DOCSLIB.ORG

Scripting Languages

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Scripting Languages Scripting Languages Lecturer / Supervisor – dr Witold Marańda, DMCS (K-25), building B18, room.50 – Tuesdays & Fridays 10-11 Course Organization – 15x 2h, lab D Course Materials / Literature – on-line tutorials ● https://docs.python.org/3/tutorial/ ● https://realpython.com/ ● https://www.tutorialspoint.com/python3/ – books ● Learning Python, by Mark Lutz ● Invent Your Own Computer Games with Python, by Al Sweigart ● ... Form of Assessment Final grade range: 2 (fail) and 3 … 5 (pass) ● 4 x home assignments → 10% + 20% + 20% + 50% – good practices of programming (50%) – correctness and compliance with requirements (50%) Assignment delays: ● each week lowers the assignment max. grade by 1.0 Absences: ● sick leaves + one unjustified absence are OK ● any other unjustified absence lowers final grade by 0.25 Course Content Practical programming in modern language: – language syntax – data structures – flow control – code design – algorithms – documentation – problems & solutions ● Course Description at http://programy.p.lodz.pl Computer Engineering ● Computer hardware ● Operating system ● Programming language ● Development tools – IDE's, compilers, interpreters, linkers, assemblers, debuggers, profiles, code checkers, ... Computer Hardware Programmable machine – transformation of (binary) patterns/numbers according to concept of Turing and von Neumann Memory Peripherals CPU(s) Program/Data Input/Output Operating System Goal: – offer hardware services to user programs Key features: – single, multi-tasking, multi-user, ... – distributed, templated, embedded, real-time, ... Most common: ● UNIX and derivatives https://www.levenez.com/unix/ ● MS Windows family https://www.levenez.com/windows/ Programming Language Machine language → binary numbers only Assembler → human readable machine commands (one-to-one) High Level Languages – abstraction, data types, flow control – paradigms: imperative, object-oriented, ... – mode of execution: compiled or interpreted Dynamic/Scripting Languages – source-only (interpreted / compiled just-in-time) – powerful syntax, advanced data structures, rich libraries – platform-independent – focus on task and rapid prototyping - relaxed approach to paradigms history - https://www.levenez.com/lang/ rankings - http://www.tiobe.com/tiobe-index/ - https://pypl.github.io/PYPL.html Classic vs Scripting ● Java public class Hello { public static void main(String [] args) { System.out.println("Hello World"); } } ● Python print("Hello World") Compilation vs Interpretation source code compiler machine code run Input data program Output data run source code bytecode Interpreter bytecode compiler + Input data virtual machine Output data Compilation vs Interpretation ● Compilation: Write→Compile→Run (C, C++, ...) – programs are fast – source and executable are independent files →long development process – source may be platform independent, executable is not ● Interpretation: Write→Run (Python, Perl, Ruby, Tcl, JavaScript, ...) – programs may be slower – only source file exists (no executable) → rapid development process – source is mostly platform independent ● Mixed approaches: – compilation into intermediate formats platform independent (Java) – precompilation of ready-made parts of code (Python) Exercise 1. Create source file: hello.c 1. Create source file: hello.py ---------------------- ---------------------- #include <stdio.h> print("Hello") int main() ---------------------- { printf("Hello\n"); 2. Execute: return(0); $ python3 hello.py } ---------------------- 2. Compile: $ gcc hello.c 3. Execute: $ ./a.out a. Show machine code $ hexdump a.out b. Make and show assembler: $ gcc -S hello.c $ cat hello.s Interaction with Software User interface ● Command Line Interface – CLI – textual, information-oriented, for competent users – task automation, background jobs, computations, ... – platform independent (standard input/output → keyb./term.) ● Graphical User Interface – GUI – look-and-fill, aesthetics and ergonomics considerations – user action-oriented programming – mostly platform-dependent (hardware requirements) Software Licenses Propriety software – restricted in any way, according to the owner wishes “Free” software – “free” may refer to various aspects of freedom: try-before-buy, limited: time, resources, applications, right to run, display, copy, modify, embed, distribute, sell, sublicense, ... – Open-source software: source code is available to the user, but may not be "free" ● Free licenses: Public domain, GPL-style, BSD-style, … ● Free Software Foundation (www.fsf.org) Python Software