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

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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 usin, do
echo $SHELL or
cat /etc/passwd | grep `id -un`