Bash Shell Connecting to a Unix/Linux System
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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 -
Ardpower Documentation Release V1.2.0
ardPower Documentation Release v1.2.0 Anirban Roy Das Sep 27, 2017 Contents 1 Introduction 1 2 Screenshot 3 3 Documentaion 5 3.1 Overview.................................................5 3.2 Installation................................................7 3.3 Usage................................................... 12 4 Indices and tables 13 i ii CHAPTER 1 Introduction Its a custom Oh-My-Zsh Theme inspired by many custom themes suited for a perfect ZSH Environment under Byobu with Tmux Backend. 1 ardPower Documentation, Release v1.2.0 2 Chapter 1. Introduction 3 ardPower Documentation, Release v1.2.0 CHAPTER 2 Screenshot 4 Chapter 2. Screenshot CHAPTER 3 Documentaion You can also find PDF version of the documentation here. Overview We will start with understanding the individual components of an entire CLI. Generally we don’t put much attention to what we do. We just fire up a terminal or some say sheel and start typing our commands and get the result. That’s all. But there are a lot of things that goes behind all this. Terminal The very first component is the Terminal. So what is a Terminal? A terminal emulator, terminal application, term, or tty for short, is a program that emulates a video ter- minal within some other display architecture. Though typically synonymous with a shell or text terminal, the term terminal covers all remote terminals, including graphical interfaces. A terminal emulator inside a graphical user interface is often called a terminal window.A terminal window allows the user access to a text terminal and all its applications such as command-line interfaces (CLI) and text user interface (TUI) applications. -
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 -
Unix Systems: Shell Scripting (III)
Unix Systems: Shell Scripting (III) Bruce Beckles University of Cambridge Computing Service 1 Introduction • Who: ! Bruce Beckles, e-Science Specialist, UCS • What: ! Unix Systems: Shell Scripting (III) course ! Follows on from “Unix Systems: Shell Scripting (II)” ! Part of the Scientific Computing series of courses • Contact (questions, etc): ! [email protected] • Health & Safety, etc: ! Fire exits • Please switch off mobile phones! [email protected] Unix Systems: Shell Scripting (III) 2 As this course is part of the Scientific Computing series of courses run by the Computing Service, all the examples that we use will be more relevant to scientific computing than to system administration, etc. This does not mean that people who wish to learn shell scripting for system administration and other such tasks will get nothing from this course, as the techniques and underlying knowledge taught are applicable to shell scripts written for almost any purpose. However, such individuals should be aware that this course was not designed with them in mind. For details of the “Unix Systems: Shell Scripting (II)” course, see: http://www.cam.ac.uk/cs/courses/coursedesc/linux.html#script2 2 What we don’t cover • Different types of shell: ! We are using the Bourne-Again SHell (bash). • Differences between versions of bash • Very advanced shell scripting – try this course instead: ! “Programming: Python for Absolute Beginners” [email protected] Unix Systems: Shell Scripting (III) 3 bash is probably the most common shell on modern Unix/Linux systems – in fact, on most modern Linux distributions it will be the default shell (the shell users get if they don’t specify a different one). -
Korn Shell Variables
V4.1 cover Front cover Korn and Bash Shell Programming (Course code AL32) Student Notebook ERC 1.0 IBM Certified Course Material Student Notebook Trademarks IBM® is a registered trademark of International Business Machines Corporation. The following are trademarks of International Business Machines Corporation in the United States, or other countries, or both: AIX® AIX 5L™ Language Environment® OS/2® POWER™ RISC System/6000® RS/6000® Java and all Java-based trademarks are trademarks of Sun Microsystems, Inc. in the United States, other countries, or both. Windows is a trademark of Microsoft Corporation in the United States, other countries, or both. UNIX® is a registered trademark of The Open Group in the United States and other countries. Linux® is a registered trademark of Linus Torvalds in the United States, other countries, or both. Other company, product, or service names may be trademarks or service marks of others. October 2007 edition The information contained in this document has not been submitted to any formal IBM test and is distributed on an “as is” basis without any warranty either express or implied. The use of this information or the implementation of any of these techniques is a customer responsibility and depends on the customer’s ability to evaluate and integrate them into the customer’s operational environment. While each item may have been reviewed by IBM for accuracy in a specific situation, there is no guarantee that the same or similar results will result elsewhere. Customers attempting to adapt these techniques to their own environments do so at their own risk. © Copyright International Business Machines Corporation 2007. -
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. -
Individual Coursework 5: Implementing a UNIX Shell Introduction
