Linux

Linux is today’s dominant Internet server platform. System administrators and Web developers need deep Linux fluency, including expert knowledge of shells and the command line. This is the only guide with everything you need to achieve that level of Linux mastery. Renowned Linux expert Mark Sobell has brought together comprehensive, insightful guidance on the tools sysadmins, developers, and power users need most, and has created an outstanding day-to-day reference, updated with assistance from new coauthor Matthew Helmke.

This title is 100 percent distribution and release agnostic. Packed with hundreds of high-quality, realistic examples, it presents Linux from the ground up: the clearest explanations and most useful information about everything from filesystems to shells, editors to utilities, and programming tools to regular expressions.

Use a Mac? You’ll find coverage of the macOS command line, including macOS-only tools and utilities that other Linux/UNIX titles ignore.

A Practical Guide to Linux® Commands, Editors, and Shell Programming, Fourth Edition, is the only guide to deliver

• A MariaDB chapter to get you started with this ubiquitous relational database management system (RDBMS)
• A masterful introduction to Python for system administrators and power users
• In-depth coverage of the bash and tcsh shells, including a complete discussion of environment, inheritance, and process locality, plus coverage of basic and advanced shell programming
• Practical explanations of core utilities, from aspell to xargs, including printf and sshfs/curlftpfs, PLUS macOS—specific utilities from ditto to SetFile
• Expert guidance on automating remote backups using rsync
• Dozens of system security tips, including step-by-step walkthroughs of implementing secure communications using ssh and scp
• Tips and tricks for customizing the shell, including step values, sequence expressions, the eval builtin, and implicit command-line continuation
• High-productivity editing techniques using vim and emacs
• A comprehensive, 300-plus-page command reference section covering 102 utilities, including find, grep, sort, and tar
• Instructions for updating systems using apt-get and dnf
• And much more, including coverage of BitTorrent, gawk, sed, find, sort, bzip2, and regular expressions

For more than twenty years, serious C programmers have relied on one book for practical, in-depth knowledge of the programming interfaces that drive the UNIX and Linux kernels: W. Richard Stevens’ Advanced Programming in the UNIX® Environment. Now, once again, Rich’s colleague Steve Rago has thoroughly updated this classic work. The new third edition supports today’s leading platforms, reflects new technical advances and best practices, and aligns with Version 4 of the Single UNIX Specification.

Steve carefully retains the spirit and approach that have made this book so valuable. Building on Rich’s pioneering work, he begins with files, directories, and processes, carefully laying the groundwork for more advanced techniques, such as signal handling and terminal I/O. He also thoroughly covers threads and multithreaded programming, and socket-based IPC.

This edition covers more than seventy new interfaces, including POSIX asynchronous I/O, spin locks, barriers, and POSIX semaphores. Most obsolete interfaces have been removed, except for a few that are ubiquitous. Nearly all examples have been tested on four modern platforms: Solaris 10, Mac OS X version 10.6.8 (Darwin 10.8.0), FreeBSD 8.0, and Ubuntu version 12.04 (based on Linux 3.2).

As in previous editions, you’ll learn through examples, including more than ten thousand lines of downloadable, ISO C source code. More than four hundred system calls and functions are demonstrated with concise, complete programs that clearly illustrate their usage, arguments, and return values. To tie together what you’ve learned, the book presents several chapter-length case studies, each reflecting contemporary environments.

Advanced Programming in the UNIX® Environment has helped generations of programmers write code with exceptional power, performance, and reliability. Now updated for today’s systems, this third edition will be even more valuable.

The GNU Autotools make it easy for developers to create software that is portable across many Unix-like operating systems, and even Windows. Although the Autotools are used by thousands of open source software packages, they have a notoriously steep learning curve.

Autotools is the first book to offer programmers a tutorial-based guide to the GNU build system. Author John Calcote begins with an overview of high-level concepts and a hands-on tour of the philosophy and design of the Autotools. He then tackles more advanced details, like using the M4 macro processor with Autoconf, extending the framework provided by Automake, and building Java and C# sources. He concludes with solutions to frequent problems encountered by Autotools users.

