IOCTL$ Function

Purpose:

To allow GW-BASIC to read a "control data" string from an open character device driver.

Syntax:

IOCTL$([#]file number)

Comments:

file number is the file number open to the device.

The IOCTL$ function is generally used to get acknowledgement that an IOCTL statement succeeded or failed. It is also used to get device information, such as device width after an IOCTL statement requests it.

Examples:

10 'GW is a possible command
20 'for get device width
30 OPEN "\DEV\MYLPT" AS#1
40 IOCTYL#1, "GW"
50 'Save it in WID
60 WID=VAL(IOCTL$(#1))