COBOL PROGRAMMING BY ROY AND DASTIDAR PDF

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It is imperative , procedural and, since , object-oriented. COBOL is primarily used in business, finance, and administrative systems for companies and governments. COBOL is still widely used in applications deployed on mainframe computers , such as large-scale batch and transaction processing jobs.

But due to its declining popularity and the retirement of experienced COBOL programmers, programs are being migrated to new platforms, rewritten in modern languages or replaced with software packages. It was created as part of a US Department of Defense effort to create a portable programming language for data processing. It was originally seen as a stopgap, but the Department of Defense promptly forced computer manufacturers to provide it, resulting in its widespread adoption.

Expansions include support for structured and object-oriented programming. COBOL statements have an English-like syntax, which was designed to be self-documenting and highly readable. However, it is verbose and uses over reserved words. COBOL code is split into four divisions identification, environment, data, and procedure containing a rigid hierarchy of sections, paragraphs and sentences.

Lacking a large standard library , the standard specifies 43 statements, 87 functions and just one class. Academic computer scientists were generally uninterested in business applications when COBOL was created and were not involved in its design; it was effectively designed from the ground up as a computer language for business, with an emphasis on inputs and outputs, whose only data types were numbers and strings of text.

These weaknesses result in monolithic and, though intended to be English-like, not easily comprehensible and verbose programs. In the late s, computer users and manufacturers were becoming concerned about the rising cost of programming. At a time when new programming languages were proliferating at an ever-increasing rate, the same survey suggested that if a common business-oriented language were used, conversion would be far cheaper and faster.

On 8 April , Mary K. Hawes , a computer scientist at Burroughs Corporation , called a meeting of representatives from academia, computer users, and manufacturers at the University of Pennsylvania to organize a formal meeting on common business languages. At the April meeting, the group asked the Department of Defense DoD to sponsor an effort to create a common business language.

The delegation impressed Charles A. Portable programs would save time, reduce costs and ease modernization. Phillips agreed to sponsor the meeting and tasked the delegation with drafting the agenda. It was attended by 41 people and was chaired by Phillips. Representatives enthusiastically described a language that could work in a wide variety of environments, from banking and insurance to utilities and inventory control. They agreed unanimously that more people should be able to program and that the new language should not be restricted by the limitations of contemporary technology.

A majority agreed that the language should make maximal use of English, be capable of change, be machine-independent and be easy to use, even at the expense of power. The meeting resulted in the creation of a steering committee and short-, intermediate- and long-range committees.

The short-range committee was given to September three months to produce specifications for an interim language, which would then be improved upon by the other committees.

The short-range committee was made up of members representing six computer manufacturers and three government agencies. Work began by investigating data description, statements, existing applications and user experiences. The usefulness of the committee's work was subject of great debate. While some members thought the language had too many compromises and was the result of design by committee , others felt it was better than the three languages examined.

Some felt the language was too complex; others, too simple. Such features included boolean expressions , formulas and table subscripts indices. The specifications were presented to the Executive Committee on 4 September. They fell short of expectations: Joseph Wegstein noted that "it contains rough spots and requires some additions", and Bob Bemer later described them as a "hodgepodge". The subcommittee was given until December to improve it. At a mid-September meeting, the committee discussed the new language's name.

Despite being technically superior, FACT had not been created with portability in mind or through manufacturer and user consensus. We shortened it and got rid of a lot of unnecessary notation.

It soon became apparent that the committee was too large for any further progress to be made quickly. The sub-committee did most of the work creating the specification, leaving the short-range committee to review and modify their work before producing the finished specification. The specifications were approved by the Executive Committee on 8 January , and sent to the government printing office, which printed these as COBOL The language's stated objectives were to allow efficient, portable programs to be easily written, to allow users to move to new systems with minimal effort and cost, and to be suitable for inexperienced programmers.

The relative influences of which languages were used continues to this day in the recommended advisory printed in all COBOL reference manuals:. COBOL is an industry language and is not the property of any company or group of companies, or of any organization or group of organizations. Moreover, no responsibility is assumed by any contributor, or by the committee, in connection therewith. The authors and copyright holders of the copyrighted material used herein are as follows:.

They have specifically authorized the use of this material, in whole or in part, in the COBOL specifications. Such authorization extends to the reproduction and use of COBOL specifications in programming manuals or similar publications. Anonymous, June [70].

