timeradd, timersub, timercmp, timerclear, timerisset — timeval operations
#include <sys/time.h>
void
timeradd( |
struct timeval * | a, |
struct timeval * | b, | |
struct timeval * | res) ; |
void
timersub( |
struct timeval * | a, |
struct timeval * | b, | |
struct timeval * | res) ; |
void
timerclear( |
struct timeval * | tvp) ; |
void
timerisset( |
struct timeval * | tvp) ; |
void
timercmp( |
struct timeval * | a, |
struct timeval * | b, | |
CMP) ; |
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Note | |
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The macros are provided to operate on timeval
structures, defined
in <
sys/time.h
>
as:
struct timeval { time_t tv_sec
; /* seconds */suseconds_t tv_usec
; /* microseconds */};
timeradd
() adds the time values ina
andb
, and places the sum in thetimeval
pointed to byres
. The result is normalized such thatres->tv_usec
has a value in the range 0 to 999,999.
timersub
() subtracts the time value inb
from the time value ina
, and places the result in thetimeval
pointed to byres
. The result is normalized such thatres->tv_usec
has a value in the range 0 to 999,999.
timerclear
() zeroes out thetimeval
structure pointed to bytvp
, so that it represents the time at midnight on the morning of 1 January 1970 (the Epoch).
timerisset
() returns true (non-zero) if either field of thetimeval
structure pointed to bytvp
contains a non-zero value.
timercmp
() compares the timer values ina
andb
using the comparison operatorCMP
, and returns true (non-zero) or false (0) depending on the result of the comparison.
Copyright (c) 2007 by Michael Kerrisk <mtk-manpagesgmx.net> Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. 2007-07-31, mtk, Created |