DosQHandType

This call determines whether a handle references a file or a device.

DosQHandType (FileHandle, HandType, FlagWord)

• FileHandle (HFILE) - input : File handle.
• HandType (PUSHORT) - output : Address of the value indicating the handle type. HandType is composed of two bytes:
  • 15 - Network bit:
    • 0 = The handle refers to a local file, device, or pipe.
    • 1 = Means that the handle refers to a remote file, device, or pipe.
  • 14-8 - Reserved.
  • 7-0 - HandleClass describes the handle class. It may take on the following values in the low byte of HandleType:
    • 0 - Handle is for a disk file
    • 1 - Handle is for a character device
    • 2 - Handle is for a pipe.

Values greater than 2 are reserved.

• FlagWord (PUSHORT) - output : Address of the device driver's attribute word if HandleType indicates a local character device.

rc (USHORT) - return

Return code descriptions are:

• 0 NO_ERROR
• 6 ERROR_INVALID_HANDLE

This function allows programs that are interactive or file-oriented to determine the source of their input. For example, CMD.EXE suppresses writing prompts if the input is from a disk file.

#define INCL_DOSFILEMGR
 
USHORT  rc = DosQHandType(FileHandle, HandType, FlagWord);
 
HFILE   FileHandle;    /* File handle */
PUSHORT HandType;      /* Handle type (returned) */
PUSHORT FlagWord;      /* Device driver attribute (returned) */
 
USHORT  rc;            /* return code */

EXTRN  DosQHandType:FAR
INCL_DOSFILEMGR     EQU 1
 
PUSH   WORD    FileHandle    ;File handle
PUSH@  WORD    HandType      ;Handle type (returned)
PUSH@  WORD    FlagWord      ;Device driver attribute (returned)
CALL   DosQHandType
 
Returns WORD