Programming_418h0CWBG2BL.jpg' alt='Practice Of Programming Kernighan Pdf File' title='Practice Of Programming Kernighan Pdf File' />Computer programming Wikipedia.Computer programming often shortened to programming is a process that leads from an original formulation of a computing problem to executablecomputer programs.Programming involves activities such as analysis, developing understanding, generating algorithms, verification of requirements of algorithms including their correctness and resources consumption, and implementation commonly referred to as coding12 of algorithms in a target programming language.Source code is written in one or more programming languages.The purpose of programming is to find a sequence of instructions that will automate performing a specific task or solving a given problem.The process of programming thus often requires expertise in many different subjects, including knowledge of the application domain, specialized algorithms, and formal logic.Related tasks include testing, debugging, and maintaining the source code, implementation of the build system, and management of derived artifacts such as machine code of computer programs.These might be considered part of the programming process, but often the term software development is used for this larger process with the term programming, implementation, or coding reserved for the actual writing of source code.Software engineering combines engineering techniques with software development practices.HistoryeditProgrammable devices have existed at least as far back as 1.AD, when the automata of Al Jazari were programmable, via pegs and cams, to play various rhythms and drum patterns 3 and the 1.This document is both a tutorial and a reference on shell scripting with Bash.It assumes no previous knowledge of scripting or programming, but progresses rapidly.Jacquard loom could produce entirely different weaves by changing the program a series of pasteboard cards with holes punched in them.However, the first computer program is generally dated to 1.Ada Lovelace published an algorithm to calculate a sequence of Bernoulli numbers, intended to be carried out by Charles Babbages Analytical Engine.Practice Of Programming Kernighan Pdf File' title='Practice Of Programming Kernighan Pdf File' />It is important to realise that programming languages are a recent invention.They have been developed over a relatively short period60 yearsand are still.Data and instructions were once stored on external punched cards, which were kept in order and arranged in program decks.In the 1. 88. 0s Herman Hollerith invented the concept of storing data in machine readable form.Later a control panel plugboard added to his 1.Type I Tabulator allowed it to be programmed for different jobs, and by the late 1.IBM 6. 02 and IBM 6.However, with the concept of the stored program computers introduced in 1.Machine code was the language of early programs, written in the instruction set of the particular machine, often in binary notation.Assembly languages were soon developed that let the programmer specify instruction in a text format, e.ADD X, TOTAL, with abbreviations for each operation code and meaningful names for specifying addresses.However, because an assembly language is little more than a different notation for a machine language, any two machines with different instruction sets also have different assembly languages.High level languages allow the programmer to write programs in terms that are more abstract, and less bound to the underlying hardware.They harness the power of computers to make programming easier6 by allowing programmers to specify calculations by entering a formula directly e.Y X2 5 9. FORTRAN, the first widely used high level language to have a functional implementation, came out in 1.COBOL aimed at commercial data processing, and Lisp for computer research.Programs were mostly still entered using punched cards or paper tape.See computer programming in the punch card era.By the late 1. 96.Text editors were developed that allowed changes and corrections to be made much more easily than with punched cards.Modern programmingeditQuality requirementseditWhatever the approach to development may be, the final program must satisfy some fundamental properties.The following properties are among the most important Reliability how often the results of a program are correct.This depends on conceptual correctness of algorithms, and minimization of programming mistakes, such as mistakes in resource management e.Robustness how well a program anticipates problems due to errors not bugs.This includes situations such as incorrect, inappropriate or corrupt data, unavailability of needed resources such as memory, operating system services and network connections, user error, and unexpected power outages.Usability the ergonomics of a program the ease with which a person can use the program for its intended purpose or in some cases even unanticipated purposes.Such issues can make or break its success even regardless of other issues.This involves a wide range of textual, graphical and sometimes hardware elements that improve the clarity, intuitiveness, cohesiveness and completeness of a programs user interface.Portability the range of computer hardware and operating system platforms on which the source code of a program can be compiledinterpreted and run.This depends on differences in the programming facilities provided by the different platforms, including hardware and operating system resources, expected behavior of the hardware and operating system, and availability of platform specific compilers and sometimes libraries for the language of the source code.Maintainability the ease with which a program can be modified by its present or future developers in order to make improvements or customizations, fix bugs and security holes, or adapt it to new environments.Good practices8 during initial development make the difference in this regard.This quality may not be directly apparent to the end user but it can significantly affect the fate of a program over the long term.Efficiencyperformance Measure of system resources a program consumes processor time, memory space, slow devices such as disks, network bandwidth and to some extent even user interaction the less, the better.This also includes careful management of resources, for example cleaning up temporary files and eliminating memory leaks.Readability of source codeeditIn computer programming, readability refers to the ease with which a human reader can comprehend the purpose, control flow, and operation of source code.It affects the aspects of quality above, including portability, usability and most importantly maintainability.Readability is important because programmers spend the majority of their time reading, trying to understand and modifying existing source code, rather than writing new source code.Unreadable code often leads to bugs, inefficiencies, and duplicated code.A study9 found that a few simple readability transformations made code shorter and drastically reduced the time to understand it. Baixar Jogos De Super Nintendo Para Emulador Android Bluestacks . Following a consistent programming style often helps readability.However, readability is more than just programming style.Many factors, having little or nothing to do with the ability of the computer to efficiently compile and execute the code, contribute to readability.Some of these factors include The presentation aspects of this such as indents, line breaks, color highlighting, and so on are often handled by the source code editor, but the content aspects reflect the programmers talent and skills.Various visual programming languages have also been developed with the intent to resolve readability concerns by adopting non traditional approaches to code structure and display.Integrated development environments IDEs aim to integrate all such help.Techniques like Code refactoring can enhance readability.Algorithmic complexityeditThe academic field and the engineering practice of computer programming are both largely concerned with discovering and implementing the most efficient algorithms for a given class of problem.For this purpose, algorithms are classified into orders using so called Big O notation, which expresses resource use, such as execution time or memory consumption, in terms of the size of an input.Expert programmers are familiar with a variety of well established algorithms and their respective complexities and use this knowledge to choose algorithms that are best suited to the circumstances.MethodologieseditThe first step in most formal software development processes is requirements analysis, followed by testing to determine value modeling, implementation, and failure elimination debugging.There exist a lot of differing approaches for each of those tasks.One approach popular for requirements analysis is Use Case analysis.
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