awtk/docs/fscript_iostream_inet.md

## TCP/UDP 客户端扩展函数

### 1.iostream\_tcp\_create

> 创建 TCP 客户端输入输出流对象。
----------------------------

#### 原型

```js
iostream_tcp_create(host, port) => object
```

#### 示例

```js
var a = iostream_tcp_create("localhost", 1234);
```

### 2.iostream\_udp\_create

> 创建 UDP 客户端输入输出流对象。
----------------------------

#### 原型

```js
iostream_udp_create(host, port) => object
```

#### 示例

```js
var a = iostream_udp_create("localhost", 4000);
```

### 完整示例

```js
//
//start tcp echo server first
//socat -v tcp-l:1234,fork exec:'/bin/cat'
//

var a = iostream_tcp_create("localhost", 1234)
var b = iostream_get_ostream(a)
var c = iostream_get_istream(a)

assert(ostream_write_uint8(b, 1) == 1)
assert(ostream_write_uint16(b, 2)== 2)
assert(ostream_write_uint32(b, 3) == 4)
assert(ostream_write_uint64(b, 4) == 8)
assert(ostream_write_float(b, 5) == 4)
assert(ostream_write_double(b, 6) == 8)
assert(ostream_write_string(b, "hello\n") == 6)

assert(istream_read_uint8(c) == 1)
assert(istream_read_uint16(c) == 2)
assert(istream_read_uint32(c) == 3)
assert(istream_read_uint64(c) == 4)
assert(istream_read_float(c) == 5)
assert(istream_read_double(c) == 6)
assert(istream_read_string(c, 6) == "hello\n")

```

```js
//
// start udp echo server first
// ./bin/udp_recv 4000
//

var a = iostream_udp_create("localhost", 4000)
var b = iostream_get_ostream(a)
var c = iostream_get_istream(a)

assert(ostream_write_uint8(b, 1) == 1)
assert(ostream_write_uint16(b, 2)== 2)
assert(ostream_write_uint32(b, 3) == 4)
assert(ostream_write_uint64(b, 4) == 8)
assert(ostream_write_float(b, 5) == 4)
assert(ostream_write_double(b, 6) == 8)
assert(ostream_write_string(b, "hello\n") == 6)

assert(istream_read_uint8(c) == 1)
assert(istream_read_uint16(c) == 2)
assert(istream_read_uint32(c) == 3)
assert(istream_read_uint64(c) == 4)
assert(istream_read_float(c) == 5)
assert(istream_read_double(c) == 6)
assert(istream_read_string(c, 6) == "hello\n")
```