wchar functions under Android NDK

Issue

Here is my simplified code:

static void WriteToFile(const wchar_t* msg) {
  FILE* f = fopen("/sdcard/mytest.txt", "w");
  fprintf(f, "%ls\n", msg);
  fclose(f);

}

// Somewhere else in the code
const wchar_t* msg = L"Hello world";
WriteToFile(msg);

Using %ls to format a wchar string seems to work fine in Windows and Ubuntu. However, on Android, it writes only the first character H in the file.

I even tried to convert wchar to mbs:

char buf[100];
wcstombs(buf, msg, 100);

However, buf still ends up having just one character H in it.

I have a feeling that it is happening because wchar is four bytes long on Android. However, I would think the NDK must be aware of this.

How do I fix this? Regards.

Solution

Instead of using wcstombs, etc., use APIs from libiconv (https://www.gnu.org/software/libiconv/). You may have to build libiconv library for Android.

Answered By - Peter