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[glibc/history.git] / time / time.h
blobeb7549ddf46c654ed7436305c9272b0b136379ee
1 /* Copyright (C) 1991-2003,2006,2009 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library 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 GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
20 * ISO C99 Standard: 7.23 Date and time <time.h>
23 #ifndef _TIME_H
25 #if (! defined __need_time_t && !defined __need_clock_t && \
26 ! defined __need_timespec)
27 # define _TIME_H 1
28 # include <features.h>
30 __BEGIN_DECLS
32 #endif
34 #ifdef _TIME_H
35 /* Get size_t and NULL from <stddef.h>. */
36 # define __need_size_t
37 # define __need_NULL
38 # include <stddef.h>
40 /* This defines CLOCKS_PER_SEC, which is the number of processor clock
41 ticks per second. */
42 # include <bits/time.h>
44 /* This is the obsolete POSIX.1-1988 name for the same constant. */
45 # if !defined __STRICT_ANSI__ && !defined __USE_XOPEN2K
46 # ifndef CLK_TCK
47 # define CLK_TCK CLOCKS_PER_SEC
48 # endif
49 # endif
51 #endif /* <time.h> included. */
53 #if !defined __clock_t_defined && (defined _TIME_H || defined __need_clock_t)
54 # define __clock_t_defined 1
56 # include <bits/types.h>
58 __BEGIN_NAMESPACE_STD
59 /* Returned by `clock'. */
60 typedef __clock_t clock_t;
61 __END_NAMESPACE_STD
62 #if defined __USE_XOPEN || defined __USE_POSIX || defined __USE_MISC
63 __USING_NAMESPACE_STD(clock_t)
64 #endif
66 #endif /* clock_t not defined and <time.h> or need clock_t. */
67 #undef __need_clock_t
69 #if !defined __time_t_defined && (defined _TIME_H || defined __need_time_t)
70 # define __time_t_defined 1
72 # include <bits/types.h>
74 __BEGIN_NAMESPACE_STD
75 /* Returned by `time'. */
76 typedef __time_t time_t;
77 __END_NAMESPACE_STD
78 #if defined __USE_POSIX || defined __USE_MISC || defined __USE_SVID
79 __USING_NAMESPACE_STD(time_t)
80 #endif
82 #endif /* time_t not defined and <time.h> or need time_t. */
83 #undef __need_time_t
85 #if !defined __clockid_t_defined && \
86 ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_clockid_t)
87 # define __clockid_t_defined 1
89 # include <bits/types.h>
91 /* Clock ID used in clock and timer functions. */
92 typedef __clockid_t clockid_t;
94 #endif /* clockid_t not defined and <time.h> or need clockid_t. */
95 #undef __clockid_time_t
97 #if !defined __timer_t_defined && \
98 ((defined _TIME_H && defined __USE_POSIX199309) || defined __need_timer_t)
99 # define __timer_t_defined 1
101 # include <bits/types.h>
103 /* Timer ID returned by `timer_create'. */
104 typedef __timer_t timer_t;
106 #endif /* timer_t not defined and <time.h> or need timer_t. */
107 #undef __need_timer_t
110 #if !defined __timespec_defined && \
111 ((defined _TIME_H && \
112 (defined __USE_POSIX199309 || defined __USE_MISC)) || \
113 defined __need_timespec)
114 # define __timespec_defined 1
116 # include <bits/types.h> /* This defines __time_t for us. */
118 /* POSIX.1b structure for a time value. This is like a `struct timeval' but
119 has nanoseconds instead of microseconds. */
120 struct timespec
122 __time_t tv_sec; /* Seconds. */
123 long int tv_nsec; /* Nanoseconds. */
126 #endif /* timespec not defined and <time.h> or need timespec. */
127 #undef __need_timespec
130 #ifdef _TIME_H
131 __BEGIN_NAMESPACE_STD
132 /* Used by other time functions. */
133 struct tm
135 int tm_sec; /* Seconds. [0-60] (1 leap second) */
136 int tm_min; /* Minutes. [0-59] */
137 int tm_hour; /* Hours. [0-23] */
138 int tm_mday; /* Day. [1-31] */
139 int tm_mon; /* Month. [0-11] */
140 int tm_year; /* Year - 1900. */
141 int tm_wday; /* Day of week. [0-6] */
142 int tm_yday; /* Days in year.[0-365] */
143 int tm_isdst; /* DST. [-1/0/1]*/
145 #ifdef __USE_BSD
146 long int tm_gmtoff; /* Seconds east of UTC. */
147 __const char *tm_zone; /* Timezone abbreviation. */
148 #else
149 long int __tm_gmtoff; /* Seconds east of UTC. */
150 __const char *__tm_zone; /* Timezone abbreviation. */
151 #endif
153 __END_NAMESPACE_STD
154 #if defined __USE_XOPEN || defined __USE_POSIX || defined __USE_MISC
155 __USING_NAMESPACE_STD(tm)
156 #endif
159 #ifdef __USE_POSIX199309
160 /* POSIX.1b structure for timer start values and intervals. */
161 struct itimerspec
163 struct timespec it_interval;
164 struct timespec it_value;
167 /* We can use a simple forward declaration. */
168 struct sigevent;
170 #endif /* POSIX.1b */
172 #ifdef __USE_XOPEN2K
173 # ifndef __pid_t_defined
174 typedef __pid_t pid_t;
175 # define __pid_t_defined
176 # endif
177 #endif
180 __BEGIN_NAMESPACE_STD
181 /* Time used by the program so far (user time + system time).
