Linux - how to see if an application is installed

I am creating an Automatic group that looks for installed application Nessus on CentOS Linux servers. In Web reports its easy just look at property Packages Installed - Linux and contains Nessus. I am not having any luck creating relevance that can look for Nessus. This in the property relevance that is already running:
if not exists rpm then “” else unique values of names of packages of rpm
I am new to Linux, any ideas?

This is what I used to get the splunk info across linux/aix/solaris.

if name of operating system contains "Linux"
then ( if exist package “splunkforwarder” of rpm
then (name of package “splunkforwarder” of rpm, version of package “splunkforwarder” of rpm) as string
else “LinuxSplunkForwarderNotFound,NA” )
else if name of operating system contains "SunOS"
then ( if exist name of pkginfo “splunkforwarder” of pkgdb
then ( name of pkginfo “splunkforwarder” of it , version of pkginfo “splunkforwarder” of it ) of pkgdb as string
else “SunOSSplunkForwarderNotFound,NA” )
else (“N/A”)

And to get the full pkg list

if (name of operating system contains “Linux”)
then ((names of it, versions of it) of packages of rpm)
else if (name of operating system contains “SunOS”)
then ((pkginst of it, versions of it) of pkginfos of pkgdb)
else if (name of operating system contains “AIX”)
then ((lpp_name of it, version of it) of filesets of products of object repository)
else if (name of operating system contains “HP-UX”)
then bundles of software depot
else NotFound

Thanks for the suggestions,
I ended up just doing this in my relevance and it seems to be working:

(exists package “Nessus” of rpm)

2 Likes