user@linux:~$ cat setup_deb_local_server.sh

#!/bin/bash
#1. mkdir <packagedir>
#2. dpkg-scanpackages packagedir | gzip > packagedir/Packages.gz
#3. user@linux:~$ cat /etc/apt/sources.list.d/test.list
#deb [trusted=yes] file:////home/user/ local_deb/

#4. apt-get update

# https://unix.stackexchange.com/questions/87130/how-to-quickly-create-a-local-apt-repository-for-random-packages-using-a-debian#

# https://www.cyberciti.biz/faq/sudo-append-data-text-to-file-on-linux-unix-macos/

DEB_DIR="/home/user/SX03.000_lite/l4e_deb_packages"
DEB_LOCAL_DIR="~/local_debs"

function mkdir_package(){
    if [ -d $DEB_LOCAL_DIR ]; then
        rm -rf $DEB_LOCAL_DIR
    else
        mkdir ~/local_debs
    fi
    cp $DEB_DIR/*.deb ~/local_debs
}

function reflash_deb(){
    echo "first make sure you move deb to dir"
    dpkg-scanpackages ~/local_debs | gzip > ~/local_debs/Packages.gz
}

function change_source_lists(){
    pushd /etc/apt/sources.list.d
    (sudo rm cuda-10-2-local-10.2.89.list  nvidia-l4t-apt-source.list visionworks-sfm-repo.list visionworks-repo.list  visionworks-tracking-repo.list)
    if [ -f eswin-apt-source.list ]; then
        (sudo mv eswin-apt-source.list eswin_deb.list.backup )
    else
      (sudo rm /etc/test_deb.list)
        #(sudo touch /etc/test_deb.list)

   fi
    (echo -e "deb [trusted=yes] file:/// /home/user/local_debs/" | sudo tee -a  /etc/apt/sources.list.d/test_deb.list)

    popd

    pushd /etc/apt
    (sudo mv sources.list sources.list.backup)
    popd
}

mkdir_package
reflash_deb
change_source_lists