.\"	$NetBSD: timespec_get.3,v 1.9 2025/04/22 14:25:50 uwe Exp $
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Kamil Rytarowski.
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.Dd April 22, 2025
.Dt TIMESPEC_GET 3
.Os
.
.Sh NAME
.Nm timespec_get ,
.Nm timespec_getres
.Nd get current calendar time
.
.Sh LIBRARY
.Lb libc
.
.Sh SYNOPSIS
.
.In time.h
.
.Ft int
.Fn timespec_get "struct timespec *ts" "int base"
.
.Ft int
.Fn timespec_getres "struct timespec *ts" "int base"
.
.Sh DESCRIPTION
The
.Fn timespec_get
function sets the interval pointed to by
.Fa ts
to hold the current calendar time based on the specified time base in
.Fa base .
It is the
.Tn ISO C
equivalent to the
.Tn POSIX
function
.Xr clock_gettime 2 .
.Pp
The base
.Dv TIME_UTC
returns the time since the epoch.
This time is expressed in seconds and nanoseconds since midnight (0 hour), January 1, 1970.
In
.Nx ,
this corresponds to
.Dv CLOCK_REALTIME .
.Pp
The base
.Dv TIME_MONOTONIC
returns the seconds and nanoseconds since an implementation-defined reference
point in such a way that a second call will never return a value less than the
first.
In
.Nx ,
this corresponds to
.Dv CLOCK_MONOTONIC .
.Pp
The resolution of each timer can be queried using
.Fn timespec_getres .
Each successive call to this function will return the same value for a
specific clock.
It is the
.Tn ISO C
equivalent to the
.Tn POSIX
function
.Xr clock_getres 2 .
.Sh RETURN VALUES
These functions return the passed non-zero value of
.Fa base
if successful, otherwise 0 on failure.
.Sh SEE ALSO
.Xr clock_gettime 2 ,
.Xr gettimeofday 2 ,
.Xr time 3
.Sh STANDARDS
The
.Fn timespec_get
function with a
.Fa base
of
.Dv TIME_UTC
conforms to
.St -isoC-2011 .
The
.Fa base
of
.Dv TIME_MONOTONIC
is specified in
.St -isoC-2023 .
.Pp
The
.Fn timespec_getres
function conforms to
.St -isoC-2023 .
.Sh HISTORY
The
.Fn timespec_get
function first appeared in
.Nx 8.0 .
.Pp
The
.Fn timespec_getres
function first appeared in
.Nx 11.0 .
.Sh AUTHORS
.An Kamil Rytarowski Aq Mt kamil@NetBSD.org
.An Nia Alarie Aq Mt nia@NetBSD.org