|
Remarks |
filenum&
is the handle of a currently open file. fattr is an integer
between -3 and 3 that specifies the type of information required, according
to the following table:
|
fattr |
Definition |
|
-3 |
The device type. Returns 1 for a file,
2 for a device. COMM, TCP and UDP are classified as
devices. |
|
-2 |
Logical first byte (base) position of a disk file.
By default, PowerBASIC opens files with a default first location of 1,
but this can be overridden via the BASE= clause of the OPEN
statement. This function can be useful when the base is not
known or when performing SEEK operations. |
|
-1 |
The minimum amount of data that can be read or written
at one time. For RANDOM files,
it is the record length. For INPUT
files, it is the input buffer length (set with LEN= in the OPEN statement).
For BINARY, OUTPUT
and APPEND, there is no buffering,
so it always returns 1 (1 byte). |
|
0 |
The open state. TRUE (non-zero) if open, FALSE (zero)
if closed. |
|
1 |
The file mode (which may be a combination of the
following): |
|
|
(for example, an APPEND file will return 8 + 2 =
10). |
|
2 |
The operating system file handle for the file.
This handle can be used with particular Windows API calls files to manipulate
files opened with PowerBASIC, and with the OPEN
HANDLE statement. |
|
3 |
Enumerates existing file numbers. This mode
enumerates existing file numbers, in the range of 1 to 32767. FILEATTR(1,3)
returns the first located file number, FILEATTR(2,3) the second, and so
on until -1 is returned to indicate that there are no more file numbers
active. The file numbers returned are not guaranteed to be returned
in any particular sequence, nor be open. You can use FILEATTR(#filenum,0)
to determine whether a given file number is open or closed.
The number symbol [#] is optional, but recommended for clarity. |
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