HPlogo Using KSAM XL and KSAM 64 > Appendix B BASIC/V Intrinsics

Calling a KSAM Procedure

MPE documents

Complete PDF
Table of Contents
Index

E0300 Edition 4 ♥
E0394 Edition 3

The KSAM interface procedures are called from a BASIC program with a CALL statement of the following general form: 

  statementlabel CALL procname (filenumber, status [,parameterlist])
Where:
statementlabel

The number of the statement in the program.

procname

The KSAM access procedure to which control is transferred.

filenumber

A numeric variable whose value identifies an open KSAM file. This parameter must be present. Its value is assigned when the file is opened and must not be changed until the file is closed.

status

A 4-character string variable to which a code is returned that indicates whether the current operation was successful or not, and if not, the reason for failure.

parameterlist

A set of one or more parameters that, if present, further define input/output operations on this file.

The first two parameters, filenumber and status are included in every KSAM procedure call, except BKERROR and BKVERSION. The parameters in parameterlist depend on the procedure in which they are used. Some parameterlist parameters are optional and, if omitted, default values are assigned by KSAM. Such parameters are indicated by brackets in the procedure call format. The required parameters filenumber and status are both variables, the first numeric, the second string. Other parameters are either variables or expressions. Expressions are either variables or constants, or a combination of both. The data type of the parameter depends on its definition in the procedure. The procedure call formats specify the data type of each parameter.

Depending on the procedure, certain variables can be assigned values as a result of executing the procedure. The procedure itself is never assigned a value.

Optional Parameters

When parameters in parameterlist are optional, those parameters are surrounded by brackets. In a series of optional parameters, the enclosing brackets are nested. For example: 

  CALL name (filenum, status[,param1[,param2[,param3]]])
This notation tells you that parameters can be omitted only from the end of the optional list; parameters cannot be omitted from the middle or beginning of the list. For example, if you want to specify param3, you must also specify the preceding parameters, param1 and param2. If you specify param2, you can omit the following parameter param3, but not the preceding param1.



Overview

Status Parameter