GNU/Linux |
CentOS 5.1 |
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difftime(3) |
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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. The two times are specified in calendar time, which represents the time elapsed since the Epoch (00:00:00 on January 1, 1970, Coordinated Universal Time (UTC)).
SVr4, 4.3BSD, C99
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.
SVr4, 4.3BSD, POSIX.1-2001.
date(1), gettimeofday(2), time(2), ctime(3), gmtime(3), localtime(3)
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difftime(3) | ![]() |