TechBot startup script (modified from https://www.spigotmc.org/threads/minecraft-manager-control-script-linux.44517/)

bot.sh

#!/bin/bash
#
# /etc/init.d/techbot
#
# techbot   Manages techbot
# 
### BEGIN INIT INFO
# Provides:   techbot
# Required-Start: $local_fs $remote_fs screen-cleanup
# Required-Stop:  $local_fs $remote_fs
# Should-Start:   $network
# Should-Stop:    $network
# Default-Start:  2 3 4 5
# Default-Stop:   0 1 6
# Short-Description:    TechBot
# Description:    Manages TechBot
### END INIT INFO

#
### SETTINGS
#
SERVICE="TechBot"
SERVICE_JAR="${SERVICE}.jar"
# Linux Username
USERNAME='nicholas'
# Root Folder
SERVICE_PATH="/home/${USERNAME}/${SERVICE}"
# RAM to Allocate
RAM='30M'
# Server Java Command
INVOCATION="java -server -Xmx${RAM} -Xms5M -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256M -jar $SERVICE_JAR > latest.log"

ME=`whoami`
as_user() {
	if [ $ME == $USERNAME ] ; then
		bash -c "$1"
	else
		su - $USERNAME -c "$1"
	fi
}

bot_start() {
	if pgrep -u $USERNAME -f $SERVICE_JAR > /dev/null
	then
		echo "$SERVICE is already running."
	else
		echo "Starting $SERVICE..."
		cd $SERVICE_PATH
		as_user "cd $SERVICE_PATH && screen -dmS $SERVICE $INVOCATION"
		# Wait 5 seconds to start up
		sleep 5
		if pgrep -u $USERNAME -f $SERVICE_JAR > /dev/null
		then
			# Print output
			tail -n $[`wc -l "$SERVICE_PATH/latest.log" | awk '{print $1}'`] "$SERVICE_PATH/latest.log"
		else
			echo "Could not start $SERVICE."
		fi
	fi
}

bot_stop() {
	if pgrep -u $USERNAME -f $SERVICE_JAR > /dev/null
	then
		pre_log_len=`wc -l "$SERVICE_PATH/latest.log" | awk '{print $1}'`
		echo "$SERVICE is running. Stopping server..."
		as_user "screen -p 0 -S $SERVICE -X eval 'stuff \"!stop\"\015'"
		# Wait 15 seconds to finish stopping
		sleep 15
		# Print output
		tail -n $[`wc -l "$SERVICE_PATH/latest.log" | awk '{print $1}'`-$pre_log_len] "$SERVICE_PATH/latest.log"
	else
		echo "$SERVICE is not running..."
	fi
}

bot_command() {
	command="$1";
	if [ "$command" == "" ]
	then
		usage
		return
	fi
	if pgrep -u $USERNAME -f $SERVICE_JAR > /dev/null
	then
		pre_log_len=`wc -l "$SERVICE_PATH/latest.log" | awk '{print $1}'`
		echo "$SERVICE is running. Executing $command..."
		as_user "screen -p 0 -S $SERVICE -X eval 'stuff \"$command\"\015'"
		# Wait 3 seconds for the command to run and print to the log file
		sleep 3
		# Print output
		tail -n $[`wc -l "$SERVICE_PATH/latest.log" | awk '{print $1}'`-$pre_log_len] "$SERVICE_PATH/latest.log"
	else
		echo "$SERVICE is not running..."
	fi
}

usage() {
    echo "Usage: bot  [ start | stop | restart | status | run \"command\" ]"
}

#Start-Stop here
case "$1" in
	start)
		bot_start
	;;
	stop)
		bot_stop
	;;
	restart)
		bot_stop
		bot_start
	;;
	status)
		if pgrep -u $USERNAME -f $SERVICE_JAR > /dev/null
		then
			echo "$SERVICE is running."
		else
			echo "$SERVICE is not running."
		fi
	;;
	run)
	    bot_command "$*"
	;;
	*)
		usage
	;;
esac

exit 0