Shell Programming and Scripting

I need to write a script that check users authenting to a particular server

ssh -l [user] [servername]

if sucessfull

echo loggin sucess

else

echo login invalid


Any Suggestions ?

Not sure if i am right,The message while be displayed only upon the successful login using the below command,

ssh -l user hostname "echo login successful"

Thanks
Nagarajan Ganesan.

Thanks for posting, I just want to validate i dont want to login

But the above command will prompt for password,if the user is authenticated then the echo command is executed on the remote host and exits.It will not establish a sesssion on the remote host.

Thanks
Nagarajan Ganesan.

Thanks Nagraj,

Can I skip the Question
Are you sure you want to continue connecting (yes/no)? yes[/B]

[sriram@unixguy ~]$ ssh -l root 127.0.0.1 "echo login successful"
The authenticity of host '127.0.0.1 (127.0.0.1)' can't be established.
RSA key fingerprint is 8a:57:60:90:49:98:1d:39:50:20:76:f2:5b:cb:a8:4c.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '127.0.0.1' (RSA) to the list of known hosts.
root@127.0.0.1's password:
login successful