time—get current calendar time (as single number) #include <time.h>
time_t time(time_t *t);
Description
time looks up the best available representation of the current
time and returns it, encoded as a time_t. It stores the same
value at t unless the argument is NULL.
Returns
A -1 result means the current time is not available; otherwise the
result represents the current time.
Portability
ANSI C requires time.
Supporting OS subroutine required: Some implementations require
gettimeofday.