The AWK Manual Edition 1.0 December 1995
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At—At, Batch—Execute Commands at a Later Time
at—at, batch—execute commands at a later time at [–csm] [–f script] [–qqueue] time [date] [+ increment] at –l [ job...] at –r job... batch at and batch read commands from standard input to be executed at a later time. at allows you to specify when the commands should be executed, while jobs queued with batch will execute when system load level permits. Executes commands read from stdin or a file at some later time. Unless redirected, the output is mailed to the user. Example A.1 1 at 6:30am Dec 12 < program 2 at noon tomorrow < program 3 at 1945 pm August 9 < program 4 at now + 3 hours < program 5 at 8:30am Jan 4 < program 6 at -r 83883555320.a EXPLANATION 1. At 6:30 in the morning on December 12th, start the job. 2. At noon tomorrow start the job. 3. At 7:45 in the evening on August 9th, start the job. 4. In three hours start the job. 5. At 8:30 in the morning of January 4th, start the job. 6. Removes previously scheduled job 83883555320.a. awk—pattern scanning and processing language awk [ –fprogram–file ] [ –Fc ] [ prog ] [ parameters ] [ filename...] awk scans each input filename for lines that match any of a set of patterns specified in prog. Example A.2 1 awk '{print $1, $2}' file 2 awk '/John/{print $3, $4}' file 3 awk -F: '{print $3}' /etc/passwd 4 date | awk '{print $6}' EXPLANATION 1. Prints the first two fields of file where fields are separated by whitespace. 2. Prints fields 3 and 4 if the pattern John is found. -
System Calls and I/O
System Calls and I/O CS 241 January 27, 2012 Copyright ©: University of Illinois CS 241 Staff 1 This lecture Goals Get you familiar with necessary basic system & I/O calls to do programming Things covered in this lecture Basic file system calls I/O calls Signals Note: we will come back later to discuss the above things at the concept level Copyright ©: University of Illinois CS 241 Staff 2 System Calls versus Function Calls? Copyright ©: University of Illinois CS 241 Staff 3 System Calls versus Function Calls Function Call Process fnCall() Caller and callee are in the same Process - Same user - Same “domain of trust” Copyright ©: University of Illinois CS 241 Staff 4 System Calls versus Function Calls Function Call System Call Process Process fnCall() sysCall() OS Caller and callee are in the same Process - Same user - OS is trusted; user is not. - Same “domain of trust” - OS has super-privileges; user does not - Must take measures to prevent abuse Copyright ©: University of Illinois CS 241 Staff 5 System Calls System Calls A request to the operating system to perform some activity System calls are expensive The system needs to perform many things before executing a system call The computer (hardware) saves its state The OS code takes control of the CPU, privileges are updated. The OS examines the call parameters The OS performs the requested function The OS saves its state (and call results) The OS returns control of the CPU to the caller Copyright ©: University of Illinois CS 241 Staff 6 Steps for Making a System Call -
Modern Programming Languages CS508 Virtual University of Pakistan
Modern Programming Languages (CS508) VU Modern Programming Languages CS508 Virtual University of Pakistan Leaders in Education Technology 1 © Copyright Virtual University of Pakistan Modern Programming Languages (CS508) VU TABLE of CONTENTS Course Objectives...........................................................................................................................4 Introduction and Historical Background (Lecture 1-8)..............................................................5 Language Evaluation Criterion.....................................................................................................6 Language Evaluation Criterion...................................................................................................15 An Introduction to SNOBOL (Lecture 9-12).............................................................................32 Ada Programming Language: An Introduction (Lecture 13-17).............................................45 LISP Programming Language: An Introduction (Lecture 18-21)...........................................63 PROLOG - Programming in Logic (Lecture 22-26) .................................................................77 Java Programming Language (Lecture 27-30)..........................................................................92 C# Programming Language (Lecture 31-34) ...........................................................................111 PHP – Personal Home Page PHP: Hypertext Preprocessor (Lecture 35-37)........................129 Modern Programming Languages-JavaScript -
