How to return from shell 'read' command passed in expect script?
 

I have a shell script that calls an expect script I wrote to ssh login to another host and get user input regarding that host's network configuration. I pass four arguments to the expect script: the remote host ip address, the username, the password, and the list of commands to run. My expect script is below:

#!/usr/bin/expect
# Usage: expectssh <host> <ssh user> <ssh password> <script>

set timeout 60
set prompt "(%|#|\\$) $"
set commands [lindex $argv 3];

spawn ssh [lindex $argv 1]@[lindex $argv 0]

expect {
"*assword:" {
send -- "[lindex $argv 2]\r"
expect -re "$prompt"
send -- "$commands\r"
}

"you sure you want to continue connecting" {
send -- "yes\r"
expect "*assword:"
send -- "[lindex $argv 2]\r"
expect -re "$prompt"
send -- "$commands\r"
}

timeout {
exit }

expect -re $prompt
send -- "exit\r"
}

The script runs well, except that if I send a command such as 'read' that requires user input, the script does not continue or exit after the user presses enter. It just hangs.

The commands I pass to the expect script and it's call are as follows:
SCRIPT='hostname > response.txt;netstat -rn;read net_card?"What is the network interface card number? " >> response.txt; read net_mask?"What is the subnet mask? " >> response.txt'

/usr/bin/expect ./expectssh.exp $hostip $usr $pswd "$SCRIPT"

Any suggestions on how I can pass a command to my expect script that requires user input without it hanging?

On a side note because I know it will come up - I am not allowed to do key-based automatic SSH login. I have to prompt for a username and password, which is done from my main shell script.

Thanks for any suggestions and help you can provide!

seems like setting up ssh with keys is far simpler (and secure) than to kludge something together to bypass the password prompt.

I was able to fix my problem. What was missing was an 'interact' command following the read statement so that it would wait for user input (implemented through an if statement). I also moved the commands to be run into a separate -re $prompt block within the expect command and just called exp_continue at the end of the "*assword:" and "you sure you want to continue connecting" conditions. The updated code is below if anyone is interested:

expect {
-re "(.*)assword:" {
send -s "[lindex $argv 2]\r"
exp_continue
}
"denied, please try again" {
send_user "Invalid password or account.\n"
exit 5
}
"incorrect" {
send_user "Invalid password or account.\n"
exit 5
}
"you sure you want to continue connecting" {
send -s "yes\r"
exp_continue
}
-re $prompt {
foreach cmd $commands {
send -- "$cmd\r"

if {[string first "read" "$cmd"] != -1} {
interact "\r" return
send -- "\r"
}
}
}
timeout {
send_user "Connection to host [lindex $argv 0] timed out."
exit 10
}
eof {
send_user "Connection to host failed."
exit
}
}