
118 Usage: %s [OPTION]... [+FORMAT]\n\
119 or: %s [OPTION] [MMDDhhmm[[CC]YY][.ss]]\n\
121 program_name, program_name);
123 Display the current time in the given FORMAT, or set the system date.\n\
125 -d, --date=STRING display time described by STRING, not `now'\n\
126 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
127 -I, --iso-8601[=TIMESPEC] output an ISO-8601 compliant date/time string.\n\
128 TIMESPEC=`date' (or missing) for date only,\n\
129 `hours', `minutes', or `seconds' for date and\n\
130 time to the indicated precision.\n\
131 -r, --reference=FILE display the last modification time of FILE\n\
132 -R, --rfc-822 output RFC-822 compliant date string\n\
133 -s, --set=STRING set time described by STRING\n\
134 -u, --utc, --universal print or set Coordinated Universal Time\n\
135 --help display this help and exit\n\
136 --version output version information and exit\n\
140 FORMAT controls the output. The only valid option for the second form\n\
141 specifies Coordinated Universal Time. Interpreted sequences are:\n\
144 %%a locale's abbreviated weekday name (Sun..Sat)\n\
145 %%A locale's full weekday name, variable length (Sunday..Saturday)\n\
146 %%b locale's abbreviated month name (Jan..Dec)\n\
147 %%B locale's full month name, variable length (January..December)\n\
148 %%c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
149 %%d day of month (01..31)\n\
150 %%D date (mm/dd/yy)\n\
151 %%e day of month, blank padded ( 1..31)\n\
155 %%j day of year (001..366)\n\
158 %%m month (01..12)\n\
159 %%M minute (00..59)\n\
161 %%p locale's AM or PM\n\
162 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
163 %%s seconds since 00:00:00, Jan 1, 1970 (a GNU extension)\n\
164 %%S second (00..60)\n\
165 %%t a horizontal tab\n\
166 %%T time, 24-hour (hh:mm:ss)\n\
167 %%U week number of year with Sunday as first day of week (00..53)\n\
168 %%V week number of year with Monday as first day of week (01..53)\n\
169 %%w day of week (0..6); 0 represents Sunday\n\
170 %%W week number of year with Monday as first day of week (00..53)\n\
171 %%x locale's date representation (mm/dd/yy)\n\
172 %%X locale's time representation (%%H:%%M:%%S)\n\
173 %%y last two digits of year (00..99)\n\
174 %%Y year (1970...)\n\
175 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
176 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
178 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
179 the following modifiers between `%%' and a numeric directive.\n\
181 `-' (hyphen) do not pad the field\n\
182 `_' (underscore) pad the field with spaces\n\
184 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
189 /* Set the TZ environment variable. */
192 set_tz (const char *tz_eq_zone)
194 if (putenv (tz_eq_zone) != 0)
195 error (1, 0, "memory exhausted");
199 /* Parse each line in INPUT_FILENAME as with --date and display each
200 resulting time and date. If the file cannot be opened, tell why
201 then exit. Issue a diagnostic for any lines that cannot be parsed.
202 If any line cannot be parsed, return nonzero; otherwise return zero. */
205 batch_convert (const char *input_filename, const char *format)
213 char *initial_TZ IF_LINT (= NULL);
215 if (strcmp (input_filename, "-") == 0)
217 input_filename = _("standard input");
222 in_stream = fopen (input_filename, "r");
223 if (in_stream == NULL)
225 error (1, errno, "`%s'", input_filename);
234 initial_TZ = getenv ("TZ");
235 if (initial_TZ == NULL)
237 initial_TZ = xstrdup ("TZ=");
241 size_t tz_len = strlen (initial_TZ);
242 char *buf = xmalloc (3 + tz_len + 1);
243 memcpy (mempcpy (buf, "TZ=", 3), initial_TZ, tz_len + 1);
251 line_length = getline (&line, &buflen, in_stream);
254 /* FIXME: detect/handle error here. */
260 /* When given a universal time option, restore the initial
261 value of TZ before parsing each string. */
265 when = get_date (line, NULL);
269 if (line[line_length - 1] == '\n')
270 line[line_length - 1] = '\0';
271 error (0, 0, _("invalid date `%s'"), line);
277 show_date (format, when);
283 if (fclose (in_stream) == EOF)
284 error (2, errno, "`%s'", input_filename);
293 main (int argc, char **argv)
