1 /* date - print or set the system date and time
2 Copyright (C) 1989-1999 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>
32 /* The official name of this program (e.g., no `g' prefix). */
33 #define PROGRAM_NAME "date"
35 #define AUTHORS "David MacKenzie"
47 static void show_date PARAMS ((const char *format, time_t when));
49 /* The name this program was run with, for error messages. */
52 /* If non-zero, display time in RFC-822 format for mail or news. */
53 static int rfc_format = 0;
55 /* If nonzero, print or set Coordinated Universal Time. */
56 static int universal_time = 0;
58 static struct option const long_options[] =
60 {"date", required_argument, NULL, 'd'},
61 {"file", required_argument, NULL, 'f'},
62 {"reference", required_argument, NULL, 'r'},
63 {"rfc-822", no_argument, NULL, 'R'},
64 {"set", required_argument, NULL, 's'},
65 {"uct", no_argument, NULL, 'u'},
66 {"utc", no_argument, NULL, 'u'},
67 {"universal", no_argument, NULL, 'u'},
68 {GETOPT_HELP_OPTION_DECL},
69 {GETOPT_VERSION_OPTION_DECL},
73 #define TZ_UTC0 "TZ=UTC0"
76 # define TZSET tzset ()
78 # define TZSET /* empty */
81 #define MAYBE_SET_TZ_UTC0 \
82 do { if (universal_time) set_tz (TZ_UTC0); } while (0)
88 fprintf (stderr, _("Try `%s --help' for more information.\n"),
93 Usage: %s [OPTION]... [+FORMAT]\n\
94 or: %s [OPTION] [MMDDhhmm[[CC]YY][.ss]]\n\
96 program_name, program_name);
98 Display the current time in the given FORMAT, or set the system date.\n\
100 -d, --date=STRING display time described by STRING, not `now'\n\
101 -f, --file=DATEFILE like --date once for each line of DATEFILE\n\
102 -r, --reference=FILE display the last modification time of FILE\n\
103 -R, --rfc-822 output RFC-822 compliant date string\n\
104 -s, --set=STRING set time described by STRING\n\
105 -u, --utc, --universal print or set Coordinated Universal Time\n\
106 --help display this help and exit\n\
107 --version output version information and exit\n\
111 FORMAT controls the output. The only valid option for the second form\n\
112 specifies Coordinated Universal Time. Interpreted sequences are:\n\
115 %%a locale's abbreviated weekday name (Sun..Sat)\n\
116 %%A locale's full weekday name, variable length (Sunday..Saturday)\n\
117 %%b locale's abbreviated month name (Jan..Dec)\n\
118 %%B locale's full month name, variable length (January..December)\n\
119 %%c locale's date and time (Sat Nov 04 12:02:33 EST 1989)\n\
120 %%d day of month (01..31)\n\
121 %%D date (mm/dd/yy)\n\
122 %%e day of month, blank padded ( 1..31)\n\
126 %%j day of year (001..366)\n\
129 %%m month (01..12)\n\
130 %%M minute (00..59)\n\
132 %%p locale's AM or PM\n\
133 %%r time, 12-hour (hh:mm:ss [AP]M)\n\
134 %%s seconds since 00:00:00, Jan 1, 1970 (a GNU extension)\n\
135 %%S second (00..61)\n\
136 %%t a horizontal tab\n\
137 %%T time, 24-hour (hh:mm:ss)\n\
138 %%U week number of year with Sunday as first day of week (00..53)\n\
139 %%V week number of year with Monday as first day of week (01..52)\n\
140 %%w day of week (0..6); 0 represents Sunday\n\
141 %%W week number of year with Monday as first day of week (00..53)\n\
142 %%x locale's date representation (mm/dd/yy)\n\
143 %%X locale's time representation (%%H:%%M:%%S)\n\
144 %%y last two digits of year (00..99)\n\
145 %%Y year (1970...)\n\
146 %%z RFC-822 style numeric timezone (-0500) (a nonstandard extension)\n\
147 %%Z time zone (e.g., EDT), or nothing if no time zone is determinable\n\
149 By default, date pads numeric fields with zeroes. GNU date recognizes\n\
150 the following modifiers between `%%' and a numeric directive.\n\
152 `-' (hyphen) do not pad the field\n\
153 `_' (underscore) pad the field with spaces\n\
155 puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
160 /* Set the TZ environment variable. */
163 set_tz (const char *tz_eq_zone)
165 if (putenv (tz_eq_zone) != 0)
166 error (1, 0, "memory exhausted");
170 /* Parse each line in INPUT_FILENAME as with --date and display each
171 resulting time and date. If the file cannot be opened, tell why
172 then exit. Issue a diagnostic for any lines that cannot be parsed.
