UNIX/Linux Fundamentals – Lecture 1
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It's Complicated but It's Probably Already Booting Your Computer
FAQ SYSTEMD SYSTEMD It’s complicated but it’s probably already booting your computer. dynamically connect to your network, a runlevel of 1 for a single-user mode, GRAHAM MORRISON while syslogd pools all the system runlevel 3 for the same command messages together to create a log of prompt we described earlier, and Surely the ‘d’ in Systemd is everything important. Another daemon, runlevel 5 to launch a graphical a typo? though it lacks the ‘d’, is init – famous environment. Changing this for your No –it’s a form of Unix notation for being the first process that runs on next boot often involved editing the used to signify a daemon. your system. /etc/inittab file, and you’d soon get used to manually starting and stopping You mean like those little Isn’t init used to switch your own services simply by executing devils inhabiting Dante’s between the command-line the scripts you found. underworld? and the graphical desktop? There is a link in that Unix usage For many of us, yes. This was the You seem to be using the past of the term daemon supposedly main way of going from the tense for all this talk about the comes from Greek mythology, where desktop to a command line and back init daemon… daemons invisibly wove their magic again without trying to figure out which That’s because the and benign influence. The word is today processes to kill or start manually. aforementioned Systemd wants more commonly spelt ‘demon’, which Typing init 3 would typically close any to put init in the past. -
Getting to Grips with Unix and the Linux Family
Getting to grips with Unix and the Linux family David Chiappini, Giulio Pasqualetti, Tommaso Redaelli Torino, International Conference of Physics Students August 10, 2017 According to the booklet At this end of this session, you can expect: • To have an overview of the history of computer science • To understand the general functioning and similarities of Unix-like systems • To be able to distinguish the features of different Linux distributions • To be able to use basic Linux commands • To know how to build your own operating system • To hack the NSA • To produce the worst software bug EVER According to the booklet update At this end of this session, you can expect: • To have an overview of the history of computer science • To understand the general functioning and similarities of Unix-like systems • To be able to distinguish the features of different Linux distributions • To be able to use basic Linux commands • To know how to build your own operating system • To hack the NSA • To produce the worst software bug EVER A first data analysis with the shell, sed & awk an interactive workshop 1 at the beginning, there was UNIX... 2 ...then there was GNU 3 getting hands dirty common commands wait till you see piping 4 regular expressions 5 sed 6 awk 7 challenge time What's UNIX • Bell Labs was a really cool place to be in the 60s-70s • UNIX was a OS developed by Bell labs • they used C, which was also developed there • UNIX became the de facto standard on how to make an OS UNIX Philosophy • Write programs that do one thing and do it well. -
If Data Is Confidential and Available but Altered Decryption of Altered Data Usually Gives Garbage Exception: Electronic-Codeboo
38 40 If Data is Confidential and Available but Altered Encryption • do not use ECB–Mode • use CBC– or CTR–mode (recommendation Schneier/Ferguson) • use AES or one of the finalists – Twofish (Schneier, Ferguson, Kelsey, Whiting, Wagner, Hall) decryption of altered data usually gives garbage – Serpent (Anderson, Biham, Knudsen) – MARS (Coppersmith et al., IBM) exception: electronic-codebook-mode (ECB) (uses independent blocks) – RC6 (Rivest, patented by RSA) 39 41 ECB-Mode Encrypted Penguin If Data is Non-Alterable and Confidential but not Available ,,Your message with authenticator 08931281763e1de003e5f930c449bf791c9f0db6 encryption is block by block has been received, but unfortunately the server is down. ❀ every block gets another color Your mail-service will never be accessible.” Example: lavabit.com, Snowden’s e-Mail-Provider 42 44 Authorization: Who is Allowed to Do All This? Problem: Person/Process/Role ⇐⇒ String (2) How to link a person to a string? • Person knows something (password, secret cryptographic key). • Person has something (token, USB–key, chipcard). Authorized entities only. • Person is something (biometrics, fingerprint etc.). Only Bob is allowed to enter here. We have to identify persons, processes and their roles. 