Int 21 Fn 52 U - Dos 2+ Internal - "sysvars" - Get List Of Lists (Cont.)
17h WORD counter for last open of FCB
(these are separate to determine the times of the
latest I/O and open)
---
19h WORD relative cluster within file of last cluster accessed
1Bh WORD absolute cluster number of last cluster accessed
0000h if file never read or written???
1Dh WORD number of sector containing directory entry
(see #1041)
1Fh BYTE number of dir entry within sector (byte offset/32)
20h 11 BYTEs filename in FCB format (no path/period, blank-padded)
2Bh DWORD (SHARE.EXE) pointer to previous SFT sharing same file
2Fh WORD (SHARE.EXE) network machine number which opened file
(Windows Enhanced mode DOSMGR uses the virtual machine
ID as the machine number; see INT 2F/AX=1683h)
31h WORD PSP segment of file's owner (see #1066 at AH=26h)
(first three entries for AUX/CON/PRN contain segment
of IO.SYS startup code)
33h WORD offset within SHARE.EXE code segment of
sharing record (see #1323) 0000h = none
See Also: #1325,#1326,#1328
Format of DOS 4.0-6.0 system file tables and FCB tables:
Offset Size Description (Table 1328)
00h DWORD pointer to next file table (offset FFFFh if last)
04h WORD number of files in this table
06h 3Bh bytes per file
Offset Size Description
00h WORD number of file handles referring to this file
FFFFh if in use but not referenced
02h WORD file open mode (see AX=6C00h,#1090 at AH=3Dh)
bit 15 set if this file opened via FCB
04h BYTE file attribute (see #1107 at AX=4301h)
05h WORD device info word (see also #1110 at AX=4400h)
bit 15 set if remote file
bit 14 set means do not set file date/time on closing
bit 13 set if named pipe
bit 12 set if no inherit
bit 11 set if network spooler
bit 7 set if device, clear if file (only if local)
bits 6-0 as for AX=4400h
07h DWORD pointer to device driver header if character device
else pointer to DOS Drive Parameter Block
(see #1083 at AH=32h) or REDIR data
0Bh WORD starting cluster of file (local files only)
0Dh WORD file time in packed format (see #1351)
0Fh WORD file date in packed format (see #1352)
11h DWORD file size
15h DWORD current offset in file (SFT)
LRU counters (FCB table, two WORDs)
---local file---
19h WORD relative cluster within file of last cluster accessed
1Bh DWORD number of sector containing directory entry
1Fh BYTE number of dir entry within sector (byte offset/32)
---network redirector---
19h DWORD pointer to REDIRIFS record
1Dh 3 BYTEs ???
------
20h 11 BYTEs filename in FCB format (no path/period, blank-padded)
2Bh DWORD (SHARE.EXE) pointer to previous SFT sharing same file
2Fh WORD (SHARE.EXE) network machine number which opened file
(Windows Enhanced mode DOSMGR uses the virtual machine
ID as the machine number; see INT 2F/AX=1683h)
31h WORD PSP segment of file's owner (see #1066 at AH=26h)
(first three entries for AUX/CON/PRN contain segment
of IO.SYS startup code)
33h WORD offset within SHARE.EXE code segment of
sharing record (see #1281) 0000h = none
35h WORD (local) absolute cluster number of last clustr accessed
(redirector) ???
37h DWORD pointer to IFS driver for file, 0000000h if native DOS
Note: the OS/2 2.0 DOS Boot Session does not properly fill in the filename
field due to incomplete support for SFTs; the OS/2 2.0 DOS Window
does not appear to support SFTs at all
See Also: #1325,#1326,#1327
Format of current directory structure (CDS) (array, LASTDRIVE entries):
Offset Size Description (Table 1329)
00h 67 BYTEs ASCIZ path in form X:\PATH (local) or UNC form
\\SERVER\PATH (network, see notes below)
43h WORD drive attributes (also see note below) (see also AX=5F07h)
bit 15: uses network redirector \ invalid if 00, installable
bit 14: physical drive / file system if 11
bit 13: JOIN'ed \ path above is true path that would be
bit 12: SUBST'ed / needed if not under SUBST or JOIN
bit 7: remote drive hidden from redirector's assign-list and
exempt from network connection make/break commands;
set for CD-ROM drives by MSCDEX (not supported by
CORELCDX)
45h DWORD pointer to Drive Parameter Block for drive
(see #1083 at AH=32h)
---local drives---
49h WORD starting cluster of current directory
0000h = root, FFFFh = never accessed
4Bh WORD ??? seems to be FFFFh always
4Dh WORD ??? seems to be FFFFh always
---network drives---
49h DWORD pointer to redirector or REDIRIFS record, or FFFFh:FFFFh
(DOS 4 only) available for use by IFS driver
4Dh WORD stored user data from INT 21/AX=5F03h