Python Network programming Learning socket socket

Previously also learned the socket programming, this time want to systematically study the use of Python network programming. Do this, for testing progress, also leave notes and footprints for the follow-up.

Socket common functions get host name and host address

Socket.gethostname ()

Socket.gethostbyname ()

Import Socket

host = Socket.gethostname ()
IP = socket.gethostbyname (host)
# can also resolve IP IP for external Services
= Socket.gethostbyname (' www.baidu.com ')

Interchange IPv4 address called 32-bit binary

Socket.inet_aton ()

Socket.inet_ntoa ()

Import Socket

Socket.inet_aton (' 127.0.0.1 ')
socket.inet_ntoa (' \x7f\x00\x00\x01 ')

Specify port and protocol find service name

Socket.getservbyport ()

Import Socket

# Look for HTTP and HTTPS services, such as no return notfound error
socket.getservbyport (' TCP ')
Socket.getservbyport (443, ' TCP ')

Inter-rotating host byte sequence and network byte order

Socket.ntohl ()/socket.ntohs ()

Socket.htonl ()/socket.htons () socket timeout

Socket.gettimeout ()

Socket.settimeout ()

Import Socket

# Set up a socket object
sock = Socket.socket (socket.af_inet, socket. SOCK_STREAM)

#  Timeout time defaults to empty
sock.settimeout (MB)
sock.gettimeout ()

Socket exception

Socket.error () General exception

Socket.gaierror () address exception

Socket.timeout () Timeout exception modify socket buffer

Socket.getsockopt ()

Socket.setsockopt ()

Import socket

sock = Socket.socket (socket.af_inet, socket. SOCK_STREAM)
# query buffer size
sock.getsockopt (socket. Sol_socket, SOCKET. SO_SNDBUF)
sock.getsockopt (socket. Sol_socket, SOCKET. SO_SNDBUF) 
# set size
sock.setsockopt (socket. Sol_socket, SOCKET. SO_SNDBUF, 2048)
sock.setsockopt (socket. Sol_socket, SOCKET. SO_SNDBUF, 2048) 
# set up reuse sockets

Set Socket blocking mode

Non-blocking: Socket encounters exception throws error socket.setblocking (0)

Blocking: Failure to encounter error does not prevent operation Socket.setblocking (1)

Get Network time server time (NTP proctol)

Import ntplib
import time

ntp = ntplib. NTPClient ()
res = ntp.request (' pool.ntp.org ')
print time.ctime (res.tx_time)

Practice socket client/server simple communication

Service side

Import Socket

# Initializes a socket
sock = Socket.socket (socket.af_inet, socket. SOCK_STREAM)

# SET SOCKET reusable
sock.setsockopt (socket. Sol_socket, SOCKET. SO_REUSEADDR, 1)

# bind socket
sock.bind ((' localhost ', 8888)

# Listen for client links, maximum number is 5
sock.listen (5) while

True:
    # Blocking, receiving
    client, add = sock.accept ()
    data = CLIENT.RECV (2048)
    print "Data:", data, ' \ n ', ' Host: ' , add, ' \ n '
    # close
    client.close 

Client

Import Socket

# Initializes a socket
sock = Socket.socket (socket.af_inet, socket. SOCK_STREAM)

# Link service-side
sock.connect ((' localhost ', 8888))

try:
    # Send data
    sock.sendall ("from Client socket! ")

Except Socket.error, E:
    print "error!"

Finally:
    # close
    sock.close ()

Two terminal communications

Service side

duck@duck:~/sockdir/chapter_1$ python sersock.py 
data:from client socket! 
Host: (' 127.0.0.1 ', 53910)

Client

duck@duck:~/sockdir/chapter_1$ python clisock.py