This thoroughly revised second edition has been updated to cover the latest versions of the Autotools. It includes five new chapters on topics like pkg-config, unit and integration testing with Autotest, internationalizing with GNU tools, the portability of gnulib, and using the Autotools with Windows. As with the first edition, you'll focus on two projects: Jupiter, a simple “Hello, world!” program, and FLAIM, an existing, complex open source effort containing four separate but interdependent projects. Follow along as the author takes Jupiter’s build system from a basic makefile to a full-fledged Autotools project, and then as he converts the FLAIM projects from complex, hand-coded makefiles to the powerful and flexible GNU build system.

Learn how to:

• Master the Autotools build system to maximize your software’s portability
• Generate Autoconf configuration scripts to simplify the compilation process
• Produce portable makefiles with Automake
• Build cross-platform software libraries with Libtool
• Write your own Autoconf macros

This detailed introduction to the GNU Autotools is indispensable for developers and programmers looking to gain a deeper understanding of this complex suite of tools. Stop fighting against the system and make sense of it all with the second edition of Autotools!

Take your Linux skills to the next level! Whether you're a system administrator, software developer, site reliability engineer, or enthusiastic hobbyist, this practical, hands-on book will help you work faster, smarter, and more efficiently. You'll learn how to create and run complex commands that solve real business problems, process and retrieve information, and automate manual tasks.

You'll also truly understand what happens behind the shell prompt, so no matter which commands you run, you can be more successful in everyday Linux use and more competitive on the job market.

As you build intermediate to advanced command-line skills, you'll learn how to:

• Choose or construct commands that get your work done quickly
• Run commands efficiently and navigate the Linux filesystem with ease
• Build powerful, complex commands out of simpler ones
• Transform text files and query them like databases to achieve business goals
• Control Linux point-and-click features from the command line

GNU make is the most widely used build automation tool, but it can be challenging to master and its terse language can be tough to parse for even experienced programmers. Those who run into difficulties face a long, involved struggle, often leaving unsolved problems behind and GNU make's vast potential untapped.

The GNU Make Book demystifies GNU make and shows you how to use its best features. You'll find a fast, thorough rundown of the basics of variables, rules, targets, and makefiles. Learn how to fix wastefully long build times and other common problems, and gain insight into more advanced capabilities, such as complex pattern rules. With this utterly pragmatic manual and cookbook, you'll make rapid progress toward becoming a more effective user.

You'll also learn how to:

• Master user-defined functions, variables, and path handling
• Weigh the pitfalls and advantages of GNU make parallelization
• Handle automatic dependency generation, rebuilding, and non-recursive make
• Modify the GNU make source and take advantage of the GNU Make Standard Library
• Create makefile assertions and debug makefiles

GNU make is known for being tricky to use, but it doesn't have to be. If you’re looking for a deeper understanding of this indispensable tool, you'll find The GNU Make Book to be an indispensable guide.

Unlike some operating systems, Linux doesn’t try to hide the important bits from you—it gives you full control of your computer. But to truly master Linux, you need to understand its internals, like how the system boots, how networking works, and what the kernel actually does.

In this third edition of the bestselling How Linux Works, author Brian Ward peels back the layers of this well-loved operating system to make Linux internals accessible. This edition has been thoroughly updated and expanded with added coverage of Logical Volume Manager (LVM), virtualization, and containers.

You'll learn:

• How Linux boots, from boot loaders to init (systemd)
• How the kernel manages devices, device drivers, and processes
• How networking, interfaces, firewalls, and servers work
• How development tools work and relate to shared libraries
• How to write effective shell scripts

You’ll also explore the kernel and examine key system tasks inside user-space processes, including system calls, input and output, and filesystem maintenance. With its combination of background, theory, real-world examples, and thorough explanations, How Linux Works, 3rd Edition will teach you what you need to know to take control of your operating system.

