!!Package Info
How to tell if the package is installed:

{{{pkginfo |grep VRTSobgui}}}

!!Get version info from an installed package
!Solaris
{{{pkgparam NOVLsubag VERSION
8.7.3.3
}}}
!Linux
{{{rpm -qi NOVLsubag 2>/dev/null | grep "Version" | awk '{print $3}'
8.7.3.3
}}}

Or, by querying for only the desired details:

{{{rpm -q --qf %{VERSION} NOVLsubag
8.7.3.3
}}}

!!Get version info from a package file
!Solaris
{{{pkgparam -d NDSserv.pkg NDSserv VERSION
8.7.3.2
}}}
!Linux
{{{rpm -qp --qf %{VERSION} NDSserv-8.7.3.2-35.i386.rpm
8.7.3.2
}}}

!!Find out a package which a file belongs to
!Solaris
{{{% pkgchk -l -p /usr/lib/sendmail
Pathname: /usr/lib/sendmail
Type: regular file
Expected mode: 4555
Expected owner: root
Expected group: bin
Expected file size (bytes): 650720
Expected sum(1) of contents: 22626
Expected last modification: Apr 07 04:13:53 1999
Referenced by the following packages:
        SUNWsndmu
Current status: installed

%
}}}
 *Plagarized from a [Solaris Command Reference|http://www.optix.org/~dxy/solaris/command/].
!Linux
{{{rpm -qf /usr/sbin/sendmail
sendmail-8.12.11-4.RHEL3.1
}}}