Shell Scripting, Globs, and Ranges
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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 -
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. -
SOAP / REST and IBM I
1/11/18 SOPA / REST and IBM i Tim Rowe- [email protected] Business Architect Application Development © 2017 International Business Machines Corporation Using a REST API with Watson https://ibm-i-watson-test.mybluemix.net/ 2 © 2017 International Business Machines Corporation 1 1/11/18 ™ What is an API - Agenda •What is an API •What is a Web Service •SOAP vs REST – What is SOAP – What is REST – Benefits – Drawbacks 3 © 2017 International Business Machines Corporation ™ Connections Devices There Here Applications 4 © 2017 International Business Machines Corporation 2 1/11/18 ™ 5 © 2017 International Business Machines Corporation ™ 6 © 2017 International Business Machines Corporation 3 1/11/18 ™ 7 © 2017 International Business Machines Corporation ™ 8 © 2017 International Business Machines Corporation 4 1/11/18 ™ API Definition Application Programming Interface 9 © 2017 International Business Machines Corporation ™ API Definition 10 © 2017 International Business Machines Corporation 5 1/11/18 ™ APIs - Simple Simple way to connect endpoints. Send a request and receive a response. 11 © 2017 International Business Machines Corporation ™ Example Kitchen 12 © 2017 International Business Machines Corporation 6 1/11/18 ™ 13 © 2017 International Business Machines Corporation ™ Not just a buzz-word, but rather the evolution of services- oriented IT. Allows users, businesses & partners the ability to interact in new and different ways resulting in the growth (in some cases the revolution) of business. 14 © 2017 International Business Machines Corporation -
Shell Variables
Shell Using the command line Orna Agmon ladypine at vipe.technion.ac.il Haifux Shell – p. 1/55 TOC Various shells Customizing the shell getting help and information Combining simple and useful commands output redirection lists of commands job control environment variables Remote shell textual editors textual clients references Shell – p. 2/55 What is the shell? The shell is the wrapper around the system: a communication means between the user and the system The shell is the manner in which the user can interact with the system through the terminal. The shell is also a script interpreter. The simplest script is a bunch of shell commands. Shell scripts are used in order to boot the system. The user can also write and execute shell scripts. Shell – p. 3/55 Shell - which shell? There are several kinds of shells. For example, bash (Bourne Again Shell), csh, tcsh, zsh, ksh (Korn Shell). The most important shell is bash, since it is available on almost every free Unix system. The Linux system scripts use bash. The default shell for the user is set in the /etc/passwd file. Here is a line out of this file for example: dana:x:500:500:Dana,,,:/home/dana:/bin/bash This line means that user dana uses bash (located on the system at /bin/bash) as her default shell. Shell – p. 4/55 Starting to work in another shell If Dana wishes to temporarily use another shell, she can simply call this shell from the command line: [dana@granada ˜]$ bash dana@granada:˜$ #In bash now dana@granada:˜$ exit [dana@granada ˜]$ bash dana@granada:˜$ #In bash now, going to hit ctrl D dana@granada:˜$ exit [dana@granada ˜]$ #In original shell now Shell – p. -
UNIX X Command Tips and Tricks David B
SESUG Paper 122-2019 UNIX X Command Tips and Tricks David B. Horvath, MS, CCP ABSTRACT SAS® provides the ability to execute operating system level commands from within your SAS code – generically known as the “X Command”. This session explores the various commands, the advantages and disadvantages of each, and their alternatives. The focus is on UNIX/Linux but much of the same applies to Windows as well. Under SAS EG, any issued commands execute on the SAS engine, not necessarily on the PC. X %sysexec Call system Systask command Filename pipe &SYSRC Waitfor Alternatives will also be addressed – how to handle when NOXCMD is the default for your installation, saving results, and error checking. INTRODUCTION In this paper I will be covering some of the basics of the functionality within SAS that allows you to execute operating system commands from within your program. There are multiple ways you can do so – external to data steps, within data steps, and within macros. All of these, along with error checking, will be covered. RELEVANT OPTIONS Execution of any of the SAS System command execution commands depends on one option's setting: XCMD Enables the X command in SAS. Which can only be set at startup: options xcmd; ____ 30 WARNING 30-12: SAS option XCMD is valid only at startup of the SAS System. The SAS option is ignored. Unfortunately, ff NOXCMD is set at startup time, you're out of luck. Sorry! You might want to have a conversation with your system administrators to determine why and if you can get it changed. -
Bash Guide for Beginners
