1/* Copyright (C) 1991-2022 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) __THROW;
103
104#ifdef __USE_XOPEN
105/* Parse S according to FORMAT and store binary time information in TP.
106 The return value is a pointer to the first unparsed character in S. */
107extern char *strptime (const char *__restrict __s,
108 const char *__restrict __fmt, struct tm *__tp)
109 __THROW;
110#endif
111
112#ifdef __USE_XOPEN2K8
113/* Similar to the two functions above but take the information from
114 the provided locale and not the global locale. */
115
116extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
117 const char *__restrict __format,
118 const struct tm *__restrict __tp,
119 locale_t __loc) __THROW;
120#endif
121
122#ifdef __USE_GNU
123extern char *strptime_l (const char *__restrict __s,
124 const char *__restrict __fmt, struct tm *__tp,
125 locale_t __loc) __THROW;
126#endif
127
128
129#ifndef __USE_TIME_BITS64
130/* Return the `struct tm' representation of *TIMER
131 in Universal Coordinated Time (aka Greenwich Mean Time). */
132extern struct tm *gmtime (const time_t *__timer) __THROW;
133
134/* Return the `struct tm' representation
135 of *TIMER in the local timezone. */
136extern struct tm *localtime (const time_t *__timer) __THROW;
137
138#else
139# ifdef __REDIRECT_NTH
140extern struct tm*__REDIRECT_NTH (gmtime, (const time_t *__timer), __gmtime64);
141extern struct tm *__REDIRECT_NTH (localtime, (const time_t *__timer),
142 __localtime64);
143# else
144# define gmtime __gmtime64
145# define localtime __localtime64
146# endif
147#endif
148
149
150#if defined __USE_POSIX || __GLIBC_USE (ISOC2X)
151# ifndef __USE_TIME_BITS64
152/* Return the `struct tm' representation of *TIMER in UTC,
153 using *TP to store the result. */
154extern struct tm *gmtime_r (const time_t *__restrict __timer,
155 struct tm *__restrict __tp) __THROW;
156
157/* Return the `struct tm' representation of *TIMER in local time,
158 using *TP to store the result. */
159extern struct tm *localtime_r (const time_t *__restrict __timer,
160 struct tm *__restrict __tp) __THROW;
161# else
162# ifdef __REDIRECT_NTH
163extern struct tm*__REDIRECT_NTH (gmtime_r, (const time_t *__restrict __timer,
164 struct tm *__restrict __tp),
165 __gmtime64_r);
166
167extern struct tm*__REDIRECT_NTH (localtime_r, (const time_t *__restrict __t,
168 struct tm *__restrict __tp),
169 __localtime64_r);
170# else
171# define gmtime_r __gmtime64_r
172# define localtime_r __localtime_r
173# endif
174# endif
175#endif /* POSIX || C2X */
176
177/* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
178 that is the representation of TP in this format. */
179extern char *asctime (const struct tm *__tp) __THROW;
180
181/* Equivalent to `asctime (localtime (timer))'. */
182#ifndef __USE_TIME_BITS64
183extern char *ctime (const time_t *__timer) __THROW;
184#else
185# ifdef __REDIRECT_NTH
186extern char *__REDIRECT_NTH (ctime, (const time_t *__timer), __ctime64);
187# else
188# define ctime __ctime64
189# endif
190#endif
191
192#ifdef __USE_POSIX
193/* Reentrant versions of the above functions. */
194
195/* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
196 that is the representation of TP in this format. */
197extern char *asctime_r (const struct tm *__restrict __tp,
198 char *__restrict __buf) __THROW;
199
200/* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'. */
201#ifndef __USE_TIME_BITS64
202extern char *ctime_r (const time_t *__restrict __timer,
203 char *__restrict __buf) __THROW;
204#else
205# ifdef __REDIRECT_NTH
206extern char *__REDIRECT_NTH (ctime_r, (const time_t *__restrict __timer,
207 char *__restrict __buf), __ctime64_r);
208# else
209# define ctime_r __ctime64_r
210# endif
211#endif
212
213#endif /* POSIX */
214
215
216/* Defined in localtime.c. */
217extern char *__tzname[2]; /* Current timezone names. */
218extern int __daylight; /* If daylight-saving time is ever in use. */
219extern long int __timezone; /* Seconds west of UTC. */
220
221
222#ifdef __USE_POSIX
223/* Same as above. */
224extern char *tzname[2];
225
226/* Set time conversion information from the TZ environment variable.
