time.h File Reference

#include <signal.h>
#include <stddef.h>
#include <stdint.h>
#include <sys/types.h>

Include dependency graph for time.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	timespec
struct	itimerspec
struct	tm

Macros
#define	CLOCK_REALTIME   0
#define	CLOCK_MONOTONIC   1
#define	TIMER_ABSTIME   1

Functions
int	clock_getres (clockid_t clockid, struct timespec *res)
	Get the resolution (precision) of the specified clock ID. More...
int	clock_gettime (clockid_t clockid, struct timespec *tp)
	Retrieve the time of the specified clock ID. More...
int	clock_settime (clockid_t clockid, const struct timespec *tp)
	Set the time of the specified clock ID. More...
int	timer_create (clockid_t clockid, struct sigevent *sevp, timer_t *timerid)
	Create a new per-thread interval timer. More...
int	timer_delete (timer_t timerid)
	Delete the timer specified with the timer ID. More...
int	timer_settime (timer_t timerid, int flags, const struct itimerspec *new_value, struct itimerspec *old_value)
	Arm or disarm the timer specified by the timer ID. More...
int	timer_gettime (timer_t timerid, struct itimerspec *curr_value)
	Return the timer interval and the time until next expiration. More...
time_t	time (time_t *tloc)
	Return the time as the number of seconds since 1970-01-01 00:00:00 +0000 (UTC) More...
int	nanosleep (const struct timespec *req, struct timespec *rem)
	Suspend execution for a specified time. More...
int	clock_nanosleep (clockid_t clockid, int flags, const struct timespec *req, struct timespec *rem)
	High-resolution sleep with clock selection. More...
struct tm *	localtime (const time_t *timep)
struct tm *	localtime_r (const time_t *timep, struct tm *result)
struct tm *	gmtime (const time_t *timep)
struct tm *	gmtime_r (const time_t *timep, struct tm *result)
time_t	mktime (struct tm *tm)
size_t	strftime (char *s, size_t max, const char *format, const struct tm *tm)
char *	strptime (const char *s, const char *format, struct tm *tm)
char *	ctime (const time_t *timep)
char *	ctime_r (const time_t *timep, char *buf)

Function Documentation

clock_getres()

int clock_getres	(	clockid_t	clockid,
		struct timespec *	res
	)

Get the resolution (precision) of the specified clock ID.

Parameters

clk_id	The clock ID to provide.
res	The time object for returning the clock resolution.

Return values

int	0 on success and nonzero error number on error.

clock_gettime()

int clock_gettime	(	clockid_t	clockid,
		struct timespec *	tp
	)

Retrieve the time of the specified clock ID.

Parameters

clk_id	The clock ID to provide.
tp	The time object for returning the time.

Return values

int	0 on success and nonzero error number on error.

clock_nanosleep()

int clock_nanosleep	(	clockid_t	clockid,
		int	flags,
		const struct timespec *	req,
		struct timespec *	rem
	)

High-resolution sleep with clock selection.

Parameters

clockid	The clock ID to use.
flags	TIMER_ABSTIME for absolute time, otherwise relative.
req	Requested sleep time.
rem	Remaining time if interrupted (optional).

Return values

int	0 on success and nonzero error number on error.

clock_settime()

int clock_settime	(	clockid_t	clockid,
		const struct timespec *	tp
	)

Set the time of the specified clock ID.

Parameters

clk_id	The clock ID to provide.
tp	The time object for setting the clock.

Return values

int	0 on success and nonzero error number on error.

nanosleep()

int nanosleep	(	const struct timespec *	req,
		struct timespec *	rem
	)

Suspend execution for a specified time.

Parameters

req	Requested sleep time.
rem	Remaining time if interrupted (optional).

Return values

int	0 on success and nonzero error number on error.

time()

time_t time

(

time_t *

tloc

)

Return the time as the number of seconds since 1970-01-01 00:00:00 +0000 (UTC)

Parameters

tloc	Same as return value if tloc is not NULL.

Return values

time_t

The time in seconds.

timer_create()

int timer_create	(	clockid_t	clockid,
		struct sigevent *	sevp,
		timer_t *	timerid
	)

Create a new per-thread interval timer.

Parameters

clk_id	The clock ID to provide.
sevp	For signaling an event when the timer expired.
timerid	For returning the ID of the newly created timer.

Return values

int	0 on success and nonzero error number on error.

timer_delete()

int timer_delete

(

timer_t

timerid

)

Delete the timer specified with the timer ID.

Parameters

timerid

The timer ID to provide.

Return values

int	0 on success and nonzero error number on error.

timer_gettime()

int timer_gettime	(	timer_t	timerid,
		struct itimerspec *	curr_value
	)

Return the timer interval and the time until next expiration.

Parameters

timerid	The timer ID to provide.
curr_value	The timer object for returning the timer time.

Return values

int	0 on success and nonzero error number on error.

timer_settime()

int timer_settime	(	timer_t	timerid,
		int	flags,
		const struct itimerspec *	new_value,
		struct itimerspec *	old_value
	)

Arm or disarm the timer specified by the timer ID.

Parameters

timerid	The timer ID to provide.
flags	Not used.
new_value	Pointer the the new timer setting.
old_value	Pointer to the memory space for storing the old timer setting.

Return values

int	0 on success and nonzero error number on error.