AutoHotkey Community

[mare]

Thanks for the explaination, i'm begining to understand DllCalling but for now i'll skip that part, i need more practise.

I have managed to split encrypted data in two pieces, first written where data was read, second somewhere in the file, but now i have some extra bytes that i would like to delete.
I tried to write blank value on that position with offset setting, it only writes 0000 0000...

How can i delete those bytes, i want to write NULL ?

[Laszlo]

If you have hex buffers, write 0x00... there. In binary buffers use NumPut(0,...), before writing to disk.

[mare]

I dont know what hex buffers are, if this is what you meant, from Hex Editor:

[Laszlo]

I meant by Hex Buffer the AHK variable containing hex digits, which are used in the file I/O in the functions in this thread.

The BinWrite function does not do anything in your code, because there is no data (empty string). If you want to write 8 NUL bytes, set "del = 0000000000000000" (16 0-chars).

[mare]

No no no, i want to delete those 8 bytes, remove them compleately from file,
I'm trying to write 0x00 and again it overwrites them to 0000...

Again, i want to delete those 8 bytes.
That's why i tried to write empty value.

[Laszlo]

Read the file in a (hex or binary) buffer, delete the unwanted entries from the buffer and write the whole buffer back to disk. In case of the hex buffer you need StringLeft/Right, in case of the binary buffer you need DllCall("RtlMoveMemory"...

[mare]

Yes i know that but i dont know how to delete unwanted entries.

[Laszlo]

[mare]

Either i dont understand your script or you dont understand my problem.
I was able to split 123456 to 123 and 456 for example, but i have an extra bytes allready written in the file that i want to delete.

Original file is 200 bytes, encrypted is 208 bytes, so i want to delete those 8 bytes.

[Laszlo]

I don’t understand your problem. I said: "Read the file in a (hex or binary) buffer, delete the unwanted entries from the buffer and write the buffer back to disk." If the unwanted entries are in the end of the buffer, you only need to specify a shorter length (n), otherwise you need to copy pieces of the buffer to another (or the same) variable, and write that one to disk.

[mare]

I think i understand you now, you meant, read whole file, delete unwanted, and write file again from begining to end.
Something like this perhaps:

[Laszlo]

read-file, delete it, process data, write same file

If you want to truncate the file, you could do it faster with Windows system calls, but you have to browse MSDN for the details

[Guest]

[mare]

Thanks, it seems that those 8 extra bytes of 0000 does not have effect on file, file is working properly, file size is changed only, but that is not really a problem.

[xazax]

I have trouble with this function.

res := BinWrite(file,v,0,%k%)

where file: %A_WorkingDir%\Filename
v : 8b
k: 25E59F

I want to write a byte on offset 25E59F from anything to 8B

The Function returns here: