Using SPECIAL Files

Example

of

Specifying

a

Sequential

File

 

 

 

 

 

 

 

 

 

Figure 162

shows

an

example

of

how

to

specify

a

SEQ

file

in an

ILE

member.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

*.. 1 + 2 + 3 + 4 + 5 + 6 + 7 + *

FFilename++IPEASFRlen+LKlen+AIDevice+.Keywords+++++++++++++++++++++++++++++

 

 

FTIMECDS

IP

E

 

DISK

 

 

 

 

 

 

 

 

 

 

FPAYOTIME

O

F 132

SEQ

 

 

 

 

 

 

 

 

 

 

*

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure

162.

SEQ Device

 

 

 

 

 

 

 

 

 

 

 

A SEQ

device

is

specified

for

the

PAYOTIME

file.

When the

program i

can use

a OS/400 override command to specify the actual device (su

tape,

or

diskette)

to be

associated

with

the

file

while

the

progr

example, diskette can be specified for some program runs while print specified for others. The file description, pointed to by the file actual device, in which case an override command need not be used.

Using SPECIAL Files

The RPG device name SPECIAL (positions

36 - 42 of the file descripti

tions) allows you to specify an input

and/or output device that is n

ported by the ILE RPG operations. The input and output operations f controlled by a user-written routine. The name of the user-written ro

identified in the file description specifications using

the

keyword

PGMNAME('

program name').

 

 

ILE RPG

calls

this user-written routine to open the file,

read and w

and close the file. ILE RPG also creates a parameter

list

for use

routine.

The

parameter list contains:

 

 

¹ option code parameter (option)

¹ return status parameter (status)

¹error-found parameter (error)

¹record area parameter (area).

This parameter list is accessed by the ILE RPG compiler and by th routine; it cannot be accessed by the program that contains the SPEC

The following describes the parameters in this RPG-created parameter

Option

The

option parameter

is

a one-position character field that

 

action the user-written

routine is to process. Depending on t

 

being

processed

on

the

SPECIAL file (OPEN,

CLOSE,

FEOD,

READ,

 

WRITE,

DELETE,

UPDATE),

one

of

the

following

values

is

passed to

 

the user-written routine

from

ILE

RPG:

 

 

 

 

Value

Passed Description

 

 

 

 

 

 

 

 

 

O

 

Open

the

file.

 

 

 

 

 

 

 

C

 

Close

the

file.

 

 

 

 

 

 

FForce the end of file.

Chapter 17. Accessing Externally Attached327 Devices

Page 350 Page 352
Page 351
Image 351
IBM AS/400 manual Using Special Files, Program name, Option
Page 350 Page 352

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.
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