UNIX Commands Ls – List Contents of a Directory

Copy Link

UNIX Commands ls – list contents of a directory pwd – display current directory cd – change to directory (cd test) cp – copy file (cp from_file to_file) mv – move file (mv from_file to_file) rm – delete file (rm test1) mkdir – make directory (mkdir test) rmdir – remove directory (rmdir test) man – help for given command (man cp) cat – display contents of file more – display contents of file with page breaks (next page with Space key) head – display top of file tail – display end of file grep – search for pattern in file (grep “pattern“ test1) vi – edit file (more on this later) wc – count number of lines, words, characters in a file (wc -l file.txt) cut – cut out parts of file (cut -f 2 -d : file.txt) du – report disk usage (du -h) df – report file systems and their usage (df -h) chmod – change permissions of a file (chmod a+r file.txt) ln – create a link to a file (ln -s ~/bin/prog.exe prog1.exe) Wildcards: * - matches any number of letters incl. none ? - matches any single character [] - encloses set of characters that can match the single given position - used within [] denotes range of characters ~ - followed by user name = home directory (~mcuma) Command redirection: > redirect to a new file (cat test1 > test3) >> - append to a (new or existing) file (cat test2 >> test3) | - pipe – redirect command output to another command Vi basic reference i – insert I – insert at start of line a – append A – append at end of line o – enter insert mode on a new line r – replace single letter R – replace mode x – delete letter dd – delete line D – delete from cursor to end of line u – undo G – move to end of file #G – move to line # ^ - move to start of line $ - move to end of line ctrl-f – move page forward ctrl-b – move page back :w – save current file :w filename – save file to new file :q – quit vi :wq – save and quit :q! - quit without saving :w! - force save :n filename – open another file /pattern – search forward for pattern ? - search backward for pattern; subsequent entry of / or ? searches for next occurence of pattern :s/old_text/new_text – replace next occurence on current line :s/old_text/new_text/g – replace all occurence on current line :%s/old_text/new_text/g – replace all occurences in the whole file Scripting Loops foreach VAR ($VARLIST) … end while (condition) … end break – break out of the loop continue – skip to next loop iteration Conditions if (condition) then … else … endif switch (string) case pattern1: … breaksw default: commands... breaksw endsw Conditional expressions ==, !=, >, < ,&& ,|| - equal, not equal, larger, smaller than, and, or - like in C language !($?var) – true if variable does not exist =~ - if the right hand side matches a pattern, (i.e., similar to filename matching, with asterisks and question marks.) the condition is true. !~ - if the right hand side doesn't match a pattern, the condition is true. -d $var - true if the file is a directory. -e $var - true if the file exists. -f $var - true if the file is a file. (I.e., not a directory) -o $var - true if the file is owned by the user. -r $var - true if the user has read access. -w $var - true if the user has write access. -x $var - true if the user has execute access. -z $var - true if the file is zero-length. Shell variables variables are denoted with $ - echo $VAR strings defined by set – set VAR=(1 2 3 4) numbers defined by @ - @i = 1 conversion of string to number with expr - @i = `expr $number + 0`.

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15-122: Principles of Imperative Computation, Fall 2014 Lab 11: Strings in C

15-122: Principles of Imperative Computation, Fall 2014 Lab 11: Strings in C Tom Cortina(tcortina@cs) and Rob Simmons(rjsimmon@cs) Monday, November 10, 2014 For this lab, you will show your TA your answers once you complete your activities. Autolab is not used for this lab. SETUP: Make a directory lab11 in your private 15122 directory and copy the required lab files to your lab11 directory: cd private/15122 mkdir lab11 cp /afs/andrew.cmu.edu/usr9/tcortina/public/15122-f14/*.c lab11 1 Storing and using strings using C Load the file lab11ex1.c into a text editor. Read through the file and write down what you think the output will be before you run the program. (The ASCII value of 'a' is 97.) Then compile and run the program. Be sure to use all of the required flags for the C compiler. Answer the following questions on paper: Exercise 1. When word is initially printed out character by character, why does only one character get printed? Exercise 2. Change the program so word[3] = 'd'. Recompile and rerun. Explain the change in the output. Run valgrind on your program. How do the messages from valgrind correspond to the change we made? Exercise 3. Change word[3] back. Uncomment the code that treats the four character array word as a 32-bit integer. Compile and run again. Based on the answer, how are bytes of an integer stored on the computer where you are running your code? 2 Arrays of strings Load the file lab11ex2.c into a text editor.
PS TEXT EDIT Reference Manual Is Designed to Give You a Complete Is About Overview of TEDIT

