To allow a normal user to run root privileged commands, you have to use sudo.
Sudo allows a user to run commands as superuser or another user.
To set your user to be able to use sudo to act as superuser, a number of steps have to be done.
# visudo
Uncomment the below line and save. visudo uses vi as the text editor, so to save just press 'Esc' and then ':wq'.
%wheel ALL=(ALL) ALL
Add your user to the group wheel (You can use any name for the group as long as you add it to the sudoers file). As example, we will use 'foo' as our username.
usermod -G wheel foo
To make all the superuser's environment variable available to the user, edit /home/foo/.bash_profile.
vi /home/foo/.bash_profile
Add the following lines, append if the line already exist.
PATH=$PATH:/sbin:/usr/sbin export PATH
Save the file
To activate the changes, run:
. .bash_profile
Now, you can use superuser environment variables, but without tab completion feature. To enable tab completion edit /home/foo/.bashrc.
vi /home/foo/.bashrc
Add the following line
complete -cf sudo
Save the file.
To activate the changes, run:
. .bashrc
Logout and login back.
Now you can use sudo to execute root privileged commands, you inherited the root environment variables and you can use tab completion while using sudo.