Passing Prototyped Parameters

To pass a parameter by read-only reference, specify the keyword CONST definition specification of the parameter definition in the prototype. page 138 shows an example of a prototype definition for the ILE CEE AP CEETSTA (Test for omitted argument).

*------------------------------------------------------------------

 

 

 

 

 

* CEETSTA (Test for omitted argument)

-- ILE CEE API

 

*

1. Presence flag

 

 

Output

Binary(4)

*

2. Argument number

 

 

Input

Binary(4)

*------------------------------------------------------------------

 

 

 

 

 

D CEETSTA

PR

 

 

EXTPROC('CEETSTA')

D

Present

 

10I

0

 

 

D

ArgNum

 

10I

0

CONST

 

D

Feedback

 

12A

 

OPTIONS(*OMIT)

 

...

 

 

 

 

 

 

D HaveParm

S

10I

0

 

 

...

 

 

 

 

 

 

C

 

CALLP

CEETSTA(HaveParm : 3 : *OMIT)

C

 

IF

HaveParm = 1

 

*

do something with third parameter

 

C

 

ENDIF

 

 

 

 

 

 

 

 

 

 

 

 

Figure

65.

Prototype for ILE CEE API CEETSTA with CONST Parameter

The second

parameter

passed to CEETSTA can be any numeric field, a lite

built-in

function, or

expression.

Using Operational Descriptors

Sometimes it is necessary to

pass a

parameter to

a procedure even

t

data

type

is not

precisely

known to the called procedure, (for examp

types

of

strings).

In

these

instancesoperationalyoudescriptorscan use

to

 

 

provide descriptive information to the called procedure regarding the

 

parameter.

The additional information allows the procedure to

properly

i

string. You

should

only

use

operational

descriptors

when they

are expe

called procedure.

Many ILE bindable APIs expect operational descriptorsSystem API. ReferIn the-

ence, if any parameter is defined as 'by descriptor', then you shoul tional descriptors to the API. An example of this is the ILE CEE API (Convert Seconds to Character Timestamp). The second and third parameters require an operational descriptor.

Note: Currently, the ILE RPG compiler only supports operational descriptors character and graphic fields and subfields. Operational descripto available for data structures, arrays, or tables. In addition, o descriptors are not available for data of type numeric, date, basing pointer or procedure pointer.

Operational

descriptors have

no

effect on

the parameters being passed

way that they are passed.

When a procedure is passed

operational

which it

does not expect,

the

operational

descriptors are

simply ignor

You can request operational descriptors for both prototyped and non-pro parameters. For prototyped parameters, you specify the keyword OPDESC prototype definition. For non-prototyped parameters, you specify (D) as tion code extender of the CALLB operation. In either case, operationa

138 ILE RPG for AS/400 Programmer's Guide

Page 161 Page 163
Page 162
Image 162
IBM AS/400 manual Using Operational Descriptors, Ile Cee Api, Ceetsta Extprocceetsta
Page 161 Page 163

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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