Subj : file modes
To : Chris Hoppman
From : Jasen Betts
Date : Sun Jul 04 2004 02:02 pm
Hello Chris.
02 Jul 04 23:08, you wrote to all:
CH> How would you go about setting file modes in tp?
CH> Like
CH> fm_deny_read_write;
CH> fm_allow_read_write;
CH> filemode := ??
Get yourself a good dos reference like "Ralf Brown's interrupt list"
(inter*.zip) the TP internals ar closely linked with DOS,
=== Cut ===
the following tables are takes from the above.
Bitfields for access and sharing modes:
Bit(s) Description (Table 0521)
2-0 access mode
000 read only
001 write only
010 read/write
011 (DOS 5+ internal) passed to redirector on EXEC to allow
case-sensitive filenames
3 reserved (0)
6-4 sharing mode (DOS 3+)
000 compatibility mode
001 "DENYALL" prohiboth read and write access by others
010 "DENYWRITE" prohiwrite access by others
011 "DENYREAD" prohiread access by others
100 "DENYNONE" allow full access by others
111 network FCB (only available during server call)
7 inheritance
if set, file is private to current process and will not be inherited
by child processes
(Table 0522)
Values of DOS file sharing behavior:
| Second and subsequent Opens
First |Compat Deny Deny Deny Deny
Open | All Write Read None
|R W RW R W RW R W RW R W RW R W RW
- - - - -| - - - - - - - - - - - - - - - - -
Compat R |Y Y Y N N N 1 N N N N N 1 N N
W |Y Y Y N N N N N N N N N N N N
RW|Y Y Y N N N N N N N N N N N N
- - - - -|
Deny R |C C C N N N N N N N N N N N N
All W |C C C N N N N N N N N N N N N
RW|C C C N N N N N N N N N N N N
- - - - -|
Deny R |2 C C N N N Y N N N N N Y N N
Write W |C C C N N N N N N Y N N Y N N
RW|C C C N N N N N N N N N Y N N
- - - - -|
Deny R |C C C N N N N Y N N N N N Y N
Read W |C C C N N N N N N N Y N N Y N
RW|C C C N N N N N N N N N N Y N
- - - - -|
Deny R |2 C C N N N Y Y Y N N N Y Y Y
None W |C C C N N N N N N Y Y Y Y Y Y
RW|C C C N N N N N N N N N Y Y Y
Legend: Y = open succeeds, N = open fails with error code 05h
C = open fails, INT 24 generated
1 = open succeeds if file read-only, else fails with error code
2 = open succeeds if file read-only, else fails with INT 24
-------------------------------------------------------------------------------
Jasen
