Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Overview of this book

The shell remains one of the most powerful tools on a computer system — yet a large number of users are unaware of how much one can accomplish with it. Using a combination of simple commands, we will see how to solve complex problems in day to day computer usage.Linux Shell Scripting Cookbook, Second Edition will take you through useful real-world recipes designed to make your daily life easy when working with the shell. The book shows the reader how to effectively use the shell to accomplish complex tasks with ease.The book discusses basics of using the shell, general commands and proceeds to show the reader how to use them to perform complex tasks with ease.Starting with the basics of the shell, we will learn simple commands with their usages allowing us to perform operations on files of different kind. The book then proceeds to explain text processing, web interaction and concludes with backups, monitoring and other sysadmin tasks.Linux Shell Scripting Cookbook, Second Edition serves as an excellent guide to solving day to day problems using the shell and few powerful commands together to create solutions.
Table of Contents (16 chapters)
Linux Shell Scripting Cookbook
About the Authors
About the Reviewers

Collecting information about logged in users, boot logs, and boot failures

Collecting information about the operating environment, logged in users, the time for which the computer has been powered on, and boot failures are very helpful. This recipe will go through a few commands used to gather information about a live machine.

Getting ready

This recipe will introduce commands who, w, users, uptime, last, and lastb.

How to do it...

  1. To obtain information about users currently logged into the machine use:

    $ who
    slynux   pts/0   2010-09-29 05:24 (slynuxs-macbook-pro.local)
    slynux   tty7    2010-09-29 07:08 (:0) 

    This output lists the login name, the TTY used by the users, login time, and remote hostname (or X display information) about logged in users.


    TTY (the term comes from TeleTYpewriter) is the device file associated with a text terminal which is created in /dev when a terminal is newly spawned by the user (for example, /dev/pts/3). The device path for the current terminal can be found...