RPG

Programming

in ILE

step process, see

Chapter 7,

“Creating

a

Program

with the CRTRPGMOD and

CRTPGM Commands” on page 73. For

more information on service programs, see

Chapter 8, “Creating

a Service

Program”

on

page 91.

Program Management

ILE provides a common basis for:

¹ Managing program flow

¹Sharing resources

¹ Using application program interfaces (APIs)

¹ Handling exceptions during a program's run time

It gives RPG users much better control over resources than was prev sible.

ILE programs and service programs are activated into activation groups

specified at program-creation time. The process of

getting a

program

program

ready

to

run

is

known as activation. Activation allocates resou

job so that

one

or

more

programs can

run in that

space.

If

the

s

group

for

a

program

does

not exist when the program

is

called, then

within

the

job

to

hold the program's

activation.

 

 

 

 

 

An activation

group

is

the

key element

governing an

ILE

application's

re

and behavior. For example, you can scope commitment-control operations t activation group level. You can also scope file overrides and shared paths to the activation group of the running application. Finally, the program upon termination is also affected by the activation group in program runs.

For more information on activation groups, see “Managing Activation Groups” page 109.

You can dynamically allocate storage for a run-time array using the provided for all ILE programming languages. These APIs allow single- and language applications to access a central set of storage management f offer a storage model to languages that do not now provide one. RPG storage management capabilities using operation codes. For more informa storage management, see “Managing Dynamically-Allocated Storage” on page 1

Program Call

In ILE, you can write applications in which ILE RPG programsand OPM programs continue to interrelate through the traditional use of dynami calls. When using such calls, the calling program specifies the name o program on a call statement. The called program's name is resolved to at run time, just before the calling program passes control to the c

You

can also write ILE applications

that can

interrelate with faster

calls

involve

calls

between

procedures.

A procedure is a self-containe

that

performs

a

task and

then returns to the caller. An ILE RPG modu

an optional

main

procedure

followed

by

zero

or more subprocedures.

Chapter 2. RPG Programming in ILE19

Page 43
Image 43
IBM AS/400 manual Program Management, Program Call, Ile, Procedure Followed Zero Or more subprocedures

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.