kc3-lang/libbsd

diff --git a/COPYING b/COPYING
index 5b1e8c3..9ffc6b4 100644
--- a/COPYING
+++ b/COPYING
@@ -90,6 +90,7 @@ Files:
  include/bsd/netinet/ip_icmp.h
  include/bsd/sys/bitstring.h
  include/bsd/sys/queue.h
+ include/bsd/sys/time.h
  include/bsd/timeconv.h
  include/bsd/vis.h
  man/bitstring.3bsd
@@ -209,6 +210,37 @@ License: BSD-3-clause-Peter-Wemm
  SUCH DAMAGE.
 
 Files:
+ man/timeradd.3bsd
+Copyright:
+ Copyright © 2009 Jukka Ruohonen <jruohonen@iki.fi>
+ Copyright © 1999 Kelly Yancey <kbyanc@posi.net>
+ All rights reserved.
+License: BSD-3-clause-John-Birrell
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ 1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+ 3. Neither the name of the author nor the names of any co-contributors
+    may be used to endorse or promote products derived from this software
+    without specific prior written permission.
+ .
+ THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ SUCH DAMAGE.
+
+Files:
  man/setproctitle.3bsd
 Copyright:
  Copyright © 1995 Peter Wemm <peter@FreeBSD.org>
@@ -235,11 +267,12 @@ Files:
  man/fmtcheck.3bsd
  man/humanize_number.3bsd
  man/stringlist.3bsd
+ man/timeval.3bsd
  src/fmtcheck.c
  src/humanize_number.c
  src/stringlist.c
 Copyright:
- Copyright © 1994, 1997-2000, 2002, 2008 The NetBSD Foundation, Inc.
+ Copyright © 1994, 1997-2000, 2002, 2008, 2010 The NetBSD Foundation, Inc.
  All rights reserved.
  .
  Some code was contributed to The NetBSD Foundation by Allen Briggs.
@@ -256,6 +289,9 @@ Copyright:
  .
  Some code is derived from software contributed to The NetBSD Foundation
  by Christos Zoulas.
+ .
+ Some code is derived from software contributed to The NetBSD Foundation
+ by Jukka Ruohonen.
 License: BSD-2-clause-NetBSD
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
diff --git a/include/Makefile.am b/include/Makefile.am
index b8140d9..6c74b44 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -6,6 +6,7 @@ nobase_include_HEADERS = \
 	bsd/sys/endian.h \
 	bsd/sys/poll.h \
 	bsd/sys/queue.h \
+	bsd/sys/time.h \
 	bsd/sys/tree.h \
 	bsd/netinet/ip_icmp.h \
 	bsd/bitstring.h \
diff --git a/include/bsd/sys/time.h b/include/bsd/sys/time.h
new file mode 100644
index 0000000..0aaf0e2
--- /dev/null
+++ b/include/bsd/sys/time.h
@@ -0,0 +1,138 @@
+/*	$OpenBSD: time.h,v 1.36 2016/09/12 19:41:20 guenther Exp $	*/
+/*	$NetBSD: time.h,v 1.18 1996/04/23 10:29:33 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1982, 1986, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)time.h	8.2 (Berkeley) 7/10/94
+ */
+
+#ifdef LIBBSD_OVERLAY
+#include_next <sys/time.h>
+#else
+#include <sys/time.h>
+#endif
+
+#ifndef LIBBSD_SYS_TIME_H
+#define LIBBSD_SYS_TIME_H
+
+#ifndef TIMEVAL_TO_TIMESPEC
+#define	TIMEVAL_TO_TIMESPEC(tv, ts) {					\
+	(ts)->tv_sec = (tv)->tv_sec;					\
+	(ts)->tv_nsec = (tv)->tv_usec * 1000;				\
+}
+#endif
+
+#ifndef TIMESPEC_TO_TIMEVAL
+#define	TIMESPEC_TO_TIMEVAL(tv, ts) {					\
+	(tv)->tv_sec = (ts)->tv_sec;					\
+	(tv)->tv_usec = (ts)->tv_nsec / 1000;				\
+}
+#endif
+
+/* Operations on timevals. */
+#ifndef timerclear
+#define	timerclear(tvp)		(tvp)->tv_sec = (tvp)->tv_usec = 0
+#endif
+
+#ifndef timerisset
+#define	timerisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
+#endif
+
+#ifndef timercmp
+#define	timercmp(tvp, uvp, cmp)						\
+	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