NEW TO THIS EDITION:

• Hands-on coverage of the LVM, journald logging system, and IPv6
• Additional chapter on virtualization, featuring containers and cgroups
• Expanded discussion of systemd

Covers systemd-based installations

Learn Linux in a Month of Lunches shows you how to install and use Linux for all the things you do with your OS, like connecting to a network, installing software, and securing your system. Whether you're just curious about Linux or have to get up and running for your job, you'll appreciate how this book concentrates on the tasks you need to know how to do in 23 easy lessons.

If you use Linux in development or operations and need a structured approach to help you dive deeper, this book is for you. Author Michael Hausenblas also provides tips and tricks for improving your workflow with this open source operating system. Whether you're a developer, software architect, or site reliability engineer, this hands-on guide focuses on ways to use Linux for your everyday needs, from development to office-related tasks.

Along the way, you'll gain hands-on experience with modern Linux terminals and shells, and learn how to manage your workloads. You'll understand how to run Linux applications by using containers, systemd, modern filesystems, and immutable distros such as Flatcar and Bottlerocket.

• Use Linux as a modern work environment, rather than just from an admin perspective
• Learn critical components such as the Linux kernel, terminal multiplexer, human-friendly shells, and portable shell scripting
• Become familiar with access control, from file permissions to capabilities, and understand the role of filesystems as a fundamental building block
• Learn about application dependency management and containers
• Gain hands-on experience with the Linux networking stack and tooling, including DNS
• Apply modern operating system observability to manage your workloads
• Become familiar with interprocess communication, virtual machines, and selected security topics

If you’re getting started along the exciting path of hacking, cybersecurity, and pentesting, Linux Basics for Hackers is an excellent first step. Using Kali Linux, an advanced penetration testing distribution of Linux, you’ll learn the basics of using the Linux operating system and acquire the tools and techniques you’ll need to take control of a Linux environment.

First, you’ll learn how to install Kali on a virtual machine and get an introduction to basic Linux concepts. Next, you’ll tackle broader Linux topics like manipulating text, controlling file and directory permissions, and managing user environment variables. You’ll then focus in on foundational hacking concepts like security and anonymity and learn scripting skills with bash and Python. Practical tutorials and exercises throughout will reinforce and test your skills as you learn how to:

• Cover your tracks by changing your network information and manipulating the rsyslog logging utility
• Write a tool to scan for network connections, and connect and listen to wireless networks
• Keep your internet activity stealthy using Tor, proxy servers, VPNs, and encrypted email
• Write a bash script to scan open ports for potential targets
• Use and abuse services like MySQL, Apache web server, and OpenSSH
• Build your own hacking tools, such as a remote video spy camera and a password cracker Hacking is complex, and there is no single way in. Why not start at the beginning with Linux Basics for Hackers?

Covers Kali Linux and Python 3

"If you're just getting started or working your way to expert level, getting a copy of this book might be one of the best things you can do to develop your cybersecurity skills." —Sandra Henry-Stocker, Network World

"The information provided can help even a general user to get more comfortable with the Linux operating system without feeling overwhelmed by more complex, security-related topics and usage. While we could all benefit from more attention to security, Linux Basics for Hackers just might inspire the next crop of budding techies into the security rock stars of tomorrow." —Tim Everson, The Ethical Hacker Network

"Linux Basics for Hackers is immediately practical. Its quick and dirty approach to exploring and using a Linux system was welcome." —Jesse Smith, DistroWatch Weekly

"If you are starting out in Computer Science and want to get up to speed quickly on Linux and Unix like operating systems, working through this book will put you well ahead of your fellow students, and quickly." —Greg Laden, Greg Laden's Blog

Linux is by far the most-used kernel on embedded systems. Thanks to its subsystems, the Linux kernel supports almost all of the application fields in the industrial world. This updated second edition of Linux Device Driver Development is a comprehensive introduction to the Linux kernel world and the different subsystems that it is made of, and will be useful for embedded developers from any discipline.

