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).

    From Mary, Queen of Scots, trapped by her own code, to the Navajo Code Talkers who helped the Allies win World War II, to the incredible (and incredibly simple) logisitical breakthrough that made Internet commerce secure, The Code Book tells the story of the most powerful intellectual weapon ever known: secrecy.Throughout the text are clear technical and mathematical explanations, and portraits of the remarkable personalities who wrote and broke the world’s most difficult codes. Accessible, compelling, and remarkably far-reaching, this book will forever alter your view of history and what drives it. It will also make you wonder how private that e-mail you just sent really is.

    Setting up and maintaining a Linux server requires understanding not only the hardware, but the ins and outs of the Linux operating system along with its supporting cast of utilities as well as layers of applications software. There's basic documentation online but there's a lot beyond the basics you have to know, and this only comes from people with hands-on, real-world experience. This kind of "know how" is what we sought to capture in Linux Server Hacks.Linux Server Hacks is a collection of 100 industrial-strength hacks, providing tips and tools that solve practical problems for Linux system administrators. Every hack can be read in just a few minutes but will save hours of searching for the right answer. Some of the hacks are subtle, many of them are non-obvious, and all of them demonstrate the power and flexibility of a Linux system. You'll find hacks devoted to tuning the Linux kernel to make your system run more efficiently, as well as using CVS or RCS to track the revision to system files. You'll learn alternative ways to do backups, how to use system monitoring tools to track system performance and a variety of secure networking solutions. Linux Server Hacks also helps you manage large-scale Web installations running Apache, MySQL, and other open source tools that are typically part of a Linux system.O'Reilly's new Hacks Series proudly reclaims the term "hacking" for the good guys. Hackers use their ingenuity to solve interesting problems. Rob Flickenger is an experienced system administrator, having managed the systems for O'Reilly Network for several years. (He's also into community wireless networking and he's written a book on that subject for O'Reilly.) Rob has also collected the best ideas and tools from a number of other highly skilled contributors.Written for users who already understand the basics, Linux Server Hacks is built upon the expertise of people who really know what they're doing.

    Apache: The Definitive Guide, written and reviewed by key members of the Apache Group, is the only complete guide on the market today that describes how to obtain, set up, and secure the Apache software.Apache was originally based on code and ideas found in the most popular HTTP server of the time: NCSA httpd 1.3 (early 1995). It has since evolved into a far superior system that can rival (and probably surpass) almost any other Unix-based HTTP server in terms of functionality, efficiency, and speed. The new version now includes support for Win32 systems. This new second edition of Apache: The Definitive Guide fully describes Windows support and all the other Apache 1.3 features. Contents include:The history of the Apache Group Obtaining and compiling the server Configuring and running Apache on Unix and Windows, including such topics as directory structures, virtual hosts, and CGI programming The Apache 1.3 Module API Apache security A complete list of configuration directives With Apache: The Definitive Guide, web administrators new to Apache can get up to speed more quickly than ever before by working through the tutorial demo. Experienced administrators and CGI programmers, and web administrators moving from Unix to Windows, will find the reference sections indispensable. Apache: The Definitive Guide is the definitive documentation for the world's most popular web server. Includes CD-ROM with Apache manuals and demo sites discussed in the book.

    Difficult issues need to be figured out, such as scalability, consistency, reliability, efficiency, and maintainability. In addition, we have an overwhelming variety of tools, including relational databases, NoSQL datastores, stream or batch processors, and message brokers. What are the right choices for your application? How do you make sense of all these buzzwords?In this practical and comprehensive guide, author Martin Kleppmann helps you navigate this diverse landscape by examining the pros and cons of various technologies for processing and storing data. Software keeps changing, but the fundamental principles remain the same. With this book, software engineers and architects will learn how to apply those ideas in practice, and how to make full use of data in modern applications. Peer under the hood of the systems you already use, and learn how to use and operate them more effectively Make informed decisions by identifying the strengths and weaknesses of different tools Navigate the trade-offs around consistency, scalability, fault tolerance, and complexity Understand the distributed systems research upon which modern databases are built Peek behind the scenes of major online services, and learn from their architectures

    citizen recognized its ominous potential. Armed with clear evidence of computer espionage, he began a highly personal quest to expose a hidden network of spies that threatened national security. But would the authorities back him up? Cliff Stoll's dramatic firsthand account is "a computer-age detective story, instantly fascinating [and] astonishingly gripping" (Smithsonian). Cliff Stoll was an astronomer turned systems manager at Lawrence Berkeley Lab when a 75-cent accounting error alerted him to the presence of an unauthorized user on his system. The hacker's code name was "Hunter" -- a mysterious invader who managed to break into U.S. computer systems and steal sensitive military and security information. Stoll began a one-man hunt of his own: spying on the spy. It was a dangerous game of deception, broken codes, satellites, and missile bases -- a one-man sting operation that finally gained the attention of the CIA...and ultimately trapped an international spy ring fueled by cash, cocaine, and the KGB.