182 The result / CLOCKS_PER_SECOND is program time in seconds. */
183 extern clock_t clock (void) __THROW;
185 /* Return the current time and put it in *TIMER if TIMER is not NULL. */
186 extern time_t time (time_t *__timer) __THROW;
188 /* Return the difference between TIME1 and TIME0. */
189 extern double difftime (time_t __time1, time_t __time0)
190 __THROW __attribute__ ((__const__));
192 /* Return the `time_t' representation of TP and normalize TP. */
193 extern time_t mktime (struct tm *__tp) __THROW;
196 /* Format TP into S according to FORMAT.
197 Write no more than MAXSIZE characters and return the number
198 of characters written, or 0 if it would exceed MAXSIZE. */
199 extern size_t strftime (char *__restrict __s, size_t __maxsize,
200 __const char *__restrict __format,
201 __const struct tm *__restrict __tp) __THROW;
202 __END_NAMESPACE_STD
204 # ifdef __USE_XOPEN
205 /* Parse S according to FORMAT and store binary time information in TP.
206 The return value is a pointer to the first unparsed character in S. */
207 extern char *strptime (__const char *__restrict __s,
208 __const char *__restrict __fmt, struct tm *__tp)
209 __THROW;
210 # endif
212 # ifdef __USE_XOPEN2K8
213 /* Similar to the two functions above but take the information from
214 the provided locale and not the global locale. */
215 # include <xlocale.h>
217 extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
218 __const char *__restrict __format,
219 __const struct tm *__restrict __tp,
220 __locale_t __loc) __THROW;
221 # endif
223 # ifdef __USE_GNU
224 extern char *strptime_l (__const char *__restrict __s,
225 __const char *__restrict __fmt, struct tm *__tp,
226 __locale_t __loc) __THROW;
227 # endif
230 __BEGIN_NAMESPACE_STD
231 /* Return the `struct tm' representation of *TIMER
232 in Universal Coordinated Time (aka Greenwich Mean Time). */
233 extern struct tm *gmtime (__const time_t *__timer) __THROW;
235 /* Return the `struct tm' representation
236 of *TIMER in the local timezone. */
237 extern struct tm *localtime (__const time_t *__timer) __THROW;
238 __END_NAMESPACE_STD
240 # if defined __USE_POSIX || defined __USE_MISC
241 /* Return the `struct tm' representation of *TIMER in UTC,
242 using *TP to store the result. */
243 extern struct tm *gmtime_r (__const time_t *__restrict __timer,
244 struct tm *__restrict __tp) __THROW;
246 /* Return the `struct tm' representation of *TIMER in local time,
247 using *TP to store the result. */
248 extern struct tm *localtime_r (__const time_t *__restrict __timer,
249 struct tm *__restrict __tp) __THROW;
250 # endif /* POSIX or misc */
252 __BEGIN_NAMESPACE_STD
253 /* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
254 that is the representation of TP in this format. */
255 extern char *asctime (__const struct tm *__tp) __THROW;
257 /* Equivalent to `asctime (localtime (timer))'. */
258 extern char *ctime (__const time_t *__timer) __THROW;
259 __END_NAMESPACE_STD
261 # if defined __USE_POSIX || defined __USE_MISC
262 /* Reentrant versions of the above functions. */
264 /* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
265 that is the representation of TP in this format. */
266 extern char *asctime_r (__const struct tm *__restrict __tp,
267 char *__restrict __buf) __THROW;
269 /* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'. */
270 extern char *ctime_r (__const time_t *__restrict __timer,
271 char *__restrict __buf) __THROW;
272 # endif /* POSIX or misc */
275 /* Defined in localtime.c. */
276 extern char *__tzname[2]; /* Current timezone names. */
277 extern int __daylight; /* If daylight-saving time is ever in use. */
278 extern long int __timezone; /* Seconds west of UTC. */
281 # ifdef __USE_POSIX
282 /* Same as above. */
283 extern char *tzname[2];
285 /* Set time conversion information from the TZ environment variable.
