Changing environment variables

Question

I just changed my /etc/environment file to:

M2_HOME=/usr/local/apache-maven/apache-maven-3.1.1
M2=$M2_HOME/bin
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
PATH=$M2:$PATH
JAVA_HOME=/usr/local/jdk1.6.0_45
PATH=$JAVA_HOME:$PATH

(trying to do something similar to this)

However, when I tried checking the environment variables by typing, for instance echo "$M2", the result is an empty line for all the variables and $PATH is the same as before editing the file. Why didn't my changes operate? I tried closing and opening the shell, but nothing happens.

Solution 1

/etc/environment takes a proper re-login to take effect, because it is processed by PAM at login. Further, as @przemo noted, it is not run or sourced as a script, so variables are not expanded. Put such variables in a .sh file in /etc/profile.d/:

sudo tee -a /etc/profile.d/my_vars.sh <<"EOF"
export M2_HOME=/usr/local/apache-maven/apache-maven-3.1.1
export M2=$M2_HOME/bin
export PATH=$M2:$PATH
export JAVA_HOME=/usr/local/jdk1.6.0_45
export PATH=$JAVA_HOME:$PATH
EOF

This will also take a re-login to take full effect, but you can test it out immediately by running a login shell:

$ bash -l
$ echo $PATH
/usr/local/jdk1.6.0_45:/usr/local/apache-maven/apache-maven-3.1.1/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

As Gunnar has pointed out, the default assignment to PATH should remain in /etc/environment, and shouldn't be added to the above script. See this community wiki page for more information.

Solution 2

/etc/environment is not a script file, you cannot use variables, for further reading I recommend https://help.ubuntu.com/community/EnvironmentVariables

Comments

[Gunnar Hjalmarsson]

I would have left the original PATH assignment in /etc/environment where it is located by default. Otherwise I agree.

[muru]

@GunnarHjalmarsson I saw the variables being set before PATH and thought OP may have modified it in some way. So I copy-pasted that part. On closer examination, I agree, that looks like the default PATH and I'll edit the answer.