Create ssh public key from private key

If you have a private key and want to create the public key from that (to put in ~/.ssh/authorized_keys, for example), do the following:

ssh-keygen -f <my_private_key> -y > <my_public_key>

For example:

ssh-keygen -f ~/.ssh/id_rsa -y > ~/.ssh/id_rsa.pub


If you are using this to ssh with keys, add my_public_key (eg. ~/.ssh/id_rsa.pub) to ~/.ssh/authorized_keys on the remote server.

Then ssh with the private key to the remote server to test.

Find the PID number with nothing else

Use this combination to find a PID number without anything else in the output:

ps -ef | grep -v grep | grep ssh | cut -d" " -f3
3012

Enjoy that kungfu knife-kick combo.

Write on my Linux wall

To display a text message to other users logged into a *nix system, use the wall command. For example:

wall "Deploying new .ear file in five minutes."


This will send the message to all users logged into the system, whether they be physically on a console, via ssh or ftp.