Python socket for UNIX socket and dash string operation

Python socket library can implement TCP and UDP, UNIX sockets in Linux is also possible, some programs in interprocess communication is the use of UNIX sockets, if we want to view its communication information to debug, you can use Python to forge its interface, Get content

Reference: https://docs.python.org/2/library/socket.html

import socketimport os if __name__ ==  ' _ _main__ ':          sock = socket.socket (Socket.AF_UNIX,  socket. SOCK_STREAM)       if os.path.exists ('/tmp/unix.d '):           os.unlink ('/tmp/unix.d ')       sock.bind ('/ Var/run/rrdcached.sock ')          sock.listen (5)           while True:          Connection,address = sock.accept ()               print  "data : %s"%connection.recv (1024x768)           #connection. Send ("Hello")          connection.close () 

Reference: http://www.2cto.com/os/201305/210033.html

Bash under string operations:

Support ${parameter:offset:length},${parameter:offset}

[Email protected] ~/test $ string= ' Hello '

[Email protected] ~/test $ echo ${string:1:3}

Gl.

[Email protected] ~/test $ echo ${string:1}

Ello

[Email protected] ~/test $ echo $

/bin/bash

Dash: Not supported, workaround: Use expr or cut external commands instead

$ String= ' Hello '

$ expr substr "$string" 2 3

Gl.

$ echo "$string" | Cut-c2-4

Gl.

$ expr substr "$string" 2 "${#string}"

Ello

$ echo "$string" | cut-c2-

Ello

$ echo $

Dash

$

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Python socket for UNIX socket and dash string operation