Reasoning About Programs Need: Definition of Works/Correct: a Specification (And Bugs) but Programs Fail All the Time
Good programs, broken programs? Goal: program works (does not fail) Reasoning about Programs Need: definition of works/correct: a specification (and bugs) But programs fail all the time. Why? A brief interlude on 1. Misuse of your code: caller did not meet assumptions specifications, assertions, and debugging 2. Errors in your code: mistake causes wrong computation 3. Unpredictable external problems: • Out of memory, missing file, network down, … • Plan for these problems, fail gracefully. 4. Wrong or ambiguous specification, implemented correctly Largely based on material from University of Washington CSE 331 A Bug's Life, ca. 1947 A Bug's Life Defect: a mistake in the code Think 10 per 1000 lines of industry code. We're human. -- Grace Hopper Error: incorrect computation Because of defect, but not guaranteed to be visible Failure: observable error -- program violates its specification Crash, wrong output, unresponsive, corrupt data, etc. Time / code distance between stages varies: • tiny (<second to minutes / one line of code) • or enormous (years to decades to never / millons of lines of code) "How to build correct code" Testing 1. Design and Verify Make correctness more likely or provable from the start. • Can show that a program has an error. 2. Program Defensively • Can show a point where an error causes a failure. Plan for defects and errors. • Cannot show the error that caused the failure. • make testing more likely to reveal errors as failures • Cannot show the defect that caused the error. • make debugging failures easier 3. Test and Validate Try to cause failures. • Can improve confidence that the sorts of errors/failures • provide evidence of defects/errors targeted by the tests are less likely in programs similar • or increase confidence of their absence to the tests. -
101 Useful Linux Commands - Haydenjames.Io
101 Useful Linux Commands - haydenjames.io Some of these commands require elevated permissions (sudo) to run. Enjoy! 1. Execute the previous command used: !! 2. Execute a previous command starting with a specific letter. Example: !s 3. Short way to copy or backup a file before you edit it. For example, copy nginx.conf cp nginx.conf{,.bak} 4. Toggle between current directory and last directory cd - 5. Move to parent (higher level) directory. Note the space! cd .. 6. Go to home directory cd ~ 7. Go to home directory cd $HOME 8. Go to home directory (when used alone) cd 9. Set permissions to 755. Corresponds to these permissions: (-rwx-r-x-r-x), arranged in this sequence: (owner-group-other) chmod 755 <filename> 10. Add execute permission to all users. chmod a+x <filename> 11. Changes ownership of a file or directory to . chown <username> 12. Make a backup copy of a file (named file.backup) cp <file> <file>.backup 13. Copy file1, use it to create file2 cp <file1> <file2> 14. Copy directory1 and all its contents (recursively) into directory2 cp -r <directory1> <directory2>/ 15. Display date date 16. Zero the sdb drive. You may want to use GParted to format the drive afterward. You need elevated permissions to run this (sudo). dd if=/dev/zero of=/dev/sdb 17. Display disk space usage df -h 18. Take detailed messages from OS and input to text file dmesg>dmesg.txt 19. Display a LOT of system information. I usually pipe output to less. You need elevated permissions to run this (sudo). -
“Linux at the Command Line” Don Johnson of BU IS&T We’Ll Start with a Sign in Sheet
“Linux at the Command Line” Don Johnson of BU IS&T We’ll start with a sign in sheet. We’ll end with a class evaluation. We’ll cover as much as we can in the time allowed; if we don’t cover everything, you’ll pick it up as you continue working with Linux. This is a hands-on, lab class; ask questions at any time. Commands for you to type are in BOLD The Most Common O/S Used By BU Researchers When Working on a Server or Computer Cluster Linux is a Unix clone begun in 1991 and written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers across the Net. 64% of the world’s servers run some variant of Unix or Linux. The Android phone and the Kindle run Linux. a set of small Linux is an O/S core programs written by written by Linus Richard Stallman and Torvalds and others others. They are the AND GNU utilities. http://www.gnu.org/ Network: ssh, scp Shells: BASH, TCSH, clear, history, chsh, echo, set, setenv, xargs System Information: w, whoami, man, info, which, free, echo, date, cal, df, free Command Information: man, info Symbols: |, >, >>, <, ;, ~, ., .. Filters: grep, egrep, more, less, head, tail Hotkeys: <ctrl><c>, <ctrl><d> File System: ls, mkdir, cd, pwd, mv, touch, file, find, diff, cmp, du, chmod, find File Editors: gedit, nedit You need a “xterm” emulation – software that emulates an “X” terminal and that connects using the “SSH” Secure Shell protocol. ◦ Windows Use StarNet “X-Win32:” http://www.bu.edu/tech/support/desktop/ distribution/xwindows/xwin32/ ◦ Mac OS X “Terminal” is already installed Why? Darwin, the system on which Apple's Mac OS X is built, is a derivative of 4.4BSD-Lite2 and FreeBSD. -
