fwrite()文件损坏C ++ [英] fwrite() File Corruption C++

问题描述

我是C ++的新手(从C#迁移过来)，所以我不确定这到底是怎么回事.我想做的是从文件中读取图像并将其写入输出文件，但是每当我这样做时，文件的某些部分似乎已损坏.

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.

我已经检查了内存中的数据并且它实际上匹配，所以我认为罪魁祸首一定是fwrite()发生的事情，尽管它总是可能只是我做错了什么.

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.

以下是一些示例数据: http://pastebin.com/x0eZin6K

Here's some sample data: http://pastebin.com/x0eZin6K

还有我的代码:

// 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;
        ZeroMemory(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;

推荐答案

您是否正在Windows上运行此代码?对于不需要文本翻译的文件，必须以二进制模式打开它们:

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+");

这就是您的输出文件中发生的情况:

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
                  ^^

C运行时库可以帮助您将\n转换为\r\n.

The C runtime library helpfully translated your \n to \r\n.

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