Linux for Beginners

by Jason Cannon

You can further increase the security of your SSH key by giving it a passphrase. In this case it takes something you have -- the key -- and something you know -- the passphrase -- to gain access to your account. If you feel confident that your key will only be under your control, you can forgo providing a passphrase for your key. This will allow you to log into servers without typing a password at all. Having an SSH key without a passphrase can allow you to automate and schedule tasks that

The downside to creating several aliases is that when you are on a system that does not have your aliases you might feel lost. If you want to be able to work effectively on any system that you have access to, keep your alias usage to a minimum. Another way to handle this situation is to copy your configuration files to each system that you work on.

The contents of .profile or .bash_profile are only executed for interactive sessions. If you are not aware of this subtle difference it may leave you scratching your head as to why something works perfectly when you log in and type a command versus when you just ssh in to run that same command. For example, if you define an alias for ll in ~/.bash_profile it will work during an interactive session but it will not be available during a non-interactive session.

You can save yourself some hassle by making your interactive and non-interactive sessions behave the same. To do this, configure .bash_profile to reference .bashrc and put all of your configuration in .bashrc. You can read in the contents of another file by using the source command or dot operator.