NAME
adjfreq —
correct the rate of the system
clock
SYNOPSIS
#include
<sys/types.h>
#include <sys/time.h>
int
adjfreq(const
int64_t *freq, int64_t
*oldfreq);
DESCRIPTION
adjfreq()
adjusts the rate in which time progresses if freq is
non-null. The unit of the rate of adjustment is nanoseconds per second,
shifted left 32 bits to allow for fractional values.
If oldfreq is non-null, the current value is returned.
Only the superuser may adjust the frequency.
RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
ERRORS
adjfreq() will fail if:
- [
EFAULT] - Either of the arguments point outside the process's allocated address space.
- [
EPERM] - The freq argument is non-null and the process's effective user ID is not that of the superuser.
- [
EINVAL] - freq is less than -500000 ppm or greater than 500000 ppm.
SEE ALSO
HISTORY
The adjfreq() function call first appeared
in OpenBSD 4.0.