ProSoft Technology MVI69E-LDM - Manual (Page 48)

Contents MVI69E-LDM ♦ "C" Programmable
Developer's Manual Linux Application Development Module
Page 48 of 130 ProSoft Technology, Inc.
August 21, 2014
To execute the sample:
1 Go to the default home directory /psft/sample .
2 Type the command ./Client_Sample ip.address.of.server to run the program. The IP
address of the server node must be provided in order for the server to know which node
is executing the server program.
3 The client will send a connection request to the server, print the response from the
server to the console, and then exit.
Reviewing the source code for Client_Sample , you will see that the main program:
 registers
sigquit_handler for four signals.
 checks command line and print usage message if required.
 opens the backplane using
open_backplane() . See the detailed description in
backplane_sample .
 creates a socket with a call to socket() .
 initializes the server address (serv_addr) structure:
o indicates that an IP4 address is going to be used with AF_INET .
o sets the destination port is the well known port SERVER_PORT_NUMBER .
o converts the string version of the server IP address to binary with inet_pton() .
 connect() is called to create the TCP connection to the server.
 When the sockets are connected, the server sends the date and time from the server as
a message back to the clients. The client then uses the read() function to receive the
buffer of data and prints the contents to the console.