static void
check_dirname(volatile VALUE *dir)
{
    char *path, *pend;

    rb_secure(2);
    FilePathValue(*dir);
    path = RSTRING_PTR(*dir);
    if (path && *(pend = rb_path_end(rb_path_skip_prefix(path)))) {
	*dir = rb_str_new(path, pend - path);
    }
}

/*
 * Document-method: setsockopt
 * call-seq:
 *   setsockopt(level, optname, optval)
 *   setsockopt(socketoption)
 *
 * Sets a socket option. These are protocol and system specific, see your
 * local system documentation for details.
 *
 * === Parameters
 * * +level+ is an integer, usually one of the SOL_ constants such as
 *   Socket::SOL_SOCKET, or a protocol level.
 *   A string or symbol of the name, possibly without prefix, is also
 *   accepted.
 * * +optname+ is an integer, usually one of the SO_ constants, such
 *   as Socket::SO_REUSEADDR.
 *   A string or symbol of the name, possibly without prefix, is also
 *   accepted.
 * * +optval+ is the value of the option, it is passed to the underlying
 *   setsockopt() as a pointer to a certain number of bytes. How this is
 *   done depends on the type:
 *   - Fixnum: value is assigned to an int, and a pointer to the int is
 *     passed, with length of sizeof(int).
 *   - true or false: 1 or 0 (respectively) is assigned to an int, and the
 *     int is passed as for a Fixnum. Note that +false+ must be passed,
 *     not +nil+.
 *   - String: the string's data and length is passed to the socket.
 * * +socketoption+ is an instance of Socket::Option
 *
 * === Examples
 *
 * Some socket options are integers with boolean values, in this case
 * #setsockopt could be called like this:
 *   sock.setsockopt(:SOCKET, :REUSEADDR, true)
 *   sock.setsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR, true)
 *   sock.setsockopt(Socket::Option.bool(:INET, :SOCKET, :REUSEADDR, true))
 *
 * Some socket options are integers with numeric values, in this case
 * #setsockopt could be called like this:
 *   sock.setsockopt(:IP, :TTL, 255)
 *   sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_TTL, 255)
 *   sock.setsockopt(Socket::Option.int(:INET, :IP, :TTL, 255))
 *
 * Option values may be structs. Passing them can be complex as it involves
 * examining your system headers to determine the correct definition. An
 * example is an +ip_mreq+, which may be defined in your system headers as:
 *   struct ip_mreq {
 *     struct  in_addr imr_multiaddr;
 *     struct  in_addr imr_interface;
 *   };
 *
 * In this case #setsockopt could be called like this:
 *   optval = IPAddr.new("224.0.0.251").hton +
 *            IPAddr.new(Socket::INADDR_ANY, Socket::AF_INET).hton
 *   sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP, optval)
 *
*/
static VALUE
bsock_setsockopt(int argc, VALUE *argv, VALUE sock)
{
UNRUBBY_SOCKET_HACK;
    VALUE lev, optname, val;
    int family, level, option;
    rb_io_t *fptr;
    int i;
    char *v;
    int vlen;

    if (argc == 1) {
        lev = rb_funcall(argv[0], rb_intern("level"), 0);
        optname = rb_funcall(argv[0], rb_intern("optname"), 0);
        val = rb_funcall(argv[0], rb_intern("data"), 0);
    }
    else {
        rb_scan_args(argc, argv, "30", &lev, &optname, &val);
    }

    rb_secure(2);
    GetOpenFile(sock, fptr);
    family = rsock_getfamily(fptr->fd);
    level = rsock_level_arg(family, lev);
    option = rsock_optname_arg(family, level, optname);

    switch (TYPE(val)) {
      case T_FIXNUM:
	i = FIX2INT(val);
	goto numval;
      case T_FALSE:
	i = 0;
	goto numval;
      case T_TRUE:
	i = 1;
      numval:
	v = (char*)&i; vlen = (int)sizeof(i);
	break;
      default:
	StringValue(val);
	v = RSTRING_PTR(val);
	vlen = RSTRING_LENINT(val);
	break;
//.........这里部分代码省略.........

