Declaration for Linux Shell
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ROADS and BRIDGES: the UNSEEN LABOR BEHIND OUR DIGITAL INFRASTRUCTURE Preface
Roads and Bridges:The Unseen Labor Behind Our Digital Infrastructure WRITTEN BY Nadia Eghbal 2 Open up your phone. Your social media, your news, your medical records, your bank: they are all using free and public code. Contents 3 Table of Contents 4 Preface 58 Challenges Facing Digital Infrastructure 5 Foreword 59 Open source’s complicated relationship with money 8 Executive Summary 66 Why digital infrastructure support 11 Introduction problems are accelerating 77 The hidden costs of ignoring infrastructure 18 History and Background of Digital Infrastructure 89 Sustaining Digital Infrastructure 19 How software gets built 90 Business models for digital infrastructure 23 How not charging for software transformed society 97 Finding a sponsor or donor for an infrastructure project 29 A brief history of free and public software and the people who made it 106 Why is it so hard to fund these projects? 109 Institutional efforts to support digital infrastructure 37 How The Current System Works 38 What is digital infrastructure, and how 124 Opportunities Ahead does it get built? 125 Developing effective support strategies 46 How are digital infrastructure projects managed and supported? 127 Priming the landscape 136 The crossroads we face 53 Why do people keep contributing to these projects, when they’re not getting paid for it? 139 Appendix 140 Glossary 142 Acknowledgements ROADS AND BRIDGES: THE UNSEEN LABOR BEHIND OUR DIGITAL INFRASTRUCTURE Preface Our modern society—everything from hospitals to stock markets to newspapers to social media—runs on software. But take a closer look, and you’ll find that the tools we use to build software are buckling under demand. -
Shell Scripting with Bash
Introduction to Shell Scripting with Bash Charles Jahnke Research Computing Services Information Services & Technology Topics for Today ● Introductions ● Basic Terminology ● How to get help ● Command-line vs. Scripting ● Variables ● Handling Arguments ● Standard I/O, Pipes, and Redirection ● Control Structures (loops and If statements) ● SCC Job Submission Example Research Computing Services Research Computing Services (RCS) A group within Information Services & Technology at Boston University provides computing, storage, and visualization resources and services to support research that has specialized or highly intensive computation, storage, bandwidth, or graphics requirements. Three Primary Services: ● Research Computation ● Research Visualization ● Research Consulting and Training Breadth of Research on the Shared Computing Cluster (SCC) Me ● Research Facilitator and Administrator ● Background in biomedical engineering, bioinformatics, and IT systems ● Offices on both CRC and BUMC ○ Most of our staff on the Charles River Campus, some dedicated to BUMC ● Contact: [email protected] You ● Who has experience programming? ● Using Linux? ● Using the Shared Computing Cluster (SCC)? Basic Terminology The Command-line The line on which commands are typed and passed to the shell. Username Hostname Current Directory [username@scc1 ~]$ Prompt Command Line (input) The Shell ● The interface between the user and the operating system ● Program that interprets and executes input ● Provides: ○ Built-in commands ○ Programming control structures ○ Environment -
An Automated Binary Security Update System for Freebsd
An Automated Binary Security Update System for FreeBSD Colin Percival Computing Lab, Oxford University [email protected] Abstract that a large number of people find the task of applying security patches and rebuilding affected programs to be difficult and/or confusing. Given that releases are on av- With the present trend towards increased reliance upon erage several months – and several security holes – old computer systems, the provision and prompt application by the time they are installed, the possibility arises that of security patches is becoming vital. Developers of all a new user will find his system compromised before he operating systems must generally be applauded for their has a chance to bring it up to date. success in this area; systems administrators, however, are often found lacking. Furthermore, there are some circumstances where build- ing from source is undesirable. Some embedded sys- Anecdotal evidence suggests that for FreeBSD much of tems might lack sufficient disk space to store the entire the difficulty arises out of the need to recompile from the source and object trees; some system administrators re- source code after applying security patches. Many peo- move part or all of the build toolchain in an (arguably ple, after spending years using closed-source point-and- misguided) attempt to thwart any attempt to build a click operating systems, find the concept of recompiling rootkit; and the purveyors of application-specific ‘toast- software to be entirely foreign, and even veteran users ers’ might very likely wish to keep the complexity of of open source software are often less than prompt about building from source entirely hidden from their users. -