Bash Guide for Beginners Machtelt Garrels Garrels BVBA <tille wants no spam _at_ garrels dot be> Version 1.11 Last updated 20081227 Edition Bash Guide for Beginners Table of Contents Introduction.........................................................................................................................................................1 1. Why this guide?...................................................................................................................................1 2. Who should read this book?.................................................................................................................1 3. New versions, translations and availability.........................................................................................2 4. Revision History..................................................................................................................................2 5. Contributions.......................................................................................................................................3 6. Feedback..............................................................................................................................................3 7. Copyright information.........................................................................................................................3 8. What do you need?...............................................................................................................................4 9. Conventions used in this -
Configuring Your Login Session
SSCC Pub.# 7-9 Last revised: 5/18/99 Configuring Your Login Session When you log into UNIX, you are running a program called a shell. The shell is the program that provides you with the prompt and that submits to the computer commands that you type on the command line. This shell is highly configurable. It has already been partially configured for you, but it is possible to change the way that the shell runs. Many shells run under UNIX. The shell that SSCC users use by default is called the tcsh, pronounced "Tee-Cee-shell", or more simply, the C shell. The C shell can be configured using three files called .login, .cshrc, and .logout, which reside in your home directory. Also, many other programs can be configured using the C shell's configuration files. Below are sample configuration files for the C shell and explanations of the commands contained within these files. As you find commands that you would like to include in your configuration files, use an editor (such as EMACS or nuTPU) to add the lines to your own configuration files. Since the first character of configuration files is a dot ("."), the files are called "dot files". They are also called "hidden files" because you cannot see them when you type the ls command. They can only be listed when using the -a option with the ls command. Other commands may have their own setup files. These files almost always begin with a dot and often end with the letters "rc", which stands for "run commands". -
Bash Tutorial
Bash Shell Lecturer: Prof. Andrzej (AJ) Bieszczad Email: [email protected] Phone: 818-677-4954 Bash Shell The shell of Linux • Linux has a variety of different shells: – Bourne shell (sh), C shell (csh), Korn shell (ksh), TC shell (tcsh), Bour ne Again shell (bash). • Certainly the most popular shell is “bash”. Bash is an sh- compatible shell that incorporates useful features from the Korn shell (ksh) and C shell (csh). • It is intended to conform to the IEEE POSIX P1003.2/ISO 9945.2 Shell and Tools standard. • It offers functional improvements over sh for both programming and interactive use. Bash Shell Programming or Scripting ? • bash is not only an excellent command line shell, but a scripting language in itself. Shell scripting allows us to use the shell's abilities and to automate a lot of tasks that would otherwise require a lot of commands. • Difference between programming and scripting languages: – Programming languages are generally a lot more powerful and a lot faster than scriptin g languages. Programming languages generally start from source code and are compil ed into an executable. This executable is not easily ported into different operating syste ms. – A scripting language also starts from source code, but is not compiled into an executabl e. Rather, an interpreter reads the instructions in the source file and executes each inst ruction. Interpreted programs are generally slower than compiled programs. The main a dvantage is that you can easily port the source file to any operating system. bash is a s cripting language. Other examples of scripting languages are Perl, Lisp, and Tcl. -
Rc the Plan 9 Shell
Rc ߞ The Plan 9 Shell Tom Duff [email protected]−labs.com ABSTRACT Rc is a command interpreter for Plan 9 that provides similar facilities to UNIXߣs Bourne shell, with some small additions and less idiosyncratic syntax. This paper uses numerous examples to describe rcߣs features, and contrasts rc with the Bourne shell, a model that many readers will be familiar with. 1. Introduction Rc is similar in spirit but different in detail from UNIXߣs Bourne shell. This paper describes rcߣs principal features with many small examples and a few larger ones. It assumes familiarity with the Bourne shell. 2. Simple commands For the simplest uses rc has syntax familiar to Bourne-shell users. All of the fol lowing behave as expected: date cat /lib/news/build who >user.names who >>user.names wc <file echo [a−f]*.c who | wc who; date vc *.c & mk && v.out /*/bin/fb/* rm −r junk || echo rm failed! 3. Quotation An argument that contains a space or one of rcߣs other syntax characters must be enclosed in apostrophes (’): rm ’odd file name’ An apostrophe in a quoted argument must be doubled: echo ’How’’s your father?’ 4. Patterns An unquoted argument that contains any of the characters *?[is a pattern to be matched against file names. A * character matches any sequence of characters, ? matches any single character, and [class] matches any character in the class, unless the first character of class is ~, in which case the class is complemented. The class may 2 also contain pairs of characters separated by −, standing for all characters lexically between the two. -