43 45 Problem: Person/Process/Role ⇐⇒ String (1) Proof of Identity is Called Authentication Person identified by picture String identified by equality relation. 46 48 Proof of Identity: Links Person to a String Third party guarantees real identity. Has something: ID–card. 47 49 Proof of True Source is Called Authenticity -
Introduction to Unix Shell (Part I)
Introduction to Unix shell (part I) Evgeny Stambulchik Faculty of Physics, Weizmann Institute of Science, Rehovot 7610001, Israel Joint ICTP-IAEA School on Atomic Processes in Plasmas February 27 – March 3, 2017 Trieste, Italy Contrary to popular belief, Unix is user friendly. It just happens to be very selective about who it decides to make friends with. Unknown Initially used at Bell Labs, but soon licensed to academy (notably, U. of California, Berkeley) and commercial vendors (IBM, Sun, etc). There are two major products that came out of Berkeley: LSD and Unix. We don’t believe this to be a coincidence. Jeremy S. Anderson, Unix systems administrator Historical overview (kind of) Unix is a family of multiuser, multitasking operating systems stemming from the original Unix developed in the 1970’s at Bell Labs by Ken Thompson, Dennis Ritchie1, and others. Some consider Unix to be the second most important invention to come out of AT&T Bell Labs after the transistor. Dennis Ritchie 1Also famous for creating the C programming language. Historical overview (kind of) Unix is a family of multiuser, multitasking operating systems stemming from the original Unix developed in the 1970’s at Bell Labs by Ken Thompson, Dennis Ritchie1, and others. Some consider Unix to be the second most important invention to come out of AT&T Bell Labs after the transistor. Dennis Ritchie Initially used at Bell Labs, but soon licensed to academy (notably, U. of California, Berkeley) and commercial vendors (IBM, Sun, etc). There are two major products that came out of Berkeley: LSD and Unix. -
INTERIX: UNIX Application Portability to Windows NT Via an Alternative Environment Subsystem
INTERIX: UNIX Application Portability to Windows NT via an Alternative Environment Subsystem Stephen R. Walli Softway Systems, Inc. 185 Berry Street, Suite 5514, San Francisco, CA 94107 [email protected] 0. Introduction today. It does this in a price competitive manner with respect to the hardware platforms on which This paper was originally written for and it runs. The problem becomes protecting the presented at the USENIX Windows NT huge investment in applications development over Workshop, Seattle, Washington, August 1997. the past decade or more in UNIX applications. The original paper was presented under the How does one leverage and protect the existing OPENNT name. It has been updated to reflect application base while moving to Windows NT? the current architecture and experience with INTERIX. 2. Alternatives 1. The Problem There are several ways to move existing applications to Windows NT. These range from Walli’s First Law of Applications Portability: the expense of a complete re-write of the Every useful application outlives the platform on application to some form of application port. We which it was developed and deployed. will briefly look at the pros and cons of the following: Application source code portability is one of the • cornerstones of most open systems definitions. a complete re-write of the application to the The intention is that if an application is written to Win32 environment subsystem • a particular model of source-code portability, it the UNIX emulation library approach to can port relatively easily to any platform that porting the application supports the portability model. This model is • the common library strategy for porting often based on source code portability standards applications such as the ISO/IEEE family of POSIX • the Microsoft POSIX subsystem standards [1,2] and ISO/ANSI C[3], and • the INTERIX subsystem specifications that include these standards such as the Open Group's Single UNIX Specification[4]. -
