.\" SPDX-License-Identifier: BSD-2-Clause .\" .\" Copyright (c) 2014 Baptiste Daroussin <[email protected]> .\" Copyright (c) 2025 Aaron LI <[email protected]> .\" 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. .\" .Dd April 3, 2025 .Dt TIMEOUT 1 .Os .Sh NAME .Nm timeout .Nd run a command with a time limit .Sh SYNOPSIS .Nm .Op Fl f | Fl -foreground .Op Fl k Ar time | Fl -kill-after Ar time .Op Fl p | Fl -preserve-status .Op Fl s Ar signal | Fl -signal Ar signal .Op Fl v | Fl -verbose .Ar duration .Ar command .Op Ar arg ... .Sh DESCRIPTION .Nm Timeout starts the .Ar command with its .Ar arg list. If the .Ar command is still running after .Ar duration , it is killed by sending the .Ar signal , or .Dv SIGTERM if the .Fl s option is unspecified. The special .Ar duration , zero, signifies no limit. Therefore, a signal is never sent if .Ar duration is 0. .Pp The signal dispositions inherited by the .Ar command are the same as the dispositions that .Nm inherited, except for the signal that will be sent upon timeout, which is reset to take the default action and should terminate the process. .Pp If .Nm receives the .Dv SIGALRM signal, it will behave as if the time limit has been reached and send the specified signal to .Ar command . For any other signals delivered to .Nm , it will propagate them to .Ar command , with the exception of .Dv SIGKILL and .Dv SIGSTOP . If you want to prevent the .Ar command from being timed out, send .Dv SIGKILL to .Nm . .Pp The options are as follows: .Bl -tag -width indent .It Fl f , Fl -foreground Only time out the .Ar command itself, but do not propagate signals to its descendants. See the .Sx IMPLEMENTATION NOTES section for more details. .It Fl k Ar time , Fl -kill-after Ar time Send a .Dv SIGKILL signal if .Ar command is still running after .Ar time since the first signal was sent. .It Fl p , Fl -preserve-status Always exit with the same status as .Ar command , even if the timeout was reached. .It Fl s Ar signal , Fl -signal Ar signal Specify the signal to send on timeout. By default, .Dv SIGTERM is sent. .It Fl v , Fl -verbose Show information to .Xr stderr 4 about timeouts, signals to be sent, and the .Ar command exits. .El .Ss Duration Format The .Ar duration and .Ar time are non-negative integer or real (decimal) numbers, with an optional suffix specifying the unit. Values without an explicit unit are interpreted as seconds. .Pp Supported unit suffixes 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 IMPLEMENTATION NOTES If the .Fl -foreground option is not specified, .Nm runs as the reaper (see also .Xr procctl 2 ) of the .Ar command and its descendants, and will wait for all the descendants to terminate. This behavior might cause surprises if there are descendants running in the background, because they will ignore .Dv SIGINT and .Dv SIGQUIT signals. For example, the following command that sends a .Dv SIGTERM signal will complete in 2 seconds: .Dl $ timeout -s TERM 2 sh -c 'sleep 4 & sleep 5' However, this command that sends a .Dv SIGINT signal will complete in 4 seconds: .Dl $ timeout -s INT 2 sh -c 'sleep 4 & sleep 5' .Sh EXIT STATUS If the time limit was reached and the .Fl -preserve-status option is not specified, the exit status is 124. Otherwise, .Nm exits with the same exit status as the .Ar command . For example, .Nm will terminate itself with the same signal if the .Ar command is terminated by a signal. .Pp If an error occurred, the following exit values are returned: .Bl -tag -offset indent with indent -compact .It 125 An error other than the two described below occurred. For example, an invalid duration or signal was specified. .It 126 The .Ar command was found but could not be executed. .It 127 The .Ar command could not be found. .El .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. The exit status is 124 since .Fl -preserve-status is not used: .Bd -literal -offset indent $ timeout 2 sleep 4 $ echo $? 124 .Ed .Pp Same as above but preserving status. The exit status is 128 + signal number (15 for .Dv SIGTERM ) for most shells: .Bd -literal -offset indent $ timeout --preserve-status 2 sleep 4 $ echo $? 143 .Ed .Pp Same as above but sending .Dv SIGALRM (signal number 14) instead of .Dv 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 .Dv SIGTERM signal after 1 minute and send a .Dv 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 expected to conform to the .St -p1003.1-2024 specification. .Sh HISTORY The .Nm command first appeared in .Fx 10.3 . .Pp The initial .Fx work was 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 [email protected] , .An Vsevolod Stakhov Aq Mt [email protected] and .An Aaron LI Aq Mt [email protected]
