DIFFTIME(3) Linux Programmer's Manual DIFFTIME(3)NAMEdifftime - calculate time difference
SYNOPSIS
#include <time.h>
double difftime(time_t time1, time_t time0);
DESCRIPTION
The difftime() function returns the number of seconds elapsed between
time time1 and time time0, represented as a double. Each of the times
is specified in calendar time, which means its value is a measurement
(in seconds) relative to the Epoch, 1970-01-01 00:00:00 +0000 (UTC).
CONFORMING TO
SVr4, 4.3BSD, C89, C99.
NOTES
On a POSIX system, time_t is an arithmetic type, and one could just
define
#define difftime(t1,t0) (double)(t1 - t0)
when the possible overflow in the subtraction is not a concern. On
other systems, the data type time_t might use some other encoding where
subtraction doesn't work directly.
SEE ALSOdate(1), gettimeofday(2), time(2), ctime(3), gmtime(3), localtime(3)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A
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be found at http://www.kernel.org/doc/man-pages/.
GNU 2010-02-25 DIFFTIME(3)