+	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
+	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
+#endif
+
+#ifndef timeradd
+#define	timeradd(tvp, uvp, vvp)						\
+	do {								\
+		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
+		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
+		if ((vvp)->tv_usec >= 1000000) {			\
+			(vvp)->tv_sec++;				\
+			(vvp)->tv_usec -= 1000000;			\
+		}							\
+	} while (0)
+#endif
+
+#ifndef timersub
+#define	timersub(tvp, uvp, vvp)						\
+	do {								\
+		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
+		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
+		if ((vvp)->tv_usec < 0) {				\
+			(vvp)->tv_sec--;				\
+			(vvp)->tv_usec += 1000000;			\
+		}							\
+	} while (0)
+#endif
+
+/* Operations on timespecs. */
+#ifndef timespecclear
+#define	timespecclear(tsp)		(tsp)->tv_sec = (tsp)->tv_nsec = 0
+#endif
+
+#ifndef timespecisset
+#define	timespecisset(tsp)		((tsp)->tv_sec || (tsp)->tv_nsec)
+#endif
+
+#ifndef timespeccmp
+#define	timespeccmp(tsp, usp, cmp)					\
+	(((tsp)->tv_sec == (usp)->tv_sec) ?				\
+	    ((tsp)->tv_nsec cmp (usp)->tv_nsec) :			\
+	    ((tsp)->tv_sec cmp (usp)->tv_sec))
+#endif
+
+#ifndef timespecadd
+#define	timespecadd(tsp, usp, vsp)					\
+	do {								\
+		(vsp)->tv_sec = (tsp)->tv_sec + (usp)->tv_sec;		\
+		(vsp)->tv_nsec = (tsp)->tv_nsec + (usp)->tv_nsec;	\
+		if ((vsp)->tv_nsec >= 1000000000L) {			\
+			(vsp)->tv_sec++;				\
+			(vsp)->tv_nsec -= 1000000000L;			\
+		}							\
+	} while (0)
+#endif
+
+#ifndef timespecsub
+#define	timespecsub(tsp, usp, vsp)					\
+	do {								\
+		(vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec;		\
+		(vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec;	\
+		if ((vsp)->tv_nsec < 0) {				\
+			(vsp)->tv_sec--;				\
+			(vsp)->tv_nsec += 1000000000L;			\
+		}							\
+	} while (0)
+#endif
+
+#endif
diff --git a/man/Makefile.am b/man/Makefile.am
index 92da18d..fe0c335 100644
--- a/man/Makefile.am
+++ b/man/Makefile.am
@@ -132,6 +132,8 @@ dist_man_MANS = \
 	TAILQ_PREV.3bsd \
 	TAILQ_REMOVE.3bsd \
 	TAILQ_SWAP.3bsd \
+	TIMESPEC_TO_TIMEVAL.3bsd \
+	TIMEVAL_TO_TIMESPEC.3bsd \
 	arc4random.3bsd \
 	arc4random_addrandom.3bsd \
 	arc4random_buf.3bsd \
@@ -213,6 +215,17 @@ dist_man_MANS = \
 	strunvis.3bsd \
 	strvis.3bsd \
 	strvisx.3bsd \
+	timeradd.3bsd \
+	timerclear.3bsd \
+	timercmp.3bsd \
+	timerisset.3bsd \
+	timersub.3bsd \
+	timespecadd.3bsd \
+	timespecclear.3bsd \
+	timespeccmp.3bsd \
+	timespecisset.3bsd \
+	timespecsub.3bsd \
+	timeval.3bsd \
 	tree.3bsd \
 	unvis.3bsd \
 	vis.3bsd \
diff --git a/man/TIMESPEC_TO_TIMEVAL.3bsd b/man/TIMESPEC_TO_TIMEVAL.3bsd
new file mode 100644
index 0000000..e47176e
--- /dev/null
+++ b/man/TIMESPEC_TO_TIMEVAL.3bsd
@@ -0,0 +1 @@
+.so man3/timeval.3bsd
diff --git a/man/TIMEVAL_TO_TIMESPEC.3bsd b/man/TIMEVAL_TO_TIMESPEC.3bsd
new file mode 100644
index 0000000..e47176e
--- /dev/null
+++ b/man/TIMEVAL_TO_TIMESPEC.3bsd
@@ -0,0 +1 @@
+.so man3/timeval.3bsd
diff --git a/man/libbsd.7 b/man/libbsd.7
index 216bc01..19af0aa 100644
--- a/man/libbsd.7
+++ b/man/libbsd.7
@@ -108,6 +108,7 @@ be prefixed with
 .It In sys/endian.h
 .It In sys/poll.h
 .It In sys/queue.h
+.It In sys/time.h
 .It In sys/tree.h
 .It In timeconv.h
 .It In unistd.h
@@ -191,6 +192,8 @@ might disappear on the next SONAME bump.
