Using a Prototyped Call

To call a prototyped program or procedure follow these general steps:

1.Include the prototype of the program or procedure to be called specifications.

2.Enter the prototype name of the program or procedure in the exte

 

field, followed by the parameters if any, within parentheses. Separ

 

parameters with

a

colon

(:).

Factor

1

must

be

blank.

The

following

example shows

a call to a procedure Switch, which changes

of

the

indicator

that

is

passed to it,

in

this

case *IN10..

 

C

 

 

CALLP

Switch(*in10)

 

 

 

 

A maximum

of

255 parameters

are

allowed

on

a

program call, and a maximum

399

for

a

procedure

call.

 

 

 

 

 

 

You can use CALLP from anywhere within the module. If the keyword EXTPG specified on the prototype, the call will be a dynamic external call; be a bound procedure call.

Note

that

if CALLP is used to call a

procedure

which returns

a

value,

not be available to the caller. If

the value

is required,

call

the

within

an

expression.

 

 

 

 

Calling within an Expression

If a

prototyped

procedure is defined to return a

value

then

you mu

dure within an expression if you want to make use of

the

return

valu

procedure name in

a manner that is consistent with the

data type

of

return

value. For

example, if a procedure is defined

to

return

a

num

call to the procedure within an expression must be where a numeric wo expected.

Figure 61 shows the prototype for a procedure CVTCHR that takes a nume parameter and returns a character string. Figure 62 shows how the proc might be used in an expression.

*Prototype for CVTCHR

*- returns a character representation of the numeric param￿eter

 

* Examples: CVTCHR(5) returns '5

'

 

 

*

CVTCHR(15-124) returns '-109

'

D CVTCHR

PR

31A

 

 

D

NUM

 

30P 0

VALUE

 

 

 

 

 

 

 

Figure

61.

Prototype for CVTCHR

 

 

 

 

 

 

 

 

 

C

 

EVAL

STRING =

'Address: ' +

 

C

 

 

 

%TRIM(CVTCHR(StreetNum))

C

 

 

 

+ ' ' + StreetName

 

 

* If STREETNUM = 427 and STREETNAME =

'Mockingbird Lane', afte￿r the

 

* EVAL operation STRING = 'ADDRESS: 427 Mockingbird Lane'

 

 

 

 

 

Figure

62.

Calling a Prototyped Procedure within an Expression

 

134 ILE RPG for AS/400 Programmer's Guide

Page 157 Page 159
Page 158
Image 158
IBM AS/400 Calling within an Expression, Using a Prototyped Call, 31A, 30P, Address + TRIMCVTCHRStreetNum + + StreetName
Page 157 Page 159

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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