IBM Natural

No, There is not GOTO statement in Natural.

There is a Perform statement which is used to call a

subroutine.

A subroutine is a a block of code which is to be executed

several times within an object.

Flat - sequential or VSAM files

We use File aid for sequential files for the following

reason:

1. Copy from one file to another only selected amount of

records.

2. To browse or edit through the file using a copybook.

3. For impact analysis on a particular file.

Yes, it is possible. The below JCL can list the source of

the Natural program to a dataset and it can be very well

downloaded using option 6.

//STEP1 EXEC NATBATT

//SYSOUT DD SYSOUT=*

//CMPRINT DD DSN=USERID.MYNATPGM,

// DISP=(NEW,CATLG,DELETE),

// SPACE=(CYL,(1,1),RLSE),RECFM=FBA,LRECL=133

//SYSIN DD *

LOGON NATLIB

L MYNATPGM

FIN

/*

NATLIB = YOUR NATURAL LIBRARY

MYNATPGM = YOUR NATURAL PROGRAM

Parameters can be passed with the PERFORM statement from

the invoking object to the

external subroutine. These parameters must be defined

either in the DEFINE DATA PARAMETER

statement of the subroutine, or in a parameter data area

used by the subroutine.

An external subroutine can access the global data area used

by the invoking object.

In addition, an external subroutine can have its own local

data area, in which the fields that are to be used

only within the subroutine are defined.

However, an external subroutine cannot have its own global

data area.

You use the following steps to check whether the input file

is empty

Step A. Read work file #WK-Number once #WK-Record

Step B. At End of File

Write "Input file is Empty"

End-Endfile

The first step will read the first record in the file and

the next step will see the End of File condition. If the

File is empty, the program will write that we have an Empty

input file to spool.

Escape Routine is generally used to interupt the processing

of Subprogram or Subroutine to return Control back to the

next statement from where this subprogram or routine was

called.

This statement will return an error if not placed within a

subprogram, subroutine or processing loop.