Testing font unicode coverage info with FreeType OS/2 table, not very reliable though

fontinfo.c

#include <ft2build.h>
#include FT_FREETYPE_H
#include <freetype/tttables.h>

const char *rangeForBit(int i)
{
    switch (i)
    {
    case 43:
        return "Box Drawing";
    case 48:
        return "CJK Symbols And Punctuation";
    case 49:
        return "Hiragana";
    case 50:
        return "Katakana";
    case 51:
        return "Bopomofo";
    case 52:
        return "Hangul Compatibility Jamo";
    case 54:
        return "Enclosed CJK Letters And Months";
    case 55:
        return "CJK Compatibility";
    case 56:
        return "Hangul Syllables";
    case 57:
        return "Non-Plane 0";
    case 59:
        return "CJK Unified Ideographs";
    case 61:
        return "CJK Strokes, CJK Compatibility Ideographs, CJK Compatibility Ideographs Supplement";
    case 63:
        return "Arabic Presentation Forms-A";
    default:
        return NULL;
    }
}

int main(int argc, char *argv[])
{
    FT_Library library;
    FT_Face    face;
    int error, i;

    if (argc < 2)
        return 0;

    FT_Init_FreeType( &library );

    error = FT_New_Face(library, argv[1], 0, &face);
    if (error) {
        printf("Cannot open file %s\n", argv[1]);
        return error;
    }

    TT_OS2 *os2 = (TT_OS2*) FT_Get_Sfnt_Table(face, ft_sfnt_os2);

    printf("glyphs: %ld\n", face->num_glyphs);

    FT_ULong mask = 1L;
    for (i = 32; i < 64; i++) {
        if (os2->ulUnicodeRange2 & mask) {
            const char *r = rangeForBit(i);
            printf("bit %d = 1 (%s)\n", i, (r ? r : ""));
        }
        mask = mask << 1;
    }

    return 0;
}