Index: head/usr.bin/timeout/timeout.1
===================================================================
--- head/usr.bin/timeout/timeout.1	(revision 362993)
+++ head/usr.bin/timeout/timeout.1	(revision 362994)
@@ -1,150 +1,206 @@
 .\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 .\"
 .\" Copyright (c) 2014 Baptiste Daroussin <bapt@FreeBSD.org>
 .\" 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.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 28, 2018
+.Dd July 7, 2020
 .Dt TIMEOUT 1
 .Os
 .Sh NAME
 .Nm timeout
 .Nd run a command with a time limit
 .Sh SYNOPSIS
 .Nm
 .Op Fl -signal Ar sig | Fl s Ar sig
 .Op Fl -preserve-status
 .Op Fl -kill-after Ar time | Fl k Ar time
 .Op Fl -foreground
 .Ar duration
 .Ar command
 .Op Ar args ...
 .Sh DESCRIPTION
 .Nm
 starts the
 .Ar command
 with its
 .Ar args .
 If the
 .Ar command
 is still running after
 .Ar duration ,
 it is killed.
 By default,
 .Dv SIGTERM
 is sent.
 The special
 .Ar duration ,
 zero, signifies no limit.
 Therefore a signal is never sent if
 .Ar duration
 is 0.
 .Pp
 The options are as follows:
 .Bl -tag -width indent
 .It Fl -preserve-status
 Exit with the same status as
 .Ar command ,
 even if it times out and is killed.
 .It Fl -foreground
 Do not propagate timeout to the children of
 .Ar command .
 .It Fl s Ar sig , Fl -signal Ar sig
 Specify the signal to send on timeout.
 By default,
 .Dv SIGTERM
 is sent.
 .It Fl k Ar time , Fl -kill-after Ar time
 Send a
 .Dv SIGKILL
 signal if
 .Ar command
 is still running after
 .Ar time
 after the first signal was sent.
 .El
 .Sh DURATION FORMAT
 .Ar duration
 and
 .Ar time
 are non-negative integer or real (decimal) numbers, with an optional
 unit-specifying suffix.
 Values without an explicit unit are interpreted as seconds.
 .Pp
 Supported unit symbols are:
 .Bl -tag -width indent -compact
 .It Cm s
 seconds
 .It Cm m
 minutes
 .It Cm h
 hours
 .It Cm d
 days
 .El
 .Sh EXIT STATUS
 If the timeout was not reached, the exit status of
 .Ar command
 is returned.
 .Pp
 If the timeout was reached and
 .Fl -preserve-status
 is set, the exit status of
 .Ar command
 is returned.
 If
 .Fl -preserve-status
 is not set, an exit status of 124 is returned.
 .Pp
 If
 .Ar command
 exits after receiving a signal, the exit status returned is the signal number
 plus 128.
 .Pp
 If
 .Ar command
 refers to a non-existing program, the exit status returned is 127.
 .Pp
 If
 .Ar command
 is an otherwise invalid program, the exit status returned is 126.
 .Pp
 If an invalid parameter is passed to
 .Fl s
 or
 .Fl k ,
 the exit status returned is 125.
+.Sh EXAMPLES
+Run
+.Xr sleep 1
+with a time limit of 4 seconds.
+Since the command completes in 2 seconds, the exit status is 0:
+.Bd -literal -offset indent
+$ timeout 4 sleep 2
+$ echo $?
+0
+.Ed
+.Pp
+Run
+.Xr sleep 1
+for 4 seconds and terminate process after 2 seconds.
+124 is returned since no
+.Fl -preserve-status
+is used:
+.Bd -literal -offset indent
+$ timeout 2 sleep 4
+$ echo $?
+124
+.Ed
+.Pp
+Same as above but preserving status.
+Exit status is 128 + signal number (15 for
+.Va SIGTERM )
+.Bd -literal -offset indent
+$ timeout --preserve-status 2 sleep 4
+$ echo $?
+143
+.Ed
+.Pp
+Same as above but sending
+.Va SIGALRM
+(signal number 14) instead of
+.Va SIGTERM
+.Bd -literal -offset indent
+$ timeout --preserve-status -s SIGALRM 2 sleep 4
+$ echo $?
+142
+.Ed
+.Pp
+Try to
+.Xr fetch 1
+the single page version of the
+.Fx
+Handbook.
+Send a
+.Va SIGTERM
+signal after 1 minute and send a
+.Va SIGKILL
+signal 5 seconds later if the process refuses to stop:
+.Bd -literal -offset indent
+timeout -k 5s 1m fetch \\
+https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/book.html
+.Ed
 .Sh SEE ALSO
 .Xr kill 1 ,
 .Xr signal 3
 .Sh HISTORY
 The
 .Nm
 command first appeared in
 .Fx 10.3 .
 .Sh AUTHORS
 .An Baptiste Daroussin Aq Mt bapt@FreeBSD.org
 and
 .An Vsevolod Stakhov Aq Mt vsevolod@FreeBSD.org