// returns number of files written to zip file
static int zipDataDir(S progID, File outZip) {
  ret dir2zip_recurse(getProgramDir(progID), outZip);
}

static File zipDataDir(S progID) {
  File file = null;
  while licensed {
    S date = ymd() + "-" + hms();
    file = userHome("JavaX-Backup/" + formatSnippetIDOpt(progID) + ".data." + date + ".zip");
    if (file.exists()) sleep(100); else break;
  }
  zipDataDir(progID, file);
  ret file;
}