Chapter Contents |
Previous |
Next |
difftime |
Portability: | ISO/ANSI C conforming |
SYNOPSIS | |
DESCRIPTION | |
RETURN VALUE | |
CAUTION | |
EXAMPLE | |
RELATED FUNCTIONS | |
SEE ALSO |
SYNOPSIS |
#include <time.h> double difftime(time_t time2, time_t time1);
DESCRIPTION |
difftime
computes the difference
time2 - time1
in
seconds, where
time2
and
time1
are values of type
time_t
(such as those returned by the
time
function).
RETURN VALUE |
difftime
returns the difference between the two times in seconds.
CAUTION |
difftime
is implemented as a macro. If its arguments are not of type
time_t
, the results are not meaningful.
EXAMPLE |
#include <time.h> #include <stdio.h> main() { double x; time_t last_written; /* time data last written */ /* time(&last_written); */ /* if data are more than 1 week old */ if ((x = difftime(time(NULL), last_written)) > 7 * 86400) puts("Warning: These data are obsolete"); else printf("Data was last accessed %lf seconds ago.\n", x); }
RELATED FUNCTIONS |
SEE ALSO |
Chapter Contents |
Previous |
Next |
Top of Page |
Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.