286 If TZ is not defined, a locale-dependent default is used. */
287 extern void tzset (void) __THROW;
288 # endif
290 # if defined __USE_SVID || defined __USE_XOPEN
291 extern int daylight;
292 extern long int timezone;
293 # endif
295 # ifdef __USE_SVID
296 /* Set the system time to *WHEN.
297 This call is restricted to the superuser. */
298 extern int stime (__const time_t *__when) __THROW;
299 # endif
302 /* Nonzero if YEAR is a leap year (every 4 years,
303 except every 100th isn't, and every 400th is). */
304 # define __isleap(year) \
305 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
308 # ifdef __USE_MISC
309 /* Miscellaneous functions many Unices inherited from the public domain
310 localtime package. These are included only for compatibility. */
312 /* Like `mktime', but for TP represents Universal Time, not local time. */
313 extern time_t timegm (struct tm *__tp) __THROW;
315 /* Another name for `mktime'. */
316 extern time_t timelocal (struct tm *__tp) __THROW;
318 /* Return the number of days in YEAR. */
319 extern int dysize (int __year) __THROW __attribute__ ((__const__));
320 # endif
323 # ifdef __USE_POSIX199309
324 /* Pause execution for a number of nanoseconds.
326 This function is a cancellation point and therefore not marked with
327 __THROW. */
328 extern int nanosleep (__const struct timespec *__requested_time,
329 struct timespec *__remaining);
332 /* Get resolution of clock CLOCK_ID. */
333 extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
335 /* Get current value of clock CLOCK_ID and store it in TP. */
336 extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
338 /* Set clock CLOCK_ID to value TP. */
339 extern int clock_settime (clockid_t __clock_id, __const struct timespec *__tp)
340 __THROW;
342 # ifdef __USE_XOPEN2K
343 /* High-resolution sleep with the specified clock.
345 This function is a cancellation point and therefore not marked with
346 __THROW. */
347 extern int clock_nanosleep (clockid_t __clock_id, int __flags,
348 __const struct timespec *__req,
349 struct timespec *__rem);
351 /* Return clock ID for CPU-time clock. */
352 extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
353 # endif
356 /* Create new per-process timer using CLOCK_ID. */
357 extern int timer_create (clockid_t __clock_id,
358 struct sigevent *__restrict __evp,
359 timer_t *__restrict __timerid) __THROW;
361 /* Delete timer TIMERID. */
362 extern int timer_delete (timer_t __timerid) __THROW;
364 /* Set timer TIMERID to VALUE, returning old value in OVLAUE. */
365 extern int timer_settime (timer_t __timerid, int __flags,
366 __const struct itimerspec *__restrict __value,
367 struct itimerspec *__restrict __ovalue) __THROW;
369 /* Get current value of timer TIMERID and store it in VLAUE. */
370 extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
371 __THROW;
373 /* Get expiration overrun for timer TIMERID. */
374 extern int timer_getoverrun (timer_t __timerid) __THROW;
375 # endif
378 # ifdef __USE_XOPEN_EXTENDED
379 /* Set to one of the following values to indicate an error.
380 1 the DATEMSK environment variable is null or undefined,
381 2 the template file cannot be opened for reading,
382 3 failed to get file status information,
383 4 the template file is not a regular file,
384 5 an error is encountered while reading the template file,
385 6 memory allication failed (not enough memory available),
386 7 there is no line in the template that matches the input,
387 8 invalid input specification Example: February 31 or a time is
388 specified that can not be represented in a time_t (representing
389 the time in seconds since 00:00:00 UTC, January 1, 1970) */
390 extern int getdate_err;
392 /* Parse the given string as a date specification and return a value
393 representing the value. The templates from the file identified by
394 the environment variable DATEMSK are used. In case of an error
395 `getdate_err' is set.
397 This function is a possible cancellation points and therefore not
398 marked with __THROW. */
399 extern struct tm *getdate (__const char *__string);
400 # endif
402 # ifdef __USE_GNU
403 /* Since `getdate' is not reentrant because of the use of `getdate_err'
404 and the static buffer to return the result in, we provide a thread-safe
405 variant. The functionality is the same. The result is returned in
406 the buffer pointed to by RESBUFP and in case of an error the return
407 value is != 0 with the same values as given above for `getdate_err'.
409 This function is not part of POSIX and therefore no official
410 cancellation point. But due to similarity with an POSIX interface
411 or due to the implementation it is a cancellation point and
412 therefore not marked with __THROW. */
413 extern int getdate_r (__const char *__restrict __string,
414 struct tm *__restrict __resbufp);
415 # endif
417 __END_DECLS
419 #endif /* <time.h> included. */
421 #endif /* <time.h> not already included. */