为 char16_t 寻找 _wfindfirst 的 c++ 等效项

Question

I have filenames using char16_t characters:

char16_t Text[2560] = u"ThisIsTheFileName.txt";
char16_t const* Filename = Text;

How can I check if the file exists already? I know that I can do so for wchar_t using _wfindfirst() . But I need char16_t here.

Is there an equivalent function to _wfindfirst() for char16_t ?

Background for this is that I need to work with Unicode characters and want my code working on Linux (32-bit) as well as on other platforms (16-bit).

Answer 1

findfirst() is the counterpart to _wfindfirst() .

However, both findfirst() and _wfindfirst() are specific to Windows. findfirst() accepts ANSI (outdated legacy stuff). _wfindfirst() accepts UTF-16 in the form of wchar_t (which is not exactly the same thing as char16_t ).

ANSI and UTF-16 are generally not used on Linux. findfirst() / _wfindfirst() are not included in the gcc compiler.

Linux uses UTF-8 for its Unicode format. You can use access() to check for file permission, or use opendir() / readdir() / closedir() as the equivalent to findfirst() .

If you have a UTF-16 filename from Windows, you can convert the name to UTF-8, and use the UTF-8 name in Linux. See How to convert UTF-8 std::string to UTF-16 std::wstring?

Consider using std::filesystem in C++17 or higher.

Note that a Windows or Linux executable is 32-bit or 64-bit, that doesn't have anything to do with the character set. Some very old systems are 16-bit, you probably don't come across them.