Environment Variables Flashcards
BASH and SHELL
/bin/bash (shell)
CPU
The type of cpu installed on your system
DISPLAY
Where your x-windows commands sholdub e sent (video card monitor)
ENV
name of the file bash read to configure teh environment (defualt /etc/bash.bashrc)
EUID
The UID of the current user
HISTFILE
stores number of commands saved in command history file (default ~/.bash_history)
HISTSIZE
the amount of commands stored in history (default 1000)
HOME
path to current user’s home directory
HOST and HOSTNAME
what it says hostname of system
LOGNAME
stors username of current user
/var/spool/mail/username OR /var/mail/username
where the mail for the current user is
MANPTH
path to the systems ‘man’ program
OLDPWD
prior current directory
OSTYPE
the type of OS being run (Linux)
PATH
list of directorys to be searched when running a command prompt
PSI
stores variales used to create shell prompt
PWD
the current directory
USER and USERNAME
the username of teh current user
How to display all environment vairables?
env
How to set the value of a variable
VARIABLE=value
how to APPEND to a variable? (like PATH
VAR=$VARnewstuff
PATH=$PATH:/var/opt
change a variable so that its available to all login shells??
export VAR=value
export VAR=$VARappended value
how to make custom env super persistant even when system shuts down
export in a .bash_profile.
make every user have a custom env variable
add a variable to the global .bash_profile
In /etc/profile
!! always be careful when configuring a global etc file
/bin/bash (shell) is stored in wich env?
BASH and SHELL
Type of cpu installed on your system
CPU
where your x-windows commands should be sent
DISPLAY
name of the file bash read to configure teh environment
ENV
UID of the current user
EUID
stores path to the file keeping bash history
HISTFILE
amount of commands to store in histoyr
HISTSIZE
path to current user’s home
HOME
stores username of current user
LOGNAME
/var/spool/mail/username OR /var/mail/username
path to system’s ‘man’
MANPATH
prior currenty directory
OLDPWD
the type of os being run
OSTYPE
list of dirs to be searched when running a command
PATH
stores values to be used to create shell prompt
PSI
current dir
PWD
username of current uzer
USER or USERNAME
