如何使用 std::ifstream 读取具有宽字符串路径的二进制文件
我正在读取二进制文件：
const size_t stBuffer = 256;
char buffer[stBuffer];
std::wstring wPath(L"blah");
std::wifstream ifs(wPath.c_str(), std::wifstream::in | std::wifstream::binary)
while (ifs.good())
{
ifs.read(buffer, sizeof(buffer));
...
}
但我意识到这不是真正的二进制读取。 ifstream 实际上读取一个字节并将其转换为宽字符。因此，如果二进制文件的内容为 0x112233...ff，我实际上读取的是 0x110022003300...ff00。
这对我来说没有多大意义：首先，我只需要使用宽 fstream，因为文件名不是拉丁文。其次，如果我说fstream是二进制的，为什么read读取宽字符？下面的代码做了我想要的。有没有办法使用 std fstreams 来实现这一点？
FILE* ifs = _wfopen(L"blah", L"rb");
while (!feof(ifs))
{
size_t numBytesRead = fread(buffer, 1, sizeof(buffer), ifs);
...
}
I am reading a binary file as:
const size_t stBuffer = 256;
char buffer[stBuffer];
std::wstring wPath(L"blah");
std::wifstream ifs(wPath.c_str(), std::wifstream::in | std::wifstream::binary)
while (ifs.good())
{
ifs.read(buffer, sizeof(buffer));
...
}
But I am realizing this is not a true binary read. The ifstream actually reads a byte and converts it to a wide char. So if the binary file has the content 0x112233...ff, I actually read 0x110022003300...ff00.
This doesn't make much sense to me: first, I only need to use a wide fstream because the file name is non Latin. Second, if I say the fstream is binary, why does read read wide chars? The code below does what I want. Is there a way to achieve that using std fstreams?
FILE* ifs = _wfopen(L"blah", L"rb");
while (!feof(ifs))
{
size_t numBytesRead = fread(buffer, 1, sizeof(buffer), ifs);
...
}
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当前的 C++ 标准不提供宽字符路径。即使 wchar_t 版本也会收到常规的 const char* 文件名。您已经使用了编译器扩展，因此请继续将此扩展与普通 ifstream 一起使用：
编辑：考虑使用 utf- 8 个字符串 而不是宽字符串，并使用 Boost.Nowide （尚未在boost）来打开文件。
编辑： Boost.Nowide 在 boost 中被接受。此外，Windows 10 添加了对 UTF- 的支持8 位于其窄字符串 API 中，可以通过清单启用。这使得所有宽字符接口几乎不可移植且冗余。
The current C++ standard doesn't provide wide char paths. Even the wchar_t version receives a regular const char* filename. You already used a compiler extension, so continue using this extension with a normal ifstream:
EDIT: consider using utf-8 strings instead of wide strings and use Boost.Nowide (not yet in boost) to open files.
EDIT: Boost.Nowide was accepted in boost. Also Windows 10 added support for UTF-8 in its narrow-string API, which can be enabled through a manifest. This makes all the wide-char interfaces pretty much unportable and redundant.