1/* Copyright (C) 1991-2024 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
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.
8
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.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18/*
19 * ISO C99 Standard: 7.23 Date and time <time.h>
20 */
21
22#ifndef _TIME_H
23#define _TIME_H 1
24
25#include <features.h>
26
27#define __need_size_t
28#define __need_NULL
29#include <stddef.h>
30
31/* This defines CLOCKS_PER_SEC, which is the number of processor clock
32 ticks per second, and possibly a number of other constants. */
33#include <bits/time.h>
34
35/* Many of the typedefs and structs whose official home is this header
36 may also need to be defined by other headers. */
37#include <bits/types/clock_t.h>
38#include <bits/types/time_t.h>
39#include <bits/types/struct_tm.h>
40
41#if defined __USE_POSIX199309 || defined __USE_ISOC11
42# include <bits/types/struct_timespec.h>
43#endif
44
45#ifdef __USE_POSIX199309
46# include <bits/types/clockid_t.h>
47# include <bits/types/timer_t.h>
48# include <bits/types/struct_itimerspec.h>
49struct sigevent;
50#endif
51
52#ifdef __USE_XOPEN2K
53# ifndef __pid_t_defined
54typedef __pid_t pid_t;
55# define __pid_t_defined
56# endif
57#endif
58
59#ifdef __USE_XOPEN2K8
60# include <bits/types/locale_t.h>
61#endif
62
63#ifdef __USE_ISOC11
64/* Time base values for timespec_get. */
65# define TIME_UTC 1
66#endif
67
68__BEGIN_DECLS
69
70/* Time used by the program so far (user time + system time).
71 The result / CLOCKS_PER_SEC is program time in seconds. */
72extern clock_t clock (void) __THROW;
73
74#ifndef __USE_TIME_BITS64
75/* Return the current time and put it in *TIMER if TIMER is not NULL. */
76extern time_t time (time_t *__timer) __THROW;
77
78/* Return the difference between TIME1 and TIME0. */
79extern double difftime (time_t __time1, time_t __time0)
80 __THROW __attribute__ ((__const__));
81
82/* Return the `time_t' representation of TP and normalize TP. */
83extern time_t mktime (struct tm *__tp) __THROW;
84#else
85# ifdef __REDIRECT_NTH
86extern time_t __REDIRECT_NTH (time, (time_t *__timer), __time64);
87extern double __REDIRECT_NTH (difftime, (time_t __time1, time_t __time0),
88 __difftime64) __attribute__ ((__const__));
89extern time_t __REDIRECT_NTH (mktime, (struct tm *__tp), __mktime64);
90# else
91# define time __time64
92# define difftime __difftime64
93# define mktime __mktime64
94# endif
95#endif
96
97/* Format TP into S according to FORMAT.
98 Write no more than MAXSIZE characters and return the number
99 of characters written, or 0 if it would exceed MAXSIZE. */
100extern size_t strftime (char *__restrict __s, size_t __maxsize,
101 const char *__restrict __format,
102 const struct tm *__restrict __tp)
103 __THROW __nonnull((1, 3, 4));
104
105#ifdef __USE_XOPEN
106/* Parse S according to FORMAT and store binary time information in TP.
