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TIMEOUT(1) General Commands Manual TIMEOUT(1)

timeoutrun a command with a time limit

timeout [--signal sig | -s sig] [--preserve-status] [--kill-after time | -k time] [--foreground] duration command [args ...]

timeout starts the command with its args. If the command is still running after duration, it is killed. By default, SIGTERM is sent. The special duration, zero, signifies no limit. Therefore a signal is never sent if duration is 0.

The options are as follows:

Exit with the same status as command, even if it times out and is killed.
Do not propagate timeout to the children of command.
sig, --signal sig
Specify the signal to send on timeout. By default, SIGTERM is sent.
time, --kill-after time
Send a SIGKILL signal if command is still running after time after the first signal was sent.

duration and time are non-negative integer or real (decimal) numbers, with an optional unit-specifying suffix. Values without an explicit unit are interpreted as seconds.

Supported unit symbols are:

seconds
minutes
hours
days

If the timeout was not reached, the exit status of command is returned.

If the timeout was reached and --preserve-status is set, the exit status of command is returned. If --preserve-status is not set, an exit status of 124 is returned.

If command exits after receiving a signal, the exit status returned is the signal number plus 128.

If command refers to a non-existing program, the exit status returned is 127.

If command is an otherwise invalid program, the exit status returned is 126.

If an invalid parameter is passed to -s or -k, the exit status returned is 125.

Run sleep(1) with a time limit of 4 seconds. Since the command completes in 2 seconds, the exit status is 0:

$ timeout 4 sleep 2
$ echo $?
0

Run sleep(1) for 4 seconds and terminate process after 2 seconds. 124 is returned since no --preserve-status is used:

$ timeout 2 sleep 4
$ echo $?
124

Same as above but preserving status. Exit status is 128 + signal number (15 for SIGTERM):

$ timeout --preserve-status 2 sleep 4
$ echo $?
143

Same as above but sending SIGALRM (signal number 14) instead of SIGTERM:

$ timeout --preserve-status -s SIGALRM 2 sleep 4
$ echo $?
142

Try to fetch(1) the PDF version of the FreeBSD Handbook. Send a SIGTERM signal after 1 minute and send a SIGKILL signal 5 seconds later if the process refuses to stop:

$ timeout -k 5s 1m fetch \
> https://download.freebsd.org/ftp/doc/en/books/handbook/book.pdf

kill(1), nohup(1), signal(3), daemon(8)

The timeout utility is compliant with the specification.

The timeout command first appeared in FreeBSD 10.3.

Baptiste Daroussin <bapt@FreeBSD.org> and
Vsevolod Stakhov <vsevolod@FreeBSD.org>

June 17, 2024 dev