Information Management Technology Library PS TEXT EDIT™ Reference Manual Abstract This manual describes PS TEXT EDIT, a multi-screen block mode text editor. It provides a complete overview of the product and instructions for using each command. Part Number 058059 Tandem Computers Incorporated Document History Edition Part Number Product Version OS Version Date First Edition 82550 A00 TEDIT B20 GUARDIAN 90 B20 October 1985 (Preliminary) Second Edition 82550 B00 TEDIT B30 GUARDIAN 90 B30 April 1986 Update 1 82242 TEDIT C00 GUARDIAN 90 C00 November 1987 Third Edition 058059 TEDIT C00 GUARDIAN 90 C00 July 1991 Note The second edition of this manual was reformatted in July 1991; no changes were made to the manual’s content at that time. New editions incorporate any updates issued since the previous edition. Copyright All rights reserved. No part of this document may be reproduced in any form, including photocopying or translation to another language, without the prior written consent of Tandem Computers Incorporated. Copyright 1991 Tandem Computers Incorporated. Contents What This Book Is About xvii Who Should Use This Book xvii How to Use This Book xvii Where to Go for More Information xix What’s New in This Update xx Section 1 Introduction to TEDIT What Is PS TEXT EDIT? 1-1 TEDIT Features 1-1 TEDIT Commands 1-2 Using TEDIT Commands 1-3 Terminals and TEDIT 1-3 Starting TEDIT 1-4 Section 2 TEDIT Topics Overview 2-1 Understanding Syntax 2-2 Note About the Examples in This Book 2-3 BALANCED-EXPRESSION 2-5 CHARACTER 2-9 058059 Tandem Computers
Unibasic 9.3 Reference Guide

Unibasic - Dynamic Concepts Wiki 6/19/17, 1244 PM Unibasic From Dynamic Concepts Wiki Contents 1 UniBasic 2 About this Guide 2.1 Conventions 3 Installation & Configuration 3.1 Configuring Unix for UniBasic 3.1.1 Number of Processes 3.1.2 Number of Open Files 3.1.3 Number of Open i-nodes 3.1.4 Number of Locks 3.1.5 Message Queues 3.2 Unix Accounting & Protection System 3.3 Creating a Unix Account for UniBasic 3.4 UniBasic Security & Licensing 3.4.1 Software Licensing 3.4.2 Hardware Licensing 3.5 Loading the Installation File 3.5.1 Loading the UniBasic Installation File 3.5.2 Loading the UniBasic Development File 3.6 ubinstall - Installing UniBasic Packages 3.6.1 Errors During Installation 3.7 Configuring a UniBasic Environment 3.7.1 Directories and Paths 3.7.2 Filenames and Pathnames 3.7.3 Organizing Logical Units and Packnames 3.7.4 Environment Variables 3.7.5 Setting up .profile for Multiple Users 3.8 Command Line Interpreter 3.9 Launching UniBasic From Unix 3.10 Terminating a UniBasic Process 3.11 Licensing a New Installation 3.12 Changing the SSN Activation Key 3.13 Launching UniBasic Ports at Startup 3.14 Configuring Printer Drivers 3.15 Configuring Serial Printers 3.16 Configuring Terminal Drivers 3.17 Creating a Customized Installation Media 4 Introduction To UniBasic 4.1 Data 4.1.1 Numeric Data 4.1.1.1 Numeric Precision 4.1.1.2 Special Notes on %3 and %6 Numerics https://engineering.dynamic.com/mediawiki/index.php?title=Unibasic&printable=yes Page 1 of 397 Unibasic - Dynamic Concepts Wiki 6/19/17, 1244 PM 4.1.1.3 Integers Stored in Floating-Point
How to Write Shell Script

