IBM Version 4 manual Description of an API, Parameters, Locks, Authorities

nonobject information that represents data known to the system, such as mation or system status.

Description of an API

Most APIs have similar topic headings. The following lists the API topic each with an overview and details on how to use the information.

Parameters

The Parameters box describes how to call the API. The first column in eters box lists the required order of the parameters. The second co

parameter

used

on

the

call.

The

third

column

lists

whether

the parameter

is

defined

for

input,

out

and

output. Input

parameters

and

fields

are

not

changed

by

the

API.

the

same

value

on the return from the API call as they do

before

t

contrast,

output

parameters are

changed. Any

information that

an API call

in an output parameter or output

field

before

the call

to

the

API

c

return from the

call

to

the

API.

In the fourth column of the Parameters box is the type of data de parameter. CHAR(*) represents a data type that is not known, such as c binary, and so on, or a length that is x)notrepresentsknown. xBinary(bytes of a binary value. CHAR(x) representsx bytes of character data. When calling the QWDRJOBD API, for example, there is an 8-byte character format name, binary value named length of receiver variable, and a variable-length re able. The receiver variable is a structure made up of several charac fields. For more information on format names, see “Format Name” on page 3-

RPG Call

Statement—Parameter

Example:

In

this

example

program,

you

must

pass

5

parameters

to

use

the

API. For

example,

your RPG

CALL

statement

look

like

the

following:

C

CALL 'QWDRJOBD'

C

PARM

QWDBH

Receiver Var.

C

PARM

RCVLEN

Length QWDBH

C

PARM

FORMAT

Format Name

C

PARM

LFNAM

Qual. Job Desc

C

PARM

QUSBN

Error Code

Note:

There is no parameter for the HOLD information. The first paramet

receiver

variable (QWDBH),

is

where

the

information

is

passed ba

the

job

description

API.

You

will

receive

a

data

structure that

mation, and you will need

to find the specific location within th

ture

for where

the

HOLD

information

is stored.

Authorities				and	Locks
The		Authorities and				Locks	topic lists			all	the authorities that you need
API.		This		topic also lists the locks						that the API uses. To use an API,
have		the		correct		authority		to	the	following:
Ÿ	The		API		itself
Ÿ	All		the	objects		that	the	API	uses
Ÿ	Any		locks		that the API places				on	any	objects

3-2System API Programming V4R1