107 The return value is a pointer to the first unparsed character in S. */
108extern char *strptime (const char *__restrict __s,
109 const char *__restrict __fmt, struct tm *__tp)
110 __THROW;
111#endif
112
113#ifdef __USE_XOPEN2K8
114/* Similar to the two functions above but take the information from
115 the provided locale and not the global locale. */
116
117extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
118 const char *__restrict __format,
119 const struct tm *__restrict __tp,
120 locale_t __loc) __THROW;
121#endif
122
123#ifdef __USE_GNU
124extern char *strptime_l (const char *__restrict __s,
125 const char *__restrict __fmt, struct tm *__tp,
126 locale_t __loc) __THROW;
127#endif
128
129
130#ifndef __USE_TIME_BITS64
131/* Return the `struct tm' representation of *TIMER
132 in Universal Coordinated Time (aka Greenwich Mean Time). */
133extern struct tm *gmtime (const time_t *__timer) __THROW;
134
135/* Return the `struct tm' representation
136 of *TIMER in the local timezone. */
137extern struct tm *localtime (const time_t *__timer) __THROW;
138
139#else
140# ifdef __REDIRECT_NTH
141extern struct tm*__REDIRECT_NTH (gmtime, (const time_t *__timer), __gmtime64);
142extern struct tm *__REDIRECT_NTH (localtime, (const time_t *__timer),
143 __localtime64);
144# else
145# define gmtime __gmtime64
146# define localtime __localtime64
147# endif
148#endif
149
150
151#if defined __USE_POSIX || __GLIBC_USE (ISOC2X)
152# ifndef __USE_TIME_BITS64
153/* Return the `struct tm' representation of *TIMER in UTC,
154 using *TP to store the result. */
155extern struct tm *gmtime_r (const time_t *__restrict __timer,
156 struct tm *__restrict __tp) __THROW;
157
158/* Return the `struct tm' representation of *TIMER in local time,
159 using *TP to store the result. */
160extern struct tm *localtime_r (const time_t *__restrict __timer,
161 struct tm *__restrict __tp) __THROW;
162# else
163# ifdef __REDIRECT_NTH
164extern struct tm*__REDIRECT_NTH (gmtime_r, (const time_t *__restrict __timer,
165 struct tm *__restrict __tp),
166 __gmtime64_r);
167
168extern struct tm*__REDIRECT_NTH (localtime_r, (const time_t *__restrict __t,
169 struct tm *__restrict __tp),
170 __localtime64_r);
171# else
172# define gmtime_r __gmtime64_r
173# define localtime_r __localtime_r
174# endif
175# endif
176#endif /* POSIX || C2X */
177
178/* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
179 that is the representation of TP in this format. */
180extern char *asctime (const struct tm *__tp) __THROW;
181
182/* Equivalent to `asctime (localtime (timer))'. */
183#ifndef __USE_TIME_BITS64
184extern char *ctime (const time_t *__timer) __THROW;
185#else
186# ifdef __REDIRECT_NTH
187extern char *__REDIRECT_NTH (ctime, (const time_t *__timer), __ctime64);
188# else
189# define ctime __ctime64
190# endif
191#endif
192
193#ifdef __USE_POSIX
194/* Reentrant versions of the above functions. */
195
196/* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
197 that is the representation of TP in this format. */
198extern char *asctime_r (const struct tm *__restrict __tp,
199 char *__restrict __buf) __THROW;
200
201/* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'. */
202#ifndef __USE_TIME_BITS64
203extern char *ctime_r (const time_t *__restrict __timer,
204 char *__restrict __buf) __THROW;
205#else
206# ifdef __REDIRECT_NTH
207extern char *__REDIRECT_NTH (ctime_r, (const time_t *__restrict __timer,
208 char *__restrict __buf), __ctime64_r);
209# else
210# define ctime_r __ctime64_r
211# endif
212#endif
213
214#endif /* POSIX */
215
216
217/* Defined in localtime.c. */
218extern char *__tzname[2]; /* Current time zone abbreviations. */
219extern int __daylight; /* If daylight-saving time is ever in use. */
220extern long int __timezone; /* Seconds west of UTC. */
221
222
223#ifdef __USE_POSIX
224/* Same as above. */
225extern char *tzname[2];
226
227/* Set time conversion information from the TZ environment variable.
