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Awk - A Tutorial and Introduction - by Bruce Barnett

Awk - A Tutorial and Introduction - by Bruce Barnett
Your browser does not have Javascript enabled. I use Javascript for analytics, and to show ads which pay for the maintenance Last modified: Thu Apr 23 16:37:47 EDT 2015 Part of the Unix tutorials And then there's My blog Table of Contents Copyright 1994,1995 Bruce Barnett and General Electric Company Copyright 2001, 2004, 2013, 2014 Bruce Barnett All rights reserved You are allowed to print copies of this tutorial for your personal use, and link to this page, but you are not allowed to make electronic copies, or redistribute this tutorial in any form without permission. Original version written in 1994 and published in the Sun Observer Awk is an extremely versatile programming language for working on files. The examples given below have the extensions of the executing script as part of the filename. Why learn AWK? In the past I have covered grep and sed. AWK - the (very old) original from AT&T NAWK - A newer, improved version from AT&T GAWK - The Free Software foundation's version Basic Structure

KSH script BASICS Contents Principle of ScriptVariablesBranchingLoopingCommandline ArgumentsComparisonsVariable ManipulationsKsh Regular ExpressionsFunctionsData RedirectionPipesCoprocessesRead Input from User and from FilesSpecial VariablesAction on Success or Failure of a CommandTrivial CalculationsNumerical Calculations using "bc""grep""sed""awk""perl" Principle of Script Defining the Shell Type To make a ksh script (which is a ksh program) crate a new file with a starting line like:#! Four Types of Lines A script has four types of lines: The shell defining line at the top, empty lines, commentary lines starting with a # and command lines. #! Start and End of Script The script starts at the first line and ends either when it encounters an "exit" or the last line. Start and End of Command A command starts with the first word on a line or if it's the second command on a line with the first word after a";'. print -n "Name: "; read name; print "" Name and Permissions of Script File Variables Filling in Using Arrays ?

Famous Awk One-Liners Explained, Part I I noticed that Eric Wendelin wrote an article "awk is a beautiful tool." In this article he said that it was best to introduce Awk with practical examples. I totally agree with Eric. When I was learning Awk, I first went through Awk - A Tutorial and Introduction by Bruce Barnett, which was full of examples to try out; then I created an Awk cheat sheet to have the language reference in front of me; and finally I went through the famous Awk one-liners (link to .txt file), which were compiled by Eric Pement. This is going to be a three-part article in which I will explain every single one-liner in Mr. Eric Pement's Awk one-liner collection consists of five sections: The first part of the article will explain the first two sections: "File spacing" and "Numbering and calculations." I recommend that you print out my Awk cheat sheet before you proceed. These one-liners work with all versions of awk, such as nawk (AT&T's new awk), gawk (GNU's awk), mawk (Michael Brennan's awk) and oawk (old awk).

Bash Hackers Wiki Frontpage man/man1/ksh.html man page Ksh is a command and programming language that executes commands read from a terminal or a file. Rksh is a restricted version of the command interpreter ksh; it is used to set up login names and execution environments whose capabilities are more controlled than those of the standard shell. Rpfksh is a profile shell version of the command interpreter ksh; it is used to to execute commands with the attributes specified by the user's profiles (see See Invocation below for the meaning of arguments to the shell. Definitions A metacharacter is one of the following characters: ; & ( ) | < > new-line space tab A blank is a tab or a space. A command is a sequence of characters in the syntax of the shell language. Commands A simple-command is a list of variable assignments (see Variable Assignments below) or a sequence of blank separated words which may be preceded by a list of variable assignments (see Environment below). A pipeline is a sequence of one or more commands separated by |.

