1/* Copyright (C) 1991-2020 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/* Return the current time and put it in *TIMER if TIMER is not NULL. */
75extern time_t time (time_t *__timer) __THROW;
76
77/* Return the difference between TIME1 and TIME0. */
78extern double difftime (time_t __time1, time_t __time0)
79 __THROW __attribute__ ((__const__));
80
81/* Return the `time_t' representation of TP and normalize TP. */
82extern time_t mktime (struct tm *__tp) __THROW;
83
84
85/* Format TP into S according to FORMAT.
86 Write no more than MAXSIZE characters and return the number
87 of characters written, or 0 if it would exceed MAXSIZE. */
88extern size_t strftime (char *__restrict __s, size_t __maxsize,
89 const char *__restrict __format,
90 const struct tm *__restrict __tp) __THROW;
91
92#ifdef __USE_XOPEN
93/* Parse S according to FORMAT and store binary time information in TP.
94 The return value is a pointer to the first unparsed character in S. */
95extern char *strptime (const char *__restrict __s,
96 const char *__restrict __fmt, struct tm *__tp)
97 __THROW;
98#endif
99
100#ifdef __USE_XOPEN2K8
101/* Similar to the two functions above but take the information from
102 the provided locale and not the global locale. */
103
104extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
105 const char *__restrict __format,
106 const struct tm *__restrict __tp,
107 locale_t __loc) __THROW;
108#endif
109
110#ifdef __USE_GNU
111extern char *strptime_l (const char *__restrict __s,
112 const char *__restrict __fmt, struct tm *__tp,
113 locale_t __loc) __THROW;
114#endif
115
116
117/* Return the `struct tm' representation of *TIMER
118 in Universal Coordinated Time (aka Greenwich Mean Time). */
119extern struct tm *gmtime (const time_t *__timer) __THROW;
120
121/* Return the `struct tm' representation
122 of *TIMER in the local timezone. */
123extern struct tm *localtime (const time_t *__timer) __THROW;
124
125#if defined __USE_POSIX || __GLIBC_USE (ISOC2X)
126/* Return the `struct tm' representation of *TIMER in UTC,
127 using *TP to store the result. */
128extern struct tm *gmtime_r (const time_t *__restrict __timer,
129 struct tm *__restrict __tp) __THROW;
130
131/* Return the `struct tm' representation of *TIMER in local time,
132 using *TP to store the result. */
133extern struct tm *localtime_r (const time_t *__restrict __timer,
134 struct tm *__restrict __tp) __THROW;
135#endif /* POSIX || C2X */
136
137/* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
138 that is the representation of TP in this format. */
139extern char *asctime (const struct tm *__tp) __THROW;
140
141/* Equivalent to `asctime (localtime (timer))'. */
142extern char *ctime (const time_t *__timer) __THROW;
143
144#if defined __USE_POSIX || __GLIBC_USE (ISOC2X)
145/* Reentrant versions of the above functions. */
146
147/* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
148 that is the representation of TP in this format. */
149extern char *asctime_r (const struct tm *__restrict __tp,
150 char *__restrict __buf) __THROW;
151
152/* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'. */
153extern char *ctime_r (const time_t *__restrict __timer,
154 char *__restrict __buf) __THROW;
155#endif /* POSIX || C2X */
156
157
158/* Defined in localtime.c. */
159extern char *__tzname[2]; /* Current timezone names. */
160extern int __daylight; /* If daylight-saving time is ever in use. */
161extern long int __timezone; /* Seconds west of UTC. */
162
163
164#ifdef __USE_POSIX
165/* Same as above. */
166extern char *tzname[2];
167
168/* Set time conversion information from the TZ environment variable.
169 If TZ is not defined, a locale-dependent default is used. */
170extern void tzset (void) __THROW;
171#endif
172
173#if defined __USE_MISC || defined __USE_XOPEN
174extern int daylight;
175extern long int timezone;
176#endif
177
178
179/* Nonzero if YEAR is a leap year (every 4 years,
180 except every 100th isn't, and every 400th is). */
181#define __isleap(year) \
182 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
183
184
185#ifdef __USE_MISC
186/* Miscellaneous functions many Unices inherited from the public domain
187 localtime package. These are included only for compatibility. */
188
189/* Like `mktime', but for TP represents Universal Time, not local time. */
190extern time_t timegm (struct tm *__tp) __THROW;
191
192/* Another name for `mktime'. */
193extern time_t timelocal (struct tm *__tp) __THROW;
194
195/* Return the number of days in YEAR. */
196extern int dysize (int __year) __THROW __attribute__ ((__const__));
197#endif
198
199
200#ifdef __USE_POSIX199309
201/* Pause execution for a number of nanoseconds.
