timespec_get

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

#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)