Compare FT and OSX font weights for a font

whatsthefont.c

#include <CoreFoundation/CoreFoundation.h>
#include <CoreGraphics/CoreGraphics.h>
#include <CoreText/CoreText.h>
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_TRUETYPE_TABLES_H
#include FT_SFNT_NAMES_H
#include FT_TRUETYPE_IDS_H
#ifndef FT_SFNT_OS2
#define FT_SFNT_OS2 ft_sfnt_os2
#endif

int
main(int argc, char** argv)
{
  if (argc == 2) {
    char* filepath = *(argv+1);
    FT_Library library;
    FT_Face face;

    CFStringRef cffilepath = CFStringCreateWithCString(NULL, filepath, kCFStringEncodingUTF8);
    CFURLRef url = CFURLCreateWithFileSystemPath(NULL, cffilepath, kCFURLPOSIXPathStyle, false);
    CGDataProviderRef data = CGDataProviderCreateWithURL(url);
    CGFontRef cgfont = CGFontCreateWithDataProvider(data);
    CTFontRef ctfont = CTFontCreateWithGraphicsFont(cgfont, 0.0, NULL, NULL);

    CFDictionaryRef dict = CTFontCopyTraits(ctfont);
    CFNumberRef cfnumber = (CFNumberRef)CFDictionaryGetValue(dict, kCTFontWeightTrait);
    double value;

    if (cfnumber != NULL && CFNumberGetValue(cfnumber, kCFNumberCGFloatType, &value)) {
      CFNumberGetValue(cfnumber, kCFNumberFloat64Type, &value);
      if (!FT_Init_FreeType(&library) && !FT_New_Face(library, (const char*)filepath, 0, &face)) {
        TT_OS2* table = (TT_OS2*)FT_Get_Sfnt_Table(face, FT_SFNT_OS2);
        printf("%u %f\n", table->usWeightClass, value);
      }
    }
  }
}