file.c:610
static VALUE
test_b(obj, fname)
    VALUE obj, fname;
{
#ifndef S_ISBLK
#   ifdef S_IFBLK
#	define S_ISBLK(m) ((m & S_IFMT) == S_IFBLK)
#   else
#	define S_ISBLK(m) (0)  /* anytime false */
#   endif
#endif

#ifdef S_ISBLK
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    if (S_ISBLK(st.st_mode)) return Qtrue;

#endif
    return Qfalse;
}
