gettimeofday

Get the current wall clock time. See remarks below.

Syntax

#include <sys/time.h>

int gettimeofday (struct timeval *restrict tp, void *restrict tzp);

Parameters

tp

The structure that will receive the current time.
tzp

Optional argument specifying the timezone. This argument is currently ignored.

Return Value

The return value is null if successful. Otherwise, the return value is negative and errno is set:

EINVAL

The tp argument is not valid.

Remarks

Since most microcontrollers do not contain a real-time (wall time) clock, this system call returns the current system timer counting since the system was booted. In order to get the correct wall time, compensate with a real-time clock.

The time resulution is decided by the system tick timer, which operates at 1 KHz (1 millisecond resolution).

The internal counter is an unsigned 32-bit value, be wary of overflow.