2.4 Setting your environment

If you want to use the newly installed package by default you will need to modify the relevant variables in your environment, such as PATH, LD_LIBRARY_PATH, INFOPATH, etc. These variables inform your system of the locations of relevant files on it. For example, PATH contains a list of all directories that contain executable files.

There is a sample script setup.sh in the top-level source directory which can be used to set the main environment variables.

$ source setup.sh

Note that you need to load this file into the current shell with the source command, instead of executing it (which would only apply the definitions temporarily in a subshell).

After loading this file, your environment variables should include the target directory so you can run the new packages directly:

$ echo $PATH
/gnu/bin:/usr/local/bin:/usr/bin:/bin
$ which hello
/gnu/bin/hello

If you want to restore your original environment variables they are saved in the variables ORIG_PATH, ORIG_LD_LIBRARY_PATH, etc.

$ PATH=$ORIG_PATH
$ LD_LIBRARY_PATH=$ORIG_LD_LIBRARY_PATH