```bash
[[ -z ${!VAR_NEW+x} ]] || continue
```
`!` does indirect variable expansion; `+x` tests for whether the variable is set, and substitutes `x` iff it is, so the `-z` condition is true iff `$VAR_NEW` is unset.
TODO
====
- [x] Download and serve images locally.
- [x] <s>Use multiple hosts (source1.48.cn, source2.48.cn, ...) for images in case we don't want to serve images locally.</s> Now serving images locally.
- [x] Possibly expand to more than ten entries.
- [x] Add a toggle to switch between China Standard Time and the local timezone for datetime display.
- [x] Include SNH48's tours (in Beijing, Guangzhou and Shenyang).
- [x] 404 page.
- [x] Write to a persistent location instead of a temp dir (faster startup).
- [x] Proper logging.
- [x] <s>Updater process not properly killed when Apache reloads.</s> Separated web server and background updater. Forking off mod_wsgi is not a good idea.
- [x] Footer.
- [x] <s>Feed? Think twice.</s> Nah, no one other than myself uses this site, and I always have an email notifier.