freebsd-skq/usr.bin/timeout/timeout.1
Ceri Davies c1a148873d sys/*/conf/*, docs: fix links to handbook
While here, fix all links to older en_US.ISO8859-1 documentation
in the src/ tree.

PR:             255026
Reported by:    Michael Büker <freebsd@michael-bueker.de>
Reviewed by:    dbaio
Approved by:    blackend (mentor), re (gjb)
MFC after:      10 days
Differential Revision: https://reviews.freebsd.org/D30265
2021-05-20 09:27:10 +01:00

207 lines
4.6 KiB
Groff

.\" 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 May 20, 2021
.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 PDF 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://download.freebsd.org/ftp/doc/en/books/handbook/book.pdf
.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