DOCUMENT RESUME Focus on the Customer. New Opportunities for 81P
DOCUMENT RESUME ED 401 858 HE 029 711 TITLE Focus on the Customer. New Opportunities for Partnering, CAUSE94. Track II. INSTITUTION CAUSE, Boulder, Colo. PUB DATE 95 NOTE 81p.; In: New Opportunities for Partnering. Proceedings of the 1994 CAUSE Annual Conference (Orlando, Florida, November 29-December 2, 1994); see HE 029 709. AVAILABLE FROM CAUSE Information Resources Library, 4840 Pearl East Circle, Suite 302E, Boulder, CO 80303 (Individual papers available to CAUSE members at cost of reproduction). PUB TYPE Reports Descriptive (141) Speeches/Conference Papers (150) EDRS PRICE MF01/PC04 Plus Postage. DESCRIPTORS College Administration; College Libraries; Colleges; *Computer Networks; Computers; Cooperation; Cooperative Programs; Educational Planning; Higher Education; *Information Management; *Information Networks; Information Systems; *Information Technology; Models; *Partnerships in Education; Student Personnel Services; Universities IDENTIFIERS Boston College MA; Campus Wide Information Systems; *CAUSE National Conference; *Customer Relations; Maricopa County Community College District AZ; Southwest Texas State University ABSTRACT Eight papers are presented from the 1994 CAUSE conference track on customer-centered partnering within and among higher education institutions in regard to information resources and technology. The papers include:(1) "Customer-Centered Collaboration: Libraries and IT," which focuses on the use of teams, total quality management, and business process reengineering (Geri Bunker and Barbara Horgan);(2) "Making Order Out of Chaos with a Computerized Lottery," which discusses the use of a class scheduling lottery at the Massachusetts Institute of Technology (Steven Anders Oakland); (3) "Customers as Partners in the Information Technology Planning Process," which describes the development of the Information Technology Planning Project at the University of Minnesota (Linda Jorn and others);(4) "Distance Education: What's Up," which focuses on new trends in distance education (Gene T. -
Perl on Windows
BrokenBroken GlassGlass Perl on Windows Chris 'BinGOs' Williams “This is your last chance. After this, there is no turning back. You take the blue pill - the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill - you stay in Wonderland and I show you how deep the rabbit-hole goes.” A bit of history ● 5.003_24 - first Windows port ● 5.004 - first Win32 and Cygwin support, [MSVC++ and Borland C++] ● 5.005 - experimental threads, support for GCC and EGCS ● 5.6.0 - experimental fork() support ● 5.8.0 - proper ithreads, fork() support, 64bit Windows [Intel IA64] ● 5.8.1 - threads support for Cygwin ● 5.12.0 - AMD64 with Mingw gcc ● 5.16.0 - buh-bye Borland C++ Time for some real archaeology Windows NT 4.0 Resource Kit CDROM ActivePerl http://www.activestate.com/perl ● July 1998 - ActivePerl 5.005 Build 469 ● March 2000 - ActivePerl 5.6.0 Build 613 ● November 2002 - ActivePerl 5.8.0 Build 804 ● November 2005 - ActivePerl 5.8.7 Build 815 [Mingw compilation support] ● August 2006 - ActivePerl 5.8.8 Build 817 [64bit] ● June 2012 - ActivePerl 5.16.0 Build 1600 ● Built with MSVC++ ● Can install or use MinGW ● PPM respositories of popular modules ● Commercial support ● PerlScript – Active Scripting engine ● Perl ISAPI Strawberry Perl http://strawberryperl.com ● July 2006 - Strawberry Perl 5.8.8 Alpha 1 released ● April 2008 - Strawberry Perl 5.10.0.1 and 5.8.8.1 released ● January 2009 - first portable release ● April 2010 - 64bit and 32bit releases ● May 2012 - Strawberry Perl 5.16.0.1 released ● August -
Team Unknown ]
