DSK_SETLOGICALMAP
- Category
- IOCTL_DISK (08h)
- Function
- DSK_SETLOGICALMAP (03h)
- Description
- Set Logical Map
Description
This function sets the next logical drive letter that is used to reference the drive.
Parameter Packet Format
| Field | Length | C Datatype |
|---|---|---|
| Command Information | BYTE | UCHAR |
Data Packet Format
| Field | Length | C Datatype |
|---|---|---|
| Logical Drive Number | BYTE | UCHAR |
Returns
Possible values are shown in the following list:
| Code | Description |
|---|---|
| 0 | NO_ERROR |
| 1 | ERROR_INVALID_FUNCTION |
| 6 | ERROR_INVALID_HANDLE |
| 15 | ERROR_INVALID_DRIVE |
| 31 | ERROR_GEN_FAILURE |
| 87 | ERROR_INVALID_PARAMETER |
| 111 | ERROR_BUFFER_OVERFLOW |
| 115 | ERROR_PROTECTION_VIOLATION |
| 117 | ERROR_INVALID_CATEGORY |
| 119 | ERROR_BAD_DRIVER_LEVEL |
| 163 | ERROR_UNCERTAIN_MEDIA |
| 165 | ERROR_MONITORS_NOT_SUPPORTED |
Remarks
When copying diskettes on a drive whose physical drive number has more than one logical drive letter assigned to it, the operating system issues diskette swap prompts to tell the user which logical drive letter is currently referencing the physical drive number. Function 03h is typically used to avoid this prompt by setting a drive number (corresponding to the drive letter) that is referenced in the next I/O request. The last logical drive letter assigned to the physical drive is determined by calling DSK_GETLOGICALMAP. On entry, a logical drive number (1=A, 2=B, and so forth) is specified. On return, this byte specifies the logical drive currently mapped to the drive that the specified file handle is opened on. A zero is returned if there is only one logical drive mapped onto this physical drive.