bin/timeout/timeout.1

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.\" Copyright (c) 2014 Baptiste Daroussin <bapt@FreeBSD.org>
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.Dd January 4, 2025
.Dt TIMEOUT 1
.Os
.Sh NAME
.Nm timeout
.Nd run a command with a time limit
.Sh SYNOPSIS
.Nm
.Op Fl k Ar time | Fl -kill-after Ar time
.Op Fl s Ar sig | Fl -signal Ar sig
.Op Fl v | Fl -verbose
.Op Fl -foreground
.Op Fl -preserve-status
.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 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.
.It Fl s Ar sig , Fl -signal Ar sig
Specify the signal to send on timeout.
By default,
.Dv SIGTERM
is sent.
.It Fl v , Fl -verbose
Show information to stderr about any signal sent on timeout.
.It Fl -foreground
Do not propagate timeout to the children of
.Ar command .
.It Fl -preserve-status
Exit with the same status as
.Ar command ,
even if it times out and is killed.
.El
.Sh DURATION FORMAT
The
.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 -offset indent -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 an invalid parameter is passed to
.Fl s
or
.Fl k ,
the exit status returned is 125.
.Pp
If
.Ar command
is an otherwise invalid program, the exit status returned is 126.
.Pp
If
.Ar command
refers to a non-existing program, the exit status returned is 127.
.Pp
If
.Ar command
exits after receiving a signal, the exit status returned is the signal number
plus 128.
.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 nohup 1 ,
.Xr signal 3 ,
.Xr daemon 8
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2024
specification.
.Sh HISTORY
The
.Nm
command first appeared in
.Fx 10.3 .
.Pp
The
.Fx
work is compatible with GNU
.Nm
by
.An Padraig Brady ,
from GNU Coreutils 8.21.
The
.Nm
utility first appeared in GNU Coreutils 7.0.
.Sh AUTHORS
.An Baptiste Daroussin Aq Mt bapt@FreeBSD.org
and
.An Vsevolod Stakhov Aq Mt vsevolod@FreeBSD.org