[ Team Unknown ] Code Quality: The Open Source Perspective By Diomidis Spinellis ............................................... Publisher: Addison Wesley Professional Pub Date: April 03, 2006 Print ISBN-10: 0-321-16607-8 Print ISBN-13: 978-0-321-16607-4 Pages: 608 Slots: 2.0 Table of Contents | Index | Author Index Copyright Effective Software Development Series: Scott Meyers, Consulting Editor List of Tables List of Figures Foreword Preface Chapter 1. Introduction Section 1.1. Software Quality Section 1.2. How to Read This Book Further Reading Chapter 2. Reliability Section 2.1. Input Problems Section 2.2. Output Problems Section 2.3. Logic Problems Section 2.4. Computation Problems Section 2.5. Concurrency and Timing Problems Section 2.6. Interface Problems Section 2.7. Data-Handling Problems Section 2.8. Fault Tolerance Advice to Take Home Further Reading Chapter 3. Security Section 3.1. Vulnerable Code Section 3.2. The Buffer Overflow Section 3.3. Race Conditions Section 3.4. Problematic APIs Section 3.5. Untrusted Input Section 3.6. Result Verification Section 3.7. Data and Privilege Leakage Section 3.8. Trojan Horse Section 3.9. Tools Advice to Take Home Further Reading Chapter 4. Time Performance Section 4.1. Measurement Techniques Section 4.2. Algorithm Complexity Section 4.3. Stand-Alone Code Section 4.4. Interacting with the Operating System Section 4.5. Interacting with Peripherals Section 4.6. Involuntary Interactions Section 4.7. Caching Advice to Take Home Further Reading Chapter 5. Space Performance Section 5.1. Data Section 5.2. Memory Organization Section 5.3. Memory Hierarchies Section 5.4. The Process/Operating System Interface Section 5.5. -
Command Line Interface (Shell)
Command Line Interface (Shell) 1 Organization of a computer system users applications graphical user shell interface (GUI) operating system hardware (or software acting like hardware: “virtual machine”) 2 Organization of a computer system Easier to use; users applications Not so easy to program with, interactive actions automate (click, drag, tap, …) graphical user shell interface (GUI) system calls operating system hardware (or software acting like hardware: “virtual machine”) 3 Organization of a computer system Easier to program users applications with and automate; Not so convenient to use (maybe) typed commands graphical user shell interface (GUI) system calls operating system hardware (or software acting like hardware: “virtual machine”) 4 Organization of a computer system users applications this class graphical user shell interface (GUI) operating system hardware (or software acting like hardware: “virtual machine”) 5 What is a Command Line Interface? • Interface: Means it is a way to interact with the Operating System. 6 What is a Command Line Interface? • Interface: Means it is a way to interact with the Operating System. • Command Line: Means you interact with it through typing commands at the keyboard. 7 What is a Command Line Interface? • Interface: Means it is a way to interact with the Operating System. • Command Line: Means you interact with it through typing commands at the keyboard. So a Command Line Interface (or a shell) is a program that lets you interact with the Operating System via the keyboard. 8 Why Use a Command Line Interface? A. In the old days, there was no choice 9 Why Use a Command Line Interface? A. -
The Tragedy of Systemd
The Tragedy of systemd [email protected] @jeamland The Tragedy of systemd [email protected] @jeamland Aurynn Shaw, “Contempt Culture” http://blog.aurynn.com/2015/12/16-contempt-culture Change The Ancestry of systemd UNIX Seventh Edition Unix (1979) … housekeeping functions like… mounting filesystems, and starting “ daemons. - init(8) manual page, Seventh Edition Unix PDP-11/70, Seventh Edition Unix VAX-11/730, 4.3BSD Living Computers Museum+Labs https://livingcomputers.org Then things changed Service … housekeeping functions like… mounting filesystems, and starting “ daemons. - init(8) manual page, Seventh Edition Unix System Configuration System Configuration Service Bootstrap Automated Service Management The Idea of systemd launchd The Idea of launchd From launchd to systemd Lennart Poettering, “Rethinking PID 1” http://0pointer.net/blog/projects/systemd.html For a fast and efficient boot-up two things are crucial: “ ➤ To start less. ➤ And to start more in parallel. -Lennart Poettering, “Rethinking PID 1” An init system that is responsible for maintaining services needs to listen to “ hardware and software changes. -Lennart Poettering, “Rethinking PID 1” [I]s this kind of logic new? No, it certainly is not. The most prominent “ system that works like this is Apple's launchd system… -Lennart Poettering, “Rethinking PID 1” System Management Userspace Kernel Userspace System Kernel The Reality of systemd Adoption Fedora 15 May, 2011 openSUSE 12.2 September, 2012 CentOS 7.14.04 April, 2014 Red Hat Enterprise Linux 7.0 June, 2014 SUSE Linux Enterprise -
