difftime (3)
Leading comments
Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
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Sin...
(The comments found at the beginning of the groff file "man3/difftime.3".)
NAME
difftime - 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).
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
difftime()
| Thread safety | MT-Safe
|
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.
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.
SEE ALSO
date(1),
gettimeofday(2),
time(2),
ctime(3),
gmtime(3),
localtime(3)
COLOPHON
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