Expect: Prevent output from spawned process to appear on stdout

jlinkels · 07-03-2009, 02:47 PM

I have this expect process:

Code:

spawn -noecho telnet my.host.com
 expect {
        connected
    }

Now I get this string "connected" which is produced by the telnet server in $expect_out(buffer) which is fine.

Unfortunately, the same output is copied to the console where I started my expect script from. So the command that I send is surpressed with the -noecho flag, but whatever comes back is echoed.

I don't like that, the only solution is to redirect all output to /dev/null like:

Code:

expect -f myscript > /dev/null

But that is not what I want either, because then I don't see my own messages.

Any idea how to surpress all output produced by the spawned process?

jlinkels

cejennings_cr · 07-13-2009, 10:53 AM

You might send it to the background by placing NOHUP at the beginning and the ampersand (&) at the end of command:

spawn -noecho NOHUP telnet my.host.com &

That should send the spawned session to the background and suppress output to the terminal.

pdavis057 · 07-23-2009, 10:04 AM

Did you try "log_user 0" ? By default, the send/expect dialogue is logged to stdout. Logging is disabled by the command “log_user 0” and reenabled by “log_user 1” (the default).

Zig

jlinkels · 08-12-2009, 09:20 PM

Yes, log_user 0 does it. Not quite apparent from the documentation.

Thanks

jlinkels