glibc/time/time.h

304 lines
10 KiB
C

/* Copyright (C) 1991-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/*
* ISO C99 Standard: 7.23 Date and time <time.h>
*/
#ifndef _TIME_H
#define _TIME_H 1
#include <features.h>
#define __need_size_t
#define __need_NULL
#include <stddef.h>
/* This defines CLOCKS_PER_SEC, which is the number of processor clock
ticks per second, and possibly a number of other constants. */
#include <bits/time.h>
/* Many of the typedefs and structs whose official home is this header
may also need to be defined by other headers. */
#include <bits/types/clock_t.h>
#include <bits/types/time_t.h>
#include <bits/types/struct_tm.h>
#if defined __USE_POSIX199309 || defined __USE_ISOC11
# include <bits/types/struct_timespec.h>
#endif
#ifdef __USE_POSIX199309
# include <bits/types/clockid_t.h>
# include <bits/types/timer_t.h>
# include <bits/types/struct_itimerspec.h>
struct sigevent;
#endif
#ifdef __USE_XOPEN2K
# ifndef __pid_t_defined
typedef __pid_t pid_t;
# define __pid_t_defined
# endif
#endif
#ifdef __USE_XOPEN2K8
# include <bits/types/locale_t.h>
#endif
#ifdef __USE_ISOC11
/* Time base values for timespec_get. */
# define TIME_UTC 1
#endif
__BEGIN_DECLS
/* Time used by the program so far (user time + system time).
The result / CLOCKS_PER_SEC is program time in seconds. */
extern clock_t clock (void) __THROW;
/* Return the current time and put it in *TIMER if TIMER is not NULL. */
extern time_t time (time_t *__timer) __THROW;
/* Return the difference between TIME1 and TIME0. */
extern double difftime (time_t __time1, time_t __time0)
__THROW __attribute__ ((__const__));
/* Return the `time_t' representation of TP and normalize TP. */
extern time_t mktime (struct tm *__tp) __THROW;
/* Format TP into S according to FORMAT.
Write no more than MAXSIZE characters and return the number
of characters written, or 0 if it would exceed MAXSIZE. */
extern size_t strftime (char *__restrict __s, size_t __maxsize,
const char *__restrict __format,
const struct tm *__restrict __tp) __THROW;
#ifdef __USE_XOPEN
/* Parse S according to FORMAT and store binary time information in TP.
The return value is a pointer to the first unparsed character in S. */
extern char *strptime (const char *__restrict __s,
const char *__restrict __fmt, struct tm *__tp)
__THROW;
#endif
#ifdef __USE_XOPEN2K8
/* Similar to the two functions above but take the information from
the provided locale and not the global locale. */
extern size_t strftime_l (char *__restrict __s, size_t __maxsize,
const char *__restrict __format,
const struct tm *__restrict __tp,
locale_t __loc) __THROW;
#endif
#ifdef __USE_GNU
extern char *strptime_l (const char *__restrict __s,
const char *__restrict __fmt, struct tm *__tp,
locale_t __loc) __THROW;
#endif
/* Return the `struct tm' representation of *TIMER
in Universal Coordinated Time (aka Greenwich Mean Time). */
extern struct tm *gmtime (const time_t *__timer) __THROW;
/* Return the `struct tm' representation
of *TIMER in the local timezone. */
extern struct tm *localtime (const time_t *__timer) __THROW;
#if defined __USE_POSIX || __GLIBC_USE (ISOC2X)
/* Return the `struct tm' representation of *TIMER in UTC,
using *TP to store the result. */
extern struct tm *gmtime_r (const time_t *__restrict __timer,
struct tm *__restrict __tp) __THROW;
/* Return the `struct tm' representation of *TIMER in local time,
using *TP to store the result. */
extern struct tm *localtime_r (const time_t *__restrict __timer,
struct tm *__restrict __tp) __THROW;
#endif /* POSIX || C2X */
/* Return a string of the form "Day Mon dd hh:mm:ss yyyy\n"
that is the representation of TP in this format. */
extern char *asctime (const struct tm *__tp) __THROW;
/* Equivalent to `asctime (localtime (timer))'. */
extern char *ctime (const time_t *__timer) __THROW;
#if defined __USE_POSIX || __GLIBC_USE (ISOC2X)
/* Reentrant versions of the above functions. */
/* Return in BUF a string of the form "Day Mon dd hh:mm:ss yyyy\n"
that is the representation of TP in this format. */
extern char *asctime_r (const struct tm *__restrict __tp,
char *__restrict __buf) __THROW;
/* Equivalent to `asctime_r (localtime_r (timer, *TMP*), buf)'. */
extern char *ctime_r (const time_t *__restrict __timer,
char *__restrict __buf) __THROW;
#endif /* POSIX || C2X */
/* Defined in localtime.c. */
extern char *__tzname[2]; /* Current timezone names. */
extern int __daylight; /* If daylight-saving time is ever in use. */
extern long int __timezone; /* Seconds west of UTC. */
#ifdef __USE_POSIX
/* Same as above. */
extern char *tzname[2];
/* Set time conversion information from the TZ environment variable.
