catch bash script output from expect, expect hangs

Question

I currently use expect to pass password to rsync to copy files across unix servers
test.sh

 ./expect.sh $password rsync -azvr  $username@$host:$file ./$dir

expect.sh

#!/usr/bin/expect -f                                                                                                                                                                                
eval spawn [lrange $argv 1 end]
#expect  "(yes/no)?"                                                                                                                                                                                
#send "yes\r"                                                                                                                                                                                       
expect "*?assword:*"
send [lindex $argv 0]
send \r
interact

if server password got changed but not updated in script, I would like to receive a notification. however currently it would just hangs indefinitely. If I do the following in test.sh

output=`./expect.sh $password rsync -azvr  $username@$host:$file ./$dir`

Now the script would hang indefintely so I would never get a chance to handle the output. how do I solve this issue?

Answer 1

You should edit your expect script to allow for timeout and expected result after rsync.

For example:

...
set timeout 60
expect "*?assword:*"
send [lindex $argv 0]
expect {
 timeout { send_user "\nFatal Error: unable to rsync \n"; exit 1}
 "denied" { send_user "\nFatal Error: unable to rsync \n"; exit 1}
 "sent"
}

The above will exit the script in case of 60 second timeout or if received a denied response in case of bad password. Otherwise if it receives a "sent" text it continues.