Bash Crash Course + Bc + Sed + Awk∗
Bash Crash course + bc + sed + awk∗ Andrey Lukyanenko, CSE, Aalto University Fall, 2011 There are many Unix shell programs: bash, sh, csh, tcsh, ksh, etc. The comparison of those can be found on-line 1. We will primary focus on the capabilities of bash v.4 shell2. 1. Each bash script can be considered as a text file which starts with #!/bin/bash. It informs the editor or interpretor which tries to open the file, what to do with the file and how should it be treated. The special character set in the beginning #! is a magic number; check man magic and /usr/share/file/magic on existing magic numbers if interested. 2. Each script (assume you created “scriptname.sh file) can be invoked by command <dir>/scriptname.sh in console, where <dir> is absolute or relative path to the script directory, e.g., ./scriptname.sh for current directory. If it has #! as the first line it will be invoked by this command, otherwise it can be called by command bash <dir>/scriptname.sh. Notice: to call script as ./scriptname.sh it has to be executable, i.e., call command chmod 555 scriptname.sh before- hand. 3. Variable in bash can be treated as integers or strings, depending on their value. There are set of operations and rules available for them. For example: #!/bin/bash var1=123 # Assigns value 123 to var1 echo var1 # Prints ’var1’ to output echo $var1 # Prints ’123’ to output var2 =321 # Error (var2: command not found) var2= 321 # Error (321: command not found) var2=321 # Correct var3=$var2 # Assigns value 321 from var2 to var3 echo $var3 # Prints ’321’ to output -
Exercise I: Basic Unix for Manipulating NGS Data
Exercise I: Basic Unix for manipulating NGS data C. Hahn, July 2014 The purpose of this exercise is to practice manipulating NGS (Next Generation Sequencing) data using simple but incredibly powerful Unix commands. Try to solve the below tasks using your Unix skills. Do not hesitate to consult Google for help!! Hints for every task can be found on page 3 below. Possible solutions are suggested on page 4. 1. Download the testdata from https://www.dropbox.com/s/wcanmej6z03yfmt/testdata_1.tar?dl=0. Create a directory (exercise_1) in your home directory and copy the archive testdata.tar from ~/Downloads/ to this directory. 2. Decompress the archive. 3. Examine the content of the data files. For basic information on fastq format please visit: http://en.wikipedia.org/wiki/FASTQ_format. With this information try to interpret the content of your data files. Do you Know what all the lines represent? a) Which quality encoding (which offset) do these files use? b) What is the header of the third read in the file? Is this a single-end (forward) or a paired-end (reverse) read? c) What is the header of the last read in the file? Is this a forward or reverse read? 4. How many lines does the file have? 5. How many reads does the file contain? 6. How many single-end (“se” also referred to as forward reads) reads and how many paired-end (“pe” also reverse reads) reads does the file contain? 7. Extract all se/pe reads and write them to separate files testdata_1.fastq and testdata_2.fastq. -
Project1: Build a Small Scanner/Parser
Project1: Build A Small Scanner/Parser Introducing Lex, Yacc, and POET cs5363 1 Project1: Building A Scanner/Parser Parse a subset of the C language Support two types of atomic values: int float Support one type of compound values: arrays Support a basic set of language concepts Variable declarations (int, float, and array variables) Expressions (arithmetic and boolean operations) Statements (assignments, conditionals, and loops) You can choose a different but equivalent language Need to make your own test cases Options of implementation (links available at class web site) Manual in C/C++/Java (or whatever other lang.) Lex and Yacc (together with C/C++) POET: a scripting compiler writing language Or any other approach you choose --- must document how to download/use any tools involved cs5363 2 This is just starting… There will be two other sub-projects Type checking Check the types of expressions in the input program Optimization/analysis/translation Do something with the input code, output the result The starting project is important because it determines which language you can use for the other projects Lex+Yacc ===> can work only with C/C++ POET ==> work with POET Manual ==> stick to whatever language you pick This class: introduce Lex/Yacc/POET to you cs5363 3 Using Lex to build scanners lex.yy.c MyLex.l lex/flex lex.yy.c a.out gcc/cc Input stream a.out tokens Write a lex specification Save it in a file (MyLex.l) Compile the lex specification file by invoking lex/flex lex MyLex.l A lex.yy.c file is generated -