228 If TZ is not defined, a locale-dependent default is used. */
229extern void tzset (void) __THROW;
230#endif
231
232#if defined __USE_MISC || defined __USE_XOPEN
233extern int daylight;
234extern long int timezone;
235#endif
236
237
238/* Nonzero if YEAR is a leap year (every 4 years,
239 except every 100th isn't, and every 400th is). */
240#define __isleap(year) \
241 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
242
243
244#if defined __USE_MISC || __GLIBC_USE (ISOC2X)
245# ifndef __USE_TIME_BITS64
246/* Like `mktime', but for TP represents Universal Time, not local time. */
247extern time_t timegm (struct tm *__tp) __THROW;
248# else
249# ifdef __REDIRECT_NTH
250extern time_t __REDIRECT_NTH (timegm, (struct tm *__tp), __timegm64);
251# else
252# define timegm __timegm64
253# endif
254# endif
255#endif
256
257
258#ifdef __USE_MISC
259/* Miscellaneous functions many Unices inherited from the public domain
260 localtime package. These are included only for compatibility. */
261
262#ifndef __USE_TIME_BITS64
263/* Another name for `mktime'. */
264extern time_t timelocal (struct tm *__tp) __THROW;
265#else
266# ifdef __REDIRECT_NTH
267extern time_t __REDIRECT_NTH (timelocal, (struct tm *__tp), __mktime64);
268# endif
269#endif
270
271/* Return the number of days in YEAR. */
272extern int dysize (int __year) __THROW __attribute__ ((__const__));
273#endif
274
275
276#ifdef __USE_POSIX199309
277# ifndef __USE_TIME_BITS64
278/* Pause execution for a number of nanoseconds.
279
280 This function is a cancellation point and therefore not marked with
281 __THROW. */
282extern int nanosleep (const struct timespec *__requested_time,
283 struct timespec *__remaining);
284
285/* Get resolution of clock CLOCK_ID. */
286extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
287
288/* Get current value of clock CLOCK_ID and store it in TP. */
289extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp)
290 __THROW __nonnull((2));
291
292/* Set clock CLOCK_ID to value TP. */
293extern int clock_settime (clockid_t __clock_id, const struct timespec *__tp)
294 __THROW __nonnull((2));
295# else
296# ifdef __REDIRECT
297extern int __REDIRECT (nanosleep, (const struct timespec *__requested_time,
298 struct timespec *__remaining),
299 __nanosleep64);
300extern int __REDIRECT_NTH (clock_getres, (clockid_t __clock_id,
301 struct timespec *__res),
302 __clock_getres64);
303extern int __REDIRECT_NTH (clock_gettime, (clockid_t __clock_id, struct
304 timespec *__tp), __clock_gettime64)
305 __nonnull((2));
306extern int __REDIRECT_NTH (clock_settime, (clockid_t __clock_id, const struct
307 timespec *__tp), __clock_settime64)
308 __nonnull((2));
309# else
310# define nanosleep __nanosleep64
311# define clock_getres __clock_getres64
312# define clock_gettime __clock_gettime64
313# define clock_settime __clock_settime64
314# endif
315# endif
316
317
318# ifdef __USE_XOPEN2K
319/* High-resolution sleep with the specified clock.