 .Xr strmode 3bsd ,
 .Xr strnstr 3bsd ,
 .Xr strtonum 3bsd ,
+.Xr timeradd 3bsd ,
+.Xr timeval 3bsd ,
 .Xr tree 3bsd ,
 .Xr unvis 3bsd ,
 .Xr vis 3bsd ,
diff --git a/man/timeradd.3bsd b/man/timeradd.3bsd
new file mode 100644
index 0000000..df821de
--- /dev/null
+++ b/man/timeradd.3bsd
@@ -0,0 +1,159 @@
+.\" $NetBSD: timeradd.3,v 1.8 2010/06/07 18:40:16 jruoho Exp $
+.\"
+.\" Copyright (c) 2009 Jukka Ruohonen <jruohonen@iki.fi>
+.\" Copyright (c) 1999 Kelly Yancey <kbyanc@posi.net>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the author nor the names of any co-contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD: src/share/man/man3/timeradd.3,v 1.3 2003/09/08 19:57:19 ru Exp $
+.\"
+.Dd June 7, 2010
+.Dt TIMERADD 3
+.Os
+.Sh NAME
+.Nm timeradd ,
+.Nm timersub ,
+.Nm timerclear ,
+.Nm timerisset ,
+.Nm timercmp ,
+.Nm timespecadd ,
+.Nm timespecsub ,
+.Nm timespecclear ,
+.Nm timespecisset ,
+.Nm timespeccmp
+.Nd operations on time structure
+.Sh LIBRARY
+.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
+.Lb libbsd
+.Sh SYNOPSIS
+.In sys/time.h
+(See
+.Xr libbsd 7
+for include usage.)
+.Ft void
+.Fn timeradd "struct timeval *a" "struct timeval *b" "struct timeval *res"
+.Ft void
+.Fn timersub "struct timeval *a" "struct timeval *b" "struct timeval *res"
+.Ft void
+.Fn timerclear "struct timeval *tv"
+.Ft int
+.Fn timerisset "struct timeval *tv"
+.Ft int
+.Fn timercmp "struct timeval *a" "struct timeval *b" CMP
+.Ft void
+.Fn timespecadd "struct timespec *a" \
+"struct timespec *b" "struct timespec *res"
+.Ft void
+.Fn timespecsub "struct timespec *a" \
+"struct timespec *b" "struct timespec *res"
+.Ft void
+.Fn timespecclear "struct timespec *ts"
+.Ft int
+.Fn timespecisset "struct timespec *ts"
+.Ft int
+.Fn timespeccmp "struct timespec *a" "struct timespec b" CMP
+.Sh DESCRIPTION
+These macros are provided for manipulating the
+.Fa timeval
+and
+.Fa timespec
+structures described in
+.Xr timeval 3 .
+.Pp
+The
+.Fn timeradd
+and
+.Fn timespecadd
+macros add the time information stored in
+.Fa a
+to
+.Fa b ,
+storing the result in
+.Fa res .
+With
+.Fn timeradd
+the results are simplified such that the value of
+.Fa res->tv_usec
+is always less than 1,000,000 (1 second).
+With
+.Fn timespecadd
+the
+.Fa res->tv_nsec
+member of
+.Fa struct timespec
+is always less than 1,000,000,000.
+.Pp
+The
+.Fn timersub
+and
+.Fn timespecsub
+macros subtract the time information stored in
+.Fa b
+from
+.Fa a
+and store the resulting structure
+in
+.Fa res .
+.Pp
+The
+.Fn timerclear
+and
+.Fn timespecclear
+macros initialize the structures
+to midnight (0 hour) January 1st, 1970 (the Epoch).
+In other words, they set the members of the structure to zero.
+.Pp
+The
+.Fn timerisset
+and
+.Fn timespecisset
+macros return true if the input structure
+is set to any time value other than the Epoch.
+.Pp
+The
+.Fn timercmp
+and
+.Fn timespeccmp
+macros compare
+.Fa a
+to
+.Fa b
+using the comparison operator given in
+.Fa CMP .
+The result of the comparison is returned.
