UNIX for Dummies Questions & Answers

dear all,
I know that this question has been asked before frequently, but I really don't get it. My question is composed of several ones.

First:To telnet through a script, I was told to use the way described below, and it works for me, but i don't understand the syntax here. according to the piping, echoing the username, the password and the commands are done first, then the telnetting.. How is that?!
( echo open hostname
sleep 5
echo username
sleep 1
echo password
sleep 1
echo some more output, etc. ) | telnet

Second: Is that the only way that I can do telnet through a script in UNIX?
Third: What about SSH, I know that I can't do the samething with ssh, Is there another way??
Thanks for your concern...
Marawan

definitely not the only way. do you know any other programming languages? eg Perl/Python ? if you know them, there are telnet modules you can use to program telnet sessions.

ssh can execute remote commands. check your man page. it should be something like this: ssh <options> command

SSH is much more powerful, you use the command line and arguments to do the authentication and then stdin/stdout/stderr are effectively pure pipes to the shell or program at the remote end.

If you have your public key installed in your $HOME/.ssh/authorized_keys on the remote machine then all you need to do is things like

to get a remote directory listing...

Code:

ssh remote-host-name ls -l

or

Code:

ssh fred@foobar ls -l

or to unpack a tar file on a remote machine....

Code:

cat some.tar | ssh remote-host tar xvf -

Take a look at this thread also, hope it helps a bit.