227 If TZ is not defined, a locale-dependent default is used. */
228extern void tzset (void) __THROW;
229#endif
230
231#if defined __USE_MISC || defined __USE_XOPEN
232extern int daylight;
233extern long int timezone;
234#endif
235
236
237/* Nonzero if YEAR is a leap year (every 4 years,
238 except every 100th isn't, and every 400th is). */
239#define __isleap(year) \
240 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
241
242
243#ifdef __USE_MISC
244/* Miscellaneous functions many Unices inherited from the public domain
245 localtime package. These are included only for compatibility. */
246
247#ifndef __USE_TIME_BITS64
248/* Like `mktime', but for TP represents Universal Time, not local time. */
249extern time_t timegm (struct tm *__tp) __THROW;
250/* Another name for `mktime'. */
251extern time_t timelocal (struct tm *__tp) __THROW;
252#else
253# ifdef __REDIRECT_NTH
254extern time_t __REDIRECT_NTH (timegm, (struct tm *__tp), __timegm64);
255extern time_t __REDIRECT_NTH (timelocal, (struct tm *__tp), __mktime64);
256# else
257# define timegm __timegm64
258# endif
259#endif
260
261/* Return the number of days in YEAR. */
262extern int dysize (int __year) __THROW __attribute__ ((__const__));
263#endif
264
265
266#ifdef __USE_POSIX199309
267# ifndef __USE_TIME_BITS64
268/* Pause execution for a number of nanoseconds.
269
270 This function is a cancellation point and therefore not marked with
271 __THROW. */
272extern int nanosleep (const struct timespec *__requested_time,
273 struct timespec *__remaining);
274
275/* Get resolution of clock CLOCK_ID. */
276extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
277
278/* Get current value of clock CLOCK_ID and store it in TP. */
279extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
280
281/* Set clock CLOCK_ID to value TP. */
282extern int clock_settime (clockid_t __clock_id, const struct timespec *__tp)
283 __THROW;
284# else
285# ifdef __REDIRECT
286extern int __REDIRECT (nanosleep, (const struct timespec *__requested_time,
287 struct timespec *__remaining),
288 __nanosleep64);
289extern int __REDIRECT_NTH (clock_getres, (clockid_t __clock_id,
290 struct timespec *__res),
291 __clock_getres64);
292extern int __REDIRECT_NTH (clock_gettime, (clockid_t __clock_id, struct
293 timespec *__tp), __clock_gettime64);
294extern int __REDIRECT_NTH (clock_settime, (clockid_t __clock_id, const struct
295 timespec *__tp), __clock_settime64);
296# else
297# define nanosleep __nanosleep64
298# define clock_getres __clock_getres64
299# define clock_gettime __clock_gettime64
300# define clock_settime __clock_settime64
301# endif
302# endif
303
304
305# ifdef __USE_XOPEN2K
306/* High-resolution sleep with the specified clock.
