Expect Script for CLI - bash

Question

UPDATE: I am really frustrated at this point. I've tried moving the expect code to its own file and calling it from the bash script.
...
if [[ "$okay" == "OK" ]]
then
echo "PASSWORD ACCEPTED"
echo "Modifying User Passwords..."
COUNTER=0
while [ $COUNTER -lt $num ]; do
let index=COUNTER+1
tmp=user_$index
echo "Changing Password for " ${!tmp}
tmp2=$(${!tmp})
echo $tmp2
sh ./input.sh ${current_user} ${pass} ${password} ${tmp2}
let COUNTER=COUNTER+1
done
...
input.sh
expect -f
#------------------------------------------------------
set current_user [lindex $argv 0]
set pass [lindex $argv 1]
set password [lindex $argv 2]
set tmp2 [lindex $argv 3]
echo "EXPECT SCRIPT RUNNING"
sudo passwd ${!tmp2}
expect -exact "[sudo] password for $current_user: "
send "$pass\r"
expect -exact "New password: "
send "$password\r"
I would greatly, greatly appreciate it if someone could help me out.
I am writing a script that will allow a Linux admin to quickly change passwords of its users.
#!/usr/bin/expect
# Check password for strength
# ----------------------------------------------
read -p "What's your username?" current_user
read -p "What's the root password?" pass
read -p "How many users?" num
COUNTER=0
while [ $COUNTER -lt $num ]; do
let index=COUNTER+1
read -p "Enter username$index : " user_$index
let COUNTER=COUNTER+1
done
read -p "Enter password : " password
echo
echo "Tesing password strength..."
echo
result="$(cracklib-check <<<"$password")"
okay="$(awk -F': ' '{ print $2}' <<<"$result")"
if [[ "$okay" == "OK" ]]
then
echo "PASSWORD ACCEPTED"
echo "Modifying User Passwords..."
COUNTER=0
while [ $COUNTER -lt $num ]; do
let index=COUNTER+1
tmp=user_$index
echo "Changing Password for " ${!tmp}
echo ${!tmp}
sudo passwd ${!tmp}
expect -exact "[sudo] password for $current_user: "
send "$pass\r"
expect -exact "New password: "
send "$password\r"
let COUNTER=COUNTER+1
done
#echo "$user:$password" | usr/sbin/chpasswd
else
echo "Your password was rejected - $result"
echo "Try again."
fi
However, the expect portion, which would automate the inputting of passwords, is not highlighted in my editor and does not work. I keep getting prompts to manually enter text. This is especially surprising since the script is sourcing expect, not bash. I've been trying to fix this for the past 2 hours. Can anyone please lend me a hand?

Answer 1

I see some issues in your code. At first, you have tried adding #!/usr/bin/expect in the code, which should throw you an error about the read command as,
wrong # args: should be "read channelId ?numChars?" or "read ?-nonewline? channelId"
while executing
"read -p "What's your username?" current_user"
The reason is simply because the script will be treated as Expect script and it is not following it's syntax for read. I wonder how it worked for you. :)
When it is called as shell script, in that it should be enclosed withing expect -c not simply with expect -f
When expect -c is enclosed with single quotes, it won't allow bash substitutions. So, I am going to use double quotes. (but, it we have to escape the Expect's double quotes with backslashes.)
admin="dinesh"
admin_pwd="root"
user="satheesh"
user_pwd="Hello#12E"
OUTPUT=$(expect -c "
# To suppress any other form of output generated by spawned process
log_user 0
spawn sudo passwd $user
expect {
timeout { send_user \"Timeout happened\n\";exit 0}
\"Sorry, try again\" {send_user \"Incorrect admin password\";exit 0}
\"password for $admin: $\" {send \"$admin_pwd\r\";exp_continue}
\"password: $\" {send \"$user_pwd\r\";exp_continue}
\"successfully\" {send_user \"Success\"; exit 1}
}
")
echo "Expect's return value : $?"
echo "-----Expect's response-----"
echo $OUTPUT
The Expect's return value will be available in the variable $?. This will help us to know whether the password update is successful or not. The variable OUTPUT, will have the output generated by spawned process.
Use the #!/bin/bash, not #!/usr/bin/expect, since it is actually a bash script.