Fileattr

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FileAttr

Returns an open file number's mode, system handle or encoding.

Syntax

Declare Function FileAttr ( ByVal filenum As Long, ByVal returntype As Long = 1 ) As Integer

Parameters

• filenum
• returntype

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

Return Value

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

Remarks

Usage

#include "file.bi"

result = FileAttr( filenum, [ returntype ] )

or

#include "vbcompat.bi"

result = FileAttr( filenum, [ returntype ] )

Differences from QB

• None for returntype = 1
• QBasic and 16-bit Visual Basic returned DOS file handle for returntype = 2
• returntype = 3 is new to FreeBASIC

See also

• Open

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

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Category: Operating System Functions
Kind: function

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Reproduced from the FreeBASIC Wiki Manual under the GNU Free Documentation License 1.3 — with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. Copyright © the FreeBASIC project and wiki contributors. See License.