In Unix, what does rc at the end of files like .newsrc mean?

The rc at the end of a file is related to the phrase "run commands"; its use derives from the /etc/rc.* files used to start most Unix systems. The rc suffix is commonly used for any file that contains startup information for a program. Common rc files include .newsrc, .pinerc, and .cshrc.

Many rc files have a filename that begins with a  .  (dot), which means that you normally won't see them when you use the ls command. To see the files beginning with a dot in your home directory, enter at the Unix prompt: ls -ad ~/.*

Also see:

• What do some common Unix file extensions mean?