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).
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.
This page is part of release 3.33 of the Linux man-pages project. A
description of the project, and information about reporting
bugs, can be found at http://man7.org/linux/man-pages/.
|
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. References consulted: Linux libc source code Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) 386BSD man pages Modified Sat Jul 24 19:48:17 1993 by Rik Faith (faithcs.unc.edu) |