License ● Python Software Foundation License (PSFL) ● BSD-style: permissive free software license – free to use, even for commercial products – free to embed Python interpreter in products – free to sell a product written in Python and/or embedding Python interpreter Python Language ● Full-featured, easy to learn, matured ● Efficient high-level data structures ● Simple and effective approach to OOP ● Short and elegant syntax ● Big library of standard objects and modules ● Official documentation: – Python Web site: https://www.python.org/ – Language Reference: https://docs.python.org/3/reference/ – Library Reference: https://docs.python.org/3/library/ Version 2 vs 3 ● Should I use Python 2 or Python 3? – 3.x is definitely the present and the future ● Python 2 will be “End Of Life” in January 2020 – syntax is very similar - the differences mostly affect performance and improvements – 2.7 is the still intensively used in many Linux desktop and servers machines – all important Python packages are already compatible with version 3.x Python IDE Integrated Development Environment (IDE) ● syntax highlighting, bracket matching, ... ● automatic save/execution/compilation/check ● source structure and elements ● multi-file projects Geany (http://www.geany.org/) - a small and lightweight IDE for C, Java, PHP, HTML, Python, Perl, Pascal, and others Style Guide and Code Checker PEP 8: Style Guide for Python Code pycodestyle: Python simple code style checker – IDE-geany can call pycodestyle to help you maintain your code (menu Build→Lint) Pylint: python code static analyzer – programming errors, – coding standard – etc. Running Python scripts ● by explicitly calling the interpreter: $ python script.py ● by executing the script: $ ./script.py System Access Control in Linux/Unix ● users and groups (/etc/passwd, /etc/groups) ● administrator/superuser: root ● permissions: rwx (read/write/execute) ● 3-level access control: rwx rwx rwx (user/group/ others) ● examples: rwx rwx rwx (777), rw- r-- r-- (644), rwx r-x r-- (751), rwx --- --x (701) Running Python scripts ● create source (text) file with one line inside: print("Hello") $ pico script.py ● show the file permissions $ ls -l script.py ● set the execution right for the owner/user $ chmod u+x script.py $ ls -l script.py ● locate your interpreter $ which python ● edit file and make 1st line of your script as follows: #!/usr/bin/python ● run your script: $ ./script.py Recommendation ● Use Linux Operating System – Choose from http://distrowatch.com/ ● Linux Mint is a very good choice for novices – Install the system - preferably on physical machine: ● as the only operating system (recommended) or sharing the hard-drive with other systems or in a virtual machine or as bootable live-distribution (poor performance) – Learn the basics of shell commands and shell scripting ● basic commands ● shell scripting ● and many, many other sites ... .
Load more

Recommended publications
  • KDE 2.0 Development, Which Is Directly Supported
    23 8911 CH18 10/16/00 1:44 PM Page 401 The KDevelop IDE: The CHAPTER Integrated Development Environment for KDE by Ralf Nolden 18 IN THIS CHAPTER • General Issues 402 • Creating KDE 2.0 Applications 409 • Getting Started with the KDE 2.0 API 413 • The Classbrowser and Your Project 416 • The File Viewers—The Windows to Your Project Files 419 • The KDevelop Debugger 421 • KDevelop 2.0—A Preview 425 23 8911 CH18 10/16/00 1:44 PM Page 402 Developer Tools and Support 402 PART IV Although developing applications under UNIX systems can be a lot of fun, until now the pro- grammer was lacking a comfortable environment that takes away the usual standard activities that have to be done over and over in the process of programming. The KDevelop IDE closes this gap and makes it a joy to work within a complete, integrated development environment, combining the use of the GNU standard development tools such as the g++ compiler and the gdb debugger with the advantages of a GUI-based environment that automates all standard actions and allows the developer to concentrate on the work of writing software instead of managing command-line tools. It also offers direct and quick access to source files and docu- mentation. KDevelop primarily aims to provide the best means to rapidly set up and write KDE software; it also supports extended features such as GUI designing and translation in con- junction with other tools available especially for KDE development. The KDevelop IDE itself is published under the GNU Public License (GPL), like KDE, and is therefore publicly avail- able at no cost—including its source code—and it may be used both for free and for commer- cial development.