A US Navy evaluation found compilation speeds of 3—11 statements per minute. By mid, they had increased to 11— statements per minute. This was then replaced by the COBOL Extended specifications in , which introduced the sort and report writer facilities. They described new versions in , , and , including changes such as new inter-program communication, debugging and file merging facilities as well as improved string-handling and library inclusion features. The Programming Language Committee was not well-known, however.

It was also poor, lacking the funds to make public documents, such as minutes of meetings and change proposals, freely available. These made up 44 changes, which rendered existing statements incompatible with the new standard.

The proposed standard commonly called COBOL differed significantly from the previous one, causing concerns about incompatibility and conversion costs. In January , Joseph T. Brophy described previous conversions of their million-line code base as "non-productive" and a "complete waste of our programmer resources". During the first public review period, the committee received 2, responses, of which 1, were negative form letters. Fewer than a dozen of the responses were in favor of the proposed standard.

In , the DPMA withdrew its opposition to the standard, citing the responsiveness of the committee to public concerns. In the same year, a National Bureau of Standards study concluded that the proposed standard would present few problems. The second public review drew another 1, mainly negative responses, while the last drew just 25, by which time many concerns had been addressed. It was published in late Sixty features were changed or deprecated and many [ quantify ] were added, such as: [92] [93].

The new standard was adopted by all national standard bodies, including ANSI. Two amendments followed in and , the first introducing intrinsic functions and the other providing corrections. Some vendors including Micro Focus , Fujitsu , and IBM introduced object-oriented syntax based on drafts of the full revision. The final approved ISO standard was approved and published in late NET Framework. Three corrigenda were published for the standard: two in and one in COBOL suffered from poor support: no compilers completely supported the standard.

Micro Focus found that it was due to a lack of user demand for the new features and due to the abolition of the NIST test suite, which had been used to test compiler conformance. The standardization process was also found to be slow and under-resourced. COBOL includes the following changes: []. Near the end of the 20th century, the year problem Y2K was the focus of significant COBOL programming effort, sometimes by the same programmers who had designed the systems decades before.

After the clean-up effort put into these programs for Y2K, a survey found that many remained in use. Instead, some businesses have migrated their systems from expensive mainframes to cheaper, more modern systems, while maintaining their COBOL programs. Many of these systems had been in the process of conversion to more modern programming languages prior to the pandemic, but the process had to be put on hold.

More complex conditions can be "abbreviated" by removing repeated conditions and variables. Words include reserved words and user-defined identifiers. They are up to 31 characters long and may include letters, digits, hyphens and underscores. Literals include numerals e. A COBOL program is split into four divisions: the identification division, the environment division, the data division and the procedure division.

The identification division specifies the name and type of the source element and is where classes and interfaces are specified. The environment division specifies any program features that depend on the system running it, such as files and character sets. The data division is used to declare variables and parameters.

The procedure division contains the program's statements. Each division is sub-divided into sections, which are made up of paragraphs. COBOL's syntax is usually described with a unique metalanguage using braces, brackets, bars and underlining. Although Backus—Naur form did exist at the time, the committee had not heard of it. COBOL can be written in two formats: fixed the default or free.

In fixed-format, code must be aligned to fit in certain areas a hold-over from using punched cards. COBOL also introduced free-format code. Free-format code can be placed in any column of the file, as in newer programming languages. The identification division identifies the following code entity and contains the definition of a class or interface. Classes have factory objects, containing class methods and variables, and instance objects, containing instance methods and variables.

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The second edition is a revised and considerably enlarged edition of a highly acclaimed text. All PC users will find this chapter extremely useful; An in-depth discussion of the revised standard COBOL in a new chapter; Chapter on 'Introduction to Computers' completely updated to include the latest trends and developments; Chapter on 'Table Handling' thoroughly revised and more explanations included; Various features of the language have been explained with suitable examples and, wherever necessary, the basic concepts of systems analysis and design have also been discussed; Structured programming has been discussed in detail; Useful guidelines with examples have been provided for improved programming; Several complete programs have been included for an application - oriented approach; Implementation differences between different COBOL Compilers are dealt with thoroughly. Convert currency. Add to Basket. Condition: GOOD. Has little wear to the cover and pages. Contains some markings such as highlighting and writing.

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