timespec_get

 

C

Language

Headers

Type support

Program utilities

Variadic function support

Error handling

Dynamic memory management

Strings library

Algorithms

Numerics

Date and time utilities

Input/output support

Localization support

Concurrency support (C11)

Technical Specifications

Symbol index

 

Date and time utilities

Functions

Time manipulation

difftime

time

clock

timespec_get (C11)

timespec_getres (C23)

Format conversions

asctimeasctime_rasctime_s (C23)(C11)

ctimectime_rctime_s (C23)(C11)

strftime

wcsftime (C95)

gmtimegmtime_rgmtime_s (C23)(C11)

localtimelocaltime_rlocaltime_s (C23)(C11)

mktime

Constants

CLOCKS_PER_SEC

Types

tm

time_t

clock_t

timespec (C11)

 

Defined in header <time.h>
int timespec_get( struct timespec *ts, int base );	(1)	(since C11)
#define TIME_UTC /* implementation-defined */	(2)	(since C11)

1) Modifies the timespec object pointed to by ts to hold the current calendar time in the time base base.

2) Expands to a value suitable for use as the base argument of timespec_get

Other macro constants beginning with TIME_ may be provided by the implementation to indicate additional time bases

If base is TIME_UTC, then

• ts->tv_sec is set to the number of seconds since an implementation defined epoch, truncated to a whole value
• ts->tv_nsec member is set to the integral number of nanoseconds, rounded to the resolution of the system clock

Parameters

ts	-	pointer to an object of type struct timespec
base	-	TIME_UTC or another nonzero integer value indicating the time base

Return value

The value of base if successful, zero otherwise.

Notes

The POSIX function clock_gettime(CLOCK_REALTIME, ts) may also be used to populate a timespec with the time since the Epoch.

Example

Run this code

#include <stdio.h>
#include <time.h>
 
int main(void)
{
    struct timespec ts;
    timespec_get(&ts, TIME_UTC);
    char buff[100];
    strftime(buff, sizeof buff, "%D %T", gmtime(&ts.tv_sec));
    printf("Current time: %s.%09ld UTC\n", buff, ts.tv_nsec);
}

Possible output:

Current time: 02/18/15 14:34:03.048508855 UTC

References

• C17 standard (ISO/IEC 9899:2018):

• 7.27.2.5 The timespec_get function (p: 286)

• C11 standard (ISO/IEC 9899:2011):

• 7.27.2.5 The timespec_get function (p: 390)

See also

timespec (C11)	time in seconds and nanoseconds (struct)
timespec_getres (C23)	returns the resolution of calendar time based on a given time base (function)
time	returns the current calendar time of the system as time since epoch (function)