script to set up automatic reboots for minecraft server in a screen session

launch_ftb.sh

launch_dir="$HOME/rev3"
launch_script="$launch_dir/LaunchServer.sh"
session_name="ftb-server-$(date '+%s')"
command_prefix="screen -S $session_name -p 0 -X stuff"
crontab_file="/tmp/.cronjobs-$(date '+%s')"

echo "Launch directory: $launch_dir"
echo "Launch script: $launch_script"
echo "Session name: $session_name"

# dump existing cron jobs to file
crontab -l > $crontab_file

# clean up any cron jobs from prior runs
sed --in-place '/ftb-server-/d' $crontab_file

# create cron jobs for notifying players and stopping/restarting the server
echo "0 */6 * * * $command_prefix 'say Server is rebooting in 5 minutes^M' >/dev/null 2>&1" >> $crontab_file
echo "2 */6 * * * $command_prefix 'say Server is rebooting in 3 minutes^M' >/dev/null 2>&1" >> $crontab_file
echo "4 */6 * * * $command_prefix 'say Server is rebooting in 1 minute^M' >/dev/null 2>&1" >> $crontab_file
echo "5 */6 * * * $command_prefix 'stop^M' && sleep 10 && killall -s SIGKILL java >/dev/null 2>&1" >> $crontab_file
echo "7 */6 * * * cd $launch_dir && screen -dmS $session_name $launch_script" >> $crontab_file

# load cron jobs and remove temp file
crontab $crontab_file
rm $crontab_file

# start server in a new screen instance
pushd $launch_dir
screen -dmS $session_name $launch_script
popd

# output session name to temp file so that we can kill it later
echo "$session_name" > /tmp/ftb-session-name

script for stopping: https://gist.github.com/aschuhardt/0765f10edf733946d69cd1f825421b69