Beginning Portable Shell Scripting from Novice to Professional
Beginning Portable Shell Scripting From Novice to Professional Peter Seebach 10436fmfinal 1 10/23/08 10:40:24 PM Beginning Portable Shell Scripting: From Novice to Professional Copyright © 2008 by Peter Seebach All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. ISBN-13 (pbk): 978-1-4302-1043-6 ISBN-10 (pbk): 1-4302-1043-5 ISBN-13 (electronic): 978-1-4302-1044-3 ISBN-10 (electronic): 1-4302-1044-3 Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1 Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. Lead Editor: Frank Pohlmann Technical Reviewer: Gary V. Vaughan Editorial Board: Clay Andres, Steve Anglin, Ewan Buckingham, Tony Campbell, Gary Cornell, Jonathan Gennick, Michelle Lowman, Matthew Moodie, Jeffrey Pepper, Frank Pohlmann, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh Project Manager: Richard Dal Porto Copy Editor: Kim Benbow Associate Production Director: Kari Brooks-Copony Production Editor: Katie Stence Compositor: Linda Weidemann, Wolf Creek Press Proofreader: Dan Shaw Indexer: Broccoli Information Management Cover Designer: Kurt Krames Manufacturing Director: Tom Debolski Distributed to the book trade worldwide by Springer-Verlag New York, Inc., 233 Spring Street, 6th Floor, New York, NY 10013. -
GNU Grep: Print Lines That Match Patterns Version 3.7, 8 August 2021
GNU Grep: Print lines that match patterns version 3.7, 8 August 2021 Alain Magloire et al. This manual is for grep, a pattern matching engine. Copyright c 1999{2002, 2005, 2008{2021 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled \GNU Free Documentation License". i Table of Contents 1 Introduction ::::::::::::::::::::::::::::::::::::: 1 2 Invoking grep :::::::::::::::::::::::::::::::::::: 2 2.1 Command-line Options ::::::::::::::::::::::::::::::::::::::::: 2 2.1.1 Generic Program Information :::::::::::::::::::::::::::::: 2 2.1.2 Matching Control :::::::::::::::::::::::::::::::::::::::::: 2 2.1.3 General Output Control ::::::::::::::::::::::::::::::::::: 3 2.1.4 Output Line Prefix Control :::::::::::::::::::::::::::::::: 5 2.1.5 Context Line Control :::::::::::::::::::::::::::::::::::::: 6 2.1.6 File and Directory Selection:::::::::::::::::::::::::::::::: 7 2.1.7 Other Options ::::::::::::::::::::::::::::::::::::::::::::: 9 2.2 Environment Variables:::::::::::::::::::::::::::::::::::::::::: 9 2.3 Exit Status :::::::::::::::::::::::::::::::::::::::::::::::::::: 12 2.4 grep Programs :::::::::::::::::::::::::::::::::::::::::::::::: 13 3 Regular Expressions ::::::::::::::::::::::::::: 14 3.1 Fundamental Structure :::::::::::::::::::::::::::::::::::::::: -
Cygwin User's Guide
Cygwin User’s Guide Cygwin User’s Guide ii Copyright © Cygwin authors Permission is granted to make and distribute verbatim copies of this documentation provided the copyright notice and this per- mission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this documentation under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this documentation into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Free Software Foundation. Cygwin User’s Guide iii Contents 1 Cygwin Overview 1 1.1 What is it? . .1 1.2 Quick Start Guide for those more experienced with Windows . .1 1.3 Quick Start Guide for those more experienced with UNIX . .1 1.4 Are the Cygwin tools free software? . .2 1.5 A brief history of the Cygwin project . .2 1.6 Highlights of Cygwin Functionality . .3 1.6.1 Introduction . .3 1.6.2 Permissions and Security . .3 1.6.3 File Access . .3 1.6.4 Text Mode vs. Binary Mode . .4 1.6.5 ANSI C Library . .4 1.6.6 Process Creation . .5 1.6.6.1 Problems with process creation . .5 1.6.7 Signals . .6 1.6.8 Sockets . .6 1.6.9 Select . .7 1.7 What’s new and what changed in Cygwin . .7 1.7.1 What’s new and what changed in 3.2 . -
C Shell Scripts File Permissions a Simple Spelling Checker Command
Cshell scripts Asimple spelling checker mylatex1.csh #!/bin/csh #!/bin/csh tr -cs "[:alpha:]" "[\n*]" < $1 \ latex file.tex |tr"[:upper:]" "[:lower:]" \ dvips -f file.dvi > file.ps |sort -u > tempfile rm file.aux file.dvi file.log comm -23 tempfile /usr/share/dict/words rm tempfile mylatex2.csh #!/bin/csh Put one word per line \ |convert everything to lowercase \ latex $1.tex |sor t the words,remove duplicates and write the result to ’tempfile’. dvips -f $1.dvi > $1.ps rm $1.aux $1.dvi $1.log Pr int those words in ’tempfile’ that are not in the dictionary. Remove the temporar y file. Graham Kemp,Chalmers University of Technology Graham Kemp,Chalmers University of Technology File permissions Command substitution in a script ls -l To include the output from one command within the command line for another command, enclose the command whose output is to be included rwxrwx rwx within ‘backquotes‘. For example: rwxr -xr -x #!/bin/csh 111101101 echo Date and time is: date echo 1111 011 012 = 7558 echo "Your username is:" ‘whoami‘ echo "Your current directory is:" ‘pwd‘ chmod 755 file.sh chmod u+x file.sh chmod -R a+rX . Graham Kemp,Chalmers University of Technology Graham Kemp,Chalmers University of Technology Editing several files at once (1) sed scripts Suppose wewant to change ‘‘cie’’to‘‘cei’’inall files in the current grep href publications.html \ director y whose name ends with ‘‘.tex’’. |sed ’s/[ˆ"]*"//’ \ |sed ’s/".*//’ #!/bin/csh Instead of giving a single editing command on the command line,wecan ls *.tex | sed ’s/.*/sed s\/cie\/cei\/g & > &tmp/’ > s1 create a script file containing a sequence of editing commands. -
Shell Script & Advance Features of Shell Programming
Kirti Kaushik et al, International Journal of Computer Science and Mobile Computing, Vol.4 Issue.4, April- 2015, pg. 458-462 Available Online at www.ijcsmc.com International Journal of Computer Science and Mobile Computing A Monthly Journal of Computer Science and Information Technology ISSN 2320–088X IJCSMC, Vol. 4, Issue. 4, April 2015, pg.458 – 462 RESEARCH ARTICLE Shell Script & Advance Features of Shell Programming Kirti Kaushik* Roll No.15903, CS, Department of Computer science, Dronacharya College of Engineering, Gurgaon-123506, India Email: [email protected] Jyoti Yadav Roll No. 15040, CS, Department of Applied Computer science, Dronacharya College of Engineering, Gurgaon-123506, India Email: [email protected] Kriti Bhatia Roll No. 15048, CS, Department of Applied Computer science, Dronacharya College of Engineering, Gurgaon-123506, India Email: [email protected] Abstract-- In this research paper, the idea of shell scripting and writing computer programs is examined and different parts of shell programming are likewise contemplated. A shell script is a PC system intended to be controlled by the UNIX shell which is a charge line translator. The different tongues of shell scripts are thought to be scripting dialects. Regular operations performed by shell scripts incorporate document control, program execution, and printing content. A shell script can give an advantageous variety ofa framework order where unique environment settings, charge alternatives, or post-transforming apply naturally, yet in a manner that permits the new script to still go about as a completely typical UNIX summon. The real ideas like Programming in the Borne and C-shell, in which it would be clarified that how shell programming could be possible in Borne and C-shell. -
Use Perl Regular Expressions in SAS® Shuguang Zhang, WRDS, Philadelphia, PA
NESUG 2007 Programming Beyond the Basics Use Perl Regular Expressions in SAS® Shuguang Zhang, WRDS, Philadelphia, PA ABSTRACT Regular Expression (Regexp) enhance search and replace operations on text. In SAS®, the INDEX, SCAN and SUBSTR functions along with concatenation (||) can be used for simple search and replace operations on static text. These functions lack flexibility and make searching dynamic text difficult, and involve more function calls. Regexp combines most, if not all, of these steps into one expression. This makes code less error prone, easier to maintain, clearer, and can improve performance. This paper will discuss three ways to use Perl Regular Expression in SAS: 1. Use SAS PRX functions; 2. Use Perl Regular Expression with filename statement through a PIPE such as ‘Filename fileref PIPE 'Perl programm'; 3. Use an X command such as ‘X Perl_program’; Three typical uses of regular expressions will also be discussed and example(s) will be presented for each: 1. Test for a pattern of characters within a string; 2. Replace text; 3. Extract a substring. INTRODUCTION Perl is short for “Practical Extraction and Report Language". Larry Wall Created Perl in mid-1980s when he was trying to produce some reports from a Usenet-Nes-like hierarchy of files. Perl tries to fill the gap between low-level programming and high-level programming and it is easy, nearly unlimited, and fast. A regular expression, often called a pattern in Perl, is a template that either matches or does not match a given string. That is, there are an infinite number of possible text strings. -
A First Course to Openfoam
