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>
42 static void show_date __P ((const char *format, time_t when));
43 static void usage __P ((int status));
45 /* The name this program was run with, for error messages. */
48 /* If nonzero, display usage information and exit. */
51 /* If nonzero, print the version on standard output and exit. */
52 static int show_version;
54 /* If non-zero, display time in RFC-822 format for mail or news. */
55 static int rfc_format = 0;
57 /* If nonzero, print or set Coordinated Universal Time. */
58 static int universal_time = 0;
60 static struct option const long_options[] =
62 {"date", required_argument, NULL, 'd'},
63 {"file", required_argument, NULL, 'f'},
64 {"help", no_argument, &show_help, 1},
65 {"reference", required_argument, NULL, 'r'},
66 {"rfc-822", no_argument, NULL, 'R'},
67 {"set", required_argument, NULL, 's'},
68 {"uct", no_argument, NULL, 'u'},
69 {"utc", no_argument, NULL, 'u'},
70 {"universal", no_argument, NULL, 'u'},
71 {"version", no_argument, &show_version, 1},
75 #define TZ_UTC0 "TZ=UTC0"
78 # define TZSET tzset ()
80 # define TZSET /* empty */
83 #define MAYBE_SET_TZ_UTC0 \
84 do { if (universal_time) set_tz (TZ_UTC0); } while (0)
86 /* Set the TZ environment variable. */
89 set_tz (const char *tz_eq_zone)
91 if (putenv (tz_eq_zone) != 0)
92 error (1, 0, "memory exhausted");
96 /* Parse each line in INPUT_FILENAME as with --date and display each
97 resulting time and date. If the file cannot be opened, tell why
98 then exit. Issue a diagnostic for any lines that cannot be parsed.
99 If any line cannot be parsed, return nonzero; otherwise return zero. */
102 batch_convert (const char *input_filename, const char *format)
113 /* Suppress `may be used before initialized' warning. */
117 if (strcmp (input_filename, "-") == 0)
119 input_filename = _("standard input");
124 in_stream = fopen (input_filename, "r");
125 if (in_stream == NULL)
127 error (1, errno, "`%s'", input_filename);
136 initial_TZ = getenv ("TZ");
137 if (initial_TZ == NULL)
139 initial_TZ = xstrdup ("TZ=");
143 char *buf = xmalloc (3 + strlen (initial_TZ) + 1);
144 stpcpy (stpcpy (buf, "TZ="), initial_TZ);
152 line_length = getline (&line, &buflen, in_stream);
155 /* FIXME: detect/handle error here. */
161 /* When given a universal time option, restore the initial
162 value of TZ before parsing each string. */
166 when = get_date (line, NULL);
170 if (line[line_length - 1] == '\n')
171 line[line_length - 1] = '\0';
172 error (0, 0, _("invalid date ` %s'"), line);
178 show_date (format, when);
184 if (fclose (in_stream) == EOF)
185 error (2, errno, input_filename);
194 main (int argc, char **argv)
197 const char *datestr = NULL;
198 const char *set_datestr = NULL;
202 char *batch_file = NULL;
203 char *reference = NULL;
204 struct stat refstats;
207 int option_specified_date;
209 program_name = argv[0];
210 setlocale (LC_ALL, "");
211 bindtextdomain (PACKAGE, LOCALEDIR);
212 textdomain (PACKAGE);
214 while ((optc = getopt_long (argc, argv, "d:f:r:Rs:u", long_options, NULL))
233 set_datestr = optarg;
245 printf ("date (%s) %s\n", GNU_PACKAGE, VERSION);
252 n_args = argc - optind;
254 option_specified_date = ((datestr ? 1 : 0)
255 + (batch_file ? 1 : 0)
256 + (reference ? 1 : 0));
258 if (option_specified_date > 1)
261 _("the options to specify dates for printing are mutually exclusive"));
265 if (set_date && option_specified_date)
268 _("the options to print and set the time may not be used together"));
274 error (0, 0, _("too many non-option arguments"));
278 if ((set_date || option_specified_date)
279 && n_args == 1 && argv[optind][0] != '+')
282 the argument `%s' lacks a leading `+';\n\
283 When using an option to specify date(s), any non-option\n\
284 argument must be a format string beginning with `+'."),
290 datestr = set_datestr;
292 if (batch_file != NULL)
294 status = batch_convert (batch_file,
295 (n_args == 1 ? argv[optind] + 1 : NULL));
301 if (!option_specified_date && !set_date)
303 if (n_args == 1 && argv[optind][0] != '+')
305 /* Prepare to set system clock to the specified date/time
306 given in the POSIX-format. */
308 datestr = argv[optind];
309 when = posixtime (datestr);
314 /* Prepare to print the current date/time. */
315 datestr = _("undefined");
317 format = (n_args == 1 ? argv[optind] + 1 : NULL);
322 /* (option_specified_date || set_date) */
