DosQFSInfo

Bindings:  C, MASM 

This call queries information from a file system device. 

 DosQFSInfo     (DriveNumber, FSInfoLevel, FSInfoBuf, FSInfoBufSize) 
 

 DriveNumber (USHORT) - input 
    Logical drive number (0 = default, 1 = A, and so on). 

    When a logical drive is specified, the media in the drive is examined 
    (local drive only) and the request is passed to the FSD responsible 
    for managing that media or to the FSD that is attached to the drive. 

 FSInfoLevel (USHORT) - input 
    Level of file information required. 

 FSInfoBuf (PBYTE) - output 
    Address of the storage area where the system returns the requested 
    level of file information. 

    Level 1 Information 
       For FSInfoLevel = 1, information is returned in the following 
       structure: 

       filesysid (ULONG) 
          File system ID. 

       sectornum (ULONG) 
          Number of sectors per allocation unit. 

       unitnum (ULONG) 
          Number of allocation units. 

       unitavail (ULONG) 
          Number of allocation units available. 

       bytesnum (USHORT) 
          Number of bytes per sector. 

    Level 2 Information 
       For FSInfoLevel = 2, the information is returned in the following 
       format: 

       reserved (ULONG) 
          Reserved 

       volumelength (BYTE) 
          Length of the volume label, not including the null. 

       volumelabel (CHAR) 
          Volume label ASCIIZ string. 

 FSInfoBufSize (USHORT) 
    Length of the buffer. 

 rc (USHORT) - return 
    Return code descriptions are: 

    0         NO_ERROR 
    15        ERROR_INVALID_DRIVE 
    111       ERROR_BUFFER_OVERFLOW 
    124       ERROR_INVALID_LEVEL 
    125       ERROR_NO_VOLUME_LABEL 
 
 Remarks 

 Trailing blanks supplied at volume label definition time are not 
 considered to be part of the label and are therefore not returned as 
 valid label data. Volume label is limited to a length of 11 bytes. 

 Volume Serial Number is a unique 32-bit number used by OS/2 to positively 
 identify its disk/diskette volumes.  The hard error prompts the user for 
 an unmounted removable volume by displaying both the Volume Serial Number 
 (as an 8 digit hexadecimal number) and the Volume Label. 

 If there is no volume serial number on the disk/diskette, the volume 
 serial number information is returned as binary zeros.  If there is no 
 volume label on the disk/diskette, the volume label information is 
 returned as blank spaces.  If there is no volume serial number and/or 
 volume label for disk/diskette volumes formatted by DOS 3.X, this 
 information is not displayed by the Hard Error Handler.