UNIX for Advanced & Expert Users

Using unix shell script file I need to telnet to a IP further send a command to the telnet IP and get the response to a file with out using "expect" utility and I have achieved this by below command.

Code:

(sleep 3; echo admin; sleep 3; echo mypass; sleep 5;echo "show status-list"; sleep 5; echo "logout")|telnet 192.168.1.1 >>$telnet_result

But now if the user "name" or "password" is wrong we get "Failed login" when we try to telnet. I need to catch this for the first attempt itself and exit the telnet session immediately.

Code:

(sleep 3; echo admin; sleep 3; echo mypass; ... )|telnet 192.168.1.1 | grep "Failed" | " Need To Write Code here I guess To Exit if FAILED" | >>$telnet_result

Or else is their any other way or method so that I can get the "Failed Login" and exit the telenet session?. Please suggest.

Thanks
Raghunath Rao

The "with out using "expect" utility " stipulation makes this sound like homework. However try the following (though I suspect your lecturer will have mentioned it already)

Code:

man nc

Not able to achieve... any one any updates/suggestion on this.
If any other approach to telnet from shell script with out using "expect" will be of great help please suggest.
Cheers
Raghu

This is homework. The same question was asked in the homework section, which would be the correct place for this post.