Add Environment variables in Linux permanently

There are two ways to setup environment variables in linux systems ( Ubuntu , Red Hat , Fedora etc)

• Using the export method of adding environment variables to linux . However it is only temporary solution , it will make variables available only for current session.

• Editing .bash_profile file and adding it there permanently

Using export

Consider the example you want to add JAVA_HOME variable for java installation at /usr/java/

Using export we would type command like

export JAVA_HOME=/usr/java

To add it to our PATH variable we would type

export PATH=$PATH:$JAVA_HOME/bin

The above command says add the bin directory in JAVA_HOME to the PATH variable

However using export would not be permanent and would be gone when your session is over

Using bash_profile

Assuming that you are using default bash shell (See note in end )

To add environment variable permanently we have to edit the bash_profile file.

Move to your home directory (e.g /home/yourname) and type

vi .bash_profile

The above command may ask for root user rights, so in that case you have to type like

sudo vi .bash_profile

The full stop (.) before the file name makes it a hidden file

Type in the end of the file any path variable you want to add

e.g

JAVA_HOME=/usr/java/jdk1.6.0_26
export JAVA_HOME
PATH=$PATH:$JAVA_HOME/bin
export PATH

type i to enter the insert mode

then add whatever you want to the end of it. Press the escape key to exit the INSERT mode.

Type :w to write the file

Type :q to quit the vi editor

That’s it. The path variable has been stored permanently in the Linux system

NOTE:

Depending upon the shell you are using , you need to edit .profile or .bash_profile file.

To find out type echo $SHELL

If you are using ksh,

Edit ~/.profile to add any evn. variable.

e.g.

MY_LIBS=/home/my/libs export MY_LIBS

If you are using bash,

Edit ~/.bash_profile to add the env.

To find out what shell you are using, do

echo $SHELL