INTRODUCTION

COBOL (Common Business-Oriented Language) is a high-level programming language designed for business applications. Its development began in the late 1950s as a collaborative effort between government, industry, and academia. Here’s a brief overview of the history of COBOL:

1. Background and Development:
   • In the late 1950s, computer usage was expanding rapidly, and there was a need for a programming language that could handle business-oriented tasks efficiently.
   • A committee, called the Conference on Data Systems Languages (CODASYL), was formed in 1959 to develop a common business language that could be used across different computer systems.
   • CODASYL brought together representatives from various organizations, including government agencies, computer manufacturers, and businesses, to define the requirements for a new programming language.
   • The COBOL committee’s goal was to create a language that could be easily understood by non-technical business users and could handle complex data processing tasks.
2. Early Versions and Standardization:
   • The first version of COBOL, known as COBOL-60, was released in 1960. It provided a standard syntax and a set of common features for business data processing.
   • COBOL-61 and COBOL-65 were subsequent versions that introduced new features and improvements.
   • In 1968, the American National Standards Institute (ANSI) released a standard version of COBOL known as COBOL-68. This standardization helped in promoting the language’s widespread adoption.
3. Further Enhancements and Standards:
   • Over the years, various versions of COBOL were released, each adding new features and improvements. These included COBOL-74, COBOL-85, and COBOL 2002, among others.
   • COBOL-85, released in 1985, introduced modern programming language features, such as structured programming constructs, improved string handling, and more extensive support for file processing.
   • Subsequent versions, like COBOL 2002 and COBOL 2014, added support for object-oriented programming, XML processing, and other contemporary technologies.
4. Widespread Adoption and Legacy Systems:
   • COBOL quickly gained popularity and widespread adoption, especially in business and government sectors.
   • Many large organizations and government agencies developed extensive COBOL-based systems to handle critical business operations.
   • COBOL’s ease of use and its ability to handle large-scale data processing made it an attractive choice for organizations dealing with massive amounts of business data.
5. Current Status and Modernization:
   • Despite being several decades old, COBOL continues to be used extensively today, especially in legacy systems and mainframe environments.
   • Many organizations still rely on COBOL-based applications for their day-to-day operations, and these systems require maintenance and updates.
   • Efforts are underway to modernize COBOL applications, such as integrating them with modern technologies, refactoring code, or migrating to newer platforms while preserving existing functionality.

While newer programming languages have gained popularity for modern application development, COBOL continues to provide significant business benefits for organizations with legacy systems and long-standing COBOL applications. Its stability, compatibility, talent pool, and domain-specific features make it a viable option for businesses looking to maintain and enhance their existing COBOL infrastructure.

While COBOL may not be as popular in newer application development, its legacy and continued usage demonstrate its significance in supporting critical business systems over many years.

USES

COBOL is a programming language that has been widely used in various industries for several decades. Some common uses of COBOL include:

1. Business Applications: COBOL has been extensively used in the development of business applications, especially in the financial, banking, insurance, and retail sectors. Many critical core systems, such as transaction processing systems, accounting systems, and inventory management systems, are written in COBOL.
2. Legacy Systems: COBOL has a strong presence in legacy systems that have been developed over the years. These systems often handle large volumes of data and have complex business rules. As a result, many organizations continue to maintain and enhance their COBOL-based legacy systems.
3. Mainframe Computing: COBOL has a long history of being used in mainframe environments. Mainframes are large, powerful computers used by organizations to handle mission-critical applications and massive data processing tasks. COBOL’s efficiency and reliability make it well-suited for mainframe computing.
4. Government Systems: COBOL is commonly found in government agencies and public sector organizations. It is used in systems that manage tax processing, social security, healthcare, public utilities, and other governmental functions. These systems require high reliability and stability, which COBOL provides.
5. Large-Scale Data Processing: COBOL’s ability to handle large volumes of data efficiently makes it suitable for applications that require extensive data processing. This includes batch processing systems, data analysis, data conversion, and reporting applications.
6. Financial Institutions: The financial industry heavily relies on COBOL for handling transactions, managing accounts, and processing financial data. Many core banking systems, payment processing systems, and clearing systems are written in COBOL.
7. Integration with Modern Technologies: While COBOL is often associated with legacy systems, it can also be integrated with modern technologies. Many organizations leverage COBOL’s strengths in their service-oriented architectures (SOA), web services, and cloud computing environments to maintain and extend their existing COBOL applications.

Despite being an older language, COBOL continues to play a significant role in maintaining critical systems and handling large-scale data processing. The stability, reliability, and scalability of COBOL make it a valuable asset for organizations with long-standing applications and complex business rules.

BUSINESS BENEFITS

COBOL continues to offer several business benefits, especially for organizations that rely on legacy systems or have long-standing COBOL-based applications. Here are some of the key business benefits of COBOL:

1. Stability and Reliability: COBOL has a long-standing reputation for stability and reliability. Many critical business systems and applications have been built using COBOL, and they have been running successfully for decades. COBOL’s mature and well-established nature gives businesses confidence in the stability and reliability of their mission-critical systems.
2. Large Talent Pool: Despite being a language with a long history, COBOL still has a substantial talent pool of experienced developers who understand the language and its associated frameworks and tools. This availability of skilled professionals ensures that businesses can find resources to maintain and enhance their COBOL-based systems without significant recruitment challenges.
3. Cost-Effective Maintenance: Many organizations have significant investments in COBOL-based applications and systems. Rather than undergoing a complete rewrite or migration, maintaining and modernizing existing COBOL code can often be a cost-effective solution. By leveraging the existing COBOL infrastructure and expertise, businesses can continue to meet their operational needs without incurring the substantial costs and risks associated with a full replacement.
4. Compatibility with Legacy Systems: COBOL is commonly used in legacy systems, especially in mainframe environments. It offers compatibility with older hardware and software systems, allowing businesses to continue leveraging their existing technology infrastructure. This compatibility ensures a smooth transition and integration with other legacy systems and data sources, minimizing disruptions to business operations.
5. Business Domain Focus: COBOL was designed specifically for business data processing and offers features tailored to handle business-oriented tasks. It supports record and field-level data processing, file handling, and hierarchical data structures, making it well-suited for business applications. This business domain focus allows organizations to model and process their business data efficiently and accurately.
6. Integration Capabilities: COBOL has extensive capabilities for integrating with other systems and technologies. It supports various data interchange formats, such as XML and JSON, and can interact with relational databases, messaging systems, and web services. This integration capability enables businesses to connect their COBOL applications with modern technologies, cloud services, and distributed systems, ensuring seamless interoperability with the broader IT landscape.
7. Compliance and Regulation: COBOL’s history and maturity make it well-suited for industries with stringent compliance and regulatory requirements, such as finance, insurance, and government sectors. COBOL’s robustness, auditability, and ability to handle complex data processing make it a suitable choice for organizations operating in highly regulated environments.

DESIGN PRINCIPLES

COBOL is based on several key principles and theories that guided its design. Here are some fundamental theories behind COBOL:

1. English-like Syntax: COBOL was designed with an English-like syntax to make it more accessible and readable for non-technical business users. The goal was to create a programming language that business professionals could understand and work with, reducing the reliance on highly technical programmers for everyday business data processing tasks.
2. Self-Documenting Code: COBOL emphasized the importance of self-documenting code, meaning that the programs themselves should include clear and descriptive statements to explain their purpose and functionality. This principle aimed to improve the readability and maintainability of COBOL programs, making them easier to understand and modify.
3. Record and Field-Level Data Processing: COBOL was designed to handle business data that is typically organized in records and fields. It introduced the concept of the Data Division, which allowed programmers to define the structure and layout of data files in a way that closely matched the real-world business data they represented. This approach made it easier to process and manipulate business data using COBOL programs.
4. File Handling: COBOL placed significant emphasis on file handling capabilities, allowing programmers to read from and write to various types of files, such as sequential files, indexed files, and relative files. These file handling features were designed to facilitate efficient and reliable processing of business data stored in external files.
5. Division-Based Structure: COBOL introduced a structured approach to program organization by dividing programs into distinct divisions: Identification, Environment, Data, and Procedure. This division-based structure provided a clear separation of concerns and helped in organizing the program logic, data definitions, and environment specifications in a systematic manner.
6. Data Abstraction: COBOL supported data abstraction by allowing programmers to define complex data structures and hierarchical relationships. This feature enabled the representation of business entities, such as customers, invoices, or inventory items, with their associated attributes and relationships. By abstracting data in this way, COBOL facilitated the modeling of real-world business concepts within the programming language.
7. Portability and Standardization: COBOL aimed to be a portable language that could be used across different computer systems and platforms. The standardization efforts, starting with COBOL-68 and subsequent versions, ensured a consistent syntax and feature set that could be implemented by various vendors. This portability and standardization made it easier to develop and maintain COBOL programs in heterogeneous computing environments.

These theories and design principles guided the development of COBOL, making it a language specifically suited for business data processing tasks. By prioritizing readability, self-documentation, and data handling, COBOL aimed to bridge the gap between business requirements and technical implementation, enabling efficient and reliable business application development.

IMPLEMENTATIONS

COBOL can run on various computer operating systems. Here are some of the commonly used operating systems that support COBOL:

1. IBM z/OS: IBM z/OS is the primary operating system for IBM mainframe computers. It has robust support for COBOL and is commonly used for running COBOL applications in large enterprises.
2. IBM i: Formerly known as IBM AS/400 or iSeries, IBM i is an operating system designed for midrange IBM servers. It has native support for COBOL and is often used in businesses that run COBOL applications on IBM i hardware.
3. Unix and Linux: COBOL compilers and run-time environments are available for various Unix and Linux distributions. These include platforms like AIX, HP-UX, Solaris, and different distributions of Linux, such as Red Hat Enterprise Linux (RHEL), SUSE Linux Enterprise Server (SLES), and Ubuntu.
4. Microsoft Windows: COBOL compilers and run-time environments are available for Windows operating systems. This allows COBOL applications to be developed and executed on Windows-based platforms, including both server and desktop versions.
5. VMS/OpenVMS: VMS (Virtual Memory System) and its successor OpenVMS are operating systems developed by Digital Equipment Corporation (now part of Hewlett Packard Enterprise). They have support for COBOL and are commonly used in legacy systems.
6. MVS/TSO: MVS (Multiple Virtual Storage)/TSO (Time Sharing Option) is an operating system used on IBM mainframes. It provides COBOL support and is used in mainframe environments for running COBOL applications.

It’s worth noting that COBOL compilers and run-time environments are available on many other operating systems as well. The availability may vary depending on the specific compiler or vendor chosen. COBOL’s compatibility with various operating systems allows businesses to choose the platform that best suits their infrastructure and operational requirements.