You'll learn how to configure, tailor, and build the Linux kernel. Filled with real-world examples, the book covers each of the most-used subsystems in the embedded domains such as GPIO, direct memory access, interrupt management, and I2C/SPI device drivers. This book will show you how Linux abstracts each device from a hardware point of view and how a device is bound to its driver(s). You'll also see how interrupts are propagated in the system as the book covers the interrupt processing mechanisms in-depth and describes every kernel structure and API involved. This new edition also addresses how not to write device drivers using user space libraries for GPIO clients, I2C, and SPI drivers.

By the end of this Linux book, you'll be able to write device drivers for most of the embedded devices out there.

What you will learn

• Download, configure, build, and tailor the Linux kernel
• Describe the hardware using a device tree
• Write feature-rich platform drivers and leverage I2C and SPI buses
• Get the most out of the new concurrency managed workqueue infrastructure
• Understand the Linux kernel timekeeping mechanism and use time-related APIs
• Use the regmap framework to factor the code and make it generic
• Offload CPU for memory copies using DMA
• Interact with the real world using GPIO, IIO, and input subsystems

Who this book is for

This Linux OS book is for embedded system and embedded Linux enthusiasts/developers who want to get started with Linux kernel development and leverage its subsystems. Electronic hackers and hobbyists interested in Linux kernel development as well as anyone looking to interact with the platform using GPIO, IIO, and input subsystems will also find this book useful.

Device drivers literally drive everything you're interested in--disks, monitors, keyboards, modems--everything outside the computer chip and memory. And writing device drivers is one of the few areas of programming for the Linux operating system that calls for unique, Linux-specific knowledge. For years now, programmers have relied on the classic Linux Device Drivers from O'Reilly to master this critical subject. Now in its third edition, this bestselling guide provides all the information you'll need to write drivers for a wide range of devices.Over the years the book has helped countless programmers learn:

• how to support computer peripherals under the Linux operating system
• how to develop and write software for new hardware under Linux
• the basics of Linux operation even if they are not expecting to write a driver

The new edition of Linux Device Drivers is better than ever. The book covers all the significant changes to Version 2.6 of the Linux kernel, which simplifies many activities, and contains subtle new features that can make a driver both more efficient and more flexible. Readers will find new chapters on important types of drivers not covered previously, such as consoles, USB drivers, and more.Best of all, you don't have to be a kernel hacker to understand and enjoy this book. All you need is an understanding of the C programming language and some background in Unix system calls. And for maximum ease-of-use, the book uses full-featured examples that you can compile and run without special hardware.

Today Linux holds fast as the most rapidly growing segment of the computer market and continues to win over enthusiastic adherents in many application areas. With this increasing support, Linux is now absolutely mainstream, and viewed as a solid platform for embedded systems. If you're writing device drivers, you'll want this book. In fact, you'll wonder how drivers are ever written without it.

Learn to develop customized device drivers for your embedded Linux system

About This Book

• Learn to develop customized Linux device drivers
• Learn the core concepts of device drivers such as memory management, kernel caching, advanced IRQ management, and so on.
• Practical experience on the embedded side of Linux

Who This Book Is For

This book will help anyone who wants to get started with developing their own Linux device drivers for embedded systems. Embedded Linux users will benefit highly from this book.

This book covers all about device driver development, from char drivers to network device drivers to memory management.

What You Will Learn

• Use kernel facilities to develop powerful drivers
• Develop drivers for widely used I2C and SPI devices and use the regmap API
• Write and support devicetree from within your drivers
• Program advanced drivers for network and frame buffer devices
• Delve into the Linux irqdomain API and write interrupt controller drivers
• Enhance your skills with regulator and PWM frameworks
• Develop measurement system drivers with IIO framework
• Get the best from memory management and the DMA subsystem
• Access and manage GPIO subsystems and develop GPIO controller drivers

System administrators need to stay ahead of new security vulnerabilities that leave their networks exposed every day. A firewall and an intrusion detection systems (IDS) are two important weapons in that fight, enabling you to proactively deny access and monitor network traffic for signs of an attack.

