Interrupt 21h Function 7143h
Retrieves or
sets the file attributes, gets the compressed file size, or retrieves or sets
the date and time for the given file.
mov ax, 7143h
; Get or Set File Attributes
mov bl, Action ; see below
mov cx, Attributes ; see below
mov di, Date ; see below
mov cx, Time ; see below
mov si, MilliSeconds ; see below
mov dx, seg Filename ; see below
mov ds, dx
mov dx, offset Filename
int 21h
jc error
; see below for return values
Parameters
Action
Action to
take. This parameter can be one of the following values:
|
0 |
Retrieve
attributes. |
|
1 |
Set
specified attributes. |
|
2 |
Get
physical size of a compressed file. |
|
3 |
Set last
write date/time. |
|
4 |
Get last
write date/time. |
|
5 |
Set last
access date. |
|
6 |
Get last
access date. |
|
7 |
Set
creation date/time. |
|
8 |
Get
creation date/time. |
Attributes
File
attributes to set, which are used only if Action is 1. This parameter
can be a combination of these values:
|
_A_NORMAL
(0000h) |
|
|
|
|
The file
can be read from or written to. This value is valid only if used alone. |
|
|
_A_RDONLY
(0001h) |
|
|
|
|
The file
can be read from, but not written to. |
|
|
_A_HIDDEN
(0002h) |
|
|
|
|
The file is
hidden and does not appear in an ordinary directory listing. |
|
|
_A_SYSTEM
(0004h) |
|
|
|
|
The file is
part of the operating system or is used exclusively by it. |
|
|
_A_ARCH
(0020h) |
|
|
|
|
The file is
an archive file. Applications use this value to mark files for backup or
removal. |
|
Time
New time to
set, which is used only if Action is 3 (set last write date/time) or 7
(set creation date/time) The time is a packed 16-bit value with the following
form:
|
Bits |
Contents |
|
0-4 |
Second
divided by 2 |
|
5-10 |
Minute (0-59) |
|
11-15 |
Hour (0-23 on a 24-hour clock) |
Date
New date to
set, which is used only if Action is 3 (set last write date/time), 5
(set last access date), or 7 (set creation date/time). The date is a packed
16-bit value with the following form:
|
Bits |
Contents |
|
0-4 |
Day of the
month (1-31) |
|
5-8 |
Month (1 =
January, 2 = February, and so on) |
|
9-15 |
Year offset
from 1980 (that is, add 1980 to get the actual year) |
MilliSeconds
Number of 10
millisecond intervals in 2 seconds to add to the MS-DOS time. The number can be
a value in the range 0 to 199. This value is only used if Action is 7
(set creation date/time).
Filename
Address of a
null-terminated string specifying the name of the file to retrieve or set
attributes for. Long filenames are allowed.
Return Value
Clears the
carry flag if successful.
If Action
is zero (retrieve attributes), the file attributes returned in the CX register
may be a combination of the following values :
|
_A_NORMAL
(0000h) |
|
_A_RDONLY
(0001h) |
|
_A_HIDDEN
(0002h) |
|
_A_SYSTEM
(0004h) |
|
_A_VOLID
(0008h) |
|
_A_SUBDIR
(0010h) |
|
_A_ARCH
(0020h) |
If Action
is 2 (get physical size of a compressed file), the size, in bytes, of the
compressed file is returned in DX:AX. This value is the physical size of the
compressed file that is,
the actual number of bytes that the compressed file occupies on disk.
If Action
is 4 (get last write date/time) or 8 (get creation date/time), the CX register
contains the time as a packed 16-bit value with the following form:
|
Bits |
Contents |
|
0-4 |
Second
divided by 2 |
|
5-10 |
Minute (0-59) |
|
11-15 |
Hour (0-23 on a 24-hour clock) |
If Action
is 4 (get last write date/time), 6 (get last access date), or 8 (get creation
date/time), the DI register contains the date as a packed 16-bit value with the
following form:
|
Bits |
Contents |
|
0-4 |
Day of the
month (1-31) |
|
5-8 |
Month (1 =
January, 2 = February, and so on) |
|
9-15 |
Year offset
from 1980 (that is, add 1980 to get the actual year) |
If Action
is 8 (get creation date/time), the SI register contains the number of 10
millisecond intervals in 2 seconds to add to the MS-DOS time. The number can be
a value in the range of 0 to 199.
If the
function is not successful, it sets the carry flag and sets the AX register to
an error value.