difftime

Section: C Library Functions (3)
Updated: 2022-12-29
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NAME

difftime - calculate time difference  

LIBRARY

Standard C library (libc, -lc)  

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).
InterfaceAttributeValue
difftime() Thread safetyMT-Safe

 

STANDARDS

POSIX.1-2001, POSIX.1-2008, 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)


 

Index

NAME
LIBRARY
SYNOPSIS
DESCRIPTION
ATTRIBUTES
STANDARDS
NOTES
SEE ALSO

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Time: 05:19:10 GMT, April 25, 2024