mov cx, Attributes ;attributes to set
mov dx, seg FileName
mov ds, dx
mov dx, offset FileName ;ds:dx points to filename or directory name
mov ax, 4301h ;Set File Attributes
int 21h
jc error_handler ;carry set means error
Set File Attributes (Function 4301h) sets the attributes for a specified file or directory.
Attributes
Specifies the new attributes for the file or directory. This parameter can be a combination of the following values:
| Value | Meaning |
| ATTR_NORMAL (0000h) | File can be read from or written to. |
| ATTR_READONLY (0001h) | File can read from but not written to. |
| ATTR_HIDDEN (0002h) | File is hidden and does not appear in a directory listing. |
| ATTR_SYSTEM (0004h) | File is a system file. |
| ATTR_ARCHIVE (0020h) | File has been archived. |
FileName
Points to a zero-terminated ASCII string that specifies the file or directory to set attributes for. This string must be a valid MS-DOS filename or directory name and cannot contain wildcards.
If the function is successful, the carry flag is clear. Otherwise, the carry flag is set and the AX register contains an error value, which may be one of the following values:
| Value | Name |
| 0001h | ERROR_INVALID_FUNCTION |
| 0002h | ERROR_FILE_NOT_FOUND |
| 0003h | ERROR_PATH_NOT_FOUND |
| 0005h | ERROR_ACCESS_DENIED |
Only ATTR_HIDDEN and ATTR_SYSTEM are meaningful for directories.
Function 4300h Get File Attributes