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(3)						     Library Functions Manual						       difftime(3)

NAME

       difftime, difftime64 - Compares time values

LIBRARY

       Standard C Library (libc.so, libc.a)

SYNOPSIS

       #include <time.h>

       double difftime(
	       time_t time1,
	       time_t time2);

       The  following  function  declaration is a Compaq extension and does not conform to current standards. This function is provided to support
       the time64_t data type and is accessible only when the _TIME64_T feature macro is defined during compilation.  #include <time.h>

       double difftime64(
	       time64_t time64_1,
	       time64_t time64_2);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       difftime():  XPG4, XPG4-UNIX

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Specifies a time value of type time_t expressed in seconds.  Specifies a time value of type time_t expressed in seconds.  Specifies a  time
       value of type time64_t expressed in seconds.  Specifies a time value of type time64_t expressed in seconds.

DESCRIPTION

       The difftime() function returns a signed time value in seconds that is the difference between the values of the time1 and time2 parameters,
       also expressed in seconds.

       The difftime64() function works exactly as the difftime() function, but accepts arguments of type time64_t type instead	of  time_t.   This
       function  declaration  is only available when the _TIME64_T feature macro is defined during compilation. See the time(3) reference page for
       additional details.

NOTES

       The difftime() and difftime64() functions are supported for multithreaded applications.

RETURN VALUES

       Upon successful completion the difftime() function returns a value, expressed in seconds, that is the  difference  between  the	values	of
       parameters time1 and time2.

       Upon  successful  completion  the  difftime64() function returns a value,expressed in seconds, that is the difference between the values of
       parameters time64_1 and time64_2.

RELATED INFORMATION

       Functions: ctime(3), time(3), timezone(3)

       Standards: standards(5) delim off

																       difftime(3)