| NAME | SYNOPSIS | DESCRIPTION | CONFORMING TO | NOTES | SEE ALSO | COLOPHON | The Linux Programming Interface |
DIFFTIME(3) Linux Programmer's Manual DIFFTIME(3)
difftime - calculate time difference
#include <time.h>
double difftime(time_t time1, time_t time0);
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).
SVr4, 4.3BSD, C89, C99.
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.
date(1), gettimeofday(2), time(2), ctime(3), gmtime(3), localtime(3)
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GNU 2010-02-25 DIFFTIME(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface