I am trying to write a script to make a ssh tunnel persist. I am writing it to check the existence of the tunnel on port 3307 and if it is not found start it:

#!/usr/local/bin/bash
# ~/my_tunnel.sh
tunnel_up=`ps ax|grep 3307`
if [ "${tunnel_up}" = "" ]; then
ssh -fNg -C -L 3307:127.0.0.1:3306 bob@db.webstakez.com & 2>/dev/null
fi

I believe that this is not working because the grep is returning a value for the actual grep command even when the tunnel is down. As an example, I check for anything on port 3308 since the tunnel is up:

$ ps waux|grep 3308
10014 18755 0.0 0.0 1428 440 pts/0 S 12:53 0:00 grep 3308

This is a Linux system, 2.4.20-021stab028.3.777-enterprise #1 and grep does not act this way on my freebsd box. What can I do to so that this will not return the actual grep?

TIA,
Bob

try something like

tunnel_up=`ps ax|grep 3307 | grep -v 'grep'`

Perfecto!!

Thanks for the insight.

/bob

or you could:
tunnel_up=`ps ax|grep [3]307`

I am trying to get something similar established. The following code is ~/bin/mytunnel.sh

#!/bin/sh
# ~/bin/my_tunnel.sh
tunnel_up=`ps ax|grep 1080 | grep -v 'grep'`
if [ "${tunnel_up}" = "" ]; then
ssh -D 127.0.0.1:1080 andyhase@tripleyou.dyndns.org & &0 < 'password'
fi

 5: Syntax error: "&" unexpected