202
203 This function is a cancellation point and therefore not marked with
204 __THROW. */
205extern int nanosleep (const struct timespec *__requested_time,
206 struct timespec *__remaining);
207
208
209/* Get resolution of clock CLOCK_ID. */
210extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
211
212/* Get current value of clock CLOCK_ID and store it in TP. */
213extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
214
215/* Set clock CLOCK_ID to value TP. */
216extern int clock_settime (clockid_t __clock_id, const struct timespec *__tp)
217 __THROW;
218
219# ifdef __USE_XOPEN2K
220/* High-resolution sleep with the specified clock.
221
222 This function is a cancellation point and therefore not marked with
223 __THROW. */
224extern int clock_nanosleep (clockid_t __clock_id, int __flags,
225 const struct timespec *__req,
226 struct timespec *__rem);
227
228/* Return clock ID for CPU-time clock. */
229extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
230# endif
231
232
233/* Create new per-process timer using CLOCK_ID. */
234extern int timer_create (clockid_t __clock_id,
235 struct sigevent *__restrict __evp,
236 timer_t *__restrict __timerid) __THROW;
237
238/* Delete timer TIMERID. */
239extern int timer_delete (timer_t __timerid) __THROW;
240
241/* Set timer TIMERID to VALUE, returning old value in OVALUE. */
242extern int timer_settime (timer_t __timerid, int __flags,
243 const struct itimerspec *__restrict __value,
244 struct itimerspec *__restrict __ovalue) __THROW;
245
246/* Get current value of timer TIMERID and store it in VALUE. */
247extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
248 __THROW;
249
250/* Get expiration overrun for timer TIMERID. */
251extern int timer_getoverrun (timer_t __timerid) __THROW;
252#endif
253
254
255#ifdef __USE_ISOC11
256/* Set TS to calendar time based in time base BASE. */
257extern int timespec_get (struct timespec *__ts, int __base)
258 __THROW __nonnull ((1));
259#endif
260
261
262#ifdef __USE_XOPEN_EXTENDED
263/* Set to one of the following values to indicate an error.
264 1 the DATEMSK environment variable is null or undefined,
265 2 the template file cannot be opened for reading,
266 3 failed to get file status information,
267 4 the template file is not a regular file,
268 5 an error is encountered while reading the template file,
269 6 memory allication failed (not enough memory available),
270 7 there is no line in the template that matches the input,
271 8 invalid input specification Example: February 31 or a time is
272 specified that can not be represented in a time_t (representing
273 the time in seconds since 00:00:00 UTC, January 1, 1970) */
274extern int getdate_err;
275
276/* Parse the given string as a date specification and return a value
277 representing the value. The templates from the file identified by
278 the environment variable DATEMSK are used. In case of an error
279 `getdate_err' is set.
280
281 This function is a possible cancellation point and therefore not
282 marked with __THROW. */
283extern struct tm *getdate (const char *__string);
284#endif
285
286#ifdef __USE_GNU
287/* Since `getdate' is not reentrant because of the use of `getdate_err'
288 and the static buffer to return the result in, we provide a thread-safe
289 variant. The functionality is the same. The result is returned in
290 the buffer pointed to by RESBUFP and in case of an error the return
291 value is != 0 with the same values as given above for `getdate_err'.
292
293 This function is not part of POSIX and therefore no official
294 cancellation point. But due to similarity with an POSIX interface
295 or due to the implementation it is a cancellation point and
296 therefore not marked with __THROW. */
297extern int getdate_r (const char *__restrict __string,
298 struct tm *__restrict __resbufp);
299#endif
300
301__END_DECLS
302
303#endif /* time.h. */
304

source code of include/time.h