ProvideX V8.20 > Language Reference > A. Appendix

808

Input/Output and Control Options

Several directives and system functions described in this document include the use

of optional syntax elements in their formats to fine tune code and redirect processing.

Some are defined individually, and some are listed in format groups: Control

Options (ctrlopt) or File Options (fileopt). A general overview of available options

is provided below. Refer to specific directive/function descriptions for information on

the use of these options.

File Options

File options (fileopt) can be included in the syntax for Accessing Data Files, p.22.

These may be used to handle exceptions, set key position, and deal with data errors in

I/O operations:

BSY=stmtref

To trap Error #0: Record/file busy.

BSZ=num

Buffer size (in bytes) for file opens and directives that control data

flow. Block size (in KB) for file creation directives (CREATE TABLE,

KEYED, etc.).

DIR=num

Direction indicator. This adjusts the record pointer by num

records, where a positive value advances the pointer, a negative

pointer reverses the pointer, and a DIR=0 indicates no

movement. This option is not supported with use of the [WDX] tag.

DOM=stmtref

On missing record, transfer to program line number/line label.

END=stmtref

On end of file, transfer to program line number/line label.

ERR=stmtref

On error, transfer to program line number/line label.

HLP=string$

Help message identifier used with INPUT and OBTAIN.

IND=num

32-bit record index value used to uniquely identify a record in

keyed files.

For Fixed length keyed files, num represents an offset into the

data file (first record has an index of 0, second is 1, and so on).

However, some record indexes will be set aside by the system

to be used for key tables and may yield gaps where the record

indexes have been used for keys.

For Variable length keyed files, num represents a logical page

address and record index within that page. The page address is

contained in the top 24-bits (high order 3 bytes) with a record

index within that page in the lower 8 bits. For VLR files, the page

address is the actual physical address for the data page. For EFF

files, the page address is a logical page number in the file.

For TCP/IP server files, num represents an internal socket

connection to the client that can be used to manually direct

output to specific sockets.

Used with the INPUT directive, IND=num sets the starting

position (column number) of the cursor in the input field.