There are open-source COBOL compilers available that you can use to compile and run COBOL programs. Here are a few notable open-source COBOL compilers:

1. GNU Cobol (GnuCOBOL): GnuCOBOL is a free and open-source COBOL compiler. It is an actively maintained project and provides modern COBOL language features and compatibility with various operating systems, including Linux, Unix, and Windows.
2. OpenCOBOL: OpenCOBOL is an open-source COBOL compiler that aims to be compatible with COBOL-85 standards. It supports various platforms, including Linux, Unix, and Windows. While OpenCOBOL is still available for use, the project has transitioned to the GnuCOBOL project.
3. TinyCOBOL: TinyCOBOL is a small, open-source COBOL compiler. It focuses on simplicity and has a minimal footprint, making it suitable for embedded systems and resource-constrained environments.

These open-source COBOL compilers provide developers with options to compile and run COBOL programs without relying on proprietary compilers. They often offer compatibility with existing COBOL codebases and can be a cost-effective choice for maintaining and modernizing COBOL applications. It’s worth noting that the availability of features and level of standards compliance may vary across different open-source COBOL compilers, so it’s important to evaluate the specific requirements of your project when choosing a compiler.

STRUCTURE

COBOL follows a specific structure that helps organize the program’s components and define its behavior. The structure of a COBOL program consists of several divisions, sections, and paragraphs. Here’s an overview of the COBOL program structure:

1. Identification Division:
   • The Identification Division is the first division of a COBOL program and contains information about the program’s name, author, and purpose.
   • It includes the PROGRAM-ID statement, which defines the program’s name that will be used to identify it.
2. Environment Division:
   • The Environment Division specifies the configuration and resources required by the program.
   • It contains sections such as CONFIGURATION SECTION, INPUT-OUTPUT SECTION, and FILE-CONTROL section.
   • The CONFIGURATION SECTION defines the environment settings for the program.
   • The INPUT-OUTPUT SECTION describes the files and devices used for input and output operations.
   • The FILE-CONTROL section provides information about the files used in the program and their access modes.
3. Data Division:
   • The Data Division is where data elements, such as variables and data structures, are defined.
   • It consists of sections such as FILE SECTION, WORKING-STORAGE SECTION, and LINKAGE SECTION.
   • The FILE SECTION defines the structure and layout of files used by the program.
   • The WORKING-STORAGE SECTION declares variables used for temporary data storage within the program.
   • The LINKAGE SECTION is used for defining data items that are shared with other programs.
4. Procedure Division:
   • The Procedure Division contains the actual program logic and the instructions for data processing.
   • It consists of multiple sections, paragraphs, and statements that define the sequence of operations.
   • The Procedure Division is where the program performs calculations, manipulates data, and controls the flow of execution.
   • It contains various control structures such as IF-ELSE, PERFORM, and EVALUATE, which determine the program’s behavior based on conditions and loops.
5. Declarative Sections:
   • Declarative Sections are optional and used for defining exception handling routines and error processing.
   • They provide a way to handle specific conditions or errors that may occur during program execution.
   • Declarative Sections are invoked using special statements like USE, IGNORE, and WHEN.

The structure of a COBOL program promotes modular programming and readability. Divisions, sections, and paragraphs help in organizing the code and separating different concerns. This structure allows for clear separation of data definitions, program logic, and environmental settings, making it easier to understand, maintain, and enhance COBOL programs over time.

SYNTAX

COBOL has a unique syntax that is designed to resemble the English language. It uses a combination of reserved words, special characters, and punctuation to define the structure and behavior of the program. Here are some key elements of COBOL syntax:

1. Statements and Periods:
   • COBOL programs are divided into statements, which are terminated by a period (.) at the end of each line.
   • Statements can be continued onto multiple lines using a hyphen (-) at the end of the line, indicating a continuation of the statement.
2. Divisions and Sections:
   • COBOL programs are organized into divisions and sections.
   • Divisions are major sections of the program, such as Identification, Environment, Data, and Procedure divisions, which are introduced by special reserved words.
   • Sections are subdivisions within a division, and they help in organizing related parts of the program. Sections are defined using reserved words such as CONFIGURATION SECTION, DATA DIVISION, and PROCEDURE DIVISION.
3. Level Numbers and Data Items:
   • COBOL uses level numbers to define data items and their hierarchical structure.
   • Level numbers indicate the level of a data item in the hierarchy, with higher level numbers representing more significant data structures.
   • Level numbers 01-49 define data items with a record or group structure, while level numbers 77 and higher define elementary data items or individual fields.
   • Data items are declared using the level number followed by a name and optional data type and length.
4. Reserved Words:
   • COBOL has a set of reserved words that have specific meanings and functions in the language. These words cannot be used as user-defined identifiers.
   • Reserved words include statements like IF, ELSE, PERFORM, MOVE, DISPLAY, and many others that control program flow, data manipulation, and I/O operations.
5. Data Manipulation and Arithmetic Operations:
   • COBOL provides various statements and operators for data manipulation and arithmetic operations.
   • MOVE statement is used to assign values to variables or move data between variables.
   • Arithmetic operations can be performed using operators like + (addition), – (subtraction), * (multiplication), / (division), and others.
6. Conditionals and Loops:
   • COBOL supports conditionals and loops to control program flow and repetition.
   • IF-ELSE statement is used for conditional branching based on a condition.
   • PERFORM statement is used for loop structures. It can repeat a set of statements based on conditions like UNTIL or WITH TEST BEFORE/AFTER.
7. Commenting:
   • COBOL allows programmers to include comments within the code for documentation and readability.
   • Comment lines start with an asterisk (*) or a slash (/) in the indicator area of the line.

These are some of the key syntax elements in COBOL. The English-like structure of COBOL makes it relatively easy to read and understand, especially for non-technical users. However, adherence to syntax rules and proper formatting is crucial for writing correct and maintainable COBOL programs.

DATA TYPES

In COBOL (Common Business-Oriented Language), data types define the characteristics and format of data items. COBOL provides various data types to represent different kinds of data, such as numbers, characters, and dates. Here are some commonly used data types in COBOL:

1. Alphanumeric (PIC X):
   • The alphanumeric data type represents alphanumeric characters, including letters, digits, and special characters.
   • The PIC X clause is used to define alphanumeric data items.
   • Example: PIC X(10) defines a field that can hold up to 10 alphanumeric characters.
2. Numeric (PIC 9):
   • The numeric data type represents numeric values, including integers and decimal numbers.
   • The PIC 9 clause is used to define numeric data items.
   • Example: PIC 9(5) defines a field that can hold a 5-digit integer.
3. Packed-Decimal (PIC S9):
   • Packed-decimal data type represents signed numeric values with a fixed number of decimal places.
   • The PIC S9 clause is used to define packed-decimal data items.
   • Example: PIC S9(7)V99 defines a field with a 7-digit integer part and a 2-digit decimal part.
4. Binary (PIC 9 COMP):
   • The binary data type represents binary integers, typically used for efficient numeric calculations.
   • The PIC 9 COMP clause is used to define binary data items.
   • Example: PIC 9(4) COMP defines a 4-byte binary integer.
5. Date and Time (PIC A9 or PIC 9):
   • COBOL provides various data types to represent dates and times, including alphanumeric (PIC A9) and numeric (PIC 9) formats.
   • Date and time formats can vary depending on the organization’s requirements and system configurations.
6. Group Data Types:
   • COBOL allows combining multiple data items into a group data type.
   • Group data types are defined using the level numbers and can have nested structures.
   • They provide a way to organize related data items within a record or structure.
7. Usage Clauses:
   • COBOL provides usage clauses to define how data items are stored and interpreted by the program.
   • Common usage clauses include DISPLAY, BINARY, COMP-3 (for packed-decimal), and COMP (for binary).

These are some of the basic data types in COBOL. COBOL also provides additional data types, such as arrays, tables, and pointers, which offer more advanced data manipulation capabilities. When defining data items in COBOL, it’s important to consider the size, precision, and format requirements of the data to ensure accurate and efficient processing.

INPUT / OUTPIT

In COBOL, you can enter inputs from the user using the INPUT-OUTPUT SECTION and the ACCEPT statement. Here’s an example of how to accept inputs in COBOL:

IDENTIFICATION DIVISION.
PROGRAM-ID. INPUT-EXAMPLE.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 NAME PIC X(20).
01 AGE PIC 99.
01 AMOUNT PIC 9(6)V99.

PROCEDURE DIVISION.
MAIN-LOGIC.
DISPLAY "Enter your name: ".
ACCEPT NAME.
DISPLAY "Enter your age: ".
ACCEPT AGE.

DISPLAY "Enter the amount: ".
ACCEPT AMOUNT.

DISPLAY "Name: " NAME.
DISPLAY "Age: " AGE.
DISPLAY "Amount: " AMOUNT.

STOP RUN.

`

In this example, the program prompts the user to enter their name, age, and an amount. The ACCEPT statement is used to read the user input and store it in the corresponding variables (NAME, AGE, and AMOUNT). The entered values are then displayed using the DISPLAY statement.

Note that the PIC (Picture) clauses define the data types and formats of the variables. In this example, NAME is defined as a string of up to 20 characters, AGE is defined as a 2-digit numeric field, and AMOUNT is defined as a 6-digit numeric field with two decimal places.

When you run this COBOL program, it will display prompts for input, and you can enter the values as requested. After all inputs are accepted, the program will display the entered values on the screen.

FILE HANDLING

File handling in COBOL involves reading data from files, writing data to files, and performing operations on files. COBOL provides several statements and constructs to facilitate file handling operations. Here’s an overview of file handling in COBOL:

1. File Definition:
   • Before performing file operations, you need to define the files in the FILE SECTION of the Data Division.
   • Each file is associated with a file organization (sequential, indexed, or relative) and an access mode (input, output, or input/output).
   • File definitions include attributes like record length, key fields (for indexed files), and file organization-specific details.
2. File Opening and Closing:
   • To access a file, you need to open it using the OPEN statement. The OPEN statement specifies the file name, access mode, and file status.
   • After performing the required operations on the file, you need to close it using the CLOSE statement. Closing the file releases system resources and ensures data integrity.
3. Reading from Files:
   • The READ statement is used to read records from a file sequentially or based on a specific key (for indexed files).
   • When a record is read, its data is moved to the specified variables, and the file position is advanced to the next record.
   • COBOL provides different options for handling the end-of-file condition and error conditions during file reading.
4. Writing to Files:
   • The WRITE statement is used to write records to a file.
   • Data from specified variables is moved to the file record, and the record is written to the file at the current file position.
   • COBOL provides options for handling errors during file writing and specifying the action to take when writing to existing records or adding new records.
5. Updating Files:
   • COBOL allows updating records in a file using the UPDATE statement.
   • The UPDATE statement retrieves a record based on a specific key, updates the record data, and writes the updated record back to the file.
6. File Positioning:
   • COBOL provides various statements to control the file position.
   • The START statement is used to position the file at a specific record based on a key value (for indexed files).
   • The REWRITE statement modifies the data in the current record without changing its position in the file.
7. Error Handling:
   • COBOL provides file status codes that indicate the outcome of file operations.
   • These status codes can be checked using the FILE STATUS clause or the built-in file status variable (e.g., STATUS-CODE).
   • Based on the file status, you can take appropriate actions like error handling, retrying, or reporting.

