Ubuntu – How to add environment variables

It sounds like you want to do

export PATH="$PATH:~/Developer/android-studio/bin"

Then you'll be able to enter android-studio from anywhere. There's nothing magical about an environment variable named AS

If you want a shorthand, add a function to your .bashrc:

function as() { command android-studio "$@"; }

First of all, you don't want to do gradle="...". That simply creates a variable called gradle and is irrelevant (unless that variable is somehow used by gradle but you haven't said so). What you want to do is add the directory containing the gradle executable to the list of directories your system searches through when trying to find programs to run. This is what the PATH variable does.

It is also important not to overwrite the existing contents of PATH. So, to add foo to the PATH, you do:

PATH:"$PATH":foo

And not

PATH="foo"

The latter will remove everything from PATH and replace it with foo alone.

So, combining all this, you want to add the following lines to your ~/.profile (or ~/.bash_profile if that exists, but not to your ~/.bashrc):

PATH:"$PATH:$HOME/sanctus/Documents/Development/gradle-2.2/bin"

Why ~/.profile or ~/.bash_profile and not ~/.bashrc? First of all, because that's what profile is for. More importantly, ~/.bashrc is read each time you start a new shell. So, for example, each time you open a new terminal. Setting environmental variables that only need to be set once in that file, makes them be reset each time you open a terminal and that's just needless overhead.

Additionally, settings in ~/.bashrc only affect programs launched from the commandline. If you launch something using the GUI ( a menu entry or a .desktop file, for example) those variables will not be available there.

In many systems, including Ubuntu, ~/.profile is read when you log in graphically. Variables set in that file will therefore be available to GUI programs as well. Also, setting these variables in ~/.profile is preferred since that file is only read once: at login.

Additionally, this will work even if you change your shell to something other than bash, since ~/.profile is read by many of the most popular shells.

Important : If a ~/.bash_profile exists, that will be read instead of ~/.profile. So, if you do have such a file, use that one instead. My recommendation is, if you have a ~/.bash_profile, to simply delete it and add anything that was there to your standard ~/.profile.