static VALUE
env_size(VALUE rcv, SEL sel)
{
    rb_secure(4);

    char **env = GET_ENVIRON();
    int i = 0;
    while (env[i] != NULL) {
	i++;
    }
    return INT2FIX(i);
}

static VALUE fcgi_stream_write(VALUE self, VALUE str)
{
  FCGX_Stream *stream;
  int len;

  rb_secure(4);
  Data_Get_Struct(self, FCGX_Stream, stream);
  str = rb_obj_as_string(str);
  len = FCGX_PutStr(RSTRING_PTR(str), RSTRING_LEN(str), stream);
  if (len == EOF) CHECK_STREAM_ERROR(stream);
  return INT2NUM(len);
}

/*
 *  call-seq:
 *     Dir.getwd => string
 *     Dir.pwd => string
 *
 *  Returns the path to the current working directory of this process as
 *  a string.
 *
 *     Dir.chdir("/tmp")   #=> 0
 *     Dir.getwd           #=> "/tmp"
 */
static VALUE
dir_s_getwd(VALUE dir)
{
    char *path;
    VALUE cwd;

    rb_secure(4);
    path = my_getcwd();
    cwd = rb_tainted_str_new2(path);

    xfree(path);
    return cwd;
}

static VALUE Surface_s_load(VALUE klass, VALUE filename)
{
  SDL_Surface *surface;
  
  rb_secure(4);
  ExportFilenameStringValue(filename);

  surface = IMG_Load(RSTRING_PTR(filename));
  if(surface == NULL)
    rb_raise(eSDLError,"Couldn't load %s: %s",
             RSTRING_PTR(filename), SDL_GetError());
  return Surface_create(surface);
}

static VALUE
env_has_key(VALUE env, SEL sel, VALUE key)
{
    rb_secure(4);

    const char *s = StringValuePtr(key);
    if (strlen(s) != RSTRING_LEN(key)) {
	rb_raise(rb_eArgError, "bad environment variable name");
    }
    if (getenv(s) != NULL) {
	return Qtrue;
    }
    return Qfalse;
}

static VALUE
__rho_compile( VALUE obj, VALUE src)
{
    VALUE result;
    rb_thread_t *th = GET_THREAD();

    rb_secure(1);

    th->parse_in_eval++;
    result = rb_iseq_compile(src, rb_str_new2("(eval)"), INT2FIX(1));
    th->parse_in_eval--;

    return result;
}

void
rb_undef(VALUE klass, ID id)
{
    VALUE origin;
    NODE *body;

    if (rb_vm_cbase() == rb_cObject && klass == rb_cObject) {
	rb_secure(4);
    }
    if (rb_safe_level() >= 4 && !OBJ_TAINTED(klass)) {
	rb_raise(rb_eSecurityError, "Insecure: can't undef `%s'",
		 rb_id2name(id));
    }
    rb_frozen_class_p(klass);
    if (id == object_id || id == __send__ || id == idInitialize) {
	rb_warn("undefining `%s' may cause serious problem", rb_id2name(id));
    }
    body = search_method(klass, id, &origin);
    if (!body || !body->nd_body) {
	const char *s0 = " class";
	VALUE c = klass;

	if (FL_TEST(c, FL_SINGLETON)) {
	    VALUE obj = rb_iv_get(klass, "__attached__");

	    switch (TYPE(obj)) {
	      case T_MODULE:
	      case T_CLASS:
		c = obj;
		s0 = "";
	    }
	}
	else if (TYPE(c) == T_MODULE) {
	    s0 = " module";
	}
	rb_name_error(id, "undefined method `%s' for%s `%s'",
		      rb_id2name(id), s0, rb_class2name(c));
    }

    rb_add_method(klass, id, 0, NOEX_PUBLIC);

    if (FL_TEST(klass, FL_SINGLETON)) {
	rb_funcall(rb_iv_get(klass, "__attached__"),
		   singleton_undefined, 1, ID2SYM(id));
    }
    else {
	rb_funcall(klass, undefined, 1, ID2SYM(id));
    }
}

