Adding a directory to the system path allows us to run executables win that directory from the command line.

The PATH is an example of an environment variable. It is a list of directories where executable programs can be found. If we want our scripts or programs to be available from the command line we must add its directory to the PATH variable.

It can be really useful to add additional directories to the path. For me this generally happens if I have a useful script or program that I want to be able to run from any directory on my computer.

The approaches to do this are different for linux and windows.

Add Directories to Path

Windows

The procedure for adding a folder to the path in windows 7 is described here:

http://www.computerhope.com/issues/ch000549.htm

Linux

In Linux, adding to the path can generally be done by opening a terminal and typing:
export PATH=$PATH:~/scripts


Where here ~/scripts is the folder we wish to add to the path.

This ammendment of the path will be lost when we close our terminal window or logout. To make this path change permanent we can adjust the .bashrc file:
echo 'export PATH=$PATH:/usr/local/bin' >> ~/.bashrc


.bashrc is run each time you login or the terminal is loaded, so the path will be amended each time too.

We can check the current path by entering:
echo $PATH