File handling in COBOL enables reading and writing data to files, allowing programs to process and store large amounts of information. Understanding the file organization, access modes, and using the appropriate file handling statements and constructs is essential for effective data management in COBOL programs.

SAMPLES

HELLO WORLD

Here’s a classic “Hello, World!” program written in COBOL:

IDENTIFICATION DIVISION. PROGRAM-ID. HELLO-WORLD. PROCEDURE DIVISION. DISPLAY 'Hello, World!'. STOP RUN.

This COBOL program consists of four divisions:

1. IDENTIFICATION DIVISION: This division contains information about the program, such as the program name.
2. ENVIRONMENT DIVISION: This division specifies the environment in which the program runs, including file and input/output descriptions. In this example, it is omitted since we don’t need any specific environment declarations.
3. DATA DIVISION: This division defines the data used in the program, such as variables or files. It is also omitted in this simple program.
4. PROCEDURE DIVISION: This division contains the actual program logic. In this case, it consists of two statements:
   • DISPLAY: This statement outputs the string “Hello, World!” to the console.
   • STOP RUN: This statement terminates the program.

To run this COBOL program, you would typically use a COBOL compiler or interpreter. The specific steps may vary depending on the compiler or interpreter you’re using.

CALCULATOR

Here’s an example of a simple calculator program written in COBOL that performs addition, subtraction, multiplication, and division:

IDENTIFICATION DIVISION.
PROGRAM-ID. CALCULATOR.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 NUM1 PIC 9(5).
01 NUM2 PIC 9(5).
01 OPERATOR PIC X.
01 RESULT PIC 9(10).

PROCEDURE DIVISION.
DISPLAY "CALCULATOR PROGRAM"
ACCEPT NUM1
ACCEPT OPERATOR
ACCEPT NUM2
IF OPERATOR = '+'
    COMPUTE RESULT = NUM1 + NUM2
    DISPLAY "Result: ", RESULT
ELSE IF OPERATOR = '-'
    COMPUTE RESULT = NUM1 - NUM2
    DISPLAY "Result: ", RESULT
ELSE IF OPERATOR = '*'
    COMPUTE RESULT = NUM1 * NUM2
    DISPLAY "Result: ", RESULT
ELSE IF OPERATOR = '/'
    IF NUM2 = 0
        DISPLAY "Error: Division by zero is not allowed."
    ELSE
        DIVIDE NUM1 BY NUM2 GIVING RESULT
        DISPLAY "Result: ", RESULT
    END-IF
ELSE
    DISPLAY "Error: Invalid operator."

STOP RUN.

In this COBOL program, the user is prompted to enter two numbers and an operator (+, -, *, or /). The program then performs the corresponding arithmetic operation and displays the result.

The WORKING-STORAGE SECTION defines the variables used in the program:

• NUM1 and NUM2 are defined as numeric fields with a length of 5 digits.
• OPERATOR is defined as a character field to store the operator.
• RESULT is defined as a numeric field with a length of 10 digits to store the result.

In the PROCEDURE DIVISION, the program accepts the input values from the user using the ACCEPT statement. It then uses a series of IF statements to determine the operator and perform the appropriate calculation. The COMPUTE statement is used for addition, subtraction, and multiplication, while the DIVIDE statement is used for division.

If the user enters an invalid operator or attempts to divide by zero, appropriate error messages are displayed.

Finally, the program terminates with the STOP RUN statement.

INSERT LF in TEXT

Here’s an example of COBOL code that opens a file, inserts a line of text with a line feed (LF) and carriage return (CR), and saves the file:

IDENTIFICATION DIVISION.
PROGRAM-ID. FILE-INSERT.

DATA DIVISION.
FILE SECTION.
FD INPUT-OUTPUT-FILE.
01 FILE-RECORD.
05 FILE-LINE PIC X(80).

WORKING-STORAGE SECTION.
01 LINE-TO-INSERT PIC X(80) VALUE 'This is the line to be inserted.'.

PROCEDURE DIVISION.
MAIN-LOGIC.
OPEN I-O INPUT-OUTPUT-FILE.
MOVE LINE-TO-INSERT TO FILE-LINE.
WRITE FILE-RECORD.
CLOSE INPUT-OUTPUT-FILE.

STOP RUN.

In this example, the COBOL program opens a file (specified in the FD statement) in input-output mode using the OPEN I-O statement. It then moves the line of text to be inserted into the FILE-LINE data item. Finally, the WRITE statement writes the content of FILE-LINE to the file.

Please note that this code snippet assumes that you have defined the file structure and file attributes appropriately in the FILE SECTION of your COBOL program. Additionally, make sure to replace INPUT-OUTPUT-FILE with the actual name of the file you want to open and modify the LINE-TO-INSERT data item to contain the desired text to be inserted.

Remember to handle error conditions, perform appropriate file validations, and ensure that the file is opened, closed, and saved correctly based on your specific requirements and the COBOL file handling conventions used in your environment.

FORM INPUT

Here’s an example of COBOL code demonstrating a simple authorization workflow for a form input:

IDENTIFICATION DIVISION.
PROGRAM-ID. AUTHORIZATION-WORKFLOW.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 USERNAME PIC X(20).
01 PASSWORD PIC X(20).
01 AUTHORIZED-FLAG PIC X VALUE 'N'.

PROCEDURE DIVISION.
MAIN-LOGIC.
ACCEPT USERNAME.
ACCEPT PASSWORD.
PERFORM AUTHORIZATION-LOGIC.
IF AUTHORIZED-FLAG = 'Y'
    DISPLAY "Form input authorized. Processing can continue."
ELSE
    DISPLAY "Form input not authorized. Access denied."
END-IF.

STOP RUN.

AUTHORIZATION-LOGIC.
IF USERNAME = "admin" AND PASSWORD = "password"
MOVE 'Y' TO AUTHORIZED-FLAG
END-IF.

In this example, the COBOL program prompts for a USERNAME and PASSWORD input using the ACCEPT statement. The AUTHORIZATION-LOGIC paragraph is performed to check if the provided username and password match the authorized credentials (in this case, “admin” and “password”). If the authorization is successful, the AUTHORIZED-FLAG is set to ‘Y’. Finally, based on the value of the AUTHORIZED-FLAG, the program displays whether the form input is authorized or access is denied.

Please note that this code represents a simplified example and should not be considered secure or comprehensive for a real-world authorization workflow. In practice, you would need to implement proper security measures, such as hashing and salted passwords, secure storage of credentials, input validation, and access control based on user roles and permissions. Additionally, error handling and appropriate error messages should be incorporated into the code as per your specific requirements.

SORT

To sort a 20-character string into alphabetical sequence in COBOL, you can use the SORT verb along with the COLLATING SEQUENCE clause. Here’s an example code:

IDENTIFICATION DIVISION.
PROGRAM-ID. SORT-STRING.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 SORT-STRING PIC X(20) VALUE "BADCJFHIELGKNMPOQTRS".

PROCEDURE DIVISION.
MAIN-LOGIC.
DISPLAY "Before sorting: " SORT-STRING.
SORT SORT-STRING
    ASCENDING
    COLLATING SEQUENCE IS NATIONAL.

DISPLAY "After sorting: " SORT-STRING.

STOP RUN.

In this example, the SORT-STRING data item contains the 20-character string that needs to be sorted. The SORT verb is used to perform the sorting operation. The ASCENDING keyword specifies that the sorting should be done in ascending order. The COLLATING SEQUENCE IS NATIONAL clause ensures that the sorting is based on the collating sequence specified in the SORT-CONTROL paragraph or the system’s default collating sequence.

Please note that the example provided assumes that you want to sort the string using the national collating sequence. You can modify the collating sequence based on your specific requirements, such as alphabetical or alphanumeric ordering.

Remember to adjust the code according to your actual data item and program structure. Additionally, handle error conditions and incorporate appropriate error checking as per your specific needs.

COMPOUND INTEREST

Here’s an example of COBOL code to calculate compound interest on a loan with a variable period and a fixed interest rate:

IDENTIFICATION DIVISION.
PROGRAM-ID. COMPOUND-INTEREST.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 PRINCIPAL-AMOUNT PIC 9(7)V99 VALUE 10000.00.
01 INTEREST-RATE PIC 9(3)V99 VALUE 5.5.
01 TIME-PERIOD PIC 9(2) VALUE 3.
01 COMPOUND-INTEREST PIC 9(7)V99.

PROCEDURE DIVISION.
MAIN-LOGIC.
COMPUTE COMPOUND-INTEREST = PRINCIPAL-AMOUNT * (1 + (INTEREST-RATE / 100)) ** TIME-PERIOD.
DISPLAY "Principal Amount: " PRINCIPAL-AMOUNT.
DISPLAY "Interest Rate: " INTEREST-RATE "%".
DISPLAY "Time Period: " TIME-PERIOD " years".
DISPLAY "Compound Interest: " COMPOUND-INTEREST.

STOP RUN.

In this example, the COBOL program calculates the compound interest on a loan using the given principal amount (PRINCIPAL-AMOUNT), interest rate (INTEREST-RATE), and time period (TIME-PERIOD). The formula used to calculate compound interest is:

Compound Interest = Principal Amount * (1 + (Interest Rate / 100)) ^ Time Period

The COMPUTE statement performs the calculation and assigns the result to the COMPOUND-INTEREST data item.

Please note that the interest rate and time period are assumed to be in decimal format (e.g., 5.5% and 3 years). Adjust the data item definitions and computation formula based on your specific requirements, such as different data types or formulas for interest calculation.

Remember to adapt the code as per your actual data item names, program structure, and any additional requirements or computations you may have.

HANGMAN

Here’s an example of COBOL code for a simple implementation of the Hangman game:

IDENTIFICATION DIVISION.
PROGRAM-ID. HANGMAN.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 SECRET-WORD PIC X(10) VALUE "HANGMAN".
01 DISPLAY-WORD PIC X(10) VALUE SPACES.
01 GUESSED-LETTERS PIC X(26) VALUE SPACES.
01 GUESSES-LEFT PIC 99 VALUE 6.
01 INPUT-LETTER PIC X.
01 INDEX PIC 99.
01 GAME-OVER PIC X VALUE 'N'.

PROCEDURE DIVISION.
MAIN-LOGIC.
PERFORM INITIALIZE-GAME.
PERFORM GAME-LOOP UNTIL GAME-OVER = 'Y'.
PERFORM FINALIZE-GAME.
STOP RUN.

INITIALIZE-GAME.
MOVE SPACES TO DISPLAY-WORD.
MOVE SPACES TO GUESSED-LETTERS.
MOVE 6 TO GUESSES-LEFT.
MOVE 'N' TO GAME-OVER.

DISPLAY "Welcome to Hangman!"
DISPLAY "Guess the word by entering one letter at a time."
DISPLAY "You have 6 guesses. Good luck!"
DISPLAY "-----------------------".

GAME-LOOP.
PERFORM DISPLAY-GAME-STATUS.
PERFORM INPUT-LETTER.
PERFORM PROCESS-LETTER.
PERFORM CHECK-GAME-OVER.

DISPLAY-GAME-STATUS.
DISPLAY "Word: " DISPLAY-WORD
DISPLAY "Guessed Letters: " GUESSED-LETTERS
DISPLAY "Guesses Left: " GUESSES-LEFT
DISPLAY "-----------------------".

INPUT-LETTER.
DISPLAY "Enter a letter: "
ACCEPT INPUT-LETTER

PROCESS-LETTER.
MOVE FUNCTION INDEX(INPUT-LETTER) TO INDEX.

IF INDEX = 0 THEN
    DISPLAY "Invalid input. Please enter a single letter."
    PERFORM INPUT-LETTER
    PERFORM PROCESS-LETTER
END-IF.

IF GUESSED-LETTERS(INDEX:1) = ' ' THEN
    MOVE INPUT-LETTER TO GUESSED-LETTERS(INDEX:1)
ELSE
    DISPLAY "You already guessed that letter."
    PERFORM INPUT-LETTER
    PERFORM PROCESS-LETTER
END-IF.

IF SECRET-WORD(INDEX:1) = ' ' THEN
    SUBTRACT 1 FROM GUESSES-LEFT
ELSE
    REPLACE INPUT-LETTER IN SECRET-WORD BY INDEX
END-IF.

CHECK-GAME-OVER.
IF GUESSES-LEFT = 0 THEN
DISPLAY "You lost! The word was " SECRET-WORD
MOVE 'Y' TO GAME-OVER
ELSE
IF DISPLAY-WORD = SECRET-WORD THEN
DISPLAY "Congratulations! You won!"
MOVE 'Y' TO GAME-OVER
END-IF
END-IF.

FINALIZE-GAME.
DISPLAY "Thank you for playing Hangman!"

This code represents a basic implementation of the Hangman game in COBOL. It allows the player to guess the letters of a secret word, with a limited number of guesses. The secret word is initially represented by dashes, and as the player guesses correct letters, they are revealed. The game continues until the player either guesses the word correctly or runs out of guesses.

Please note that this is a simplified example, and you can enhance it further with additional features such as input validation, graphics, and a larger word bank.

WEB SERVICE

Creating a web service with COBOL involves integrating COBOL programs with modern web technologies. Here’s a general outline of the steps involved in creating a web service with COBOL:

1. Define the Web Service:
   • Identify the functionality that you want to expose as a web service.
   • Determine the input parameters, output data, and any required transformations or validations.
   • Define the web service operations and their corresponding data structures in COBOL.
2. Choose a Web Service Framework:
   • Select a web service framework that supports COBOL, such as Apache Axis, IBM WebSphere, or Micro Focus Visual COBOL.
   • Ensure that the chosen framework provides the necessary tools and libraries to develop and deploy web services.
3. Create the COBOL Program:
   • Write or modify your COBOL program to encapsulate the desired functionality.
   • Define the necessary data structures and program logic to handle the web service operations.
   • Ensure that the program can receive input parameters and return the required output data.
4. Generate the Web Service Stub:
   • Use the selected web service framework to generate the web service stub code.
   • The stub code acts as a bridge between the COBOL program and the web service infrastructure.
   • The stub code typically handles the web service protocol, message parsing, and serialization.
5. Implement Web Service Logic:
   • Incorporate the generated stub code into your COBOL program.
   • Implement the necessary web service logic, such as extracting input parameters, invoking the relevant COBOL program logic, and formatting the output data.
6. Test and Debug:
   • Test the web service functionality using appropriate testing tools or frameworks.
   • Verify that the web service responds correctly to different input scenarios and produces the expected output.
   • Debug and address any issues or errors encountered during testing.
7. Deploy the Web Service:
   • Deploy the COBOL program and associated web service artifacts to a web server or application server that supports the chosen web service framework.
   • Configure the server settings to expose the web service endpoints and make it accessible to clients.
8. Provide Documentation:
   • Document the web service interface, including the supported operations, input parameters, and expected output.
   • Provide documentation on how clients can consume and interact with the web service.
9. Monitor and Maintain:
   • Monitor the web service usage, performance, and any reported issues.
   • Maintain and update the web service as required, ensuring compatibility with evolving web service standards and protocols.

It’s important to note that the specific steps and tools may vary depending on the chosen web service framework and the infrastructure you are working with. Consult the documentation and resources provided by the web service framework you select for detailed instructions and guidelines specific to your environment.

Here’s a sample code snippet demonstrating a simple COBOL program that acts as a web service to perform a basic addition operation:`

IDENTIFICATION DIVISION.
PROGRAM-ID. ADDITION-SERVICE.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 NUM1 PIC 9(5).
01 NUM2 PIC 9(5).
01 RESULT PIC 9(6).
01 WS-ERROR-CODE PIC XX.
01 WS-ERROR-MESSAGE PIC X(50).

PROCEDURE DIVISION.
MAIN-LOGIC.
ACCEPT NUM1.
ACCEPT NUM2.
COMPUTE RESULT = NUM1 + NUM2.

DISPLAY "Content-Type: text/plain".
DISPLAY SPACE.
DISPLAY "Result: " RESULT.

STOP RUN.

`

In this example, the COBOL program acts as a simple web service that accepts two numeric inputs (NUM1 and NUM2) and performs addition. The result is then displayed in the response. This program assumes that the inputs are passed as part of the HTTP request.

Please note that this code snippet represents a minimal example to demonstrate the concept and may not cover all the necessary aspects of a complete and robust web service implementation.

In a real-world scenario, you would need to consider aspects like error handling, input validation, and appropriate response formats based on the web service standards and frameworks being used.

DEPLOYING THE CODE

Apache Axis is an open-source framework for building web services in Java. It provides tools and libraries to create, deploy, and consume web services using various protocols such as SOAP (Simple Object Access Protocol) and WSDL (Web Services Description Language). Here are some key aspects and features of Apache Axis:

1. Web Service Support:
   • Apache Axis supports the development and deployment of web services conforming to SOAP standards.
   • It provides a comprehensive set of APIs and tools for creating both server-side (provider) and client-side (consumer) components of web services.
2. WSDL Support:
   • WSDL is a standard language for describing web services. Apache Axis includes WSDL-related tools to generate WSDL files from existing Java code and to generate Java code from WSDL files.
   • This simplifies the process of exposing Java components as web services and allows Java clients to consume web services based on their WSDL definitions.
3. Data Binding:
   • Apache Axis supports various data binding techniques to convert between XML and Java objects.
   • It allows developers to choose different data binding options, such as XMLBeans, Apache XML-RPC, and JavaBeans.
4. Protocol Support:
   • Apache Axis supports multiple protocols for web service communication, including HTTP, SMTP, JMS (Java Message Service), and more.
   • It provides the flexibility to choose the appropriate protocol based on the requirements of the web service.
5. Interoperability:
   • Apache Axis focuses on interoperability and adherence to web service standards.
   • It ensures compatibility with various platforms and programming languages by adhering to SOAP standards and supporting WSDL-based service definitions.
6. Integration:
   • Apache Axis can be integrated with popular Java application servers, such as Apache Tomcat, JBoss, and IBM WebSphere.
   • It provides integration options for seamless deployment and runtime execution of web services within these application server environments.
7. Extensibility:
   • Apache Axis offers extension points and APIs that allow developers to extend its functionality and customize the behavior of web services.
   • This enables the integration of additional features and functionalities specific to the requirements of the web service application.

Apache Axis has been widely adopted as a reliable and robust framework for developing web services in the Java ecosystem. Its comprehensive feature set, adherence to web service standards, and support for interoperability make it a popular choice among developers building SOAP-based web services.

Using Apache Axis with COBOL requires integrating COBOL programs with the Java-based Axis framework. Here’s an overview of the steps involved:

1. Set up the Development Environment:
   • Ensure that you have a COBOL development environment configured and ready to use.
   • Install and set up Apache Axis, which requires a Java development environment and Apache Tomcat or another application server.
2. Define the Web Service in COBOL:
   • Identify the functionality you want to expose as a web service in your COBOL program.
   • Define the necessary data structures and program logic to handle the web service operations.
   • Consider the input parameters, output data, and any required transformations or validations.
3. Generate a Java Wrapper:
   • Use tools like COBOL-to-Java converters or COBOL-Java integration frameworks to generate a Java wrapper for your COBOL program.
   • The generated Java wrapper serves as an interface between the COBOL program and the Java-based Axis framework.
4. Integrate COBOL with Axis:
   • Incorporate the generated Java wrapper into the Axis framework.
   • Use Axis APIs and tools to create the necessary web service artifacts, such as the WSDL file and deployment descriptors.
   • Ensure that the COBOL program can be invoked by the Axis framework as a web service operation.
5. Deploy the Web Service:
   • Deploy the web service to the application server where Apache Axis is running.
   • Configure the server settings to expose the web service endpoints and make it accessible to clients.
6. Test and Consume the Web Service:
   • Use Axis tools or other web service testing tools to verify the functionality of the COBOL-based web service.
   • Develop client applications in Java or other compatible languages to consume the web service.

Please note that the exact implementation details and tools may vary based on your specific COBOL development environment and the COBOL-to-Java integration techniques you choose. It’s essential to consult the documentation and resources provided by the COBOL and Axis frameworks you are using for detailed instructions and guidelines specific to your environment.

ASSISTANCE

If you’re a beginner looking to learn COBOL, here are some good sources that can help you get started:

1. IBM COBOL Programming Guide: IBM provides comprehensive documentation and guides on COBOL programming. Their COBOL Programming Guide covers the basics of COBOL, including language syntax, data types, file handling, and program structure. You can find the guide on the IBM website.
2. “Murach’s Mainframe COBOL” by Mike Murach and Anne Prince: This book is a popular choice for beginners. It provides a hands-on approach to learning COBOL and covers topics like data definitions, program design, file handling, and debugging. It includes practical examples and exercises to reinforce your understanding.
3. “COBOL for the 21st Century” by Nancy Stern, Robert A. Stern, and James Ley: This book is often recommended for beginners and covers COBOL concepts and programming techniques. It starts with the basics and progresses to more advanced topics. It also includes numerous examples and exercises to practice COBOL programming skills.
4. COBOL Tutorials and Courses on Websites: Several websites offer free COBOL tutorials and courses for beginners. Websites like tutorialspoint.com, cobolportal.com, and cobolprogram.com provide tutorials, examples, and exercises to help you learn COBOL at your own pace.
5. Online COBOL Communities and Forums: Joining online COBOL communities and forums can be beneficial for beginners. Websites like COBOL Tech Forum, IBM Developer COBOL Community, and COBOL subreddit provide platforms to ask questions, seek guidance, and interact with experienced COBOL programmers.
6. COBOL Programming Courses: Various online learning platforms, such as Udemy, Coursera, and LinkedIn Learning, offer COBOL programming courses for beginners. These courses provide structured learning paths, video tutorials, hands-on exercises, and quizzes to help you learn COBOL effectively.

Remember to practice coding and work on small projects to reinforce your understanding of COBOL. Additionally, exploring COBOL code examples and engaging with the COBOL community can provide valuable insights and practical knowledge.