/*
 * call-seq:
 *   basicsocket.do_not_reverse_lookup = bool
 *
 * Sets the do_not_reverse_lookup flag of _basicsocket_.
 *
 *   BasicSocket.do_not_reverse_lookup = false
 *   p TCPSocket.new("127.0.0.1", 80).do_not_reverse_lookup #=> false
 *   BasicSocket.do_not_reverse_lookup = true
 *   p TCPSocket.new("127.0.0.1", 80).do_not_reverse_lookup #=> true
 *
 */
static VALUE
bsock_do_not_reverse_lookup_set(VALUE sock, VALUE state)
{
    rb_io_t *fptr;

    rb_secure(4);
    GetOpenFile(sock, fptr);
    if (RTEST(state)) {
	fptr->mode |= FMODE_NOREVLOOKUP;
    }
    else {
	fptr->mode &= ~FMODE_NOREVLOOKUP;
    }
    return sock;
}

/* Returns information about the group with specified String name, as found 
 * in /etc/group.
 *
 * The information is returned as a Struct::Group; see getgrent above for
 * details.
 *
 * e.g.  Etc.getgrnam('users') -> #<struct Struct::Group name="users",
 * passwd="x", gid=100, mem=["meta", "root"]>
 *
 */
static VALUE
etc_getgrnam(VALUE obj, VALUE nam)
{
#ifdef HAVE_GETGRENT
    struct group *grp;

    rb_secure(4);
    SafeStringValue(nam);
    grp = getgrnam(RSTRING_PTR(nam));
    if (grp == 0) rb_raise(rb_eArgError, "can't find group for %s", RSTRING_PTR(nam));
    return setup_group(grp);
#else
    return Qnil;
#endif
}

static VALUE
top_include(VALUE self, SEL sel, int argc, VALUE *argv)
{
#if 0
    rb_thread_t *th = GET_THREAD();

    rb_secure(4);
    if (th->top_wrapper) {
	rb_warning
	    ("main#include in the wrapped load is effective only in wrapper module");
	return rb_mod_include(argc, argv, th->top_wrapper);
    }
#endif
    return rb_mod_include(rb_cObject, 0, argc, argv);
}

static VALUE
env_assoc(VALUE env, SEL sel, VALUE key)
{
    rb_secure(4);

    const char *s = StringValuePtr(key);
    if (strlen(s) != RSTRING_LEN(key)) {
	rb_raise(rb_eArgError, "bad environment variable name");
    }
    const char *e = getenv(s);
    if (e != NULL) {
	return rb_assoc_new(key, rb_tainted_str_new2(e));
    }
    return Qnil;
}

VALUE
rb_dlptr_new2(VALUE klass, void *ptr, long size, freefunc_t func)
{
    struct ptr_data *data;
    VALUE val;

    rb_secure(4);
    val = TypedData_Make_Struct(klass, struct ptr_data, &dlptr_data_type, data);
    data->ptr = ptr;
    data->free = func;
    data->size = size;
    OBJ_TAINT(val);

    return val;
}

/*
 * call-seq:
 *   udpsocket.connect(host, port) => 0
 *
 * Connects _udpsocket_ to _host_:_port_.
 *
 * This makes possible to send without destination address.
 *
 *   u1 = UDPSocket.new
 *   u1.bind("127.0.0.1", 4913)
 *   u2 = UDPSocket.new
 *   u2.connect("127.0.0.1", 4913)
 *   u2.send "uuuu", 0
 *   p u1.recvfrom(10) #=> ["uuuu", ["AF_INET", 33230, "localhost", "127.0.0.1"]]
 *
 */
static VALUE
udp_connect(VALUE sock, VALUE host, VALUE port)
{
    rb_io_t *fptr;
    struct udp_arg arg;
    VALUE ret;

