* *HOSTTYPE*: optional string that is output with the version at end of
  line.

* *SNORT_IGNORE*: the list of symbols Snort should ignore when parsing the
  Lua conf.  Unknown symbols not in SNORT_IGNORE will cause warnings with
  --warn-unknown or fatals with --warn-unknown --pedantic.

* *SNORT_PROMPT*: the character sequence that is printed at startup,
  shutdown, and in the shell.  The default is the mini-pig: o")~ .

* *SNORT_PLUGIN_PATH*: an optional path where Snort can find supplemental
  shared libraries.  This is only used when Snort is building manuals.
  Modules in supplemental shared libraries will be added to the manuals.
