DS:DX address of an unopened FCB (filespec may contain '?'s)
Returns: AL 00H if a matching filename found (and DTA is filled)
ffH if no match was found
Info: The DOS default directory is searched for a file that matches
that in the FCB pointed to by DS:DX. AL returns 0ffH if no match
If a match is found, AL returns 00h, the DTA is filled with the
first byte as the drive (A=1, B=2, etc.) and the DirEntryRec of
the file is stored in the next 32 bytes.
You can use an Extended FCB in the call to select specific files
with 0ffH, 7 bytes of 00s, the drive number, and the dir entry.
In either case, the DTA is filled with a valid, unopened FCB.
Use DOS Fn 12H Find Next FCB to search for additional matches.
Notes: If you intend to search for more files, don't perform any I/O
operations on a "found" file. Copy the FCB somewhere else
The DOS 2.0+ function 4eh Find 1st File is easier to use and
employs normal d:\path\filespec format.
Although this fn has been superseded, it is still useful for
since it returns the "starting cluster number" for a file.
COMMAND.COM itself uses this in processing Dir /C.
See Also: Fn 1aH (set DTA)