difftime(3) [opendarwin man page]

DIFFTIME(3)                                                  Linux Programmer's Manual                                                 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

       This  page is part of release 4.15 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                                                                 2015-08-08                                                         DIFFTIME(3)

DIFFTIME(3P)						     POSIX Programmer's Manual						      DIFFTIME(3P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME

       difftime -- compute the difference between two calendar time values

SYNOPSIS

       #include <time.h>

       double difftime(time_t time1, time_t time0);

DESCRIPTION

       The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here
       and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.

       The difftime() function shall compute the difference between two calendar times (as returned by time()): time1- time0.

RETURN VALUE

       The difftime() function shall return the difference expressed in seconds as a type double.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       asctime(), clock(), ctime(), gmtime(), localtime(), mktime(), strftime(), strptime(), time(), utime()

       The Base Definitions volume of POSIX.1-2008, <time.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C)  2013  by	the  Institute	of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Stan-
       dard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE
/The Open Group						       2013							      DIFFTIME(3P)