    rb_secure(3);
    arg.res = rsock_addrinfo(host, port, SOCK_DGRAM, 0);
    GetOpenFile(sock, fptr);
    arg.fd = fptr->fd;
    ret = rb_ensure(udp_connect_internal, (VALUE)&arg,
		    rsock_freeaddrinfo, (VALUE)arg.res);
    if (!ret) rsock_sys_fail_host_port("connect(2)", host, port);
    return INT2FIX(0);
}

static VALUE
env_values(VALUE rcv, SEL sel)
{
    rb_secure(4);

    VALUE ary = rb_ary_new();
    char **env = GET_ENVIRON();
    while (*env != NULL) {
	const char *s = strchr(*env, '=');
	if (s != NULL) {
	    rb_ary_push(ary, env_str_new2(s + 1));
	}
	env++;
    }
    return ary;
}

static VALUE
thread_set_trace_func_m(VALUE obj, VALUE trace)
{
    rb_thread_t *th;

    rb_secure(4);
    GetThreadPtr(obj, th);
    rb_threadptr_remove_event_hook(th, call_trace_func, Qundef);

    if (NIL_P(trace)) {
	return Qnil;
    }

    thread_add_trace_func(th, trace);
    return trace;
}

static void
rb_export_method(VALUE klass, ID name, ID noex)
{
    rb_vm_method_node_t *node;
    SEL sel;

    if (klass == rb_cObject) {
	rb_secure(4);
    }

    if (!rb_vm_lookup_method2((Class)klass, name, &sel, NULL, &node)) {
	if (TYPE(klass) != T_MODULE
		|| !rb_vm_lookup_method2((Class)rb_cObject, name, &sel, NULL,
		    &node)) {
	    rb_print_undef(klass, name, 0);
	}
    }

    if (node == NULL) {
	rb_raise(rb_eRuntimeError,
		"can't change visibility of non Ruby method `%s'",
		sel_getName(sel));
    }

    long flags = (node->flags & ~VM_METHOD_PRIVATE) & ~VM_METHOD_PROTECTED;
    switch (noex) {
	case NOEX_PRIVATE:
	    flags |= VM_METHOD_PRIVATE;
	    break;

	case NOEX_PROTECTED:
	    flags |= VM_METHOD_PROTECTED;
	    break;

	default:
	    break;
    }

    if (node->flags != flags) {
	if (node->klass == (Class)klass) {
	    node->flags = flags;
	}
	else {
	    rb_vm_define_method2((Class)klass, sel, node, flags, false);
	}
    }
}

void
rb_undef(VALUE klass, ID id)
{
    if (klass == rb_cObject) {
	rb_secure(4);
    }
    if (rb_safe_level() >= 4 && !OBJ_UNTRUSTED(klass)) {
	rb_raise(rb_eSecurityError, "Insecure: can't undef `%s'",
		rb_id2name(id));
    }
    rb_frozen_class_p(klass);
    if (id == object_id || id == __send__ || id == idInitialize) {
	rb_warn("undefining `%s' may cause serious problem", rb_id2name(id));
    }

    rb_vm_undef_method((Class)klass, id, true);
}

VALUE
rb_tracepoint_disable(VALUE tpval)
{
    rb_tp_t *tp;

    rb_secure(4);
    tp = tpptr(tpval);

    if (tp->target_th) {
	rb_thread_remove_event_hook_with_data(tp->target_th->self, (rb_event_hook_func_t)tp_call_trace, tpval);
    }
    else {
	rb_remove_event_hook_with_data((rb_event_hook_func_t)tp_call_trace, tpval);
    }
    tp->tracing = 0;
    return Qundef;
}