difftime(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

DIFFTIME(3)             Linux Programmer's Manual            DIFFTIME(3)

NAME         top

       difftime - calculate time difference

SYNOPSIS         top

       #include <time.h>

       double difftime(time_t time1, time_t time0);

DESCRIPTION         top

       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         top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │Interface                             Attribute     Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │difftime()                            │ Thread safety │ MT-Safe │
       └──────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.

NOTES         top

       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         top

       date(1), gettimeofday(2), time(2), ctime(3), gmtime(3),
       localtime(3)

COLOPHON         top

       This page is part of release 5.11 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

GNU                            2021-03-22                    DIFFTIME(3)

Pages that refer to this page: ctime(3)system_data_types(7)