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
- Package name: ftp
- Version: 0.17
- Release: 51.1.el6 (el5,rhl9,fc4,suse100)
Where to get rpm from?
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)
|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
|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|