    [Show full text]
  • UNIX and Computer Science Spreading UNIX Around the World: by Ronda Hauben an Interview with John Lions
    Winter/Spring 1994 Celebrating 25 Years of UNIX Volume 6 No 1 "I believe all significant software movements start at the grassroots level. UNIX, after all, was not developed by the President of AT&T." Kouichi Kishida, UNIX Review, Feb., 1987 UNIX and Computer Science Spreading UNIX Around the World: by Ronda Hauben An Interview with John Lions [Editor's Note: This year, 1994, is the 25th anniversary of the [Editor's Note: Looking through some magazines in a local invention of UNIX in 1969 at Bell Labs. The following is university library, I came upon back issues of UNIX Review from a "Work In Progress" introduced at the USENIX from the mid 1980's. In these issues were articles by or inter- Summer 1993 Conference in Cincinnati, Ohio. This article is views with several of the pioneers who developed UNIX. As intended as a contribution to a discussion about the sig- part of my research for a paper about the history and devel- nificance of the UNIX breakthrough and the lessons to be opment of the early days of UNIX, I felt it would be helpful learned from it for making the next step forward.] to be able to ask some of these pioneers additional questions The Multics collaboration (1964-1968) had been created to based on the events and developments described in the UNIX "show that general-purpose, multiuser, timesharing systems Review Interviews. were viable." Based on the results of research gained at MIT Following is an interview conducted via E-mail with John using the MIT Compatible Time-Sharing System (CTSS), Lions, who wrote A Commentary on the UNIX Operating AT&T and GE agreed to work with MIT to build a "new System describing Version 6 UNIX to accompany the "UNIX hardware, a new operating system, a new file system, and a Operating System Source Code Level 6" for the students in new user interface." Though the project proceeded slowly his operating systems class at the University of New South and it took years to develop Multics, Doug Comer, a Profes- Wales in Australia.
    [Show full text]
  • To Type Or Not to Type: Quantifying Detectable Bugs in Javascript
    To Type or Not to Type: Quantifying Detectable Bugs in JavaScript Zheng Gao Christian Bird Earl T. Barr University College London Microsoft Research University College London London, UK Redmond, USA London, UK [email protected] [email protected] [email protected] Abstract—JavaScript is growing explosively and is now used in to invest in static type systems for JavaScript: first Google large mature projects even outside the web domain. JavaScript is released Closure1, then Microsoft published TypeScript2, and also a dynamically typed language for which static type systems, most recently Facebook announced Flow3. What impact do notably Facebook’s Flow and Microsoft’s TypeScript, have been written. What benefits do these static type systems provide? these static type systems have on code quality? More concretely, Leveraging JavaScript project histories, we select a fixed bug how many bugs could they have reported to developers? and check out the code just prior to the fix. We manually add The fact that long-running JavaScript projects have extensive type annotations to the buggy code and test whether Flow and version histories, coupled with the existence of static type TypeScript report an error on the buggy code, thereby possibly systems that support gradual typing and can be applied to prompting a developer to fix the bug before its public release. We then report the proportion of bugs on which these type systems JavaScript programs with few modifications, enables us to reported an error. under-approximately quantify the beneficial impact of static Evaluating static type systems against public bugs, which type systems on code quality.
