retrieve & update my .bashrc or .bash_aliases

customize-bash.sh

#!/bin/sh

ALIASES_URL=https://gist.githubusercontent.com/okurka12/cc3769db8e6f57dfdf091428095b7e00/raw

ALIASES_BACKUP=.bash_aliases.old
ALIASES_NEW=.bash_aliases.new

# ask if something is ok, exit if it's not
# if OPTION_Y variable is "-y", do nothing
prompt_confirm () {
    if [ "$OPTION_Y" != "-y" ]; then
        printf "%s (y/n) " "$*"
        read -r PROCEED
        if [ "$PROCEED" != "y" ]; then
            echo "abort"
            exit
        fi
    fi
}

# if $1 exists, ask if its ok to delete and then delete
safe_delete () {
    if [ -f "$1" ]; then
        prompt_confirm "delete $1?"
        echo "deleting $1"
        rm "$1"
    fi
}

# if $1 exists, ask if its ok to overwrite
ask_overwrite () {
    if [ -f "$1" ]; then
        prompt_confirm "overwrite $1?"
    fi
}

################################################################################

if [ "$1" != "aliases" ] && [ "$1" != "rc" ]; then
    echo "USAGE: $0 aliases|rc [-y]"
    exit
fi
OPTION_Y="$2"

GO_BACK_TO=$(pwd)
cd "$HOME" || exit

if [ "$1" = "aliases" ]; then
    ask_overwrite "$ALIASES_BACKUP"
    cp .bash_aliases "$ALIASES_BACKUP"

    safe_delete "$ALIASES_NEW"
    wget -O "$ALIASES_NEW" "$ALIASES_URL"

    echo "DIFFERENCES:"
    diff .bash_aliases $ALIASES_NEW
    prompt_confirm "continue?"
    cp "$ALIASES_NEW" .bash_aliases
    rm "$ALIASES_NEW"

    echo "done"
    echo "- old .bash_aliases can be found in $ALIASES_BACKUP"
    echo "- don't forget to source .bash_aliases or restart bash"

fi

if [ "$1" = "rc" ]; then
    echo "retrieving .bashrc is not implemented yet"
fi

cd "$GO_BACK_TO" || exit