fwrite() File Corruption C++
I'm somewhat of a newbie to C++ (moving from C#) so I'm not exactly sure what's going on here. What I'm trying to do is read an image out of a file and write it to an output file, but whenever I do parts of the file appear to be corrupt.
I've checked the data in memory and it actually matches, so I believe the culprit has to be something going on with fwrite(), although it could always just be something I'm doing wrong.
Here's some sample data: http://pastebin.com/x0eZin6K
And my code:
// used to figure out if reading in one giant swoop has to do with corruption
int BlockSize = 0x200;
// Read the file data
unsigned char* data = new unsigned char[BlockSize];
// Create a new file
FILE* output = fopen(CStringA(outputFileName), "w+");
for (int i = 0; i < *fileSize; i += BlockSize)
{
if (*fileSize - i > BlockSize)
{
ZeroMemory(data, BlockSize);
fread(data, sizeof(unsigned char), BlockSize, file);
// Write out the data
fwrite(data, sizeof(unsigned char), BlockSize, output);
}
else
{
int tempSize = *fileSize - i;
ZeroM开发者_JAVA技巧emory(data, tempSize);
fread(data, sizeof(unsigned char), tempSize, file);
// Write out the data
fwrite(data, sizeof(unsigned char), tempSize, output);
}
}
// Close the files, we're done with them
fclose(file);
fclose(output);
delete[] data;
delete fileSize;
Are you running this code on Windows? For files that don't need text translation, you must open them in binary mode:
FILE* output = fopen(CStringA(outputFileName), "wb+");
This is what happens in your output file:
07 07 07 09 09 08 0A 0C 14 0D 0C
07 07 07 09 09 08 0D 0A 0C 14 0D 0C
^^
The C runtime library helpfully translated your \n
to \r\n
.
You need to open the file as a binary by adding "b" to the mode.
http://www.cplusplus.com/reference/clibrary/cstdio/fopen/
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