Using environment variables with su -c

Question

I try to run nvm as a different user from a bash script. It is installed already and the NVM_DIR environment variable is set in /home/user/.bashrc:

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"

Using plain su works:

root@ubuntu:~# su user
user@:/root$ echo $NVM_DIR
/home/user/.nvm

Trying the same thing with su -c does not work though:

root@ubuntu:~# su user -c 'echo $NVM_DIR'

root@ubuntu:~#

How can I use environment variables with su -c?

Answer 1

The behavior you're observing is because su -c 'command' does not execute command in an interactive shell.

Since su doesn't appear to provide an option to do so, probably the cleanest way to do what you want is to move the NVM environment variables into a separate file, called nvm_envs say, and source that explicitly e.g.

su user -c '. ~/nvm_envs && echo $NVM_DIR'

If you want interactive bash shells to have the same environment, source the same file from your .bashrc file e.g.

if [ -r "$HOME/nvm_envs" ]; then
  . "$HOME/nvm_envs"
fi

(This is exactly how the default .profile file conditionally sources the user's env_vars file: you could use that file instead if you prefer.)

Answer 2

Try:

sudo -i -u user sh -c 'echo $NVM_DIR'