Another really great file extension that you can use for your benefit is known as BASHRC - Bash Non-Interactive Login Shell File. This type of file extension is mostly used by both Linux as well as Mac OS X. You will need to make sure that you are using an application that is terminal only. You can use this format to set user command prompt preferences and much more. You will also be able to create different paths that come in handy when you really need them to. This file can be extremely useful for executing different commands of your choice. There are different formats those different duties. Some may work on interactive login shells, while others enter credentials for login. There are hidden files that are under a BASHRC format which are hidden. There are no filename prefixes for these types of files though. There is one simple filename that they are usually always seen under.