Int 21 Fn 4E  - Dos 2+ - "findfirst" - Find First Matching File            [D]

   AH = 4Eh
   AL = special flag for use by APPEND (refer to note below)
   CX = file attribute mask (see #1107 at AX=4301h) (bits 0 and 5 ignored)
       0088h (Novell DOS 7) find first deleted file
   DS:DX -> ASCIZ file specification (may include path and wildcards)

Return: CF clear if successful
       Disk Transfer Area filled with FindFirst data block (see #1312)
   CF set on error
       AX = error code (02h,03h,12h) (see #1366 at AH=59h/BX=0000h)

Notes: for search attributes other than 08h, all files with at MOST the
     specified combination of hidden, system, and directory attributes
     will be returned.  Under DOS 2.x, searching for attribute 08h
     (volume label) will also return normal files, while under DOS 3.0+
     only the volume label (if any) will be returned.
   this call also returns successfully if given the name of a character
     device without wildcards.  DOS 2.x returns attribute 00h, size 0,
     and the current date and time.  DOS 3.0+ returns attribute 40h and
     the current date and time.
   immediately after an INT 2F/AX=B711h (APPEND return found name), the
     name at DS:DX will be overwritten; if AL=00h on entry, the actual
     found pathname will be stored, otherwise, the actual found path
     will be prepended to the original filespec without a path.
   under LANtastic, this call may be used to obtain a list of a server's
     shared resources by searching for "\\SERVER\*.*"; a list of printer
     resources may be obtained by searching for "\\SERVER\@*.*"
   under the FlashTek X-32 DOS extender, the filespec pointer is in DS:EDX
BUGS:  under DOS 3.x and 4.x, the second and subsequent calls to this function
     with a character device name (no wildcards) and search attributes
     which include the volume-label bit (08h) will fail unless there is
     an intervening DOS call which implicitly or explicity performs a
     directory search without the volume-label bit.  Such implicit
     searches are performed by CREATE (AH=3Ch), OPEN (AH=3Dh), UNLINK
     (AH=41h), and RENAME (AH=56h)
   DR DOS 3.41 and 5.0 return the Directory attribute for the volume label

See Also: AH=11h,AH=4Fh,AX=4301h,AX=714Eh,AX=71A1h,AX=F257h/SF=02h

See Also: INT 2F/AX=111Bh,INT 2F/AX=B711h

Format of FindFirst data block:
Offset Size    Description (Table 1312)
---PC-DOS 3.10, PC-DOS 4.01, MS-DOS 3.2/3.3/5.0---
 00h   BYTE    drive letter (bits 0-6), remote if bit 7 set
 01h 11 BYTEs  search template
 0Ch   BYTE    search attributes
---DOS 2.x (and some DOS 3.x???)---
 00h   BYTE    search attributes
 01h   BYTE    drive letter
 02h 11 BYTEs  search template
---WILDUNIX.COM---
 00h 12 BYTEs  15-character wildcard search pattern and drive letter (packed)
 0Ch   BYTE    search attributes
---DOS 2.x and most 3.x---
 0Dh   WORD    entry count within directory
 0Fh   DWORD   pointer to DTA???
 13h   WORD    cluster number of start of parent directory
---PC-DOS 4.01, MS-DOS 3.2/3.3/5.0---
 0Dh   WORD    entry count within directory
 0Fh   WORD    cluster number of start of parent directory
 11h  4 BYTEs  reserved
---OS/2 MVDM---
 00h   WORD    "OS2_BMP_handle"
 02h   WORD    "OS2_LastEnt"
 04h   DWORD   "OS2_Checksum"
 08h   BYTE    "OS2_usi_flag"
 09h   DWORD   used by DOS emulator for second pass for volume-label searches
 0Dh   WORD    (ret) "DOS_LastEnt" entry count within directory
 0Fh   BYTE    OS/2 Processed-FindFirst flag
       00h FindFirst processed by DOS
       42h FindFirst processed by OS/2
 10h  5 BYTEs  reserved for future use
---all versions, documented fields---
 15h   BYTE    attribute of file found
 16h   WORD    file time (see #1351 at AX=5700h)
 18h   WORD    file date (see #1352 at AX=5700h)
 1Ah   DWORD   file size
 1Eh 13 BYTEs  ASCIZ filename+extension