bash - How to pass variables from a shell script to an expect script?

Question

I've shell script as below:

#!/bin/bash

echo "Select the Gateway Server:"
echo "   1. Gateway 1"
echo "   2. Gateway 2"
echo "   3. Gateway 3"

read gatewayHost

case $gatewayHost in
    1) gateway="abc.com" ;;
    2) gateway="pqr.com" ;;
    3) gateway="xyz.com" ;;
    *) echo "Invalid choice" ;;
esac

/mypath/abc

In above script, I'm fetching gateway from user input selection & trying to pass to my abc.sh script which is expect scriptshown below:

#!/usr/bin/expect

set timeout 3
spawn ssh "james@$gateway"
expect "password:"
send "TSfdsHhtfs
";
interact

But I'm not able to pass gateway variable from shell script to expect script. Can any one tell me how to achieve this?? Please note that I need to use shell script only due to legacy reasons (Cannot use tcl script or can't do everything in expect script itself)

Answer 1

From your shell script:

/mypath/abc $gateway

From your expect script:

#!/usr/bin/expect

set gateway [lindex $argv 0]; # Grab the first command line parameter

set timeout 3
spawn ssh "james@$gateway"
expect "password:"
send "TSfdsHhtfs
";
interact