ProvideX V8.20 > Language Reference > 9. Special Command Tags

775

The parameter block is defined as follows:

struct IODLL_PARAM

{

long

handle;

/* DLL specific handle */

int

nFunction;

/* IO Function */

int

nMode;

/* Access mode (Next, KEY=, IND=, ...) */

int

lenBuffer;

/* Size of buffer */

char

*pBuffer;

/* Pointer to buffer */

int

lenRecID;

/* Length or key of index/rec# */

char

*pRecID;

/* Pointer to KEY buffer*/

int

idxRecID;

/* Key Number/Index Number/RNO (base 0) */

int

nKNOValue;

/* KNO= Specified on directive/function */

};

Where:

Identifies the specific file for the request. On the OPEN, the DLL

handle

returns this value, which is used for all subsequent calls.

Identifies the type of function being performed (OPEN, CLOSE, ...).

nFunction

Possible values include:

#define IODLL_FNC_OPEN

1

#define IODLL_FNC_CLOSE

2

#define IODLL_FNC_READ

3

#define IODLL_FNC_EXTRACT  4

#define IODLL_FNC_WRITE

5

#define IODLL_FNC_INSERT

6

#define IODLL_FNC_REMOVE

7

#define IODLL_FNC_KEYNEXT  8

#define IODLL_FNC_KEYPREV  9

#define IODLL_FNC_KEYCUR

10

#define IODLL_FNC_KEYFIRST 11

#define IODLL_FNC_KEYLAST  12

#define IODLL_FNC_RNO

13

#define IODLL_FNC_IND

14

#define IODLL_FNC_LOCK

15

#define IODLL_FNC_UNLOCK

16

#define IODLL_FNC_PURGE

17

#define IODLL_FNC_KEN

18

#define IODLL_FNC_LOAD

-1

#define IODLL_FNC_FREE

-2

Identifies the access method being applied during a READ/WRITE

nMode

operation. Possible access values include:

#define IODLL_MODE_NEXT

0

#define IODLL_MODE_BY_KEY  1

#define IODLL_MODE_BY_IND  2

#define IODLL_MODE_BY_RNO  3

Length of the data buffer used for READ/WRITE.

lenBuffer

Pointer to the data buffer to be used for READ/WRITE operations.

pBuffer