if package request results in no packages, empty string is returned. zabbix documentation explicitly states that userparameters should not return empty string (http://www.zabbix.com/documentation/1.8/manual/processes/zabbix_agentd), so it should be decided what to do about built-in items.
latest zabbix server seems to simply discard such values, but the item is not set to be unsupported.
<rudolfs> the current logic was to return NOTSUPPORTED only if no supported packaging systems are found, otherwise an empty string should mean that there are no packages installed (which might indeed be useless if another unsupported packaging system have the packages...)
<richlv> yes, but server seems to discard this value, thus the item just stops gathering values (and it also somewhat contradicts our own suggestions and behaviour with userparameters). i don't have a great solution, so just thinking aloud here
<rudolfs> Changed the logic:
1) by default, ''showpms" is used
2) [regex,showpms] lists every supported PMS followed by package list matching regex e.g. "[dpkg] pck, pck2, [rpm] pck3, [pacman]"
3) [regex,onlylist] lists all the packages matching regex and returns an empty string if no package matches the regex
<asaveljevs> Shall we start each package manager on its own line?
<asaveljevs> Fixed in r19396, fixed again in r19406.
<rudolfs> Please review changes in r19423.