296 const char *datestr = NULL;
297 const char *set_datestr = NULL;
301 char *batch_file = NULL;
302 char *reference = NULL;
303 struct stat refstats;
306 int option_specified_date;
308 program_name = argv[0];
309 setlocale (LC_ALL, "");
310 bindtextdomain (PACKAGE, LOCALEDIR);
311 textdomain (PACKAGE);
313 while ((optc = getopt_long (argc, argv, "d:f:I::r:Rs:u", long_options, NULL))
326 iso_8601_format = (optarg
327 ? XARGMATCH ("--iso-8601", optarg,
328 time_spec_string, time_spec)
338 set_datestr = optarg;
344 case_GETOPT_HELP_CHAR;
345 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
350 n_args = argc - optind;
352 option_specified_date = ((datestr ? 1 : 0)
353 + (batch_file ? 1 : 0)
354 + (reference ? 1 : 0));
356 if (option_specified_date > 1)
359 _("the options to specify dates for printing are mutually exclusive"));
363 if (set_date && option_specified_date)
366 _("the options to print and set the time may not be used together"));
372 error (0, 0, _("too many non-option arguments"));
376 if ((set_date || option_specified_date)
377 && n_args == 1 && argv[optind][0] != '+')
380 the argument `%s' lacks a leading `+';\n\
381 When using an option to specify date(s), any non-option\n\
382 argument must be a format string beginning with `+'."),
388 datestr = set_datestr;
390 if (batch_file != NULL)
392 status = batch_convert (batch_file,
393 (n_args == 1 ? argv[optind] + 1 : NULL));
399 if (!option_specified_date && !set_date)
401 if (n_args == 1 && argv[optind][0] != '+')
403 /* Prepare to set system clock to the specified date/time
404 given in the POSIX-format. */
406 datestr = argv[optind];
407 when = posixtime (datestr,
408 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
413 /* Prepare to print the current date/time. */
414 datestr = _("undefined");
416 format = (n_args == 1 ? argv[optind] + 1 : NULL);
421 /* (option_specified_date || set_date) */
422 if (reference != NULL)
424 if (stat (reference, &refstats))
425 error (1, errno, "%s", reference);
426 when = refstats.st_mtime;
430 when = get_date (datestr, NULL);
433 format = (n_args == 1 ? argv[optind] + 1 : NULL);
437 error (1, 0, _("invalid date `%s'"), datestr);
441 /* Set the system clock to the specified date, then regardless of
442 the success of that operation, format and print that date. */
443 if (stime (&when) == -1)
445 error (0, errno, _("cannot set date"));
450 /* When given a universal time option, set TZ to UTC0 after
451 parsing the specified date, but before printing it. */
454 show_date (format, when);
457 close_stdout_status (2);
462 /* Display the date and/or time in WHEN according to the format specified
463 in FORMAT, followed by a newline. If FORMAT is NULL, use the
464 standard output format (ctime style but with a timezone inserted). */
467 show_date (const char *format, time_t when)
471 size_t out_length = 0;
472 /* ISO 8601 formats, in local and UTC. See below regarding %z */
473 static char *iso_format_string[5][2] =
476 {"%Y-%m-%d", "%Y-%m-%d"},
477 {"%Y-%m-%dT%H%z", "%Y-%m-%dT%HZ"},
478 {"%Y-%m-%dT%H:%M%z", "%Y-%m-%dT%H:%MZ"},
479 {"%Y-%m-%dT%H:%M:%S%z", "%Y-%m-%dT%H:%M:%SZ"}
482 tm = localtime (&when);
486 /* Print the date in the default format. Vanilla ANSI C strftime
487 doesn't support %e, but POSIX requires it. If you don't use
488 a GNU strftime, make sure yours supports %e.
489 If you are not using GNU strftime, you want to change %z
490 in the RFC format to %Z; this gives, however, an invalid
491 RFC time format outside the continental United States and GMT. */
495 ? "%a, %_d %b %Y %H:%M:%S GMT"
496 : "%a, %_d %b %Y %H:%M:%S %z")
498 ? iso_format_string[iso_8601_format][universal_time]
499 : "%a %b %e %H:%M:%S %Z %Y"));
501 else if (*format == '\0')
510 out = (char *) xrealloc (out, out_length);
512 /* Mark the first byte of the buffer so we can detect the case
513 of strftime producing an empty string. Otherwise, this loop
514 would not terminate when date was invoked like this
515 `LANG=de date +%p' on a system with good language support. */
518 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
520 printf ("%s\n", out);