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.
Table of Contents (11 chapters)

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...