Contextual Shell History Student: Bc
ASSIGNMENT OF MASTER’S THESIS Title: Contextual Shell History Student: Bc. Šimon Let Supervisor: Ing. Lukáš Bařinka Study Programme: Informatics Study Branch: System Programming Department: Department of Theoretical Computer Science Validity: Until the end of summer semester 2020/21 Instructions Analyze shell history features and existing shell history tools. Examine how users interact with shell and shell history. Design a shell history solution based on known and documented problems. Leverage the context of commands entered by the user. Use principles of user-centered design. Implement a shell history tool that is capable of recording shell history with command context, offers history entries to the user based on the current context and provides means to search the recorded history. Suggest meaningful metrics (e.g. based on distance in history or number of characters needed to get searched command from history). Based on chosen metrics evaluate the usefulness of the recommended history entries. Perform user testing or testing based on real user data to find out the user experience of the solution. References Will be provided by the supervisor. doc. Ing. Jan Janoušek, Ph.D. doc. RNDr. Ing. Marcel Jiřina, Ph.D. Head of Department Dean Prague January 17, 2020 Master’s thesis Contextual Shell History Bc. Simonˇ Let Department of theoretical computer science Supervisor: Ing. Luk´aˇsBaˇrinka May 28, 2020 Acknowledgements I would like to thank my supervisor Ing. Luk´aˇsBaˇrinkafor his guidance and advice. His insights and expertise shaped this work significantly. Next, my thanks go to my colleagues and friends for their valuable feed- back. They helped me spot my personal biases and assumptions rooted in my personal shell workflows. -
An Introduction to the C Shell
-- -- An Introduction to the C shell William Joy (revised for 4.3BSD by Mark Seiden) Computer Science Division Department of Electrical Engineering and Computer Science University of California, Berkeley Berkeley, California 94720 ABSTRACT Csh is a newcommand language interpreter for UNIX†systems. It incorporates good features of other shells and a history mechanism similar to the redo of INTERLISP. While incorporating manyfeatures of other shells which makewriting shell programs (shell scripts) easier,most of the features unique to csh are designed more for the interac- tive UNIX user. UNIX users who have read a general introduction to the system will find a valuable basic explanation of the shell here. Simple terminal interaction with csh is possible after reading just the first section of this document. The second section describes the shell’s capabilities which you can explore after you have begun to become acquainted with the shell. Later sections introduce features which are useful, but not necessary for all users of the shell. Additional information includes an appendix listing special characters of the shell and a glossary of terms and commands introduced in this manual. Introduction A shell is a command language interpreter. Csh is the name of one particular command interpreter on UNIX.The primary purpose of csh is to translate command lines typed at a terminal into system actions, such as invocation of other programs. Csh is a user program just likeany you might write. Hopefully, csh will be a very useful program for you in interacting with the UNIX system. In addition to this document, you will want to refer to a copyofthe UNIX User Reference Manual. -
Monitoring Malicious Powershell Usage Through Log Analysis
Monitoring malicious PowerShell usage through log analysis Jesper Magnusson Computer Science and Engineering, master's level 2019 Luleå University of Technology Department of Computer Science, Electrical and Space Engineering (This page is intentionally left almost blank) Abstract Security has become a hot topic around the world but focuses more on the perime- ter than inside networks which opens up vulnerabilities. Directed cyber-attacks towards the energy sector which leverages this fact has increased and can have dis- astrous effect, even on national level. To counter this, a solution to monitor the usage of the most powerful and popular built-in tool among attackers - PowerShell - was implemented. A test-bed was set up reflecting a corporate network with two separate active directory domains, one for office clients and one for critical infrastructure. It was shown that attackers only needed to overtake the office active directory domain in order for gain easy access to the critical active directory domain. To simulate attacks of this type, a collection of malicious scripts was gathered from which a number of possible scenarios for taking over the office active directory domain via PowerShell was created. Windows has several options for logging executions of PowerShell commands on machines. The one used and deemed most beneficiary was "Module logging" with the addition of a filtered result of process creation logs. To monitor the logs created on the office client from PowerShell executions, a system based on the "ELK stack" was set up. This system gathered, processed, stored and visualized logs along with the result of their analysis. The system analyzed logs with the aid of a custom software called "ESPSA" which based on different parameters and contexts assigned every execution with a risk value indicating the level of maliciousness.