Linux Firewalls discusses the technical details of the iptables firewall and the Netfilter framework that are built into the Linux kernel, and it explains how they provide strong filtering, Network Address Translation (NAT), state tracking, and application layer inspection capabilities that rival many commercial tools. You'll learn how to deploy iptables as an IDS with psad and fwsnort and how to build a strong, passive authentication layer around iptables with fwknop.

Concrete examples illustrate concepts such as firewall log analysis and policies, passive network authentication and authorization, exploit packet traces, Snort ruleset emulation, and more with coverage of these topics:

• Passive network authentication and OS fingerprinting
• iptables log analysis and policies
• Application layer attack detection with the iptables string match extension
• Building an iptables ruleset that emulates a Snort ruleset
• Port knocking vs. Single Packet Authorization (SPA)
• Tools for visualizing iptables logs

Perl and C code snippets offer practical examples that will help you to maximize your deployment of Linux firewalls. If you're responsible for keeping a network secure, you'll find Linux Firewalls invaluable in your attempt to understand attacks and use iptables—along with psad and fwsnort—to detect and even prevent compromises.

Linux in Action is a task-based tutorial that will give you the skills and deep understanding you need to administer a Linux-based system. This hands-on book guides you through 12 real-world projects so you can practice as you learn. Each chapter ends with a review of best practices, new terms, and exercises.

The 2nd Edition of Linux Kernel Programming is an updated, comprehensive guide for new programmers to the Linux kernel. This book uses the recent 6.1 Long-Term Support (LTS) Linux kernel series, which will be maintained until Dec 2026, and also delves into its many new features. Further, the Civil Infrastructure Project has pledged to maintain and support this 6.1 Super LTS (SLTS) kernel right until August 2033, keeping this book valid for years to come!

You’ll begin this exciting journey by learning how to build the kernel from source. In a step by step manner, you will then learn how to write your first kernel module by leveraging the kernel’s powerful Loadable Kernel Module (LKM) framework. With this foundation, you will delve into key kernel internals topics including Linux kernel architecture, memory management, and CPU (task) scheduling. You’ll finish with understanding the deep issues of concurrency, and gain insight into how they can be addressed with various synchronization/locking technologies (e.g., mutexes, spinlocks, atomic/refcount operators, rw-spinlocks and even lock-free technologies such as per-CPU and RCU).

By the end of this book, you’ll have a much better understanding of the fundamentals of writing the Linux kernel and kernel module code that can straight away be used in real-world projects and products.

What you will learn

• Configure and build the 6.1 LTS kernel from source
• Write high-quality modular kernel code (LKM framework) for 6.x kernels
• Explore modern Linux kernel architecture
• Get to grips with key internals details regarding memory management within the kernel
• Understand and work with various dynamic kernel memory alloc/dealloc APIs
• Discover key internals aspects regarding CPU scheduling within the kernel, including cgroups v2
• Gain a deeper understanding of kernel concurrency issues
• Learn how to work with key kernel synchronization primitives

Who this book is for

This book is for beginner Linux programmers and developers looking to get started with the Linux kernel, providing a knowledge base to understand required kernel internal topics and overcome frequent and common development issues. A basic understanding of Linux CLI and C programming is assumed.

If you use Linux in your day-to-day work, then Linux Pocket Guide is the perfect on-the-job reference. This thoroughly updated 20th anniversary edition explains more than 200 Linux commands, including new commands for file handling, package management, version control, file format conversions, and more.

In this concise guide, author Daniel Barrett provides the most useful Linux commands grouped by functionality. Whether you're a novice or an experienced user, this practical book is an ideal reference for the most important Linux commands.

