Unknown behavior at runtime when reading a file

Question

I have the following simple code to read a file:

std::basic_ifstream<wchar_t> RFile(L"C:\\file.exe", std::ios::binary|std::ios::ate);
if (!RFile.is_open()){ cout << "Cannot open the file." << endl; return 0;}
std::streamoff fileSize = RFile.tellg();
wstring fileContent;
fileContent.reserve(fileSize);
RFile.seekg(0, std::ios::beg);
if (!RFile.read(&fileContent[0], fileSize)) cout << "An error when reading the file." << endl;
RFile.close();

There are no errors appear while compiling or runtime too but there is unknown behavior at runtime/debugging, the program doesn't end and still waiting (something like waiting for inputs).

Is there some wrong in my code?

---

EDIT

The program finally ended and completed its work, however, I noted:

• The program takes almost 32 seconds to just read 17 MB, is that normal or there is something in my code (I think that is very slow)?
• Also when using char data type instead wchar_t the reading process became fast as it should be, so, is the problem in wchar_t data type or what?

Answer 1

You're reading wstring. The size of wchar_t on your system is probably not a byte. Sizing from the filesize in bytes is not correct then.

I would use a more idiomatic approach instead of doing the manual chores:

#include <fstream>
#include <string>
#include <iostream>

int main() {
    std::wifstream file;
    try {
        file.exceptions(std::ios::failbit | std::ios::badbit);
        file.open("C:\\file.exe", std::ios::binary);

        std::wstring const content(
                std::istreambuf_iterator<wchar_t>(file), {});

        std::cout << "Read " << content.size() << " characters\n";
    } catch(std::exception const& e) {
        std::wcout << "error reading file: " << e.what() << "\n";
    }
}