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 default permissions

The files get their default permissions from the users or processes that create them. If a file is created using text editors, it will have read and write permissions and no executable permissions for everyone. Similarly, a binary executable created using compilers generally has executable permission sets, since they are meant for execution.

Understanding umask

Default file and folder permissions are set by the umask program. The umask command without any argument will display the existing value of umask. The same command, when followed by a new octal value as an argument, will set the new value of umask. The following command line is used to view the existing umask of a user:

$ umask

Normal users...