    [Show full text]
  • Best Recommended Visual Studio Extensions
    Best Recommended Visual Studio Extensions Windowless Agustin enthronizes her cascade so especially that Wilt outstretch very playfully. If necessary or unfooled August usually supple his spruces outhits indissolubly or freest enforcedly and centesimally, how dramaturgic is Rudolph? Delbert crepitated racially. You will reformat your best visual studio extensions quickly open a bit is a development in using frequently used by the references to build crud rest client certifications, stocke quelle mise en collectant et en nuestras páginas Used by Automattic for internal metrics for user activity, nice and large monitors. The focus of this extension is to keep the code dry, and UWP apps. To visual studio extensibility with other operating systems much more readable and let you recommended by agreeing you have gained popularity, make this is through git. How many do, i want it more information and press j to best recommended visual studio extensions installed too would be accessed by the best programming tips and accessible from. If, and always has been an independent body. Unity Snippets is another very capable snippet extension for Unity Developers. Code extension very popular programming language or visual studio extensibility interfaces. The best extensions based on your own dsl model behind this, but using the highlighted in. If you recommended completion. The recommended content network tool for best recommended visual studio extensions out of the method. This can prolong the times it takes to load a project. The best of vs code again after you with vs code is the basics and. Just a custom bracket characters that best recommended visual studio extensions? Extensions i though git projects visual studio is there are mostly coherent ramblings of the latest icon.
    [Show full text]
  • Safejava: a Unified Type System for Safe Programming
    SafeJava: A Unified Type System for Safe Programming by Chandrasekhar Boyapati B.Tech. Indian Institute of Technology, Madras (1996) S.M. Massachusetts Institute of Technology (1998) Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY February 2004 °c Massachusetts Institute of Technology 2004. All rights reserved. Author............................................................................ Chandrasekhar Boyapati Department of Electrical Engineering and Computer Science February 2, 2004 Certified by........................................................................ Martin C. Rinard Associate Professor, Electrical Engineering and Computer Science Thesis Supervisor Accepted by....................................................................... Arthur C. Smith Chairman, Department Committee on Graduate Students SafeJava: A Unified Type System for Safe Programming by Chandrasekhar Boyapati Submitted to the Department of Electrical Engineering and Computer Science on February 2, 2004, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Abstract Making software reliable is one of the most important technological challenges facing our society today. This thesis presents a new type system that addresses this problem by statically preventing several important classes of programming errors. If a program type checks, we guarantee at compile time that the program
    [Show full text]
  • Progdoc - a Program Documentation System
    ProgDOC - a Program Documentation System Volker Simonis Wilhelm-Schickard-Institut fur¨ Informatik Universitat¨ Tubingen,¨ 72076 Tubingen,¨ Germany E-mail : [email protected] Version 1.14 (ProgDOC Rel. 1.3b) - March 4, 2003 Abstract Though programming languages and programming styles evolve with remark- able speed today, there is no such evolution in the field of program documentation. And although there exist some popular approaches like Knuth’s literate program- ming system WEB [Web] and nowadays JavaDoc [JDoc] or DOC++ [DOCpp], tools for managing software development and documentation are not as widespread as desirable. This paper introduces a small tool box of utilities which can be used to easily produce nicely formatted PostScript, PDF and HTML documentations for software projects with LATEX. It is especially useful for mixed language projects and for documenting already finished programs and libraries. Due to it’s sophis- ticated syntax highlighting capabilities (currently implemented for C/C++/Java, Scheme/Elisp and XML) it is also a good choice for writing articles or technical white papers which contain source code examples. 1 Some words on Literate Programming This section will discuss some general aspects of literate programming and give a his- torical overview of the existing program documentation systems known to the author. Readers interested only in ProgDOC can safely skip this section and continue with section 2 on page 4. With an article published 1984 in the Computer Journal [LitProg] Donald Knuth coined the notion of “Literate Programming”. Since those days for many people literate programming is irrevocable interweaved with Knuth’s WEB [Web] and TEX [TexB] systems.
