<operating system, convention> A Unix application program
configuration file. On Unix, files named with a leading dot
are not normally shown in directory listings. Many programs
define one or more dot files in which startup or configuration
information may be optionally recorded; a user can customise
the program's behaviour by creating the appropriate file in
the current or home directory.
Dot files tend to proliferate - with every nontrivial
application program defining at least one, a user's home
directory can be filled with scores of dot files, without the
user really being aware of it. Common examples are .profile,
.cshrc, .login, .emacs, .mailrc, .forward, .newsrc, .plan,
.rhosts, .sig, .xsession.