307
308 This function is a cancellation point and therefore not marked with
309 __THROW. */
310# ifndef __USE_TIME_BITS64
311extern int clock_nanosleep (clockid_t __clock_id, int __flags,
312 const struct timespec *__req,
313 struct timespec *__rem);
314# else
315# ifdef __REDIRECT
316extern int __REDIRECT (clock_nanosleep, (clockid_t __clock_id, int __flags,
317 const struct timespec *__req,
318 struct timespec *__rem),
319 __clock_nanosleep_time64);
320# else
321# define clock_nanosleep __clock_nanosleep_time64
322# endif
323# endif
324
325/* Return clock ID for CPU-time clock. */
326extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
327# endif
328
329
330/* Create new per-process timer using CLOCK_ID. */
331extern int timer_create (clockid_t __clock_id,
332 struct sigevent *__restrict __evp,
333 timer_t *__restrict __timerid) __THROW;
334
335/* Delete timer TIMERID. */
336extern int timer_delete (timer_t __timerid) __THROW;
337
338/* Set timer TIMERID to VALUE, returning old value in OVALUE. */
339# ifndef __USE_TIME_BITS64
340extern int timer_settime (timer_t __timerid, int __flags,
341 const struct itimerspec *__restrict __value,
342 struct itimerspec *__restrict __ovalue) __THROW;
343
344/* Get current value of timer TIMERID and store it in VALUE. */
345extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
346 __THROW;
347# else
348# ifdef __REDIRECT_NTH
349extern int __REDIRECT_NTH (timer_settime, (timer_t __timerid, int __flags,
350 const struct itimerspec *__restrict __value,
351 struct itimerspec *__restrict __ovalue),
352 __timer_settime64);
353
354extern int __REDIRECT_NTH (timer_gettime, (timer_t __timerid,
355 struct itimerspec *__value),
356 __timer_gettime64);
357# else
358# define timer_settime __timer_settime64
359# define timer_gettime __timer_gettime64
360# endif
361# endif
362
363/* Get expiration overrun for timer TIMERID. */
364extern int timer_getoverrun (timer_t __timerid) __THROW;
365#endif
366
367
368#ifdef __USE_ISOC11
369# ifndef __USE_TIME_BITS64
370/* Set TS to calendar time based in time base BASE. */
371extern int timespec_get (struct timespec *__ts, int __base)
372 __THROW __nonnull ((1));
373# else
374# ifdef __REDIRECT_NTH
375extern int __REDIRECT_NTH (timespec_get, (struct timespec *__ts, int __base),
376 __timespec_get64) __nonnull ((1));
377# else
378# define timespec_get __timespec_get64
379# endif
380# endif
381#endif
382
383
384#if __GLIBC_USE (ISOC2X)
385# ifndef __USE_TIME_BITS64
386/* Set TS to resolution of time base BASE. */
387extern int timespec_getres (struct timespec *__ts, int __base)
388 __THROW;
389# else
390# ifdef __REDIRECT_NTH
391extern int __REDIRECT_NTH (timespec_getres, (struct timespec *__ts,
392 int __base),
393 __timespec_getres64);
394# else
395# define timespec_getres __timespec_getres64
396# endif
397# endif
398#endif
399
400
401#ifdef __USE_XOPEN_EXTENDED
402/* Set to one of the following values to indicate an error.
403 1 the DATEMSK environment variable is null or undefined,
404 2 the template file cannot be opened for reading,
405 3 failed to get file status information,
406 4 the template file is not a regular file,
407 5 an error is encountered while reading the template file,
408 6 memory allication failed (not enough memory available),
409 7 there is no line in the template that matches the input,
410 8 invalid input specification Example: February 31 or a time is
411 specified that can not be represented in a time_t (representing
412 the time in seconds since 00:00:00 UTC, January 1, 1970) */
413extern int getdate_err;
414
415/* Parse the given string as a date specification and return a value
416 representing the value. The templates from the file identified by
417 the environment variable DATEMSK are used. In case of an error
418 `getdate_err' is set.
419
420 This function is a possible cancellation point and therefore not
421 marked with __THROW. */
422extern struct tm *getdate (const char *__string);
423#endif
424
425#ifdef __USE_GNU
426/* Since `getdate' is not reentrant because of the use of `getdate_err'
427 and the static buffer to return the result in, we provide a thread-safe
428 variant. The functionality is the same. The result is returned in
429 the buffer pointed to by RESBUFP and in case of an error the return
430 value is != 0 with the same values as given above for `getdate_err'.
431
432 This function is not part of POSIX and therefore no official
433 cancellation point. But due to similarity with an POSIX interface
434 or due to the implementation it is a cancellation point and
435 therefore not marked with __THROW. */
436extern int getdate_r (const char *__restrict __string,
437 struct tm *__restrict __resbufp);
438#endif
439
440__END_DECLS
441
442#endif /* time.h. */
443

source code of include/time.h