Every user has two special files: .bash_profile and .bashrc, in her home
directory. These files and other files whose names start with a `.' (dot) do not normally show
up in the directory listing (also known as hidden files). See Section 3.3.9 for ways
of listing the “dot” files. The “dot” files are used for initializing applications and
for customizing your environment (see Section 5.1). For example, when you login,
the .bash_profile file sets up your session and terminal characteristics.
Many applications have special files that have names starting with a `.', usually located in your
home directory. These startup files contain initialization commands for the application. For
example, the file .vimrc contains the initialization commands for the Vim text
editor. The suffix “rc” stands for run control.
As mentioned before, the current directory is “.” and the parent directory is “..”. These
two entries are in every directory listing that includes the “dot” files.