320
321 This function is a cancellation point and therefore not marked with
322 __THROW. */
323# ifndef __USE_TIME_BITS64
324extern int clock_nanosleep (clockid_t __clock_id, int __flags,
325 const struct timespec *__req,
326 struct timespec *__rem);
327# else
328# ifdef __REDIRECT
329extern int __REDIRECT (clock_nanosleep, (clockid_t __clock_id, int __flags,
330 const struct timespec *__req,
331 struct timespec *__rem),
332 __clock_nanosleep_time64);
333# else
334# define clock_nanosleep __clock_nanosleep_time64
335# endif
336# endif
337
338/* Return clock ID for CPU-time clock. */
339extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
340# endif
341
342
343/* Create new per-process timer using CLOCK_ID. */
344extern int timer_create (clockid_t __clock_id,
345 struct sigevent *__restrict __evp,
346 timer_t *__restrict __timerid) __THROW;
347
348/* Delete timer TIMERID. */
349extern int timer_delete (timer_t __timerid) __THROW;
350
351/* Set timer TIMERID to VALUE, returning old value in OVALUE. */
352# ifndef __USE_TIME_BITS64
353extern int timer_settime (timer_t __timerid, int __flags,
354 const struct itimerspec *__restrict __value,
355 struct itimerspec *__restrict __ovalue) __THROW;
356
357/* Get current value of timer TIMERID and store it in VALUE. */
358extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
359 __THROW;
360# else
361# ifdef __REDIRECT_NTH
362extern int __REDIRECT_NTH (timer_settime, (timer_t __timerid, int __flags,
363 const struct itimerspec *__restrict __value,
364 struct itimerspec *__restrict __ovalue),
365 __timer_settime64);
366
367extern int __REDIRECT_NTH (timer_gettime, (timer_t __timerid,
368 struct itimerspec *__value),
369 __timer_gettime64);
370# else
371# define timer_settime __timer_settime64
372# define timer_gettime __timer_gettime64
373# endif
374# endif
375
376/* Get expiration overrun for timer TIMERID. */
377extern int timer_getoverrun (timer_t __timerid) __THROW;
378#endif
379
380
381#ifdef __USE_ISOC11
382# ifndef __USE_TIME_BITS64
383/* Set TS to calendar time based in time base BASE. */
384extern int timespec_get (struct timespec *__ts, int __base)
385 __THROW __nonnull ((1));
386# else
387# ifdef __REDIRECT_NTH
388extern int __REDIRECT_NTH (timespec_get, (struct timespec *__ts, int __base),
389 __timespec_get64) __nonnull ((1));
390# else
391# define timespec_get __timespec_get64
392# endif
393# endif
394#endif
395
396
397#if __GLIBC_USE (ISOC2X)
398# ifndef __USE_TIME_BITS64
399/* Set TS to resolution of time base BASE. */
400extern int timespec_getres (struct timespec *__ts, int __base)
401 __THROW;
402# else
403# ifdef __REDIRECT_NTH
404extern int __REDIRECT_NTH (timespec_getres, (struct timespec *__ts,
405 int __base),
406 __timespec_getres64);
407# else
408# define timespec_getres __timespec_getres64
409# endif
410# endif
411#endif
412
413
414#ifdef __USE_XOPEN_EXTENDED
415/* Set to one of the following values to indicate an error.
416 1 the DATEMSK environment variable is null or undefined,
417 2 the template file cannot be opened for reading,
418 3 failed to get file status information,
419 4 the template file is not a regular file,
420 5 an error is encountered while reading the template file,
421 6 memory allication failed (not enough memory available),
422 7 there is no line in the template that matches the input,
423 8 invalid input specification Example: February 31 or a time is
424 specified that can not be represented in a time_t (representing
425 the time in seconds since 00:00:00 UTC, January 1, 1970) */
426extern int getdate_err;
427
428/* Parse the given string as a date specification and return a value
429 representing the value. The templates from the file identified by
430 the environment variable DATEMSK are used. In case of an error
431 `getdate_err' is set.
432
433 This function is a possible cancellation point and therefore not
434 marked with __THROW. */
435extern struct tm *getdate (const char *__string);
436#endif
437
438#ifdef __USE_GNU
439/* Since `getdate' is not reentrant because of the use of `getdate_err'
440 and the static buffer to return the result in, we provide a thread-safe
441 variant. The functionality is the same. The result is returned in
442 the buffer pointed to by RESBUFP and in case of an error the return
443 value is != 0 with the same values as given above for `getdate_err'.
444
445 This function is not part of POSIX and therefore no official
446 cancellation point. But due to similarity with an POSIX interface
447 or due to the implementation it is a cancellation point and
448 therefore not marked with __THROW. */
449extern int getdate_r (const char *__restrict __string,
450 struct tm *__restrict __resbufp);
451#endif
452
453__END_DECLS
454
455#endif /* time.h. */
456