GNU M4, Version 1.4.7 a Powerful Macro Processor Edition 1.4.7, 23 September 2006
GNU M4, version 1.4.7 A powerful macro processor Edition 1.4.7, 23 September 2006 by Ren´eSeindal This manual is for GNU M4 (version 1.4.7, 23 September 2006), a package containing an implementation of the m4 macro language. Copyright c 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License.” i Table of Contents 1 Introduction and preliminaries ................ 3 1.1 Introduction to m4 ............................................. 3 1.2 Historical references ............................................ 3 1.3 Invoking m4 .................................................... 4 1.4 Problems and bugs ............................................. 8 1.5 Using this manual .............................................. 8 2 Lexical and syntactic conventions ............ 11 2.1 Macro names ................................................. 11 2.2 Quoting input to m4........................................... 11 2.3 Comments in m4 input ........................................ 11 2.4 Other kinds of input tokens ................................... 12 2.5 How m4 copies input to output ................................ 12 3 How to invoke macros........................ -
A Highly Configurable High-Level Synthesis Functional Pattern Library
electronics Article A Highly Configurable High-Level Synthesis Functional Pattern Library Lan Huang 1,2,‡, Teng Gao 1,‡, Dalin Li 1,†, Zihao Wang 1 and Kangping Wang 1,2,* 1 College of Computer Science and Technology, Jilin University, Changchun 130012, China; [email protected] (L.H.); [email protected] (T.G.); [email protected] (D.L.); [email protected] (Z.W.) 2 Key Laboratory of Symbolic Computation and Knowledge Engineering, Jilin University, Changchun 130012, China * Correspondence: [email protected] † Current address: Zhuhai Laboratory of Key Laboratory of Symbol Computation and Knowledge Engineering of Ministry of Education, Department of Computer Science and Technology, Zhuhai College of Jilin University, Zhuhai 519041, China. ‡ These authors contributed equally to this work. Abstract: FPGA has recently played an increasingly important role in heterogeneous computing, but Register Transfer Level design flows are not only inefficient in design, but also require designers to be familiar with the circuit architecture. High-level synthesis (HLS) allows developers to design FPGA circuits more efficiently with a more familiar programming language, a higher level of abstraction, and automatic adaptation of timing constraints. When using HLS tools, such as Xilinx Vivado HLS, specific design patterns and techniques are required in order to create high-performance circuits. Moreover, designing efficient concurrency and data flow structures requires a deep understanding of the hardware, imposing more learning costs on programmers. In this paper, we propose a set of functional patterns libraries based on the MapReduce model, implemented by C++ templates, Citation: Huang, L.; Gao,T.; Li, D.; which can quickly implement high-performance parallel pipelined computing models on FPGA with Wang, Z.; Wang, K. -
GNU M4, Version 1.4.19 a Powerful Macro Processor Edition 1.4.19, 28 May 2021
GNU M4, version 1.4.19 A powerful macro processor Edition 1.4.19, 28 May 2021 by Ren´eSeindal, Fran¸coisPinard, Gary V. Vaughan, and Eric Blake ([email protected]) This manual (28 May 2021) is for GNU M4 (version 1.4.19), a package containing an implementation of the m4 macro language. Copyright c 1989{1994, 2004{2014, 2016{2017, 2020{2021 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled \GNU Free Documentation License." i Table of Contents 1 Introduction and preliminaries ::::::::::::::::: 3 1.1 Introduction to m4 :::::::::::::::::::::::::::::::::::::::::::::: 3 1.2 Historical references :::::::::::::::::::::::::::::::::::::::::::: 3 1.3 Problems and bugs ::::::::::::::::::::::::::::::::::::::::::::: 4 1.4 Using this manual :::::::::::::::::::::::::::::::::::::::::::::: 5 2 Invoking m4::::::::::::::::::::::::::::::::::::::: 7 2.1 Command line options for operation modes ::::::::::::::::::::: 7 2.2 Command line options for preprocessor features ::::::::::::::::: 8 2.3 Command line options for limits control ::::::::::::::::::::::: 10 2.4 Command line options for frozen state ::::::::::::::::::::::::: 11 2.5 Command line options for debugging :::::::::::::::::::::::::: 11 2.6 Specifying input files on the command line :::::::::::::::::::::