173 If any line cannot be parsed, return nonzero; otherwise return zero. */
176 batch_convert (const char *input_filename, const char *format)
187 /* Suppress `may be used before initialized' warning. */
191 if (strcmp (input_filename, "-") == 0)
193 input_filename = _("standard input");
198 in_stream = fopen (input_filename, "r");
199 if (in_stream == NULL)
201 error (1, errno, "`%s'", input_filename);
210 initial_TZ = getenv ("TZ");
211 if (initial_TZ == NULL)
213 initial_TZ = xstrdup ("TZ=");
217 size_t tz_len = strlen (initial_TZ);
218 char *buf = xmalloc (3 + tz_len + 1);
219 memcpy (mempcpy (buf, "TZ=", 3), initial_TZ, tz_len + 1);
227 line_length = getline (&line, &buflen, in_stream);
230 /* FIXME: detect/handle error here. */
236 /* When given a universal time option, restore the initial
237 value of TZ before parsing each string. */
241 when = get_date (line, NULL);
245 if (line[line_length - 1] == '\n')
246 line[line_length - 1] = '\0';
247 error (0, 0, _("invalid date `%s'"), line);
253 show_date (format, when);
259 if (fclose (in_stream) == EOF)
260 error (2, errno, "`%s'", input_filename);
269 main (int argc, char **argv)
272 const char *datestr = NULL;
273 const char *set_datestr = NULL;
277 char *batch_file = NULL;
278 char *reference = NULL;
279 struct stat refstats;
282 int option_specified_date;
284 program_name = argv[0];
285 setlocale (LC_ALL, "");
286 bindtextdomain (PACKAGE, LOCALEDIR);
287 textdomain (PACKAGE);
289 while ((optc = getopt_long (argc, argv, "d:f:r:Rs:u", long_options, NULL))
308 set_datestr = optarg;
314 case_GETOPT_HELP_CHAR;
315 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
320 n_args = argc - optind;
322 option_specified_date = ((datestr ? 1 : 0)
323 + (batch_file ? 1 : 0)
324 + (reference ? 1 : 0));
326 if (option_specified_date > 1)
329 _("the options to specify dates for printing are mutually exclusive"));
333 if (set_date && option_specified_date)
336 _("the options to print and set the time may not be used together"));
342 error (0, 0, _("too many non-option arguments"));
346 if ((set_date || option_specified_date)
347 && n_args == 1 && argv[optind][0] != '+')
350 the argument `%s' lacks a leading `+';\n\
351 When using an option to specify date(s), any non-option\n\
352 argument must be a format string beginning with `+'."),
358 datestr = set_datestr;
360 if (batch_file != NULL)
362 status = batch_convert (batch_file,
363 (n_args == 1 ? argv[optind] + 1 : NULL));
369 if (!option_specified_date && !set_date)
371 if (n_args == 1 && argv[optind][0] != '+')
373 /* Prepare to set system clock to the specified date/time
374 given in the POSIX-format. */
376 datestr = argv[optind];
377 when = posixtime (datestr,
378 PDS_TRAILING_YEAR | PDS_CENTURY | PDS_SECONDS);
383 /* Prepare to print the current date/time. */
384 datestr = _("undefined");
386 format = (n_args == 1 ? argv[optind] + 1 : NULL);
391 /* (option_specified_date || set_date) */
392 if (reference != NULL)
394 if (stat (reference, &refstats))
395 error (1, errno, "%s", reference);
396 when = refstats.st_mtime;
400 when = get_date (datestr, NULL);
403 format = (n_args == 1 ? argv[optind] + 1 : NULL);
407 error (1, 0, _("invalid date `%s'"), datestr);
411 /* Set the system clock to the specified date, then regardless of
412 the success of that operation, format and print that date. */
413 if (stime (&when) == -1)
415 error (0, errno, _("cannot set date"));
420 /* When given a universal time option, set TZ to UTC0 after
421 parsing the specified date, but before printing it. */
424 show_date (format, when);
427 close_stdout_status (2);
432 /* Display the date and/or time in WHEN according to the format specified
433 in FORMAT, followed by a newline. If FORMAT is NULL, use the
434 standard output format (ctime style but with a timezone inserted). */
437 show_date (const char *format, time_t when)
441 size_t out_length = 0;
443 tm = localtime (&when);
447 /* Print the date in the default format. Vanilla ANSI C strftime
448 doesn't support %e, but POSIX requires it. If you don't use
449 a GNU strftime, make sure yours supports %e.
450 If you are not using GNU strftime, you want to change %z
451 in the RFC format to %Z; this gives, however, an invalid
452 RFC time format outside the continental United States and GMT. */
456 ? "%a, %_d %b %Y %H:%M:%S GMT"
457 : "%a, %_d %b %Y %H:%M:%S %z")
458 : "%a %b %e %H:%M:%S %Z %Y");
460 else if (*format == '\0')
469 out = (char *) xrealloc (out, out_length);
471 /* Mark the first byte of the buffer so we can detect the case
472 of strftime producing an empty string. Otherwise, this loop
473 would not terminate when date was invoked like this
474 `LANG=de date +%p' on a system with good language support. */
477 while (strftime (out, out_length, format, tm) == 0 && out[0] != '\0');
479 printf ("%s\n", out);