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.