FileOpen read and write

[SharpDressedMan]

Hi all,

I'd like to open an existing file for both reading and writing. (Just like the C function fopen() does with parameter mode = "r+").

I tried FileOpen() with parameter mode = $FO_OVERWRITE (2) but this erases the file content right at opening...

Can someone explain me how to do that, if possible ?

AutoIt help for function FileSetPos() let me think that both reading and writing to a file is allowed with AutoIt, but how doing so with an existing file ?

Thanks by advance for your help.

[JohnOne]

$FO_OVERWRITE

What did you think it would do?

What other flags did you see in the help file?

[Trong]

All in Help File !

Try:

FileOpen( "file",1+8)

$FO_READ (0) = Read mode (default)
    $FO_APPEND (1) = Write mode (append to end of file)
    $FO_OVERWRITE (2) = Write mode (erase previous contents)
    $FO_CREATEPATH (8) = Create directory structure if it doesn't exist (See Remarks).
    $FO_BINARY (16) = Force binary mode (See Remarks).
    $FO_UNICODE or $FO_UTF16_LE (32) = Use Unicode UTF16 Little Endian reading and writing mode. Reading does not override existing BOM.
    $FO_UTF16_BE (64) = Use Unicode UTF16 Big Endian reading and writing mode. Reading does not override existing BOM.
    $FO_UTF8 (128) = Use Unicode UTF8 (with BOM) reading and writing mode. Reading does not override existing BOM.
    $FO_UTF8_NOBOM (256) = Use Unicode UTF8 (without BOM) reading and writing mode.
 

a

[SharpDressedMan]

  On 4/13/2015 at 3:23 PM, JohnOne said:

$FO_OVERWRITE

What did you think it would do?

What other flags did you see in the help file?

 

Well, fopen(..., "r+") does allow overwriting part of the content of a file if you write to it, but does not overwrite the whole file.

That's certainly what I supposed when I tried this flag.

[SharpDressedMan]

  On 4/13/2015 at 3:29 PM, Trong said:

All in Help File !

Try:

FileOpen( "file",1+8)

$FO_READ (0) = Read mode (default)
    $FO_APPEND (1) = Write mode (append to end of file)
    $FO_OVERWRITE (2) = Write mode (erase previous contents)
    $FO_CREATEPATH (8) = Create directory structure if it doesn't exist (See Remarks).
    $FO_BINARY (16) = Force binary mode (See Remarks).
    $FO_UNICODE or $FO_UTF16_LE (32) = Use Unicode UTF16 Little Endian reading and writing mode. Reading does not override existing BOM.
    $FO_UTF16_BE (64) = Use Unicode UTF16 Big Endian reading and writing mode. Reading does not override existing BOM.
    $FO_UTF8 (128) = Use Unicode UTF8 (with BOM) reading and writing mode. Reading does not override existing BOM.
    $FO_UTF8_NOBOM (256) = Use Unicode UTF8 (without BOM) reading and writing mode.
 

a

 

Thanks Trong but I don't need to create the directory structure; the file I want to open already exists.(All in my post )

Edited April 13, 2015 by SharpDressedMan

[Trong]

if it doesn't exist, Else remove it (8)

[BrewManNH]

Use append mode.

[SharpDressedMan]

Thanks Trong and BrewManNH,

The answer was quite obvious but "append" did not sound to be the right thing to do, to me... as I want the file position to be set at begining of the file.

What I need to do to mimic fopen("filename", "r+") is then:

$file = FileOpen("filename", $FO_APPEND)

FileSetPos($file, 0, $FILE_BEGIN)

Thanks for your answers,