You'll learn:

• Essential concepts—commands, shells, users, and the filesystem
• File commands-creating, organizing, manipulating, and processing files of all kinds
• Sysadmin basics-superusers, processes, user management, and software installation
• Filesystem maintenance-disks, RAID, logical volumes, backups, and more
• Networking commands-working with hosts, network connections, email, and the web
• Getting stuff done-everything from math to version control to graphics and audio

The Linux Programming Interface (TLPI) is the definitive guide to the Linux and UNIX programming interface—the interface employed by nearly every application that runs on a Linux or UNIX system.

In this authoritative work, Linux programming expert Michael Kerrisk provides detailed descriptions of the system calls and library functions that you need in order to master the craft of system programming, and accompanies his explanations with clear, complete example programs.

You'll find descriptions of over 500 system calls and library functions, and more than 200 example programs, 88 tables, and 115 diagrams. You'll learn how to:

• Read and write files efficiently
• Use signals, clocks, and timers
• Create processes and execute programs
• Write secure programs
• Write multithreaded programs using POSIX threads
• Build and use shared libraries
• Perform interprocess communication using pipes, message queues, shared memory, and semaphores
• Write network applications with the sockets API

While The Linux Programming Interface covers a wealth of Linux-specific features, including epoll, inotify, and the /proc file system, its emphasis on UNIX standards (POSIX.1-2001/SUSv3 and POSIX.1-2008/SUSv4) makes it equally valuable to programmers working on other UNIX platforms.

The Linux Programming Interface is the most comprehensive single-volume work on the Linux and UNIX programming interface, and a book that's destined to become a new classic.

Discover the power of Oracle Linux 8, the free and enterprise-grade Linux distribution designed for use in any environment, with this recipe-style book.

Starting with instructions on how to obtain Oracle Linux for both X86 and ARM-based platforms, this book walks you through various installation methods, from running it as a Windows service to installing it on a Raspberry Pi. It unravels advanced topics such as system upgrades using Leapp for major version transitions and using a PXE server and kickstart files for more advanced installations. The book then delves into swapping kernels to take advantage of Oracle’s UEK, exploring boot options, managing software with DNF, and achieving high availability. Detailed recipes involving security topics will assist with tasks such as data encryption, both at rest and in motion.

For developers, it offers guidance on building RPM files, using Docker and Podman in a containerized environment, working with AppStreams, and more. For large-scale deployments, the book introduces Oracle Linux Automation Manager for enterprise-level Ansible utilization, from setting up the Ansible server to basic playbook writing. Finally, you’ll discover strategies for cloud migration.

By the end of this book, you’ll possess a comprehensive toolkit that will elevate your skills as a Linux administrator.

What you will learn

• Master the use of DNF for package management and stream-specific installations
• Implement high availability services through Podman and Oracle Linux Automation Manager
• Secure your system with Secure Boot and at-rest disk encryption techniques
• Achieve rebootless system updates using the Ksplice technology
• Optimize large-scale deployments with Oracle Linux Automation Manager and Ansible
• Gain practical insights into storage management using Btrfs and LVM

Who this book is for

This book is for existing Oracle Linux system administrators and CentOS or RHEL admins contemplating a migration to Oracle Linux 8. A foundation of basic sysadmin skills is assumed as this is not an entry-level book; it's a cookbook focused on complex and lesser-known configurations specifically for Oracle Linux 8.

Practical Linux Forensics dives into the technical details of analyzing postmortem forensic images of Linux systems that have been misused, abused, or the target of malicious attacks. This essential practitioner’s guide will show you how to locate and interpret digital evidence found on Linux desktops, servers, and IoT devices, draw logical conclusions, and reconstruct timelines of past activity after a crime or security incident. It's a book written for investigators with varying levels of Linux experience, and the techniques shown are independent of the forensic analysis platform and tools used.

Early chapters provide an overview of digital forensics as well as an introduction to the Linux operating system and popular distributions. From there, the book describes the analysis of storage, filesystems, files and directories, installed software packages, and logs. Special focus is given to examining human user activity such as logins, desktop environments and artifacts, home directories, regional settings, and peripheral devices used.

