test.c

SV * getString(CFStringRef var) {
    char *buf;
    SV *sv;
    CFIndex len = CFStringGetLength(val);
    CFIndex max = CFStringGetMaximumSizeForEncoding(len, kCFStringEncodingUTF8) + 1;
    Newxz(buf, max, char);
    CFStringGetCString(val, buf, max, kCFStringEncodingUTF8);
    CFRelease(val);
    sv = newSVpv(buf, max);
    Safefree(buf);
    return sv;
}