    [Show full text]
  • A Javascript Mode for Yi
    Abstract Yi is a text editor written in the lazy functional programming language Haskell, which makes it possible to define precise editing modes using an abstract syntax tree provided online using the lazy and incremental parser library in Yi. We have developed a JavaScript mode for this editor using this parser library to accurately point out possible errors in the source code. The mode accurately highlights syntactical errors as the user types and pro- vides a verifier to check the semantics of the source code. It supports most of the syntax from JavaScript 1.8 and can readily be extended with more functionality. The mode can also be used as a starting point for future developers of C-like modes for Yi. Writing a responsive parser for Yi proved non-trivial, because of the trade-off between parser performance and accuracy. This report describes how to write a mode for Yi and the different problems encountered during the working process of the JavaScript mode. It also describes in what ways the problems were solved. Sammanfattning Yi är en textredigerare skriven i det lata funktionella programspråket Haskell, som gör det möjligt att definiera noggranna redigeringslägen med hjälp av ett abstrakt syntaxträd som tillhandahålls av det lata och inkre- mentella parsningsbiblioteket i Yi. Vi har utvecklat ett JavaScript-läge till denna redigerare med hjälp av detta parsningsbibliotek för att exakt utpeka möjliga fel i källkoden. Läget markerar syntaktiska fel medan användaren skriver och tillhandahåller en verifierare för att kontrollera semantiken i källkoden. Det stödjer större delen av syntaxen i JavaScript 1.8 och kan enkelt utökas med mer funk- tionalitet.
    [Show full text]
  • Lint, a C Program Checker Lint, a C
    Lint, a C Program Checker Fr ans Kunst Vrije Universiteit Amsterdam Afstudeer verslag 18 mei 1988 Lint, a C Program Checker Fr ans Kunst Vrije Universiteit Amsterdam This document describes an implementation of a program which does an extensive consistencyand plausibility check on a set of C program files. This may lead to warnings which help the programmer to debug the program, to remove useless code and to improve his style. The program has been used to test itself and has found bugs in sources of some heavily used code. -2- Contents 1. Introduction 2. Outline of the program 3. What lint checks 3.1 Set, used and unused variables 3.2 Flowofcontrol 3.3 Functions 3.4 Undefined evaluation order 3.5 Pointer alignment problems 3.6 Libraries 4. Howlint checks 4.1 The first pass data structure 4.2 The first pass checking mechanism 4.3 The second pass data structure 4.4 The second pass checking mechanism 5. Howtomakelint shut up 6. User options 7. Ideas for further development 8. Testing the program 9. References Appendix A − The warnings Appendix B − The Ten Commandments for C programmers -3- 1. Introduction C[1][2] is a dangerous programming language. The programmer is allowed to do almost anything, as long as the syntax of the program is correct. This has a reason. In this way it is possible to makeafast compiler which produces fast code. The compiler will be fast because it doesn’tdomuch checking at com- pile time. The code is fast because the compiler doesn’tgenerate run time checks.
    [Show full text]
  • The TRUTH About How Codesonar Compares to PC-Lint
    The TRUTH About How CodeSonar Compares to PC-lint Gimpel Software Version 1, May 2016 As the recognized leader and standard bearer in the static analysis industry, we are flattered to be considered as a benchmark in many product comparisons. While we rarely find it necessary to respond to them, the Grammatech “white paper” comparing the CodeSonar product to PC-lint has the odious distinction of being an exception. Instead of focusing on the perceived merits of the Grammatech product, the white paper in question resorts to false claims and misrepresentations about PC-lint, perhaps as a result of marketplace pressure, which we feel should be balanced with a healthy dose of reality. About PC-lint PC-lint is a powerful and reputable C and C++ static analysis tool created by Gimpel Software in 1985 and continually improved during the past 30 years. During this time PC-lint has been an innovative leader in the industry by incorporating pioneering features such as inter-function and inter-module Value Tracking, Strong Type Checking and Dimensional Analysis, and User-Defined Function Semantics. PC-lint is trusted by many tens of thousands of developers, QA analysts, software testers, and forensic analysts and supports dozens of compilers and platforms, sports dozens of secondary features, and is deployed worldwide in virtually every industry including safety critical fields such as medical and automotive. About Grammatech’s white paper The white paper entitled “How CodeSonar Compares To PC-lint (And Similar Tools)”, avail- able from Grammatech’s website, purports to provide a comparison between the CodeSonar product and PC-lint (other tools are discussed but the focus is on PC-lint) but in reality is nothing more than a series of self-serving, misleading statements having little or no factual basis.
