All around cobol
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This document provides an overview of COBOL (Common Business Oriented Language), discussing its continued relevance and use. It notes that while COBOL is over 50 years old, it still runs 70-75% of global business systems and processes over 30 billion transactions daily. Additionally, 5 billion new lines of COBOL code are added yearly, demonstrating its enduring role in powering core banking, financial, and other transactional systems. The document also outlines the basic structure and components of a COBOL program, including its identification, environment, data, and procedure divisions as well as common statements like DISPLAY, ACCEPT, MOVE, and PERFORM.
All around cobol
- 1. All Around COBOL By V. Kishore Kumar M.C.A. Mainframe Developer Cognizant, Chennai.
- 2. Is there Still market for COBOL skills/developers? • COBOL is dead right? • All the IT developer jobs now are in modern languages like C++, .Net & Java right?
- 3. Survey Report @ 2009 • 70-75% of the business and transaction systems around the world run on COBOL. This includes credit card systems, ATMs, ticket purchasing, retail/POS systems, banking, payroll systems, telephone/cell calls, grocery stores, hospital systems, government systems, airline systems, insurance systems, automotive systems, traffic signal systems.
- 4. Survey Report @ 2009 • 90% of global financial transactions are processed in COBOL. • The language supports over 30 billion transactions per day. • There are 1.5-2 million developers, globally, working with COBOL code. • There are around 200 billion lines of COBOL code in use.
- 5. Survey Report @ 2009 • Around 5 billion lines of new COBOL code are added to live systems every year. • The investment made into COBOL systems over the past 50 years is said to be worth about $2 trillion dollars.
- 6. COBOL • COmmon Business Oriented Language – 1959. • High Level Structured Language. • Can be used with database like VSAM, DB2 or IDMS. • Can handle huge volumes of data. • COBOL applications can be easily maintained.
- 8. Program Structure • Division is a block of code, usually containing one or more sections. – It starts where the division name is encountered. – It ends with the beginning of the next division. • A COBOL program has 4 divisions. Identification Division Environment Division Data Division Procedure Division
- 9. The COBOL Divisions • Identification Division : – Names the program. – Optionally, documents the date the program was written. – The compilation date and – Other pertinent information.
- 11. • Environment Division : – Machine Dependent details such as computer used and peripheral devices. – Consists of 2 sections • The Configuration Section • The Input-Output Section Environment Division
- 12. • Input-Output Section: – Primarily used to code the FILE-CONTROL paragraph. – Associate the files to be used in program with specific I/O devices. Environment Division
- 13. • All the data used by the program is defined. • It is divided into 5 sections – File Section – Working-storage Section – Linkage Section – Report Section and – Communication Section Data Division
- 14. • File Section : – Defines all the files that will be used in the program. – There will be one File Descriptor(FD) for each file followed by a record description for each record format. Data Division
- 15. • Working-Storage Section: – Used to define any data that will be used in program but not a part of file. • Linkage Section: – Used in a subprogram that will be passed as arguments to the routine. Data Division
- 16. • Consists of a series of procedures called paragraphs, each designed to perform a specific function. • All statements are terminated by a period(.). Procedure Division
- 17. Sample COBOL Program Layout
- 20. Picture Clause • Used to specify the type and size of an elementary data item.
- 21. Data Items – Level Numbers • Levels 01-49 are used to create hierarchical data items. • The highest level item in the hierarchy will always be the 01 item. • Items which contains other items are called Group Items. • Items which don’t contain other data items are called Elementary Items.
- 22. Data Items – Level Numbers
- 23. COBOL Statements • Display • Accept • Exit, STOP • MOVE • PERFORM • Arithmetic Statements
- 24. DISPLAY Statement • Exhibit data upon the primary output device.
- 25. ACCEPT Statement • Acquire data from the primary input device or various system fields.
- 26. EXIT & STOP Statement • Used to exit routines or programs. • EXIT Program must be used only in a called Sub-Program. • Used to STOP programs. • STOP RUN Terminates the program.
- 27. MOVE Statement • Used to copy data items to other data items.
- 28. PERFORM Statement • Used to execute the code.
- 29. PERFORM Statement • Code can be executed in another area of the program and is invoked by mentioning a procedure or paragraph name. • Inline Perform, code is executed inside the perform statement.
- 30. Arithmetic Statements • ADD • SUBTRACT • MULTIPLY • DIVIDE • COMPUTE
- 31. ADD SUBTRACT
- 32. MULTIPLY
- 33. DIVIDE
- 34. DIVIDE
- 35. COMPUTE