You’ll learn how to:

• Analyze partition tables, volume management, Linux filesystems, and directory layout
• Reconstruct the Linux startup process, from system boot and kernel initialization, to systemd unit files leading up to a graphical login
• Perform historical analysis of power, temperature, and physical environment, and find evidence of sleep, hibernation, shutdowns, reboots, and crashes
• Analyze network configuration, including interfaces, addresses, network managers, DNS, wireless artifacts, VPNs, firewalls, and proxy settings
• Perform analysis of time and locale settings, internationalization (language and keyboard settings), and Linux geolocation services
• Reconstruct user login sessions, analyze desktop artifacts, and identify traces of attached peripheral devices, including disks, printers, and mobile devices

This essential guide covers all aspects of Linux system administration, from user maintenance, backups, filesystem housekeeping, storage management, and network setup to hardware and software troubleshooting and some application management. It's both a practical daily reference manual for sysadmins and IT pros and a handy study guide for those taking Linux certification exams.

You'll turn to it frequently, not only because of the sheer volume of valuable information it provides but because of the real-world examples within and the clear, useful way the information is presented. With this book at your side, you'll be able to:

• Install Linux and perform initial setup duties, such as connecting to a network
• Navigate the Linux filesystem via the command line
• Install software from repositories and source and satisfy dependencies
• Set permissions on files and directories
• Create, modify, and remove user accounts
• Set up networking
• Format and mount filesystems
• Perform basic troubleshooting on hardware and software
• Create and manage logical volumes
• Work with SELinux
• Manage a firewall and iptables
• Shut down, reboot, and recover a system
• Perform backups and restores

sed & awk describes two text processing programs that are mainstays of the UNIX programmer's toolbox.sed is a "stream editor" for editing streams of text that might be too large to edit as a single file, or that might be generated on the fly as part of a larger data processing step. The most common operation done with sed is substitution, replacing one block of text with another.awk is a complete programming language. Unlike many conventional languages, awk is "data driven" -- you specify what kind of data you are interested in and the operations to be performed when that data is found. awk does many things for you, including automatically opening and closing data files, reading records, breaking the records up into fields, and counting the records. While awk provides the features of most conventional programming languages, it also includes some unconventional features, such as extended regular expression matching and associative arrays. sed & awk describes both programs in detail and includes a chapter of example sed and awk scripts.This edition covers features of sed and awk that are mandated by the POSIX standard. This most notably affects awk, where POSIX standardized a new variable, CONVFMT, and new functions, toupper() and tolower(). The CONVFMT variable specifies the conversion format to use when converting numbers to strings (awk used to use OFMT for this purpose). The toupper() and tolower() functions each take a (presumably mixed case) string argument and return a new version of the string with all letters translated to the corresponding case.In addition, this edition covers GNU sed, newly available since the first edition. It also updates the first edition coverage of Bell Labs nawk and GNU awk (gawk), covers mawk, an additional freely available implementation of awk, and briefly discusses three commercial versions of awk, MKS awk, Thompson Automation awk (tawk), and Videosoft (VSAwk).

Systems Performance, Second Edition, covers concepts, strategy, tools, and tuning for operating systems and applications, using Linux-based operating systems as the primary example. A deep understanding of these tools and techniques is critical for developers today. Implementing the strategies described in this thoroughly revised and updated edition can lead to a better end-user experience and lower costs, especially for cloud computing environments that charge by the OS instance.

Systems performance expert and best-selling author Brendan Gregg summarizes relevant operating system, hardware, and application theory to quickly get professionals up to speed even if theyve never analyzed performance before. Gregg then provides in-depth explanations of the latest tools and techniques, including extended BPF, and shows how to get the most out of cloud, web, and large-scale enterprise systems. Key topics covered include

• Hardware, kernel, and application internals, and how they perform
• Methodologies for rapid performance analysis of complex systems
• Optimizing CPU, memory, file system, disk, and networking usage
• Sophisticated profiling and tracing with perf, Ftrace, and BPF (BCC and bpftrace)
• Performance challenges associated with cloud computing hypervisors
• Benchmarking more effectively

Featuring up-to-date coverage of Linux operating systems and environments, Systems Performance, Second Edition, also addresses issues that apply to any computer system. The book will be a go-to reference for many years to come and, like the first edition, required reading at leading tech companies.

