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I'd like to schedule a command to run after reboot on a Linux box. I know how to do this so the command consistently runs after every reboot with a @reboot crontab entry, however I only want the command to run once. After it runs, it should be removed from the queue of commands to run. I'm essentially looking for a Linux equivalent to RunOnce in the Windows world.

In case it matters:

$ uname -a
Linux devbox #1 SMP 2009-02-28 04:40:21 +0100 x86_64 x86_64 x86_64 GNU/Linux
$ bash --version
GNU bash, version 3.2.48(1)-release (x86_64-suse-linux-gnu)
Copyright (C) 2007 Free Software Foundation, Inc.
$ cat /etc/SuSE-release
SUSE Linux Enterprise Server 11 (x86_64)

Is there an easy, scriptable way to do this?

share|improve this question
RunOnce is an artifact of Windows resulting from problems completing configuration before a reboot. Is there any reason you can't run your script before reboot? The above solution appears to be a reasonable clone of RunOnce. – BillThor Jun 5 '10 at 0:49

Create an @reboot entry in your crontab to run a script called /usr/local/bin/runonce.

Create a directory structure called /etc/local/runonce.d/ran using mkdir -p.

Create the script /usr/local/bin/runonce as follows:

for file in /etc/local/runonce.d/*
    if [ ! -f "$file" ]
    mv "$file" "/etc/local/runonce.d/ran/$file.$(date +%Y%m%dT%H%M%S)"
    logger -t runonce -p "$file"

Now place any script you want run at the next reboot (once only) in the directory /etc/local/runonce.d and chown and chmod +x it appropriately. Once it's been run, you'll find it moved to the ran subdirectory and the date and time appended to its name. There will also be an entry in your syslog.

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for file in /etc/local/runonce.d/*, no? – pra Jun 5 '10 at 5:00
@pra: Thanks for spotting that. – Dennis Williamson Jun 5 '10 at 5:25
Thanks for your answer. This solution is great. It technically solves my problem, however it seems like there's a lot of preparation of infrastructure required to make this work. It's not portable. I think your solution would ideally be baked into a Linux distribution (I'm not sure why it isn't!). Your answer inspired my ultimate solution, which I've also posted as an answer. Thanks again! – Christopher Parker Jun 9 '10 at 18:51
What made you choose local3, versus any of the other facilities between 0 and 7? – Christopher Parker Jun 10 '10 at 19:49
@Christopher: A dice roll is always the best method. Seriously, though, for an example it didn't matter and that's the key my finger landed on. Besides, I don't own any eight-sided die. – Dennis Williamson Jun 10 '10 at 20:19
up vote 15 down vote accepted

I really appreciate the effort put into Dennis Williamson's answer. I wanted to accept it as the answer to this question, as it is elegant and simple, however:

  • I ultimately felt that it required too many steps to set up.
  • It requires root access.

I think his solution would be great as an out-of-the-box feature of a Linux distribution.

That being said, I wrote my own script to accomplish more or less the same thing as Dennis's solution. It doesn't require any extra setup steps and it doesn't require root access.


if [[ $# -eq 0 ]]; then
    echo "Schedules a command to be run after the next reboot."
    echo "Usage: $(basename $0) <command>"
    echo "       $(basename $0) -p <path> <command>"
    echo "       $(basename $0) -r <command>"

    while getopts ":r:p:" optionName; do
        case "$optionName" in
            r) REMOVE=1; COMMAND=$OPTARG;;
            p) SCRIPTPATH=$OPTARG;;

    SCRIPT="${HOME}/.$(basename $0)_$(echo $COMMAND | sed 's/[^a-zA-Z0-9_]/_/g')"

    if [[ ! -f $SCRIPT ]]; then
        echo "PATH=$SCRIPTPATH" >> $SCRIPT
        echo "cd $(pwd)"        >> $SCRIPT
        echo "logger -t $(basename $0) -p \"COMMAND=$COMMAND ; USER=\$(whoami) ($(logname)) ; PWD=$(pwd) ; PATH=\$PATH\"" >> $SCRIPT
        echo "$COMMAND | logger -t $(basename $0) -p" >> $SCRIPT
        echo "$0 -r \"$(echo $COMMAND | sed 's/\"/\\\"/g')\""     >> $SCRIPT
        chmod +x $SCRIPT

