FILEATTR


Returns information about an open file number

Syntax:
declare function FileAttr ( byval filenum as long, byval returntype as long = 1 ) as integer

Usage:
#include "file.bi"
result = FileAttr( filenum, [ returntype ] )

or
#include "vbcompat.bi"
result = FileAttr( filenum, [ returntype ] )

Parameters:
filenum
The file number of a file or device opened with Open
returntype
An integer value indicating the type of information to return.

Return Value:
A value associated with the return type, otherwise 0 on error.

Description:
Information about the file number is returned based on the supplied returntype
Value Description constant
1 File Mode fbFileAttrMode
2 File Handle fbFileAttrHandle
3 Encoding fbFileAttrEncoding


For File Mode, returntype = 1 (fbFileAttrMode) the return value is the sum of one or more of the following values:
Value File Mode Constant
1 Input fbFileModeInput
2 Output fbFileModeOutput
4 Random fbFileModeRandom
8 Append fbFileModeAppend
32 Binary fbFileModeBinary


For File Handle, returntype = 2 (fbFileAttrHandle), the return value is the file handle as supplied by the C Runtime for file-type devices.

On Windows only: For File Handle, returntype = 2 (fbFileAttrHandle), the value returned for COM devices is the handle returned by CreateFile() when the device was first opened. The value returned for LPT devices is the handle returned by OpenPrinter() when the device was first opened. This handle value can be passed to other Windows API functions.

On Linux only: For File Handle, returntype = 2 (fbFileAttrHandle), the value returned for COM devices is the file descriptor returned by open() when the device was first opened.

For Encoding, returntype = 3 (fbFileAttrEncoding), the return value is one of the following values:
Value Encoding Constant
0 Ascii fbFileEncodASCII
1 UTF-8 fbFileEncodUTF8
2 UTF-16 fbFileEncodUTF16
3 UTF-32 fbFileEncodUTF32


Examples:
#include "vbcompat.bi"
#include "crt.bi"

Dim f As FILE Ptr, i As Integer

'' Open a file and write some text to it

Open "test.txt" For Output As #1
f = Cast( FILE Ptr, FileAttr( 1, fbFileAttrHandle ))
For i = 1 To 10
  fprintf( f, !"Line %i\n", i )
Next i
Close #1

'' re-open the file and read the text back

Open "test.txt" For Input As #1
f = Cast( FILE Ptr, FileAttr( 1, fbFileAttrHandle ))
While feof(f) = 0
  i = fgetc(f)
  Print Chr(i);
Wend
Close #1


Differences from QB:
See also:
Back to Operating System Functions
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