+.Sh SEE ALSO
+.Xr timeval 3
+.Sh HISTORY
+The
+.Fn timeradd
+family of macros first appeared in
+.Nx 1.1 .
+These were later ported to
+.Fx 2.2.6 .
+The
+.Fn timespec
+family of macros first appeared in
+.Nx 1.2 .
diff --git a/man/timerclear.3bsd b/man/timerclear.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timerclear.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timercmp.3bsd b/man/timercmp.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timercmp.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timerisset.3bsd b/man/timerisset.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timerisset.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timersub.3bsd b/man/timersub.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timersub.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timespecadd.3bsd b/man/timespecadd.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timespecadd.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timespecclear.3bsd b/man/timespecclear.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timespecclear.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timespeccmp.3bsd b/man/timespeccmp.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timespeccmp.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timespecisset.3bsd b/man/timespecisset.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timespecisset.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timespecsub.3bsd b/man/timespecsub.3bsd
new file mode 100644
index 0000000..9ac4e5c
--- /dev/null
+++ b/man/timespecsub.3bsd
@@ -0,0 +1 @@
+.so man3/timeradd.3bsd
diff --git a/man/timeval.3bsd b/man/timeval.3bsd
new file mode 100644
index 0000000..8f0e3aa
--- /dev/null
+++ b/man/timeval.3bsd
@@ -0,0 +1,133 @@
+.\" $NetBSD: timeval.3,v 1.12 2011/04/12 08:39:26 jruoho Exp $
+.\"
+.\" Copyright (c) 2010 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Jukka Ruohonen.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd April 12, 2011
+.Dt TIMEVAL 3
+.Os
+.Sh NAME
+.Nm timeval ,
+.Nm timespec
+.Nd time structures
+.Sh LIBRARY
+.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
+.Lb libbsd
+.Sh SYNOPSIS
+.In sys/time.h
+(See
+.Xr libbsd 7
+for include usage.)
+.Ft void
+.Fn TIMEVAL_TO_TIMESPEC "struct timeval *tv" "struct timespec *ts"
+.Ft void
+.Fn TIMESPEC_TO_TIMEVAL "struct timeval *tv" "struct timespec *ts"
+.Sh DESCRIPTION
+The
+.In sys/time.h
+header, included by
+.In time.h ,
+defines various structures related to time and timers.
+.Bl -enum -offset 1n
+.It
+The following structure is used by
+.Xr gettimeofday 2 ,
+among others:
+.Bd -literal -offset indent
+struct timeval {
+	time_t		tv_sec;
+	suseconds_t	tv_usec;
+};
+.Ed
+.Pp
+The
+.Va tv_sec
+member represents the elapsed time, in whole seconds.
+The
+.Va tv_usec
+member captures rest of the elapsed time,
+represented as the number of microseconds.
+.It
+The following structure is used by
+.Xr nanosleep 2 ,
+among others:
+.Bd -literal -offset indent
+struct timespec {
+	time_t		tv_sec;
+	long		tv_nsec;
+};
+.Ed
+.Pp
+The
+.Va tv_sec
+member is again the elapsed time in whole seconds.
+The
+.Va tv_nsec
+member represents the rest of the elapsed time in nanoseconds.
+.Pp
+A microsecond is equal to one millionth of a second,
+1000 nanoseconds, or 1/1000 milliseconds.
+To ease the conversions, the macros
+.Fn TIMEVAL_TO_TIMESPEC
+and
+.Fn TIMESPEC_TO_TIMEVAL
+can be used to convert between
+.Em struct timeval
+and
+.Em struct timespec .
+.El
+.Sh EXAMPLES
+It can be stressed that the traditional
+.Tn UNIX
+.Va timeval
+and
+.Va timespec
+structures represent elapsed time, measured by the system clock.
+The following sketch implements a function suitable
+for use in a context where the
+.Va timespec
+structure is required for a conditional timeout:
+.Bd -literal -offset indent
+static void
+example(struct timespec *spec, time_t minutes)
+{
+	struct timeval elapsed;
+
+	(void)gettimeofday(&elapsed, NULL);
+
+	_DIAGASSERT(spec != NULL);
+	TIMEVAL_TO_TIMESPEC(&elapsed, spec);
+
+	/* Add the offset for timeout in minutes. */
+	spec->tv_sec = spec->tv_sec + minutes * 60;
+}
+.Ed
+.Pp
+A better alternative would use the more precise
+.Xr clock_gettime 2 .
+.Sh SEE ALSO
+.Xr timeradd 3