How to write shell script Following steps are required to write shell script: (1) Use any editor like vi or mcedit to write shell script. (2) After writing shell script set execute permission for your script as follows syntax: chmod permission your-script-name Examples: $ chmod +x your-script-name $ chmod 755 your-script-name Note: This will set read write execute(7) permission for owner, for group and other permission is read and execute only(5). (3) Execute your script as syntax: bash your-script-name sh your-script-name ./your-script-name Examples: $ bash bar $ sh bar $ ./bar NOTE In the last syntax ./ means current directory, But only . (dot) means execute given command file in current shell without starting the new copy of shell, The syntax for . (dot) command is as follows Syntax: . command-name Example: $ . foo Now you are ready to write first shell script that will print "Knowledge is Power" on screen. See the common vi command list , if you are new to vi. $ vi first # # My first shell script # clear echo "Knowledge is Power" After saving the above script, you can run the script as follows: $ ./first This will not run script since we have not set execute permission for our script first; to do this type command $ chmod 755 first $ ./first Variables in Shell To process our data/information, data must be kept in computers RAM memory. RAM memory is divided into small locations, and each location had unique number called memory location/address, which is used to hold our data. Programmer can give a unique name to this memory location/address called memory variable or variable (Its a named storage location that may take different values, but only one at a time).
IBM Education Assistance for Z/OS V2R1

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Bidirectional Programming Languages

University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations Winter 2009 Bidirectional Programming Languages John Nathan Foster University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Databases and Information Systems Commons, and the Programming Languages and Compilers Commons Recommended Citation Foster, John Nathan, "Bidirectional Programming Languages" (2009). Publicly Accessible Penn Dissertations. 56. https://repository.upenn.edu/edissertations/56 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/56 For more information, please contact [email protected]. Bidirectional Programming Languages Abstract The need to edit source data through a view arises in a host of applications across many different areas of computing. Unfortunately, few existing systems provide support for updatable views. In practice, when they are needed, updatable views are usually implemented using two separate programs: one that computes the view from the source and another that handles updates. This rudimentary design is tedious for programmers, difficult to reason about, and a nightmare to maintain. This dissertation presents bidirectional programming languages, which provide an elegant and effective mechanism for describing updatable views. Unlike programs written in an ordinary language, which only work in one direction, programs in a bidirectional language can be run both forwards and backwards: from left to right, they describe functions that map sources to views, and from right to left, they describe functions that map updated views back to updated sources. Besides eliminating redundancy, these languages can be designed to ensure correctness, guaranteeing by construction that the two functions work well together. Starting from the foundations, we define a general semantic space of well-behaved bidirectional transformations called lenses.
Reference Manual for the Icon Programming Language Version 5 (( Implementation for Limx)*

Reference Manual for the Icon Programming Language Version 5 (( Implementation for liMX)* Can A. Contain. Ralph £ Grixwoltl, and Stephen B. Watnplcr "RSI-4a December 1981, Corrected July 1982 Department of Computer Science The University of Arizona Tucson, Arizona 85721 This work was supported by the National Science Foundation under Grant MCS79-03890. Copyright © 1981 by Ralph E. Griswold All rights reserved. No part of this work may be reproduced, transmitted, or stored in any form or by any means without the prior written consent of the copyright owner. CONTENTS Chapter i Introduction 1.1 Background I 1.2 Scope ol the Manual 2 1.3 An Overview of Icon 2 1.4 Syntax Notation 2 1.5 Organization ol the Manual 3 Chapter 2 Basic Concepts and Operations 2.1 Types 4 2.2 Expressions 4 2.2.1 Variables and Assignment 4 2.2.2 Keywords 5 2.2.3 Functions 5 2.2.4 Operators 6 2.3 Evaluation of Expressions 6 2.3.1 Results 6 2.3.2 Success and Failure 7 2.4 Basic Control Structures 7 2.5 Compound Expressions 9 2.6 Loop Control 9 2.7 Procedures 9 Chapter 3 Generators and Expression Evaluation 3.1 Generators 11 3.2 Goal-Directed Evaluation 12 }.?> Evaluation of Expres.sions 13 3.4 I he Extent ol Backtracking 14 3.5 I he Reversal ol Effects 14 Chapter 4 Numbers and Arithmetic Operations 4.1 Integers 15 4.1.1 literal Integers 15 4.1.2 Integer Arithmetic 15 4.1.3 Integer Comparison 16 4.2 Real Numbers 17 4.2.1 literal Real Numbers 17 4.2.2 Real Arithmetic 17 4.2.3 Comparison of Real Numbers IS 4.3 Mixed-Mode Arithmetic IX 4.4 Arithmetic Type Conversion 19
Software II: Principles of Programming Languages

