Question

I’m looking to the equivalent of Windows _wfopen() under Mac OS X. Any idea?

I need this in order to port a Windows library that uses wchar* for its File interface. As this is intended to be a cross-platform library, I am unable to rely on how the client application will get the file path and give it to the library.

Answer 1

POSIX API in Mac OS X are usable with UTF-8 strings. In order to convert a wchar_t string to UTF-8, it is possible to use the CoreFoundation framework from Mac OS X.

Here is a class that will wrap an UTF-8 generated string from a wchar_t string.

class Utf8 { public:     Utf8(const wchar_t* wsz): m_utf8(NULL)     {         // OS X uses 32-bit wchar         const int bytes = wcslen(wsz) * sizeof(wchar_t);         // comp_bLittleEndian is in the lib I use in order to detect PowerPC/Intel         CFStringEncoding encoding = comp_bLittleEndian ? kCFStringEncodingUTF32LE                                                        : kCFStringEncodingUTF32BE;         CFStringRef str = CFStringCreateWithBytesNoCopy(NULL,                                                         (const UInt8*)wsz, bytes,                                                          encoding, false,                                                          kCFAllocatorNull                                                         );          const int bytesUtf8 = CFStringGetMaximumSizeOfFileSystemRepresentation(str);         m_utf8 = new char[bytesUtf8];         CFStringGetFileSystemRepresentation(str, m_utf8, bytesUtf8);         CFRelease(str);     }         ~Utf8()      {          if( m_utf8 )         {             delete[] m_utf8;         }     }  public:     operator const char*() const { return m_utf8; }  private:     char* m_utf8; }; 

Usage:

const wchar_t wsz = L'Here is some Unicode content: éà€œæ'; const Utf8 utf8 = wsz; FILE* file = fopen(utf8, 'r'); 

This will work for reading or writing files.