What is Linux Software?

  • It is called a Package
  • It is a file with extension “.rpm”
  • Naming convention of the file is as follows
    • <name> – <version> – <release>.<architecture>.rpm

Eg: ftp-0.17-51.1.rl6.i686.rpm

  • Package name: ftp
  • Version: 0.17
  • Release: 51.1.el6 (el5,rhl9,fc4,suse100)

 

Where to get rpm from?

  • net
  • pbone.net

 

What is rpm database?

  • It is a list of files stored in /var/lib/rpm
  • It contains information of all packages, groups installed on the system

 

What is a yum repository?

  • It is a directory on any server which contains all rpm packages and its dependency information
  • Yum command downloads the packages from this server and installed on local machine
  • Location of this server is stored in a special file under /etc/yum.repos.d/

 

What is a yum cache?

  • It is a directory (on local) where information obtained from the yum repository is stored for better performance
  • The default locations of this directory is /var/cache/yum
  • It can be changed by modifying /etc/yum.conf

 

What happens when we install a package?

  • A list of dependent packages is obtained from the yum repository
  • A check is made to find out if all dependent packages are installed or not
  • Dependent packages are installed first
  • Required packages are installed later
  • What if any packages are installed, multiple files are extracted from the packages and copied to various directories with proper file permissions and ownership.
  • The rpm database under /var/lib/rpm is updated with the new package information.

 

Rpm commands (Installing from rpm file)

Install [-ivh]

Uninstall [-ev]

Upgrade [-Uvh]

Query [-q]

 

 

commands Help Notes
rpm –q –a Query all installed packages on system
rpm –qa | grep ftp Find if ftp is installed or not
rpm –q ftp
rpm –qi nmap Complete info about nmap and packages
rpm –qa |more
rpm –ql nmap List all files installed by nmap packages

NOTE: When U Install any Packages on the system it contains:

  • File Script
  • Documentation
  • Configuration

 

Commands Help Notes
rpm –qs nmap List the scripts file installed by nmap packages
rpm –qd nmap List all doc of packages
rpm –qc nmap List config files of packages
rpm –q –requires nmap List Dependencies
rpm –q –last nmap Know when was lastly installed
rpm –qf /usr/share/ncat To check which package as installed this file and also it displays the package name
rpm –q –i –p <package.rpm> Find info about package from the rpm file not from the rpm database
rpm –ivh <package.rpm> Install the package