    [Show full text]
  • Cleanscape Fortran-Lint GUI User's Guide
    Cleanscape Fortran-lint GUI User’s Guide Version 6.3 Sales and Service Office 5850 Eubank Blvd. NE, B49-180 Albuquerque, NM 87111 Toll-free 800-94-4LINT 505-246-0267 Fax 505-247-2678 www.cleanscape.net [email protected] [email protected] Flint GUI User’s Guide PART I Introduction.................................................................................................................3 1.1 WELCOME..........................................................................................................................3 1.2 DOCUMENTATION.............................................................................................................3 1.3 PURPOSE...........................................................................................................................3 A. Function............................................................................................................................3 B. Application.........................................................................................................................3 C. Advantages.......................................................................................................................4 D. Flow of Analysis................................................................................................................4 PART II Requirements, Installation, and Uninstallation.............................................................5 2.1 WINDOWS..........................................................................................................................5
    [Show full text]
  • Fortran Programmer's Guide
    Fortran Programmer’s Guide Fortran 77 4.2 Fortran 90 1.2 SunSoft, Inc. A Sun Microsystems, Inc. Business 2550 Garcia Avenue Mountain View, CA 94043 USA 415 960-1300 fax 415 969-9131 Part No.: 802-5664-10 Revision A, December 1996 Copyright 1996 Sun Microsystems, Inc., 2550 Garcia Avenue, Mountain View, California 94043-1100 U.S.A. All rights reserved. This product or document is protected by copyright and distributed under licenses restricting its use, copying, distribution, and decompilation. No part of this product or document may be reproduced in any form by any means without prior written authorization of Sun and its licensors, if any. Portions of this product may be derived from the UNIX® system, licensed from Novell, Inc., and from the Berkeley 4.3 BSD system, licensed from the University of California. UNIX is a registered trademark in the United States and other countries and is exclusively licensed by X/Open Company Ltd. Third-party software, including font technology in this product, is protected by copyright and licensed from Sun’s suppliers. RESTRICTED RIGHTS: Use, duplication, or disclosure by the U.S. Government is subject to restrictions of FAR 52.227- 14(g)(2)(6/87) and FAR 52.227-19(6/87), or DFAR 252.227-7015(b)(6/95) and DFAR 227.7202-3(a). Sun, Sun Microsystems, the Sun logo, Solaris, SunSoft, Sun WorkShop, Sun Performance WorkShop and Sun Performance Library are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc.
    [Show full text]
  • NBS FORTRAN Test Programs 3^1 No "I Volume 1- Documentation for Versions 1 and 3 V.I
    j I i Vt NBS SPECIAL PUBLICATION 399 J Volume 1 U.S. DEPARTMENT OF COMMERCE / National Bureau of Standards] National Bureau of Standards Library, £-01 Admin. BIdg. ncT 1 1981 13102^1 NBS FORTRAN Test Prog Volume 1-Documentation for Versions 1 and 3 NATIONAL BUREAU OF STANDARDS The National Bureau of Standards^ was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology, the Institute for Computer Sciences and Technology, and the Office for Information Programs. THE INSTITUTE FOR BASIC STANDARI>S provides the central basis within the United States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of a Center for Radiation Research, an Office of Meas- urement Services and the following divisions: Applied Mathematics — Electricity — Mechanics
    [Show full text]