Book Image

CentOS Quick Start Guide

By : Shiwang Kalkhanda

Book Image

CentOS Quick Start Guide

By: Shiwang Kalkhanda

Overview of this book

Linux kernel development has been the worlds largest collaborative project to date. With this practical guide, you will learn Linux through one of its most popular and stable distributions. This book will introduce you to essential Linux skills using CentOS 7. It describes how a Linux system is organized, and will introduce you to key command-line concepts you can practice on your own. It will guide you in performing basic system administration tasks and day-to-day operations in a Linux environment. You will learn core system administration skills for managing a system running CentOS 7 or a similar operating system, such as RHEL 7, Scientific Linux, and Oracle Linux. You will be able to perform installation, establish network connectivity and user and process management, modify file permissions, manage text files using the command line, and implement basic security administration after covering this book. By the end of this book, you will have a solid understanding of working with Linux using the command line.

Preface

Who this book is for

What this book covers

To get the most out of this book

Free Chapter

Getting Started with CentOS 7

Getting Started with CentOS 7

Preparing to install CentOS 7

Performing manual installation

Accessing the command line using the console

Introducing the Bash shell

Bash shell and command execution

Command-Line and Filesystem Navigation

Command-Line and Filesystem Navigation

Understanding the CentOS 7 filesystem hierarchy

Using man pages and the help command

Managing filenames with path expansion

Managing files using command-line tools

Managing archives and compressed files

Managing Text Files

Managing Text Files

Different methods to create a text file

Editing files with the vi editor

Using text file manipulation tools

Redirecting output to files and programs

Using grep for text matching

Finding a file (locate and find commands)

User and Group Management

User and Group Management

Understanding users and groups in CentOS 7

Executing commands as superuser in CentOS 7

Creating, modifying, or deleting local user accounts

Creating, modifying, or deleting local group accounts

Managing user passwords and aging policies

Managing File Permissions

Managing File Permissions

Understanding Linux filesystem permissions

Managing file permissions

Managing file ownership

Special permissions

Managing default permissions

Managing ACL on files

Process Management

Process Management

Understanding processes

Viewing current processes

Communicating with processes using signals

Monitoring processes and load averages

Managing a processes' priority with nice and renice

Controlling jobs on the command line

Managing Networking in CentOS

Managing Networking in CentOS

Linux networking concepts

Using Linux networking commands

Managing a network with nmcli

Editing network configuration files

Configuring hostnames and name resolutions

Accessing remote logins with SSH

Transferring files in Linux

Software Package Management

Software Package Management

Managing applications using RPM

Managing applications using YUM

Managing official and third-party repositories

Creating custom repositories

Overview of Essential Advance Utilities

Overview of Essential Advance Utilities

Understanding system logging

Understanding how to control the system and services

Understanding SELinux concepts

Understanding firewall concepts in CentOS 7

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Managing user passwords and aging policies

This section covers commands that are used to manage passwords and password aging parameters in the shadow password file available in CentOS 7.

Setting a user password using the passwd command

The passwd command is used to either set the user's initial password or modify the user's existing password. The syntax of the passwd command is as follows:

$ passwd    <username>

The root user can set the password for any user to any value without knowing his current password. For a regular user, the default policy is to use at least an eight-character password, and it should not be a dictionary word, or the username, or a previous password. An example updating a user's...