How to wait for a process to complete using tcl-expect

Question

I am writing a script using expect in which I have to rlogin to some host & after that I need to send some commands. Now I want to exit to that host and relogin again to som

Answer 1

Try this construct when command is time consuming:

. . .
send "command\r"

expect {
    timeout {
        puts "Running..."
        exp_continue
    }
    "%PROMPT%" {
        puts "Finished."
    }
}

send "next command\r"
. . .

On timeout you will be continuosly waiting with exp_continue command for %PROMPT%.

Answer 2

I found this post after I ran into a race condition problem: sometimes the script completed as expected and other times it didn't. Adding a catch statement to the script ensured the desired outcome every time:

[...]
expect eof
catch wait result

Answer 3

Can you elaborate on "still script sending rest of the commands in between the previous process. "

I tried this and it worked.

spawn ssh host1
expect ":"
send pwd1
expect "%"
send "echo hi\r"
expect "%"
send "exit\r"
expect eof
spawn ssh host2    
expect ":"
send pwd2

Answer 4

you're forgetting to "hit enter". After sending exit, the way to wait for the process to end os expect eof:

send "source xyz.csh\r"
expect "%"
send "exit\r"
expect eof