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timeradd(3) [debian man page]

TIMERADD(3)						     Linux Programmer's Manual						       TIMERADD(3)

NAME
timeradd, timersub, timercmp, timerclear, timerisset - timeval operations SYNOPSIS
#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); int timerisset(struct timeval *tvp); int timercmp(struct timeval *a, struct timeval *b, CMP); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): All functions shown above: _BSD_SOURCE DESCRIPTION
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 in a and b, and places the sum in the timeval pointed to by res. The result is normalized such that res->tv_usec has a value in the range 0 to 999,999. timersub() subtracts the time value in b from the time value in a, and places the result in the timeval pointed to by res. The result is normalized such that res->tv_usec has a value in the range 0 to 999,999. timerclear() zeros out the timeval structure pointed to by tvp, so that it represents the Epoch: 1970-01-01 00:00:00 +0000 (UTC). timerisset() returns true (nonzero) if either field of the timeval structure pointed to by tvp contains a nonzero value. timercmp() compares the timer values in a and b using the comparison operator CMP, and returns true (nonzero) or false (0) depending on the result of the comparison. Some systems (but not Linux/glibc), have a broken timercmp() implementation, in which CMP of >=, <=, and == do not work; portable applications can instead use !timercmp(..., <) !timercmp(..., >) !timercmp(..., !=) RETURN VALUE
timerisset() and timercmp() return true (nonzero) or false (0). ERRORS
No errors are defined. CONFORMING TO
Not in POSIX.1-2001. Present on most BSD derivatives. SEE ALSO
gettimeofday(2), time(7) COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2010-02-25 TIMERADD(3)

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TIMERADD(3)						     Linux Programmer's Manual						       TIMERADD(3)

NAME
timeradd, timersub, timercmp, timerclear, timerisset - timeval operations SYNOPSIS
#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); int timerisset(struct timeval *tvp); int timercmp(struct timeval *a, struct timeval *b, CMP); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): All functions shown above: _BSD_SOURCE DESCRIPTION
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 in a and b, and places the sum in the timeval pointed to by res. The result is normalized such that res->tv_usec has a value in the range 0 to 999,999. timersub() subtracts the time value in b from the time value in a, and places the result in the timeval pointed to by res. The result is normalized such that res->tv_usec has a value in the range 0 to 999,999. timerclear() zeros out the timeval structure pointed to by tvp, so that it represents the Epoch: 1970-01-01 00:00:00 +0000 (UTC). timerisset() returns true (nonzero) if either field of the timeval structure pointed to by tvp contains a nonzero value. timercmp() compares the timer values in a and b using the comparison operator CMP, and returns true (nonzero) or false (0) depending on the result of the comparison. Some systems (but not Linux/glibc), have a broken timercmp() implementation, in which CMP of >=, <=, and == do not work; portable applications can instead use !timercmp(..., <) !timercmp(..., >) !timercmp(..., !=) RETURN VALUE
timerisset() and timercmp() return true (nonzero) or false (0). ERRORS
No errors are defined. CONFORMING TO
Not in POSIX.1-2001. Present on most BSD derivatives. SEE ALSO
gettimeofday(2), time(7) COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2010-02-25 TIMERADD(3)

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