RPM - RedHat Package Manager - An Overview

RedHat Package Manager ( RPM )

RPM (Red Hat Package Manager) is an default open source and most popular package management utility for Red Hat based systems like (RHEL, CentOS and Fedora). 
The tool allows system administrators and users to install, update, uninstall, query, verify and manage system software packages in Unix/Linux operating systems. 

Facts About RPM

RPM is free and released under GPL (General Public License).
RPM keeps the information of all the installed packages under /var/lib/rpm database file.
RPM is the way to install packages under Linux systems, if you’ve installed packages using source code, then rpm won’t manage it.
RPM deals with .rpm files, which contains the actual information about the packages such as: what it is, from where it comes, dependencies info, version info etc.

Five Basic Modes of RPM 


1.Install : It is used to install any RPM package.
2.Remove : It is used to erase, remove or un-install any RPM package.
3.Upgrade : It is used to update the existing RPM package.
4.Verify : It is used to query about different RPM packages.
5.Query : It is used for the verification of any RPM package.

RPM Download links:

To find a rpm package and download use the below links
http://rpmfind.net
http://www.redhat.com
http://freshrpms.net/


1.How to install RPM in linux ?


 #rpm –ivh packagename  // To install a RPM we need to use -i option.

2. How to remove a RPM ?


 #rpm -e packagename  // To remove a RPM file we need to use -e option.

3.How to Upgrade a RPM ?


 #rpm -Uvh packagename // To upgrade a RPM we need to use -U option.

4.How to check installed RPM?

 #rpm -qa packagename   // To list or find a installed RPM we need to use -q option.

5. How to List all files of an installed RPM package

 #rpm -ql packagename   // To list all files of installed rpm we need to use -ql ( query list) option.

6.How to Install a RPM Package Without Dependencies

 #rpm -ivh --nodeps packagename // To install a RPM without any dependencies we need to use --nodeps option.

7.How to check dependencies of RPM Package before Installing

 #rpm -qpR packagename   // To check the dependeny for a RPM we need to use -qpR option.


  -q : Query a package
  -p : List capabilities this package provides.
  -R: List capabilities on which this package depends.

8. How to Check an RPM Signature for a Package?


  #rpm --checksig  packagename.rpm    // We need to use the option --checksig for signature verification.

9. How to List Recently Installed RPM Packages


  #rpm -qa --last   // To list recently installed RPM we need to use --last option

10. How to Query a file that belongs which RPM Package


  #rpm -qf /etc/passwd         // To find a file owned by which package 

11.Get the Information of RPM Package Before Installing


  #rpm -qip packagename 

12. How to Verify a RPM Package


  #rpm -Vp  // To verify the installed RPM 

13.How to List all Imported RPM GPG keys


  #rpm -qa gpg-pubkey*


14. How to Remove an RPM Package Without Dependencies


  #rpm -ev --nodeps packagename // same --nodeps option we need to use


15. How To rebuild Corrupted RPM Database

  # cd /var/lib
  # rm __db*
  # rpm --rebuilddb
  # rpmdb_verify Packages