Basic Shell Scripting Slides from Wei Feinstein HPC User Services LSU HPC & LON [email protected] September 2018 Outline • Introduction to Linux Shell • Shell Scripting Basics • Variables/Special Characters • Arithmetic Operations • Arrays • Beyond Basic Shell Scripting – Flow Control – Functions • Advanced Text Processing Commands (grep, sed, awk) Basic Shell Scripting 2 Linux System Architecture Basic Shell Scripting 3 Linux Shell What is a Shell ▪ An application running on top of the kernel and provides a command line interface to the system ▪ Process user’s commands, gather input from user and execute programs ▪ Types of shell with varied features o sh o csh o ksh o bash o tcsh Basic Shell Scripting 4 Shell Comparison Software sh csh ksh bash tcsh Programming language y y y y y Shell variables y y y y y Command alias n y y y y Command history n y y y y Filename autocompletion n y* y* y y Command line editing n n y* y y Job control n y y y y *: not by default http://www.cis.rit.edu/class/simg211/unixintro/Shell.html Basic Shell Scripting 5 What can you do with a shell? ▪ Check the current shell ▪ echo $SHELL ▪ List available shells on the system ▪ cat /etc/shells ▪ Change to another shell ▪ csh ▪ Date ▪ date ▪ wget: get online files ▪ wget https://ftp.gnu.org/gnu/gcc/gcc-7.1.0/gcc-7.1.0.tar.gz ▪ Compile and run applications ▪ gcc hello.c –o hello ▪ ./hello ▪ What we need to learn today? o Automation of an entire script of commands! o Use the shell script to run jobs – Write job scripts Basic Shell Scripting 6 Shell Scripting ▪ Script: a program written for a software environment to automate execution of tasks ▪ A series of shell commands put together in a file ▪ When the script is executed, those commands will be executed one line at a time automatically ▪ Shell script is interpreted, not compiled. -
Twenty Years of Berkeley Unix : from AT&T-Owned to Freely
Twenty Years of Berkeley Unix : From AT&T-Owned to Freely Redistributable Marshall Kirk McKusick Early History Ken Thompson and Dennis Ritchie presented the first Unix paper at the Symposium on Operating Systems Principles at Purdue University in November 1973. Professor Bob Fabry, of the University of California at Berkeley, was in attendance and immediately became interested in obtaining a copy of the system to experiment with at Berkeley. At the time, Berkeley had only large mainframe computer systems doing batch processing, so the first order of business was to get a PDP-11/45 suitable for running with the then-current Version 4 of Unix. The Computer Science Department at Berkeley, together with the Mathematics Department and the Statistics Department, were able to jointly purchase a PDP-11/45. In January 1974, a Version 4 tape was delivered and Unix was installed by graduate student Keith Standiford. Although Ken Thompson at Purdue was not involved in the installation at Berkeley as he had been for most systems up to that time, his expertise was soon needed to determine the cause of several strange system crashes. Because Berkeley had only a 300-baud acoustic-coupled modem without auto answer capability, Thompson would call Standiford in the machine room and have him insert the phone into the modem; in this way Thompson was able to remotely debug crash dumps from New Jersey. Many of the crashes were caused by the disk controller's inability to reliably do overlapped seeks, contrary to the documentation. Berkeley's 11/45 was among the first systems that Thompson had encountered that had two disks on the same controller! Thompson's remote debugging was the first example of the cooperation that sprang up between Berkeley and Bell Labs. -
Scons API Docs Version 4.2
SCons API Docs version 4.2 SCons Project July 31, 2021 Contents SCons Project API Documentation 1 SCons package 1 Module contents 1 Subpackages 1 SCons.Node package 1 Submodules 1 SCons.Node.Alias module 1 SCons.Node.FS module 9 SCons.Node.Python module 68 Module contents 76 SCons.Platform package 85 Submodules 85 SCons.Platform.aix module 85 SCons.Platform.cygwin module 85 SCons.Platform.darwin module 86 SCons.Platform.hpux module 86 SCons.Platform.irix module 86 SCons.Platform.mingw module 86 SCons.Platform.os2 module 86 SCons.Platform.posix module 86 SCons.Platform.sunos module 86 SCons.Platform.virtualenv module 87 SCons.Platform.win32 module 87 Module contents 87 SCons.Scanner package 89 Submodules 89 SCons.Scanner.C module 89 SCons.Scanner.D module 93 SCons.Scanner.Dir module 93 SCons.Scanner.Fortran module 94 SCons.Scanner.IDL module 94 SCons.Scanner.LaTeX module 94 SCons.Scanner.Prog module 96 SCons.Scanner.RC module 96 SCons.Scanner.SWIG module 96 Module contents 96 SCons.Script package 99 Submodules 99 SCons.Script.Interactive module 99 SCons.Script.Main module 101 SCons.Script.SConsOptions module 108 SCons.Script.SConscript module 115 Module contents 122 SCons.Tool package 123 Module contents 123 SCons.Variables package 125 Submodules 125 SCons.Variables.BoolVariable module 125 SCons.Variables.EnumVariable module 125 SCons.Variables.ListVariable module 126 SCons.Variables.PackageVariable module 126 SCons.Variables.PathVariable module 127 Module contents 127 SCons.compat package 129 Module contents 129 Submodules 129 SCons.Action