BltIx4InfoFile


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TBLT_RETC TBLT_ENTRY BltIx4InfoFile(TBLT_FNCHAR *filenamePtr,
                                    ULONG asMode,
                                    TBLT_IX4INFO *ix4InfoPtr,
                                    TBLT_AUXPACK *apPtr);


 filenamePtr    I:name of file to get info on
 asMode         I:access-share mode used for temporary open
 ix4InfoPtr     I:structure to store the IX4 info
 apPtr          I:auxiliary pack

This routine should be called before opening an unknown IX4 file (where its node size is not known), especially to get the node size used so that a TBLT_KH structure of correct size can be allocated for the actual open.

asMode is the access-sharing mode to open the file. See BltDataOpenFile() for modes available. The file is closed before this routine exits.

TBLT_IX4INFO is the same structure as the first 44 bytes of the TBLT_KH structure starting from fileID. TBLT_IX4INFO.nodeSize is used to determine what size the TBLT_KH allocation must be to hold both the TBLT_KH structure and the node buffer. The TBLT_KH structure includes allocation for a 512-byte buffer (the typical node size). The total allocation size for TBLT_KH, then, required prior to calling BltIx4OpenFile(), is

 sizeof(TBLT_KH) + (nodeSize-512)

apPtr is the pointer to an optional auxiliary pack. Set apPtr = 0 if there is no pack. This pack lets you override the internal operating system IFS calls for this handle, and set IFS options, such as 64-bit file offsets. See the supplemental documentation for details. Once opened, apPtr is set in the TBLT_KH structure. Returns: Non-zero indicates an error, otherwise the structure at ix4InfoPtr receives the first 44 bytes of the IX4 header on disk.

All content Copyright © 1999 Cornel Huth. All rights reserved.