NAME

timespec_get, timespec_getres — get current calendar time

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <time.h>

int
timespec_get(struct timespec *ts, int base);

int
timespec_getres(struct timespec *ts, int base);

DESCRIPTION

The timespec_get() function sets the interval pointed to by ts to hold the current calendar time based on the specified time base in base. It is the ISO C equivalent to the POSIX function clock_gettime(2).

The base TIME_UTC returns the time since the epoch. This time is expressed in seconds and nanoseconds since midnight (0 hour), January 1, 1970. In NetBSD, this corresponds to CLOCK_REALTIME.

The base TIME_MONOTONIC returns the seconds and nanoseconds since an implementation-defined reference point in such a way that a second call will never return a value less than the first. In NetBSD, this corresponds to CLOCK_MONOTONIC.

The resolution of each timer can be queried using timespec_getres(). Each successive call to this function will return the same value for a specific clock. It is the ISO C equivalent to the POSIX function clock_getres(2).

RETURN VALUES

These functions return the passed non-zero value of base if successful, otherwise 0 on failure.

SEE ALSO

clock_gettime(2), gettimeofday(2), time(3)

STANDARDS

The timespec_get() function with a base of TIME_UTC conforms to ISO/IEC 9899:2011 (“ISO C11”). The base of TIME_MONOTONIC is specified in ISO/IEC 9899:2024 (“ISO C23”).

The timespec_getres() function conforms to ISO/IEC 9899:2024 (“ISO C23”).

HISTORY

The timespec_get() function first appeared in NetBSD 8.0.

The timespec_getres() function first appeared in NetBSD 11.0.

AUTHORS

Kamil Rytarowski <kamil@NetBSD.org>
Nia Alarie <nia@NetBSD.org>