UCL CS 0019 Brad Karp Individual Coursework 5: Implementing a UNIX Shell Due date: 5:05 PM GMT, 30th March 2020, EXTENDED to 6th April 2020 Value: 6% of marks for module Introduction The design of the UNIX1 system call APIs for creating and controlling processes and plumbing together their inputs and outputs is one of the gems of modern software systems architecture. To help you become fluent in using this powerful set of mechanisms in C, in this assignment you will use fork(), exec(), and several other interesting system calls to build a command shell, or shell for short. A shell reads commands on its standard input and executes them. Modern UNIXes include multiple shells (and developers over the years have created still more shells with different syntaxes and features). In your shell, you will implement simple commands, background commands, conditional commands (i.e., using the && and || operators), I/O redirection, and pipes. You will also imple- ment command interruption (i.e., with Ctrl-C). Your shell will implement a subset of the bash shell’s syntax, as defined at: http://www.gnu.org/software/bash/manual/bashref.html and will be generally compatible with bash for the features they share. You may find a tutorial on how to use the UNIX shell useful preparation for CW5; one such tutorial is available at: http://www.linuxcommand.org/lc3_learning_the_shell.php This coursework must be done in a UNIX programming environment. We recommend that all 0019 students develop in the 0019 Linux virtual machine (VM) provided for use in this class, available at: http://www.cs.ucl.ac.uk/staff/B.Karp/0019/s2020/cw.html If you happen to have another UNIX machine at your disposal (including a Mac OS machine), you may find that you can develop your solution to CW5 in that environment, but the only development environment the 0019 staff can support is the 0019 VM. -
Unix/Mac/Linux OS Malware 10/15/2020
Unix/Mac/Linux OS Malware 10/15/2020 Report #: 202010151030 Agenda • Executive Summary • Origin of Modern Operating Systems • Overview of Operating Systems o Desktop o Servers o Super Computers o Mobile o Attack Surface and CVEs • Malware Case Studies o Drovorub o Hidden Wasp o Operation Windigo o MAC Malware Slides Key: • Defending Against Malware The picture can't be displayed. Non-Technical: Managerial, strategic and high- • Summary level (general audience) The picture can't be displayed. Technical: Tactical / IOCs; requiring in-depth knowledge (system admins, IRT) TLP: WHITE, ID# 202010151030 2 Executive Summary • Unix and Unix-like systems drive most of today's computer systems. • Vulnerabilities and malware • Threat mitigation o Comprehensive security policies o Access control o Regular updates and backups o Training employees o Improving posture and maturity TLP: WHITE, ID# 202010151030 3 Modern Operating Systems "Determining the operating system on which the server runs is the most important part of hacking. Mostly, hacking is breaking into the target's system to steal data or any such purpose. Hence, the security of the system becomes the thing of prime importance." Source: Parikh, K. (2020, August) The Hackers Library Functions of Operating Systems Timeline of the Origins of Operating Systems TLP: WHITE, ID# 202010151030 4 Overview of Operating Systems (Non-Mobile) Unix Chrome OS •Derived from Original AT&T Unix •Free and open-source •Command-line input •Graphical user interface •Very popular among scientific, •Based on Linux -
The Korn Shell
UNIX Basics by Peter Collinson, Hillside Systems BEK SHAKIROV The Korn Shell ell, nobody’s perfect. I cre- the most recent version of the shell. The dtksh is large, and you probably don’t ated an incorrect impression version that you can pull from AT&T is want to use it as your login shell. W about the Korn shell in my ksh93, and has several enhancements If you do use ksh as your login shell, articleW “Over revisited” (SW Expert that increase the power of the language. then what can it do for you? Most mor- August 2000). I said that the source for For some time, David Korn has been tal users only scratch the surface of the the most recent version of the Korn shell repositioning the shell; taking it from a power of any shell they use, and para- (ksh93) was not publicly available. This program that is used to control program doxically, most of the usage of any shell statement was incorrect, and I received execution towards a powerful interpreted is made by people simply typing com- email from a couple of people (one of language. He’s been aiming to create a mands and having them executed. So, them David Korn) telling me that the “scripting language” that directly sup- I’m going to concentrate on the shell source has been available since 1999, ports many of the programming struc- features that make your life easier. pointing me to www.kornshell.com. tures and features that you will find in I suppose that most of these features The state of the art is that the program other UNIX super-tools, like awk. -
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. -
Shell Scripting, Globs, and Ranges
SHELL SCRIPTING AND CUSTOMIZATION GPI F20 · Emmanuel & Sayan PET TAX Carole Bashkin! Ran her program, bashed it Can’t convince her that bash isn’t awesome Pipin’, globbin’, multitaskin’ What’s happen? Carole Bashkin! WHAT IS A SHELL? ● A shell is the outermost layer that allows a user to interact with the operating system. ● For a programmer, it is the program that powers your terminal. ● We will focus on Unix shells, command-line interpreters for Unix-like operating systems. ● They come in many flavors. ○ zsh, bash, fish, etc. COMMAND CENTER ● Show contents of a file cat path ● Show contents of a directory ls ● Change directories cd path ● Remove a file rm src ● Move/rename a file mv src dst ● Copy a file cp src new_name ● Execute a binary ./name ● Print something echo “Hello, world!” OVER, OVER, AND OVER AGAIN ● Sometimes, you want to run the same set of commands multiple times. ○ Compiling and testing your code ○ Renaming a bunch of files ○ Initializing your git repos with a .gitignore ○ Archiving your new favorite xkcd comics ○ Setting up your dev environment on a new machine ● Shell scripts allow you to run a sequence of shell commands from a file. WRITE YOUR OWN SHELL SCRIPT ● Each script begins with a shebang followed by the commands you want to execute. ○ #!/bin/zsh ○ #!/bin/bash ○ #!/usr/bin/env python3 ● Add executable permissions to your file. ○ chmod +x script.sh ○ This changes the mode of the file to an executable. ● Run the script! ○ ./script.sh FUNCTIONS ARE SHELL SCRIPTS ● Apart from interfacing with the operating system, they support other programming constructs as well. -
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.