Famous Awk One-Liners Explained, Part II This is the second part of a three-part article on the Awk one-liners. This part will explain Awk one-liners for text conversion and substitution. See part one for introduction of the series. "What are these famous Awk one-liners?", you might wonder? Well, they are concise and beautiful Awk programs that span no more than 70 characters (less than one terminal line). If you are intrigued by this article series, I suggest that you subscribe to my posts! Eric Pement's Awk one-liner collection consists of five sections: I recommend that you print out my Awk Cheat Sheet before you proceed. Awesome news: I have written an e-book based on this article series. Grab the local copy of Awk one-liners file here awk1line.txt and let's roll. 3. 21. awk '{ sub(/\r$/,""); print }' This one-liner uses the sub(regex, repl, [string]) function. The one-liner replaces '\r' (CR) character at the end of the line with nothing, i.e., erases CR at the end. 22. awk '{ sub(/$/,"\r"); print }' 23. awk 1 Ps. 24. tr -d \r

Tech Stuff - Regular Expressions - A Gentle User Guide and Tutorial A Regular Expression is the term used to describe a codified method of searching invented, or defined, by the American mathematician Stephen Kleene. The syntax (language format) described on this page is compliant with extended regular expressions (EREs) defined in IEEE POSIX 1003.2 (Section 2.8). EREs are now commonly supported by Apache, PERL, PHP4, Javascript 1.3+, MS Visual Studio, most visual editors, vi, emac, the GNU family of tools (including grep, awk and sed) as well as many others. Translation: The page has been translated into Bulgarian, courtesy of Albert Ward - thanks. Contents A Gentle Introduction: - the Basics Simple Searches Brackets, Ranges and Negation [] , - and ^ Search Positioning (aka Anchors) ^ and $ Iteration (aka Quantifiers) ? The title is deceptive. Some Definitions before we start We are going to be using the terms literal, metacharacter, target string, escape sequence and search expression (aka regular expression) in this overview. Our Example Target Strings

An Awk Primer < PREV | NEXT > | INDEX | SITEMAP | GOOGLE | LINKS | UPDATES | BLOG | EMAIL | $Donate? | HOME An Awk Primer v1.1.4 / TOC (3 chapters) / 01 apr 14 / greg goebel / public domain * The Awk text-processing programming language is a useful and simple tool for manipulating text. [1.0] A Guided Tour Of Awk [2.0] Awk Syntax [3.0] Awk Examples, Nawk, & Awk Quick Reference

Write a Tumblelog Application with Flask and MongoEngine Introduction This tutorial describes the process for creating a basic tumblelog application using the popular Flask Python web-framework in conjunction with the MongoDB database. The tumblelog will consist of two parts: A public site that lets people view posts and comment on them.An admin site that lets you add and change posts. This tutorial assumes that you are already familiar with Flask and have a basic familiarity with MongoDB and have installed MongoDB. This tutorial uses MongoEngine as the Object Document Mapper (ODM,) this component may simplify the interaction between Flask and MongoDB. Where to get help If you’re having trouble going through this tutorial, please post a message to mongodb-user or join the IRC chat in #mongodb on irc.freenode.net to chat with other MongoDB users who might be able to help. Installation Begin by installing packages required by later steps in this tutorial. Prerequisite pip install virtualenv virtualenv myproject source myproject/bin/activate Add the Views

TDD your API » Balanced: Blog On August 16, 2012, a process kicked off at Balanced. It still isn’t finished, but this week was a major milestone, and I’d like to share our progress with you. That process is a new development methodology for APIs. How do you TDD an API? If you’re not familiar, here’s the basic outline of Test Driven Development: Write a test for some behavior you’d like to introduce into your system. To say that there’s a large amount of literature on the benefits of this approach would be an understatement. So how is this different when applied to the API context? Create a separate project for your API tests. There’s another aspect which is important, though. Push to card was the first real feature we’ve built in this way. Origins Humble beginnings. There were three big questions to tackle: How can we validate that our API is working as intended? While this was being decided, at least Issues provided a good forum to discuss things. An initial solution Some bits removed for brevity. The YAML year Whew!

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