使用Expect的密码提示不起作用

Question

I need to accept a password from keyboard containing at least one number, at least one uppercase letter, at least one lowercase letter and optional symbols # & - I wrote the following code. It always times out, but not detecting the password... Can anyone help

package require Expect
log_user 0
send "Enter Password\n"
expect  {
-re {(?=.*?[0-9])(?=.*?[a-z])(?=.*?[A-Z])[a-zA-Z0-9#&-]*} {send "Password ok"}
    timeout { send "Time out" }
    }

I had edited the code and now it is working only if the password is given in correct format at the first try...If a wrong format is given in the first try, expect will wait for the next try. But even if the next entry is correct, Expect is not detecting it and is going for the next try and finally time outs

Answer 1

You need another rule to match an unacceptable password (ie, anything ending in a newline that doesn't match the other rule), print a message, and start waiting again. The key to this is exp_continue .

send "Enter Password\n"
expect  {
    -re {(?=.*?[0-9])(?=.*?[a-z])(?=.*?[A-Z])([a-zA-Z0-9#&-]*)[\r\n]+} {
        send "Password ok"
        # Save the password for later...
        set thePassword $expect_out(1,string)
    }
    -re {[\r\n]+} {
        send "That looks like a bad password. Try again please.\n"
        exp_continue
    }
    timeout {
        send "Time out"
    }
}

The exp_continue command says “keep on expecting; we're not done yet” and it is vital for dealing with complex interactions. Also, I've anchored the match at the end of the line and added ( … ) to make the password easier to extract.