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#define INCL_DOSFILEMGR
 
USHORT DosQHandType(hf, pfsType, pusDeviceAttr)
HFILE hf;                 /* file handle                              */
PUSHORT pfsType;          /* pointer to variable for handle type      */
PUSHORT pusDeviceAttr;    /* pointer to variable for device attribute */
 
The DosQHandType function retrieves information that specifies whether the
given file handle identifies a file, device, or pipe.
 
Parameter      Description
────────────────────────────────────────────────────────────────────────────
 
hf             Identifies the file. This handle must have been created
               previously by using the DosOpen function.
 
pfsType        Specifies the type of file or device associated with the file
               handle. It can be one of the following:
 
               Value            Meaning
               ─────────────────────────────────────────────────────────────
               HANDTYPE_DEVICE  The handle is to a device, such as a
                                printer.
 
               HANDTYPE_FILE    The handle is to a file.
 
               HANDTYPE_PIPE    The handle is to a pipe.
 
               If the file or device is located on a network, this parameter
               is a combination of one of the values given above and the
               value HANDTYPE_NETWORK (0x8000).
 
pusDeviceAttr  Points to the variable that receives the device-driver
               attribute word.
 
Return Value
 
The return value is zero if the function is successful. Otherwise, it is an
error value, which may be the following:
 
     ERROR_INVALID_HANDLE
 
Comments
 
The DosQHandType function allows some interactive or file-oriented programs
to determine the source of their input. For example, the cmd.exe program
suppresses the system prompt if the input is from a disk file.
 
Example
 
This example calls the DosQHandType function to determine if standard output
has been redirected to a file. The LOBYTE macro is an important part of this
example; it allows the handle type to be determined even if the handle is to
a file or device on a network:
 
USHORT fsType, usDeviceAttr;
DosQHandType(1,                         /* file handle      */
    &fsType,                            /* type of handle   */
    &usDeviceAttr);                     /* device attribute */
if (LOBYTE(fsType) == HANDTYPE_DEVICE)
    VioWrtTTY("stdout is a device\r\n", 20, 0);
else if (LOBYTE(fsType) & HANDTYPE_FILE) {
    if (fsType & HANDTYPE_NETWORK)
        VioWrtTTY("stdout is a networked file\r\n", 28, 0);
    else
        VioWrtTTY("stdout is a local file\r\n", 24, 0);
}
 
See Also
 
DosOpen, DosQFHandState
 
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