Add string to big file

[Izebize]

Hi!

I'm working on an uploader. It uploads files throu PHP. For this I have to read a file and add some string to it. But if that file is too big, then it exits with this message: "Error allocating memory".

AU3 Snippet to illustrate my prob:

$fFile = "100MBfile.bin"        ;Contains 0x00 -> i have to use raw mode
$hFile = FileOpen($fFile, 4)    ;Open raw mode
$sFile = FileRead($hFile, FileGetSize($fFile))  ;Reads properly
FileWrite("output.txt", "StringBegin"&@CRLF& _
                        $sFile&@CRLF& _
                        'StringEnd'&@CRLF   ;Fails with allocating memory error
FileClose($hFile)

It reads the file properly, but if I add some string to it then it fails.

If you run this code with a file thats big enough then you will get the same message.

How can I add a string to big files without modifying the file itself?

Edited July 14, 2009 by Izebize

[Malkey]

A file can only be in either read or write mode; it cannot be in both.

[water]

Simply use FileWrite with a handle

$handle = Fileopen("file",2)
FileWrite($handle,"Text")
FileClose($handle)

[dantay9]

Malkey's right. You have to read what you want, close the file, then open it again in write mode. I think you want to add strings to the beginning and end of the text, not replace it. Try this:

$file = "Test.txt"
 $OpenRead = FileOpen($file, 0)
 $Read = FileRead($OpenRead, FileGetSize($file))
 
 FileClose($OpenRead)
 FileWrite("output.txt", "StringBegin" & @CRLF & $Read & @CRLF & "StringEnd")

Edited July 14, 2009 by dantay9

[Izebize]

You can see in my snippet, that I just read the file. I use write on "output.txt".

I could use ConsoleWrite, or MsgBox instead of FileWrite, but if you run it in Scite like most of us do, then your computer would not response to anything for a couple of days

Edited July 14, 2009 by Izebize

[water]

According to the help file FileWrite does "append a line of text to the end of a previously opened text file."

So simply open the file, write the record (it's automtically appended) and close the file.

Please use a handle (means: use fileopen) because "For parsing large text files this will be much slower than using filehandles."

As you want to append to a new file I would use:

filecopy("source","target",9)          ; Create a copy of the source file (replace existing file and create directory structure if missing
$handle = Fileopen("target",2)         ; Open the target file
FileWrite($handle,"Text")              ; Append text to the target file
FileClose($handle)                     ; Close target file

Edited July 14, 2009 by water

[Izebize]

I've also read the help file.

I have to add string before, and after the file.

I also have to use raw mode, because it contains 0x00 char, and if i open it a regular way it stops after 4 chars, because of the 0x00 char (null-terminated string).

As I said before, I can read the file. The only problem is I can't add any string to it.

Edited July 14, 2009 by Izebize

[SmOke_N]

  On 7/14/2009 at 2:27 PM, 'Izebize said:

I've also read the help file.

I have to add string before, and after the file.

I also have to use raw mode, because it contains 0x00 char, and if i open it a regular way it stops after 4 chars, because of the 0x00 char (null-terminated string).

As I said before, I can read the file. The only problem is I can't add any string to it.

Take a look at:

_WinAPI_CreateFile()

_WinAPI_WriteFile()

In the help file. WriteFile has the option to insert data at specific points of the file without having to read it all.

[water]

I think I understand your problem

Haven't tested it but I would try something like:

FileWrite("front.txt","line of text")
FileWrite("end.txt","line of text")
RunWait(@ComSpec & " /c " & "copy front.txt /B + 10mb.txt /B + end.txt /B output.txt /B")

This should copy the 3 input files to the output file in binary format.

[Izebize]

@SmOke_N: Thanks! It looks good, I'll check it right now.

@water: That probably works, but with this method I have to copy the big file once more every time, and that takes too much time if I want to work with hundreds of big files.

[Izebize]

Finally I got the solution.

I used DllStruct like this:

$fFile = "100MBfile.bin"        ;Contains 0x00 -> i have to use raw mode
$hFile = FileOpen($fFile, 4)    ;Open raw mode
$sStringB = "StringBEGIN"
$sStringE = "StringEND"
$tBuffer = DllStructCreate("byte["&StringLen($sStringB)&"];byte["&FileGetSize($fFile)&"];byte["&StringLen($sStringE)&"]")
DllStructSetData($tBuffer, 1, $sStringB)
DllStructSetData($tBuffer, 2, FileRead($hFile, FileGetSize($fFile)))
DllStructSetData($tBuffer, 3, $sStringE)
FileClose($hFile)
FileWrite($fNew, DllStructGetData($tBuffer, 1) & _
                DllStructGetData($tBuffer, 2) & _
                DllStructGetData($tBuffer, 3))

[trancexx]

Wow!

You are on completely different level.