Expect script ran inside of while loop exits after processing one line - bash

Question

I have a while loop as such:
#!/bin/bash
doit="/pathtocommand"
file="/pathtosourcefile"
while read -r username password; do
$doit "$username" "$password"
done < $file
And my while loop command ($doit)is an expect script.
#!/usr/bin/expect -f
## Set up variables to be passed in as command line arguments
#set username [lindex $argv 0];
#set password [lindex $argv 1];
lassign $argv username password
spawn telnet 192.168.100.101 106
expect "200 PWD Server ready"
send "USER user\r"
expect "300 please send the PASS"
send "PASS password\r"
expect "200 login OK, proceed"
## Use the line below for passwords that do not have to be enclosed with quotes
send "SETACCOUNTPASSWORD $username PASSWORD $password\r"
# Use the line below for a password that must be quoted ie one that contains a $ or a ! by escaping the double quotes
#send "SETACCOUNTPASSWORD $username PASSWORD \"$password\"\r"
expect "200 OK"
send "quit\r"
interact
The expect script should run as many times as there are lines in my file. But it stops after the first line is processed. I am fairly confident that its something in the expect script because changing the command to something like echo works.
If I debug the script I see this:
+ doit=/pathtocommand
+ file=/pathtofile
+ read -r username password
+ /pathtofile 0100 01000100
spawn telnet 192.168.100.101 106
Trying 192.168.100.101...
Connected to 192.168.100.101.
Escape character is '^]'.
200 PWD Server ready
USER user
300 please send the PASS
PASS pass
200 login OK, proceed
SETACCOUNTPASSWORD 0100 PASSWORD 01000100
200 OK
quit
+ read -r username password
It looks to me like the script tries to start over but then simply exits. Can anyone help? I am in a crunch to get this thing working. I have done this before with SSH no problem. Not sure if its a telnet thing or what.

Answer 1

The interact command in the Expect script reads from standard input. Since standard input is redirected to the file, expect will read from the file, and there won't be anything left for the shell's while loop to read the next time.
If you want expect to interact with the terminal, you should redirect its input back to /dev/tty.
$doit "$username" "$password" </dev/tty