1 /* date - print or set the system date and time
2 Copyright (C) 89, 90, 91, 92, 93, 94, 95, 96, 1997
3 Free Software Foundation, Inc.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software Foundation,
17 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 David MacKenzie <djm@gnu.ai.mit.edu> */
24 #include <sys/types.h>
45 static void show_date __P ((const char *format, time_t when));
46 static void usage __P ((int status));
48 /* The name this program was run with, for error messages. */
51 /* If nonzero, display usage information and exit. */
54 /* If nonzero, print the version on standard output and exit. */
55 static int show_version;
57 /* If non-zero, display time in RFC-822 format for mail or news. */
58 static int rfc_format = 0;
60 /* If nonzero, print or set Coordinated Universal Time. */
61 static int universal_time = 0;
63 static struct option const long_options[] =
65 {"date", required_argument, NULL, 'd'},
66 {"file", required_argument, NULL, 'f'},
67 {"help", no_argument, &show_help, 1},
68 {"reference", required_argument, NULL, 'r'},
69 {"rfc-822", no_argument, NULL, 'R'},
70 {"set", required_argument, NULL, 's'},
71 {"uct", no_argument, NULL, 'u'},
72 {"utc", no_argument, NULL, 'u'},
73 {"universal", no_argument, NULL, 'u'},
74 {"version", no_argument, &show_version, 1},
78 #define TZ_UTC0 "TZ=UTC0"
81 # define TZSET tzset ()
83 # define TZSET /* empty */
86 #define MAYBE_SET_TZ_UTC0 \
87 do { if (universal_time) set_tz (TZ_UTC0); } while (0)
89 /* Set the TZ environment variable. */
92 set_tz (const char *tz_eq_zone)
94 if (putenv (tz_eq_zone) != 0)
95 error (1, 0, "memory exhausted");
99 /* Parse each line in INPUT_FILENAME as with --date and display each
100 resulting time and date. If the file cannot be opened, tell why
101 then exit. Issue a diagnostic for any lines that cannot be parsed.
102 If any line cannot be parsed, return nonzero; otherwise return zero. */
105 batch_convert (const char *input_filename, const char *format)
116 /* Suppress `may be used before initialized' warning. */
120 if (strcmp (input_filename, "-") == 0)
122 input_filename = _("standard input");
127 in_stream = fopen (input_filename, "r");
128 if (in_stream == NULL)
130 error (1, errno, "`%s'", input_filename);
139 initial_TZ = getenv ("TZ");
140 if (initial_TZ == NULL)
142 initial_TZ = xstrdup ("TZ=");
146 char *buf = xmalloc (3 + strlen (initial_TZ) + 1);
147 stpcpy (stpcpy (buf, "TZ="), initial_TZ);
155 line_length = getline (&line, &buflen, in_stream);
158 /* FIXME: detect/handle error here. */
164 /* When given a universal time option, restore the initial
165 value of TZ before parsing each string. */
169 when = get_date (line, NULL);
173 if (line[line_length - 1] == '\n')
174 line[line_length - 1] = '\0';
175 error (0, 0, _("invalid date ` %s'"), line);
181 show_date (format, when);
187 if (fclose (in_stream) == EOF)
188 error (2, errno, input_filename);
197 main (int argc, char **argv)
200 const char *datestr = NULL;
201 const char *set_datestr = NULL;
205 char *batch_file = NULL;
206 char *reference = NULL;
207 struct stat refstats;
210 int option_specified_date;
212 program_name = argv[0];
213 setlocale (LC_ALL, "");
214 bindtextdomain (PACKAGE, LOCALEDIR);
215 textdomain (PACKAGE);
217 while ((optc = getopt_long (argc, argv, "d:f:r:Rs:u", long_options, NULL))
236 set_datestr = optarg;
248 printf ("date (%s) %s\n", GNU_PACKAGE, VERSION);
255 n_args = argc - optind;
257 option_specified_date = ((datestr ? 1 : 0)
258 + (batch_file ? 1 : 0)
259 + (reference ? 1 : 0));
261 if (option_specified_date > 1)
264 _("the options to specify dates for printing are mutually exclusive"));
268 if (set_date && option_specified_date)
271 _("the options to print and set the time may not be used together"));
277 error (0, 0, _("too many non-option arguments"));
281 if ((set_date || option_specified_date)
282 && n_args == 1 && argv[optind][0] != '+')
285 the argument `%s' lacks a leading `+';\n\
286 When using an option to specify date(s), any non-option\n\
287 argument must be a format string beginning with `+'."),
293 datestr = set_datestr;
295 if (batch_file != NULL)
297 status = batch_convert (batch_file,
298 (n_args == 1 ? argv[optind] + 1 : NULL));
304 if (!option_specified_date && !set_date)
306 if (n_args == 1 && argv[optind][0] != '+')
308 /* Prepare to set system clock to the specified date/time
309 given in the POSIX-format. */
311 datestr = argv[optind];
312 when = posixtime (datestr);
317 /* Prepare to print the current date/time. */
