All information pulled out from this link for personal notes and study. How iptables work The iptables work mainly in Internet layer and Transport layer. However, iptables can also work…Continue readingiptables
The systemd is backward compatible with SysV init. If the system has /etc/inittab file, it uses SysV init. The SystemV init (SysV init) is using runlevels to define the state…Continue readingUnderstanding SysV
The widely used beast among initialization processes is systemd. The systemd will take full control of the system, right after the kernel is loaded. After that, systemd will pull the…Continue readingUnderstanding systemd
Init process is the mother (parent) of all processes on the system. It is the first program that is executed when Linux boots up. Init processes manages all other processes…Continue readingUnderstanding init
Installing and maintaining repository based software in RHEL family of distributions is handled by YUM. Repository preferences are configured in /etc/yum.repos.d/ directory and by the /etc/yum.conf configuration file. The .rpm…Continue readingyum
RPM package manager is used by large number of Linux distributions (Red Hat Enterprise, CentOS, Fedora). Like dpkg, rpm is meant to manage local software packages. This means it can…Continue readingrpm
Library – Usually a system library is a collection of program functions. From programming basics, we can say functions are self-contained code modules or code blocks that perform a certain…Continue readingUnderstanding Shared Libraries
The /etc/apt/sources.list contains list of registered repositories. This file is filled in with those links during system installation. However, you can freely add/remove links from it. Each line represents a…Continue readingapt-get
List all installed packages List all installed packages starting with openssh Show real name of the package and show package description Show package information Show dependencies for specified package, whether…Continue readingapt-cache
The dpkg environment settings are configured in /etc/dpkg/dpkg.cfg file. Installing packages Install this package (no dependencies) List all installed packages List this installed package && list all installed packages Install…Continue readingdpkg