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Search for installed pakages
# rpm -qa | grep -i pgmname
where pgmname is name of pkg
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To mount an ISO CD image
# mount -o loop /isoimage.iso /blankfolder
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For RPM
rpm -ivh packagename -> TO install package
rpm -qip packagename ->To view package information before install
rpm -e packagename ->To uninstall package
rpm -q package ->To view if package is already inastalled

For tar.gz and tgz Both are same files with different extensions.
less filename ->TO view contents
tar -zxvf filename ->To untar the files 
And if it has a READ me follow it for install[Normally ./configure , make and make 
install is used .But see READme first before installing]