318 datestr = _("undefined");
320 format = (n_args == 1 ? argv[optind] + 1 : NULL);
325 /* (option_specified_date || set_date) */
326 if (reference != NULL)
328 if (stat (reference, &refstats))
329 error (1, errno, "%s", reference);
330 when = refstats.st_mtime;
334 when = get_date (datestr, NULL);
337 format = (n_args == 1 ? argv[optind] + 1 : NULL);
341 error (1, 0, _("invalid date `%s'"), datestr);
345 /* Set the system clock to the specified date, then regardless of
346 the success of that operation, format and print that date. */
347 if (stime (&when) == -1)
348 error (0, errno, _("cannot set date"));
351 /* When given a universal time option, set TZ to UTC0 after
352 parsing the specified date, but before printing it. */
355 show_date (format, when);
358 if (fclose (stdout) == EOF)
359 error (2, errno, _("write error"));
364 /* Display the date and/or time in WHEN according to the format specified
365 in FORMAT, followed by a newline. If FORMAT is NULL, use the
366 standard output format (ctime style but with a timezone inserted). */
369 show_date (const char *format, time_t when)
373 size_t out_length = 0;
375 tm = localtime (&when);
379 /* Print the date in the default format. Vanilla ANSI C strftime
380 doesn't support %e, but POSIX requires it. If you don't use
381 a GNU strftime, make sure yours supports %e.
382 If you are not using GNU strftime, you want to change %z
383 in the RFC format to %Z; this gives, however, an invalid
384 RFC time format outside the continental United States and GMT. */
388 ? "%a, %_d %b %Y %H:%M:%S GMT"
389 : "%a, %_d %b %Y %H:%M:%S %z")
390 : "%a %b %e %H:%M:%S %Z %Y");
392 else if (*format == '\0')
401 out = (char *) xrealloc (out, out_length);
403 /* Mark the first byte of the buffer so we can detect the case
404 of strftime producing an empty string. Otherwise, this loop
405 would not terminate when date was invoked like this
406 `LANG=de date +%p' on a system with good language support. */
409 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
411 printf ("%s\n", out);
419 fprintf (stderr, _("Try `%s --help' for more information.\n"),
424 Usage: %s [OPTION]... [+FORMAT]\n\
425 or: %s [OPTION] [MMDDhhmm[[CC]YY][.ss]]\n\
427 program_name, program_name);
429 Display the current time in the given FORMAT, or set the system date.\n\
431 -d, --date=STRING display time described by STRING, not `now'\n\
432 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
433 -r, --reference=FILE display the last modification time of FILE\n\
434 -R, --rfc-822 output RFC-822 compliant date string\n\
435 -s, --set=STRING set time described by STRING\n\
436 -u, --utc, --universal print or set Coordinated Universal Time\n\
437 --help display this help and exit\n\
438 --version output version information and exit\n\
442 FORMAT controls the output. The only valid option for the second form\n\
443 specifies Coordinated Universal Time. Interpreted sequences are:\n\
446 %%a locale's abbreviated weekday name (Sun..Sat)\n\
447 %%A locale's full weekday name, variable length (Sunday..Saturday)\n\
448 %%b locale's abbreviated month name (Jan..Dec)\n\
449 %%B locale's full month name, variable length (January..December)\n\
450 %%c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
451 %%d day of month (01..31)\n\
452 %%D date (mm/dd/yy)\n\
453 %%e day of month, blank padded ( 1..31)\n\
457 %%j day of year (001..366)\n\
460 %%m month (01..12)\n\
461 %%M minute (00..59)\n\
463 %%p locale's AM or PM\n\
464 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
465 %%s seconds since 00:00:00, Jan 1, 1970 (a GNU extension)\n\
466 %%S second (00..61)\n\
467 %%t a horizontal tab\n\
468 %%T time, 24-hour (hh:mm:ss)\n\
469 %%U week number of year with Sunday as first day of week (00..53)\n\
470 %%V week number of year with Monday as first day of week (01..52)\n\
471 %%w day of week (0..6); 0 represents Sunday\n\
472 %%W week number of year with Monday as first day of week (00..53)\n\
473 %%x locale's date representation (mm/dd/yy)\n\
474 %%X locale's time representation (%%H:%%M:%%S)\n\
475 %%y last two digits of year (00..99)\n\
476 %%Y year (1970...)\n\
477 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
478 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
480 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
481 the following modifiers between `%%' and a numeric directive.\n\
483 `-' (hyphen) do not pad the field\n\
484 `_' (underscore) pad the field with spaces\n\
486 puts (_("\nReport bugs to <sh-utils-bugs@gnu.ai.mit.edu>."));