Augmented Unix Userland
Project MXC-403 Augmented Unix Userland Major Qualifying Project Submitted to the Faculty of Worcester Polytechnic Institute in partial fulfillment of the requirements for the Degree in Bachelor of Science in Computer Science By Sam Abradi [email protected] Ian Naval [email protected] Fredric Silberberg [email protected] Submitted On: April 30, 2015 Project Advisor: Professor Michael Ciaraldi [email protected] This report represents work of WPI undergraduate students submitted to the faculty as evidence of a degree requirement. WPI routinely publishes these reports on its web site without editorial or peer review. For more information about the projects program at WPI, see http: // www. wpi. edu/ Academics/ Projects . Abstract The Unix philosophy has resulted in stringing together simple general purpose utili- ties to accomplish complex tasks. However, using text as a communication medium between these programs requires several formatting utilities to transform output from one program into valid input to another. These transformations can be very complicated and confusing. This project looked at two alternative shell designs that use different communication methods between programs, simplifying interprogram communication and leveraging existing technologies to make developing new utilities and shell scripts easier. i Contents Abstracti List of Figuresv List of Tables vi 1 Introduction1 1.1 AUU Terminology.............................1 1.2 Motivation.................................1 1.3 The AUU Project.............................3 2 JSON Shell4 2.1 Motivation: Why JSON?.........................4 2.2 JSON Protocol Design..........................4 Streams..................................4 Standards and Definitions........................5 Example Use Case: ps..........................6 2.3 Tributary.................................8 Tributary Selectors............................8 Using Tributary to Standardize Output.................9 2.4 Utilities Implemented.......................... -
Systemd from Wikipedia, the Free Encyclopedia for Other Uses, See System D (Disambiguation)
systemd From Wikipedia, the free encyclopedia For other uses, see System D (disambiguation). systemd Startup messages on Fedora 17, which uses systemd Original author(s) Lennart Poettering, Kay Sievers, Harald Hoyer, Daniel Mack, Tom Gundersen and David Herrmann Developer(s) Lennart Poettering, Kay Sievers, Harald Hoyer, Daniel Mack, Tom Gundersen, David Herrmann, and others[1] Initial release 30 March 2010 Stable release 219 (February 16, 2015) [±] (https://en.wikipedia.org/w/index.php? title=Template:Latest_stable_software_release/systemd&action=edit)[2] Written in C[3] Operating system Linux Type System software License GNU LGPL 2.1+[4] Website freedesktop.org/.../systemd/ (http://freedesktop.org/wiki/Software/systemd/) systemd is a suite of system management daemons, libraries, and utilities designed as a central management and configuration platform for the Linux computer operating system. Described by its authors as a "basic building block" for an operating system,[5] systemd can be used as a Linux init system (the process called by the Linux kernel to initialize the user space during the Linux startup process and manage all processes afterwards) replacing the UNIX System V and Berkeley Software Distribution (BSD) style daemon. The name systemd adheres to the Unix convention of making daemons easier to distinguish by having the letter d as the last letter of the filename.[6] systemd is designed for Linux and programmed exclusively for the Linux API. It is published as free and open-source software under the terms of the GNU Lesser General Public License (LGPL) version 2.1 or later.[4] One of systemd's main goals is to unify basic Linux configurations and service behaviors across all distributions.[7] The design of systemd has generated significant controversy within the free software community.