In the scripts from script's library, often we see the function updaterc updating the user's dotfiles such as ~/.bashrc. I think we should never do that since those files will be later replaced in case the user has a dotfiles repository configured.

So I have two suggestions:

First

Instead, perform these changes to the global bashrc and zshrc files, which are respectively /etc/bash.bashrc and /etc/zsh/zshrc. Those files gets sourced by bash and zsh automatically, for all the users.

This means that for free, we would earn synchronization between root and non-root user without having to update both user's dotfiles.

Second

Update /etc/bash.bashrc and /etc/zsh/zshrc to include something like . /etc/profile, because unfortunately, in Docker, /etc/profile does not get read automatically.

Then, if you take a look at /etc/profile you'll see something like:

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi

This means that any .sh under /etc/profile.d/ will get sourced by /etc/profile, and this is the recommended way to customize the system-wide Linux environment.

Then, we could convert lines such as:

echo "export SDKMAN_DIR=${SDKMAN_DIR}\nsource \${SDKMAN_DIR}/bin/sdkman-init.sh" >> /home/vscode/.bashrc
echo "export SDKMAN_DIR=${SDKMAN_DIR}\nsource \${SDKMAN_DIR}/bin/sdkman-init.sh" >> /home/vscode/.zshrc
# for root
echo "export SDKMAN_DIR=${SDKMAN_DIR}\nsource \${SDKMAN_DIR}/bin/sdkman-init.sh" >> /root/.bashrc
echo "export SDKMAN_DIR=${SDKMAN_DIR}\nsource \${SDKMAN_DIR}/bin/sdkman-init.sh" >> /root/.zshrc

with:

echo "export SDKMAN_DIR=${SDKMAN_DIR}\nsource \${SDKMAN_DIR}/bin/sdkman-init.sh" >> /etc/profile.d/sdkman.sh

Which has the benefits:

1. Works for all users (root and non-root)
2. Works for bash and zsh
3. Much safer than editing the rc directly