2.3 socket 模块API手册

前言

概述

本文档主要介绍soccket模块API。

读者对象

本文档（本指南）主要适用于以下人员：

• 技术支持工程师
• 软件开发工程师

缩略词定义

简称	说明

修订记录

文档版本号	修改说明	修改者	日期
V1.0	初版	软件部	2023-11-09

1. 概述

封装socket库，需要通过核间通信调用小核的socket接口。

2.示例

#配置 tcp/udp socket调试工具
import socket
import time

PORT=60000

def client():
    #获取地址及端口号 对应地址
    ai = socket.getaddrinfo("10.100.228.5", PORT)
    #ai = socket.getaddrinfo("10.10.1.94", PORT)
    print("Address infos:", ai)
    addr = ai[0][-1]

    print("Connect address:", addr)
    #建立socket
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
    #连接地址
    s.connect(addr)

    for i in range(10):
        str="K230 tcp client send test {0} \r\n".format(i)
        print(str)
        #print(s.send(str))
        #发送字符串
        print(s.write(str))
        time.sleep(0.2)
        #time.sleep(1)
        #print(s.recv(4096))
        #print(s.read())
    #延时1秒
    time.sleep(1)
    #关闭socket
    s.close()
    print("end")



#main()
client()

3. api定义

详见https://docs.micropython.org/en/latest/library/socket.html

3.1 定义

• classsocket.socket(af=AF_INET, type=SOCK_STREAM, proto=IPPROTO_TCP, /)¶

  Create a new socket using the given address family, socket type and protocol number. Note that specifying proto in most cases is not required (and not recommended, as some MicroPython ports may omit IPPROTO_* constants). Instead, type argument will select needed protocol automatically:# Create STREAM TCP socket socket(AF_INET, SOCK_STREAM) # Create DGRAM UDP socket socket(AF_INET, SOCK_DGRAM)

3.2 函数

• socket.close()¶

  Mark the socket closed and release all resources. Once that happens, all future operations on the socket object will fail. The remote end will receive EOF indication if supported by protocol.Sockets are automatically closed when they are garbage-collected, but it is recommended to close() them explicitly as soon you finished working with them.

• socket.bind(address)¶

  Bind the socket to address. The socket must not already be bound.

• socket.listen([**backlog**])¶

  Enable a server to accept connections. If backlog is specified, it must be at least 0 (if it’s lower, it will be set to 0); and specifies the number of unaccepted connections that the system will allow before refusing new connections. If not specified, a default reasonable value is chosen.

• socket.accept()¶

  Accept a connection. The socket must be bound to an address and listening for connections. The return value is a pair (conn, address) where conn is a new socket object usable to send and receive data on the connection, and address is the address bound to the socket on the other end of the connection.

• socket.connect(address)¶

  Connect to a remote socket at address.

• socket.send(bytes)¶

  Send data to the socket. The socket must be connected to a remote socket. Returns number of bytes sent, which may be smaller than the length of data (“short write”).

• socket.sendall(bytes)¶

  Send all data to the socket. The socket must be connected to a remote socket. Unlike send(), this method will try to send all of data, by sending data chunk by chunk consecutively.The behaviour of this method on non-blocking sockets is undefined. Due to this, on MicroPython, it’s recommended to use write() method instead, which has the same “no short writes” policy for blocking sockets, and will return number of bytes sent on non-blocking sockets.

• socket.recv(bufsize)¶

  Receive data from the socket. The return value is a bytes object representing the data received. The maximum amount of data to be received at once is specified by bufsize.

• socket.sendto(bytes, address)¶

  Send data to the socket. The socket should not be connected to a remote socket, since the destination socket is specified by address.

• socket.recvfrom(bufsize)¶

  Receive data from the socket. The return value is a pair (bytes, address) where bytes is a bytes object representing the data received and address is the address of the socket sending the data.

• socket.setsockopt(level, optname, value)¶

  Set the value of the given socket option. The needed symbolic constants are defined in the socket module (SO_* etc.). The value can be an integer or a bytes-like object representing a buffer.

• socket.settimeout(value)¶

  Note: Not every port supports this method, see below.Set a timeout on blocking socket operations. The value argument can be a nonnegative floating point number expressing seconds, or None. If a non-zero value is given, subsequent socket operations will raise an OSError exception if the timeout period value has elapsed before the operation has completed. If zero is given, the socket is put in non-blocking mode. If None is given, the socket is put in blocking mode.Not every MicroPython port supports this method. A more portable and generic solution is to use select.poll object. This allows to wait on multiple objects at the same time (and not just on sockets, but on generic stream objects which support polling). Example:# Instead of: s.settimeout(1.0) # time in seconds s.read(10) # may timeout # Use: poller = select.poll() poller.register(s, select.POLLIN) res = poller.poll(1000) # time in milliseconds if not res: # s is still not ready for input, i.e. operation timed outDifference to CPythonCPython raises a socket.timeout exception in case of timeout, which is an OSError subclass. MicroPython raises an OSError directly instead. If you use except OSError: to catch the exception, your code will work both in MicroPython and CPython.

• socket.setblocking(flag)¶

  Set blocking or non-blocking mode of the socket: if flag is false, the socket is set to non-blocking, else to blocking mode.This method is a shorthand for certain settimeout() calls:sock.setblocking(True) is equivalent to sock.settimeout(None)``sock.setblocking(False) is equivalent to sock.settimeout(0)

• socket.makefile(mode=’rb’, buffering=0, /)¶

  Return a file object associated with the socket. The exact returned type depends on the arguments given to makefile(). The support is limited to binary modes only (‘rb’, ‘wb’, and ‘rwb’). CPython’s arguments: encoding, errors and newline are not supported.Difference to CPythonAs MicroPython doesn’t support buffered streams, values of buffering parameter is ignored and treated as if it was 0 (unbuffered).Difference to CPythonClosing the file object returned by makefile() WILL close the original socket as well.

• socket.read([**size**])¶

  Read up to size bytes from the socket. Return a bytes object. If size is not given, it reads all data available from the socket until EOF; as such the method will not return until the socket is closed. This function tries to read as much data as requested (no “short reads”). This may be not possible with non-blocking socket though, and then less data will be returned.

• socket.readinto(buf**[, *nbytes*]**)¶

  Read bytes into the buf. If nbytes is specified then read at most that many bytes. Otherwise, read at most len(buf) bytes. Just as read(), this method follows “no short reads” policy.Return value: number of bytes read and stored into buf.

• socket.readline()¶

  Read a line, ending in a newline character.Return value: the line read.

• socket.write(buf)¶

  Write the buffer of bytes to the socket. This function will try to write all data to a socket (no “short writes”). This may be not possible with a non-blocking socket though, and returned value will be less than the length of buf.Return value: number of bytes written.

• exceptionsocket.error¶

  MicroPython does NOT have this exception.Difference to CPythonCPython used to have a socket.error exception which is now deprecated, and is an alias of OSError. In MicroPython, use OSError directly.