The basic settings for the screen layout after logging in (X session setup) and the basic settings for many programmes are set via so-called dot files in the HOME directory. Dot files are files whose names begin with a dot '.'. The display of the names of these files is suppressed by many directory display programmes (ls, ll and others) by default. This effectively hides the files.

Many programs specifically process the information in the dot files assigned to them in order to initialise themselves accordingly. Some of the dot files available in the default setting and their meaning are

.xsession This file is evaluated as a script of the command interpreter

script and, when executed by the command interpreter, ensures that the X session is set up and runs.

.Xdefaults/* The contents of these files are sent to the screen during the X session setup

after logging in to the screens as X resources. With

X resources can be used to influence the appearance and behaviour of X Toolkit-based programs (i.e. most GUI programs).

.config/* These files control the appearance and function of the Xfce4 software system.

.profile, .bashrc, These files are used to initialise the command interpreter (.profile: sh and

.zshrc.local ksh, .bashrc: bash, zshrc.local:zsh) in an interactive environment (XTerm terminal emulator or an SSH, Telnet or Rlogin network connection).

.environment This file is interpreted as a script of the command interpreter sh, ksh, bash or zsh and is used to initialise the command interpreter with environment variables. The .environment file is used during the X session setup by the .xsession file and during the initialisation of the command interpreter by the .profile file.

Environment variables can be used to influence the behaviour of the command interpreter and programs. Some important environment variables are

HOME this environment variable contains the path to the HOME directory.

This variable should not be changed.

PATH this environment variable determines in which directories the command interpreter searches for commands and programmes. It is a list of directories separated by colons (':').

MANPATH This environment variable defines the directories in which the manual command 'man' searches for manual pages. It is a list of directories separated by colons (':').

When changing the PATH and MANPATH environment variables, care must be taken to ensure that the content specified by the system is adopted. Your own extensions should therefore only be added at the beginning or end; e.g:

export PATH=$HOME/bin:$PATH

adds the directory $HOME/bin to the beginning of the list of directories of the environment variable PATH.

DISPLAY this environment variable contains the name of the remote X display. This variable is specified by the system when logging on to the screens and may have to be set if GUI programmes are to be started for telnet/rlogin connections.

EDITOR this environment variable determines for many programmes which editor is to be started when required.

PAGER this environment variable defines for many programmes which programme should be used to display text output page by page (paginator).