Persistent ssh tunnel.

ssh_tunnel.sh

#!/bin/sh

if [ $# -ne 1 ]
then
	echo "Syntax: `basename $0` username@domain.name"
	exit
fi

IP=$1
cmd="ssh $IP -f -n /bin/ping -i 20 localhost"

program_exists() {
	if pidof $1 > /dev/null; then
		for p in $(pidof $1)
		do
			cmdline=$(cat /proc/"$p"/cmdline | xargs -0)
			if [ "$cmdline" == "$cmd" ]; then
				return 1
			fi
		done
	fi
	return 0
}

start() {
	program_exists ssh
	if [ $? -eq 0 ]; then
		eval "$cmd > /dev/null"
	fi
}

stop() {
        if pidof ssh > /dev/null; then
                for p in $(pidof ssh)
                do
                        cmdline=$(cat /proc/"$p"/cmdline | xargs -0)
                        if [ "$cmdline" == "$cmd" ]; then
                                kill $p
                        fi
                done
        fi
}
start