If TZ is not defined, a locale-dependent default is used. */
extern void tzset (void) __THROW;
#endif
#if defined __USE_MISC || defined __USE_XOPEN
extern int daylight;
extern long int timezone;
#endif
/* Nonzero if YEAR is a leap year (every 4 years,
except every 100th isn't, and every 400th is). */
#define __isleap(year) \
((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
#ifdef __USE_MISC
/* Miscellaneous functions many Unices inherited from the public domain
localtime package. These are included only for compatibility. */
/* Like `mktime', but for TP represents Universal Time, not local time. */
extern time_t timegm (struct tm *__tp) __THROW;
/* Another name for `mktime'. */
extern time_t timelocal (struct tm *__tp) __THROW;
/* Return the number of days in YEAR. */
extern int dysize (int __year) __THROW __attribute__ ((__const__));
#endif
#ifdef __USE_POSIX199309
/* Pause execution for a number of nanoseconds.
This function is a cancellation point and therefore not marked with
__THROW. */
extern int nanosleep (const struct timespec *__requested_time,
struct timespec *__remaining);
/* Get resolution of clock CLOCK_ID. */
extern int clock_getres (clockid_t __clock_id, struct timespec *__res) __THROW;
/* Get current value of clock CLOCK_ID and store it in TP. */
extern int clock_gettime (clockid_t __clock_id, struct timespec *__tp) __THROW;
/* Set clock CLOCK_ID to value TP. */
extern int clock_settime (clockid_t __clock_id, const struct timespec *__tp)
__THROW;
# ifdef __USE_XOPEN2K
/* High-resolution sleep with the specified clock.
This function is a cancellation point and therefore not marked with
__THROW. */
extern int clock_nanosleep (clockid_t __clock_id, int __flags,
const struct timespec *__req,
struct timespec *__rem);
/* Return clock ID for CPU-time clock. */
extern int clock_getcpuclockid (pid_t __pid, clockid_t *__clock_id) __THROW;
# endif
/* Create new per-process timer using CLOCK_ID. */
extern int timer_create (clockid_t __clock_id,
struct sigevent *__restrict __evp,
timer_t *__restrict __timerid) __THROW;
/* Delete timer TIMERID. */
extern int timer_delete (timer_t __timerid) __THROW;
/* Set timer TIMERID to VALUE, returning old value in OVALUE. */
extern int timer_settime (timer_t __timerid, int __flags,
const struct itimerspec *__restrict __value,
struct itimerspec *__restrict __ovalue) __THROW;
/* Get current value of timer TIMERID and store it in VALUE. */
extern int timer_gettime (timer_t __timerid, struct itimerspec *__value)
__THROW;
/* Get expiration overrun for timer TIMERID. */
extern int timer_getoverrun (timer_t __timerid) __THROW;
#endif
#ifdef __USE_ISOC11
/* Set TS to calendar time based in time base BASE. */
extern int timespec_get (struct timespec *__ts, int __base)
__THROW __nonnull ((1));
#endif
#ifdef __USE_XOPEN_EXTENDED
/* Set to one of the following values to indicate an error.
1 the DATEMSK environment variable is null or undefined,
2 the template file cannot be opened for reading,
3 failed to get file status information,
4 the template file is not a regular file,
5 an error is encountered while reading the template file,
6 memory allication failed (not enough memory available),
7 there is no line in the template that matches the input,
8 invalid input specification Example: February 31 or a time is
specified that can not be represented in a time_t (representing
the time in seconds since 00:00:00 UTC, January 1, 1970) */
extern int getdate_err;
/* Parse the given string as a date specification and return a value
representing the value. The templates from the file identified by
the environment variable DATEMSK are used. In case of an error
`getdate_err' is set.
This function is a possible cancellation point and therefore not
marked with __THROW. */
extern struct tm *getdate (const char *__string);
#endif
#ifdef __USE_GNU
/* Since `getdate' is not reentrant because of the use of `getdate_err'
and the static buffer to return the result in, we provide a thread-safe
variant. The functionality is the same. The result is returned in
the buffer pointed to by RESBUFP and in case of an error the return
value is != 0 with the same values as given above for `getdate_err'.
This function is not part of POSIX and therefore no official
cancellation point. But due to similarity with an POSIX interface
or due to the implementation it is a cancellation point and
therefore not marked with __THROW. */
extern int getdate_r (const char *__restrict __string,
struct tm *__restrict __resbufp);
#endif
__END_DECLS
#endif /* time.h. */