gettimeofday, gettimeofday64 - read current time of day

Syntax	#include <sys/time.h> int gettimeofday(struct timeval *tp, void *tzp); int gettimeofday64(struct timeval64 *tp, void *tzp);
Description	gettimeofday() und gettimeofday64() read the current system time, expressed as seconds and microseconds since 00:00 Coordinated Universal Time (UTC), January 1, 1970. The resolution of the system clock is hardware-dependent; the time may be updated continuously or at specific time intervals. tp points to a structure of type timeval or timeval64, containing the following members: long tv_sec;           /* seconds since January 1, 1970 */ or time64_t tv_sec;  /* seconds since January 1, 1970 */ and long tv_usec;         /* and microseconds */ If tp is a null pointer, the current time is not read. tzp must be a null pointer, otherwise the behavior is undefined. Information on time zones is contained in the environment variable TZ. See timezone.
Return val.	0 -1	if successful. if an error occurs.
Notes	Programs which want to be portable must not rely on the return value -1 in the event of an error.
See also	ctime(), ftime(), timezone, sys/time.h.