c++ - 使用 ifstream 读取二进制文件

Question

我正在尝试读入 .exe 并将其写回。我的代码适用于 .txt 文件，但由于某种原因它破坏了可执行文件。我究竟做错了什么？不知道是我读错了还是写错了..

#include <string>
#include <vector>
#include <iostream>
#include <filesystem>
#include <unordered_set>

#include <Windows.h>

unsigned char *ReadFileAsBytes(std::string filepath, DWORD &buffer_len)
{
    std::ifstream ifs(filepath, std::ofstream::binary | std::ifstream::ate);
    if (!ifs.is_open())
    {
        return(nullptr);
    }

    // Go To End
    ifs.seekg(0, ifs.end);

    // Get Position (Size)
    buffer_len = static_cast<DWORD>(ifs.tellg());

    // Go To Beginning
    ifs.seekg(0, ifs.beg);

    // Allocate New Char Buffer The Size Of File
    PBYTE buffer = new BYTE[buffer_len];

    ifs.read(reinterpret_cast<char*>(buffer), buffer_len);
    ifs.close();

    return buffer;
}

void WriteToFile(std::string argLocation, unsigned char *argContents, int argSize)
{
    std::ofstream myfile;
    myfile.open(argLocation);
    myfile.write((const char *)argContents, argSize);
    myfile.close();
}

int main()
{
    // Config
    static std::string szLocation   = "C:\\Users\\Admin\\Desktop\\putty.exe";
    static std::string szOutLoc     = "C:\\Users\\Admin\\Desktop\\putty2.exe";

    DWORD dwLen;
    unsigned char *szBytesIn = ReadFileAsBytes(szLocation, dwLen);

    std::cout << "Read In " << dwLen << " Bytes" << std::endl;

    // Write To File
    WriteToFile(szOutLoc, szBytesIn, dwLen);

    system("pause");
}

Answer 1

您以二进制模式打开输入文件，但在此代码中

std::ofstream myfile;
myfile.open(argLocation);

您在没有二进制模式的情况下打开输出文件。并且没有理由单独调用 open:

std::ofstream myfile( argLocation, std::ios::out | std::ios::binary | std::ios::trunc);