Have a quick look on installed packages providing services

Sometimes, it is interesting to have a quick look on installed packages providing services to check if there is possibility to clean unused packages, or to disable (temporary or not) services which are not used and which are so wasting resources.

To get information about installed packages providing services (excluding inet and xinet) which are NEVER started (and so may be removed):
for service in $( chkconfig --list |grep "1:" |grep -v "on" |awk '{print $1}' ); do rpm -qi "$( rpm -qf /etc/init.d/$service )"; done |less

Important:
- some packages provide several services so it can appear several times with this simple command
- before removing such a package, it is important to ensure it is not providing something you need (libraries, tools, various files ...)
- you may use something else than "on" according to your OS language


To get information about installed packages providing services (excluding inet and xinet) which are started (and so using resources):
for service in $( chkconfig --list |grep "5:on" |awk '{print $1}' ); do rpm -qi "$( rpm -qf /etc/init.d/$service )"; done |less

Important:
- some packages provide several services so it can appear several times with this simple command
- you can perform this check with every runlevel replacing "5" by anything else
- you may use something else than "on" according to your OS language