Batch script to download un unpack compressed files

We need a small script that will do the following: -Download tar files from a protected URL with basic authentication (can be easily done with curl). -Automatically unpack the compressed file with tar utility. -Sync a Google Spreadsheet with the CSV data inside the packed file. The url to download will be constantly changing so we need a small backend site where we can insert the file name to download (or URL, but base URL remains constant) and submit so that the script is run. The base curl script is attached. The google Spreadsheed needs to be constantly refreshed with the new data that has been unpacked in csv. A linux server will be provided to upload the final script and to store the unpacked files. After data has been downloaded old data has to be overwritten with the new files contained in the tar file. In the script attached the dummy URL is the one that will be changing constantly.