Environment Variables

Paths

• /etc/environment

• /etc/profile

• /etc/bashrc

• ~/.bashrc

• ~/.profile

• /etc/alternatives/

Variables

• $HOME - User Home Directory

• $HOSTNAME - Hostname

• $IFS - Inter Field Separator

• $LANG - System Language

• $PATH - Executable Search Path

• $PS1 - Prompt

• $PWD - Present Working Directory

• $SHELL - Current Shell

• $TERM - Current Terminal (character mapping)

• $UID - User ID

• $UMASK - Permission mask for new files

• $USER - Username

• $LANG -

• $LS_COLORS -

• $_ -

PS1

Bash colors

# Colors
red='\[\033[00;31m\]'
green='\[\033[00;32m\]'
blue='\[\033[00;36m\]'
white='\[\033[00;39m\]'

# User Prompt
[ $UID != 0 ] && export PS1="\n${green}$ ${white}"

# Root Prompt
[ $UID == 0 ] && export PS1="\n${red}# ${white}"

# Remote Prompt
[ $SSH_CONNECTION ] && export PS1="\n${green}\h $ ${white}"

Commands

Env

Command	Type	Description
env		Show all environmental variables
env		run a program in a modified environment
update-alternatives		maintain symbolic links determining default commands
export		Set environment variable