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CS 314 Principles of Programming Languages Lecture 5: Syntax Analysis (Parsing)

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Standard TECO (Text Editor and Corrector)

Standard TECO TextEditor and Corrector for the VAX, PDP-11, PDP-10, and PDP-8 May 1990 This manual was updated for the online version only in May 1990. User’s Guide and Language Reference Manual TECO-32 Version 40 TECO-11 Version 40 TECO-10 Version 3 TECO-8 Version 7 This manual describes the TECO Text Editor and COrrector. It includes a description for the novice user and an in-depth discussion of all available commands for more advanced users. General permission to copy or modify, but not for profit, is hereby granted, provided that the copyright notice is included and reference made to the fact that reproduction privileges were granted by the TECO SIG. © Digital Equipment Corporation 1979, 1985, 1990 TECO SIG. All Rights Reserved. This document was prepared using DECdocument, Version 3.3-1b. Contents Preface ............................................................ xvii Introduction ........................................................ xix Preface to the May 1985 edition ...................................... xxiii Preface to the May 1990 edition ...................................... xxv 1 Basics of TECO 1.1 Using TECO ................................................ 1–1 1.2 Data Structure Fundamentals . ................................ 1–2 1.3 File Selection Commands ...................................... 1–3 1.3.1 Simplified File Selection .................................... 1–3 1.3.2 Input File Specification (ER command) . ....................... 1–4 1.3.3 Output File Specification (EW command) ...................... 1–4 1.3.4 Closing Files (EX command) ................................ 1–5 1.4 Input and Output Commands . ................................ 1–5 1.5 Pointer Positioning Commands . ................................ 1–5 1.6 Type-Out Commands . ........................................ 1–6 1.6.1 Immediate Inspection Commands [not in TECO-10] .............. 1–7 1.7 Text Modification Commands . ................................ 1–7 1.8 Search Commands .
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.
Sentential Form

Some definitions Recall For a grammar G, with start symbol S, any string α such that S ⇒∗ α is called a sentential form α ∗ α • If ∈ Vt , then is called a sentence in L(G) • Otherwise it is just a sentential form (not a sentence in L(G)) A left-sentential form is a sentential form that occurs in the leftmost derivation of some sentence. A right-sentential form is a sentential form that occurs in the rightmost derivation of some sentence. 1 Bottom-up parsing Goal: Given an input string w and a grammar G, construct a parse tree by starting at the leaves and working to the root. The parser repeatedly matches a right-sentential form from the language against the tree’s upper frontier. At each match, it applies a reduction to build on the frontier: • each reduction matches an upper frontier of the partially built tree to the RHS of some production • each reduction adds a node on top of the frontier The final result is a rightmost derivation, in reverse. 2 Example Consider the grammar 1 S → aABe 2 A → Abc 3 | b 4 B → d and the input string abbcde Prod’n. Sentential Form 3 a b bcde 2 a Abc de 4 aA d e 1 aABe – S The trick appears to be scanning the input and finding valid sentential forms. 3 Handles What are we trying to find? A substring α of the tree’s upper frontier that matches some production A → α where reducing α to A is one step in the reverse of a rightmost derivation We call such a string a handle.