    CRONTAB="${HOME}/.$(basename $0)_temp_crontab_$RANDOM"
    ENTRY="@reboot $SCRIPT"

    echo "$(crontab -l 2>/dev/null)" | grep -v "$ENTRY" | grep -v "^# DO NOT EDIT THIS FILE - edit the master and reinstall.$" | grep -v "^# ([^ ]* installed on [^)]*)$" | grep -v "^# (Cron version [^$]*\$[^$]*\$)$" > $CRONTAB

    if [[ $REMOVE -eq 0 ]]; then
        echo "$ENTRY" >> $CRONTAB

    crontab $CRONTAB
    rm $CRONTAB

    if [[ $REMOVE -ne 0 ]]; then
        rm $SCRIPT

Save this script (e.g.: runonce), chmod +x, and run:

$ runonce foo
$ runonce "echo \"I'm up. I swear I'll never email you again.\" | mail -s \"Server's Up\" $(whoami)"

In the event of a typo, you can remove a command from the runonce queue with the -r flag:

$ runonce fop
$ runonce -r fop
$ runonce foo

Using sudo works the way you'd expect it to work. Useful for starting a server just once after the next reboot.

myuser@myhost:/home/myuser$ sudo runonce foo
myuser@myhost:/home/myuser$ sudo crontab -l
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/root/.runonce_temp_crontab_10478 installed on Wed Jun  9 16:56:00 2010)
# (Cron version V5.0 -- $Id: crontab.c,v 1.12 2004/01/23 18:56:42 vixie Exp $)
@reboot /root/.runonce_foo
myuser@myhost:/home/myuser$ sudo cat /root/.runonce_foo
cd /home/myuser
/home/myuser/bin/runonce -r "foo"

Some notes:

  • This script replicates the environment (PATH, working directory, user) it was invoked in.
  • It's designed to basically defer execution of a command as it would be executed "right here, right now" until after the next boot sequence.
share|improve this answer
Your script looks really handy. One thing to note is that it destructively strips comments out of the crontab. – Dennis Williamson Jun 9 '10 at 21:39
@Dennis: Thanks. I originally didn't have that extra grep call in there, but all of the comments were piling up; three for every time I ran the script. I think I'll change the script to just always remove comment lines that look like those three auto-generated comments. – Christopher Parker Jun 9 '10 at 21:47
@Dennis: Done. The patterns could probably be better, but it works for me. – Christopher Parker Jun 9 '10 at 22:02
@Dennis: Actually, based on crontab.c, I think my patterns are just fine. (Search for "DO NOT EDIT THIS FILE" at – Christopher Parker Jun 10 '10 at 23:24

Set up the script in /etc/rc5.d with an S99 and have it delete itself after running.

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You can do this with the at command, although I notice you can't (at least on RHEL 5, which I tested on) use at @reboot or at reboot, but you can use at now + 2 minutes and then shutdown -r now.

This doesn't require that you system take longer than 2 minutes to run.

It may be useful where you want 0 set-up, although I do rather wish the 'runonce' command was standard kit.

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I think this answer is the most elegant:

Place script in /etc/init.d/script and self-delete with last line: rm $0

Unless the script is 100% fail-proof, probably wise to handle exceptions to avoid a fatal error loop..

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in redhat and debian systems you can do that from /etc/rc.local, it's a kind of autoexec.bat.

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That's going to get executed at each boot not just the next one only. – Dennis Williamson Jun 5 '10 at 22:46
my bad, I misread the question. Thanks for the correction – natxo asenjo Jun 6 '10 at 8:30

Create e.g. /root/


#your command here

sed -i '/' /etc/rc.local

Add to /etc/rc.local:


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I used chkconfig to have my system automatically run a script once after boot and never again. If your system uses ckconfig (Fedora, RedHat, CentOs, etc) this will work.

First the script:

# chkconfig: 345 99 10
# description: This script is designed to run once and then never again.

# Beginning of your custom one-time commands

plymouth-set-default-theme charge -R
dracut -f

# End of your custom one-time commands

# This script will run once
# If you would like to run it again.  run 'chkconfig run-once on' then reboot.
chkconfig run-once off
chkconfig --del run-once
  1. Name the script run-once
  2. Place the script in /etc/init.d/
  3. Enable the script chkconfig run-once on
  4. reboot

When the system boots your script will run once and never again.

That is, never again unless you want it to. You can always re-enable the script with the chkconfig run-once on command.

I like this solution because it puts one and only one file on the system and because the run-once command can be re-issued if needed.

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