Usage of HOSTNAME and CURRENT_USER in scripts on linux

Question

Suppose I want to edit /etc/profile:

PYTHONPATH = /home/CURRENT_USER/

1. How do I have a variable that will automatically fill in the current user?
2. What about hostname?
3. Aren't these environment variables?

Answer 1

$USER should typically be set to the current user, and $HOSTNAME to the current hostname. If not, you can also get them from the output of whoami and hostname

Also, the user's home directory is not necessarily in /home/[username]. You should use the value of $HOME instead.

Answer 2

If you wish to see all of your environmental variables available, use the following command:

bash$ set

Remember case sensitivity, for hostname you'll need $HOSTNAME, and $USER

bash$ echo $USER
sparks
bash$ echo $HOSTNAME
servername

Answer 3

Another approach is to add a call to sys.addsitedir in sitecustomize.py rather than PYTHONPATH.

However since Python 2.6 you probably don't need to do either, because /home/$USER/.local/lib/python2.6/site-packages is automatically added to sys.path. This is a good choice of standard place to put user-specific modules/packages; you wouldn't really want to add the home directory itself as a module path as it contains all sorts of things that aren't modules, which could confuse imports.

See PEP370 for details.

Answer 4

In python, call os.uname() to get the hostname (and other details in an array).