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Manual Pages  — TIME

NAME

boottime, time_second, time_uptime – system time variables

CONTENTS

SYNOPSIS

#include <sys/time.h>

extern struct timeval boottime;
extern time_t time_second;
extern time_t time_uptime;

DESCRIPTION

The boottime variable holds the system boot time.

The time_second variable is the system's "wall time" clock to the second.

The time_uptime variable is the number of seconds since boot.

The bintime(9), getbintime(9), microtime(9), getmicrotime(9), nanotime(9), and getnanotime(9) functions can be used to get the current time more accurately and in an atomic manner. Similarly, the binuptime(9), getbinuptime(9), microuptime(9), getmicrouptime(9), nanouptime(9), and getnanouptime(9) functions can be used to get the time elapse since boot more accurately and in an atomic manner. The boottime variable may be read and written without special precautions.

SEE ALSO

clock_settime(2), ntp_adjtime(2), settimeofday(2), bintime(9), binuptime(9), getbintime(9), getbinuptime(9), getmicrotime(9), getmicrouptime(9), getnanotime(9), getnanouptime(9), microtime(9), microuptime(9), nanotime(9), nanouptime(9)

Poul-Henning Kamp, Proceedings of EuroBSDCon 2002, Amsterdam, /usr/share/doc/papers/timecounter.ascii.gz, Timecounters: Efficient and precise timekeeping in SMP kernels,

Marshall Kirk McKusick, George V. Neville-Neil, The Design and Implementation of the FreeBSD Operating System, 57-61,65-66, Addison-Wesley, July 2004.


TIME (9) September 17, 2004

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