I have written the below expect script but it's not working as expected. I want the script to terminate automatically when all the commands are executed. However , the script either never terminates ( if set timeout -1 is used ) or terminates within seconds even before my commands are executed. Can someone please help ?

#!/usr/local/bin/expect

spawn su vserve
set password vserve
set PWD whoami

set cmdstr(0) "bash /apps/vpn/vserve/vserve_profile"
set cmdstr(1) "bash /apps/vpn/asap/scripts/change_loopback.sh"
set timeout -1
expect "*Password:*" {
sleep 1
send "$password\r"
send "$PWD\r"
sleep 1

for {set i 0} {$i<[array size cmdstr]} {incr i} {
send "$cmdstr($i)\r"

}

send \"exit\r\"
expect eof
}