The Linux Command Line takes you from your very first terminal keystrokes to writing full programs in Bash, the most popular Linux shell (or command line). Along the way you'll learn the timeless skills handed down by generations of experienced, mouse-shunning gurus: file navigation, environment configuration, command chaining, pattern matching with regular expressions, and more.

In addition to that practical knowledge, author William Shotts reveals the philosophy behind these tools and the rich heritage that your desktop Linux machine has inherited from Unix supercomputers of yore.

As you make your way through the book's short, easily-digestible chapters, you'll learn how to:

• Create and delete files, directories, and symlinks
• Administer your system, including networking, package installation, and process management
• Use standard input and output, redirection, and pipelines
• Edit files with Vi, the world's most popular text editor
• Write shell scripts to automate common or boring tasks
• Slice and dice text files with cut, paste, grep, patch, and sed

Once you overcome your initial "shell shock," you'll find that the command line is a natural and expressive way to communicate with your computer. Just don't be surprised if your mouse starts to gather dust.

"For those looking to master the Linux command line and get an essential understand of the core Linux command line tools, this book is a highly effective and useful guide." —Ben Rothke, RSA Conference

In order to thoroughly understand what makes Linux tick and why it works so well on a wide variety of systems, you need to delve deep into the heart of the kernel. The kernel handles all interactions between the CPU and the external world, and determines which programs will share processor time, in what order. It manages limited memory so well that hundreds of processes can share the system efficiently, and expertly organizes data transfers so that the CPU isn't kept waiting any longer than necessary for the relatively slow disks.

The third edition of Understanding the Linux Kernel takes you on a guided tour of the most significant data structures, algorithms, and programming tricks used in the kernel. Probing beyond superficial features, the authors offer valuable insights to people who want to know how things really work inside their machine. Important Intel-specific features are discussed. Relevant segments of code are dissected line by line. But the book covers more than just the functioning of the code; it explains the theoretical underpinnings of why Linux does things the way it does.

This edition of the book covers Version 2.6, which has seen significant changes to nearly every kernel subsystem, particularly in the areas of memory management and block devices. The book focuses on the following topics:

• Memory management, including file buffering, process swapping, and Direct memory Access (DMA)
• The Virtual Filesystem layer and the Second and Third Extended Filesystems
• Process creation and scheduling
• Signals, interrupts, and the essential interfaces to device drivers
• Timing
• Synchronization within the kernel
• Interprocess Communication (IPC)
• Program execution

Understanding the Linux Kernel will acquaint you with all the inner workings of Linux, but it's more than just an academic exercise. You'll learn what conditions bring out Linux's best performance, and you'll see how it meets the challenge of providing good system response during process scheduling, file access, and memory management in a wide variety of environments. This book will help you make the most of your Linux system.

Shell scripts are an efficient way to interact with your machine and manage your files and system operations. With just a few lines of code, your computer will do exactly what you want it to do. But you can also use shell scripts for many other essential (and not-so-essential) tasks.

This second edition of Wicked Cool Shell Scripts offers a collection of useful, customizable, and fun shell scripts for solving common problems and personalizing your computing environment. Each chapter contains ready-to-use scripts and explanations of how they work, why you’d want to use them, and suggestions for changing and expanding them. You’ll find a mix of classic favorites, like a disk backup utility that keeps your files safe when your system crashes, a password manager, a weather tracker, and several games, as well as 23 brand-new scripts, including:

• A ZIP code lookup tool that reports the city and state
• A Bitcoin address information retriever
• A suite of tools for working with cloud services like Dropbox and iCloud
• Tools for renaming and applying commands to files in bulk
• Image processing and editing tools

Whether you want to save time managing your system or just find new ways to goof off, these scripts are wicked cool!