323 if (reference != NULL)
325 if (stat (reference, &refstats))
326 error (1, errno, "%s", reference);
327 when = refstats.st_mtime;
331 when = get_date (datestr, NULL);
334 format = (n_args == 1 ? argv[optind] + 1 : NULL);
338 error (1, 0, _("invalid date `%s'"), datestr);
342 /* Set the system clock to the specified date, then regardless of
343 the success of that operation, format and print that date. */
344 if (stime (&when) == -1)
345 error (0, errno, _("cannot set date"));
348 /* When given a universal time option, set TZ to UTC0 after
349 parsing the specified date, but before printing it. */
352 show_date (format, when);
355 if (fclose (stdout) == EOF)
356 error (2, errno, _("write error"));
361 /* Display the date and/or time in WHEN according to the format specified
362 in FORMAT, followed by a newline. If FORMAT is NULL, use the
363 standard output format (ctime style but with a timezone inserted). */
366 show_date (const char *format, time_t when)
370 size_t out_length = 0;
372 tm = localtime (&when);
376 /* Print the date in the default format. Vanilla ANSI C strftime
377 doesn't support %e, but POSIX requires it. If you don't use
378 a GNU strftime, make sure yours supports %e.
379 If you are not using GNU strftime, you want to change %z
380 in the RFC format to %Z; this gives, however, an invalid
381 RFC time format outside the continental United States and GMT. */
385 ? "%a, %_d %b %Y %H:%M:%S GMT"
386 : "%a, %_d %b %Y %H:%M:%S %z")
387 : "%a %b %e %H:%M:%S %Z %Y");
389 else if (*format == '\0')
398 out = (char *) xrealloc (out, out_length);
400 /* Mark the first byte of the buffer so we can detect the case
401 of strftime producing an empty string. Otherwise, this loop
402 would not terminate when date was invoked like this
403 `LANG=de date +%p' on a system with good language support. */
406 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
408 printf ("%s\n", out);
416 fprintf (stderr, _("Try `%s --help' for more information.\n"),
421 Usage: %s [OPTION]... [+FORMAT]\n\
422 or: %s [OPTION] [MMDDhhmm[[CC]YY][.ss]]\n\
424 program_name, program_name);
426 Display the current time in the given FORMAT, or set the system date.\n\
428 -d, --date=STRING display time described by STRING, not `now'\n\
429 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
430 -r, --reference=FILE display the last modification time of FILE\n\
431 -R, --rfc-822 output RFC-822 compliant date string\n\
432 -s, --set=STRING set time described by STRING\n\
433 -u, --utc, --universal print or set Coordinated Universal Time\n\
434 --help display this help and exit\n\
435 --version output version information and exit\n\
439 FORMAT controls the output. The only valid option for the second form\n\
440 specifies Coordinated Universal Time. Interpreted sequences are:\n\
443 %%a locale's abbreviated weekday name (Sun..Sat)\n\
444 %%A locale's full weekday name, variable length (Sunday..Saturday)\n\
445 %%b locale's abbreviated month name (Jan..Dec)\n\
446 %%B locale's full month name, variable length (January..December)\n\
447 %%c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
448 %%d day of month (01..31)\n\
449 %%D date (mm/dd/yy)\n\
450 %%e day of month, blank padded ( 1..31)\n\
454 %%j day of year (001..366)\n\
457 %%m month (01..12)\n\
458 %%M minute (00..59)\n\
460 %%p locale's AM or PM\n\
461 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
462 %%s seconds since 00:00:00, Jan 1, 1970 (a GNU extension)\n\
463 %%S second (00..61)\n\
464 %%t a horizontal tab\n\
465 %%T time, 24-hour (hh:mm:ss)\n\
466 %%U week number of year with Sunday as first day of week (00..53)\n\
467 %%V week number of year with Monday as first day of week (01..52)\n\
468 %%w day of week (0..6); 0 represents Sunday\n\
469 %%W week number of year with Monday as first day of week (00..53)\n\
470 %%x locale's date representation (mm/dd/yy)\n\
471 %%X locale's time representation (%%H:%%M:%%S)\n\
472 %%y last two digits of year (00..99)\n\
473 %%Y year (1970...)\n\
474 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
475 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
477 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
478 the following modifiers between `%%' and a numeric directive.\n\
480 `-' (hyphen) do not pad the field\n\
481 `_' (underscore) pad the field with spaces\n\
483 puts (_("\nReport bugs to <sh-utils-bugs@gnu.org>."));