This website about Linux's zip utility says this about the
Replace (update) an existing entry in the zip archive only if it has been modified more recently than the version already in the zip archive. For example:
zip -u stuff * will add any new files in the current directory, and update any files which
have been modified since the zip archive stuff.zip was last created/modified.
My question is, if a particular file has been removed since the last time it was zipped, whether
-u will recognize that the file has been removed and thus remove it from the *.zip file? Or, lacking timestamp information (since the file is now removed), it will leave the backed up file in *.zip, since there is no "newer" file?