#include <sys/types.h> #include <time.h> time_t time(time_t *tloc);
The time() function returns the value of time in seconds since 00:00:00 UTC, January 1, 1970.
If tloc is non-zero, the return value is also stored in the location to which tloc points. If tloc points to an illegal address, time() fails and its actions are undefined.
Upon successful completion, time() returns the value of time. Otherwise, (time_t)−1 is returned and errno is set to indicate the error.
See attributes(5) for descriptions of the following attributes: