Data

Management

Operations

and

ILE

RPG I/O Operations

The

RPG program

does

not provide level checking for program-described

for

files using

the

devices

SEQ

or

SPECIAL.

For more information on how to specify level checking,Data Managemseent the manual.

Defining Program-Described Files

Program-described files are files whose records and fields are des input/output specifications in the program that uses the file. To use described file in an RPG program you must:

1. Identify the file(s) in the file description specifications.

2. If

it

is an input file,

describe

the

record and

fields in th

The

file

name

in positions

7 through

16

in

the

input

specifications

same

as

the

corresponding

name entered

in

the

file

specifications

On the record-identification entries you indicate whether you wan sequence checking of records within the file.

3. Enter the same file name as in step 1 in the FACTOR 2 field of lation specifications which require it. For example, WRITE operation

program-described

file

require a

data

structure

name

in

the

resu

4. If

it

is

an output

file,

describe

the record

and

fields

in t

In

addition,

you

specify

how the output is to

be

printed.

The

tions 7 through 16 in

the

output

specifications must be

the

same

sponding

name

entered

in the file

specifications.

 

 

 

 

A program-described file must exist on the system, and be in your before the program can run. To create a file, use one of the Cre

which can be foundCL inReferencethe (Abridged).

Data Management Operations and ILE RPG I/O Operations

Data management is the part of the operating system that controls th accessing of data by an application program. Table 17 on page 272 sh data management operations provided by the AS/400 and their correspond RPG operation. It also shows which operations are allowed for which device type.

Chapter 14. Defining Files271

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IBM AS/400 Defining Program-Described Files, Data Management Operations and ILE RPG I/O Operations, SEQ Special, Resu

AS/400 specifications

The IBM AS/400, now known as the IBM iSeries, is a midrange computer system that has been a cornerstone of enterprise computing since its introduction in 1988. Designed to provide a robust platform for business applications, the AS/400 is celebrated for its reliability, scalability, and integrated database capabilities.

One of the key features of the AS/400 is its Integrated Operating Environment, which blends hardware and software resources seamlessly. This integration allows businesses to execute diverse workloads, ranging from traditional applications to modern web-based services, all on a single platform. The operating system, OS/400 (now IBM i), offers a rich set of APIs and tools for developers, simplifying application development and management.

Another standout characteristic of the AS/400 is its built-in database, DB2 for i. This powerful relational database management system allows for efficient data handling and provides advanced features such as support for SQL, XML, and JSON, making it easier for businesses to manage their data and integrate it with other systems. The database's tight integration with the operating system enables high performance and security.

In terms of scalability, the AS/400 can accommodate small businesses as well as large enterprises, with the ability to support hundreds of users simultaneously. Its architecture allows for easy upgrades in hardware, meaning that organizations can scale their systems without replacing the entire infrastructure.

Security is another critical attribute of the AS/400. With a sophisticated security model, it offers built-in user authentication, access control, encryption, and auditing capabilities to protect data and applications from unauthorized access.

The AS/400 also supports multiple programming languages, including RPG, COBOL, Java, and PHP, giving organizations the flexibility to choose the development tools that best fit their needs. This diversity helps maintain legacy applications while also developing new ones that leverage modern technologies.

Moreover, the platform supports both traditional green-screen interfaces and modern graphical user interfaces, allowing organizations to transition smoothly into contemporary user experience paradigms.

Overall, the IBM AS/400 stands out as a resilient, flexible, and secure computing platform that enables organizations to effectively manage their business operations, streamline processes, and adapt to changing market demands. Its unique combination of integrated features and capabilities ensures that it remains relevant in today's fast-paced technology landscape.