readable?

/*
 *  call-seq:
 *     stat.readable?    => true or false
 *  
 *  Returns <code>true</code> if <i>stat</i> is readable by the
 *  effective user id of this process.
 *     
 *     File.stat("testfile").readable?   #=> true
 *     
 */

static VALUE
rb_stat_r(obj)
    VALUE obj;
{
    struct stat *st = get_stat(obj);

#ifdef USE_GETEUID
    if (geteuid() == 0) return Qtrue;
#endif
#ifdef S_IRUSR
    if (rb_stat_owned(obj))
        return st->st_mode & S_IRUSR ? Qtrue : Qfalse;
#endif
#ifdef S_IRGRP
    if (rb_stat_grpowned(obj))
        return st->st_mode & S_IRGRP ? Qtrue : Qfalse;
#endif
#ifdef S_IROTH
    if (!(st->st_mode & S_IROTH)) return Qfalse;
#endif
    return Qtrue;
}