Running a bash install script as root – how to handle regular users’ files?

I am writing some bash scripts to install and configure some programs.
Because the script needs to install packages – I run the scripts as root – which itself is no problem (i.e. I have root privileges etc).

However once the packages are installed the script needs to configure normal user files and fetch plugins etc, e.g.

• sed i s/xxx/mod_to_make/ <user_config_file>
• git clone <plugin>
• wget <plugin>
• etc

Ideally I would do this as a regular user because I don’t want these git repos and files to be owned by root,

An example program snippet is something like

#! /bin/bash

# Because this statement needs to be run as root - the entire script is 
# also run as root
apt-get install -y tmux

cat << EOF > ~/.tmux.conf
# 
# config stuff
#
EOF

Do I need to manually revert file privileges to regular user, at the end of the script, e.g.

chown $USER:$USER ~/.tmux.conf 
chmod 755 ~/.tmux.conf 

Or write 2 separate scripts 1 run by a root the other as regular user ?

Or is there a better way to handle this?

Answer

If you have a bunch of consecutive codes which should be run as regular user (not root), then you can do this:

sudo -s -u $USER<<EOF
echo "running codes as normal user"
EOF

Note: You may need to check if $USER is a regular user or root. If you run the script in a root shell, the value of $USER will be root and that’s the normal and expected behavior, i.e whatever user specific files you are creating are expected to be created in the root environment.