(Non-Compound) FileType Key
Used by GetClassFile
Registry Entry
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
\FileType
\<CLSID>
\<n> = <offset, cb,
mask, value>
Value Entries
<offset, cb, mask, value>
Offset and cb are limited to 16 bits. Offset
is from the beginning or end of the file, with a negative value for offset
being interpreted from the end of the file; cb is a the length in bytes.
Together, these values represent a particular byte range in the file. mask
is a bit mask used to perform a logical AND operation, using the byte range
spedified by offsert and cb. The result of the AND operation is
compared with If mask is omitted, it is assumed to all ones. offset
and cb are decimal unless preceded by "0x". mask and pattern
are always hex.
Remarks
Entries under
the FileType key are used by the GetClassFile2XAODC function to match patterns against various
file bytes in a non-compound file. FileType has CLSID subkeys, each of
which has a series of subkeys \0, \1, \2, ... These values contain a pattern
that, if matched, should yield the indicated CLSID. See also the GetClassFile
function.
Following are
examples of FileType entries.
\0 = 0, 4, FFFFFFFF,
ABCD1234
where the first 4 bytes must be ABCD12 34, in that order, or
\1 = 0, 4, FFFFFFFF,
9876543
where they must match 9876543, or .
\2 = -4, 4, FEFEFEFE
where the last four bytes in the file
must be FEFEFEFE.
See Also