    You'll get in-depth coverage of the C language and function libraries as well as all the newest C features, including restricted pointers, inline functions, variable-length arrays, and complex math. This jam-packed resource includes hundreds of examples and sample applications.

    That's why Elizabeth Castro has written HTML 4 for the World Wide Web, Fourth Edition: Visual QuickStart Guide, an update to her blockbuster guide to HTML 4. You'll find all the concise, practical advice--and fun examples--that made the first edition a worldwide bestseller, plus entirely new coverage of debugging, JavaScript, and using tables for page layout, and an expanded section on Cascading Style Sheets.Like all the books in the Visual QuickStart series, this one breaks even the most complex tasks into easy-to-follow steps illustrated with hundreds of screenshots and the actual code. The book presumes no prior knowledge of HTML, making it the perfect introduction for beginners. But its tabbed format and info-packed appendixes (on special HTML characters and Web-safe colors, for example) also make it a handy and indispensable reference for those who build Web pages for a living. Find out why Amazon called the previous edition a "dream guide" to HTML.

    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 FilesystemsProcess creation and schedulingSignals, interrupts, and the essential interfaces to device driversTimingSynchronization within the kernelInterprocess Communication (IPC)Program executionUnderstanding 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.

    The authors explain each category of vulnerability using real-world examples, screen shots and code extracts. The book is extremely practical in focus, and describes in detail the steps involved in detecting and exploiting each kind of security weakness found within a variety of applications such as online banking, e-commerce and other web applications. The topics covered include bypassing login mechanisms, injecting code, exploiting logic flaws and compromising other users. Because every web application is different, attacking them entails bringing to bear various general principles, techniques and experience in an imaginative way. The most successful hackers go beyond this, and find ways to automate their bespoke attacks. This handbook describes a proven methodology that combines the virtues of human intelligence and computerized brute force, often with devastating results.The authors are professional penetration testers who have been involved in web application security for nearly a decade. They have presented training courses at the Black Hat security conferences throughout the world. Under the alias "PortSwigger," Dafydd developed the popular Burp Suite of web application hack tools.

    Discover how the basic TCP/IP technology has survived and evolved over two decades of exponential growth, and understand the TCP/IP protocols and technical advances. This edition explains emerging technologies such as Mobile IP, Virtual Private Networks, resource reservation with RSVP, and Ipv6. Comer reveals how to master TCP/IP and how the Internet works. The reader is required to have a modest background in the fundamentals of computer systems, but does not need sophisticated mathematics. As with previous editions, this edition provides an introduction to physical networks and then shows how they are combined to form an internet. It states design principles clearly, and discusses motivations and consequences. THIS NEW EDITION OF VOLUME 1: *Explains how voice and video are sent over IP internets and how IP Telephony operates *Describes Mobile IP (a technology that allows a computer to move fr

    These tools help programmers build compilers and interpreters, but they also have a wider range of applications.The second edition contains completely revised tutorial sections for novice users and reference sections for advanced users. This edition is twice the size of the first and has an expanded index.The following material has been added:Each utility is explained in a chapter that covers basic usage and simple, stand-alone applications How to implement a full SQL grammar, with full sample code Major MS-DOS and Unix versions of lex and yacc are explored in depth, including AT&T lex and yacc, Berkeley yacc, Berkeley/GNU Flex, GNU Bison, MKS lex and yacc, and Abraxas PCYACC

    With a blend of software engineering facts and thought-provoking opinions, Fred Brooks offers insight for anyone managing complex projects. These essays draw from his experience as project manager for the IBM System/360 computer family and then for OS/360, its massive software system. Now, 45 years after the initial publication of his book, Brooks has revisited his original ideas and added new thoughts and advice, both for readers already familiar with his work and for readers discovering it for the first time.The added chapters contain (1) a crisp condensation of all the propositions asserted in the original book, including Brooks' central argument in The Mythical Man-Month: that large programming projects suffer management problems different from small ones due to the division of labor; that the conceptual integrity of the product is therefore critical; and that it is difficult but possible to achieve this unity; (2) Brooks' view of these propositions a generation later; (3) a reprint of his classic 1986 paper "No Silver Bullet"; and (4) today's thoughts on the 1986 assertion, "There will be no silver bullet within ten years."

    In an instructive and conversational tone, Cody clearly explains how to program SAS, illustrating with one or more real-life examples and giving a detailed description of how the program works.

    Building on the successful top-down approach of previous editions, this fourth edition continues with an early emphasis on application-layer paradigms and application programming interfaces, encouraging a hands-on experience with protocols and networking concepts.