Bi-directional client server communication using tcp/ip?

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C

Ubuntu

application

TCP/IP

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Hi,

I have developed a server and client code using tcp/ip protocol, which enables the client to send data to server and the same data is received from server to client.

I would like to know how to keep the client open all the time, same like as server. I should not keep executing the client every time.

I am giving the code for further reference

Server code:

#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
void str_echo(int s)
{
	FILE *fp,*fp1;
	char buf[2000];
	//receiving data from client
	recv(s,buf,2000,0);
	puts("Message from Client...");
	fputs(buf,stdout);
	send(s,buf,2000,0);
	}
int main()
{
 	int ls,cs,len;
 	struct sockaddr_in serv,cli;
 	pid_t pid;
 	puts("I am Server...");
	//creating socket
	ls=socket(AF_INET,SOCK_STREAM,0);
 	puts("Socket Created Successfully...");
	//socket address structure
 	serv.sin_family=AF_INET;
 	serv.sin_addr.s_addr=INADDR_ANY;
 	serv.sin_port=htons(6777);
 	bind(ls,(struct sockaddr*)&serv,sizeof(serv));
 	puts("Binding Done...");
 	listen(ls,3);
 	puts("Listening for Client...");
 	for(; ;)
 	{
		len=sizeof(cli);
		//accepting client connection
		cs=accept(ls,(struct sockaddr*)&cli,&len);
		puts("\nConnected to Client...");
		//creating child process
		if((pid=vfork()) == 0)
		{
			puts("Child process created...");
			close(ls);
			str_echo(cs);
			close(cs);
			exit(0);
		}
	close(cs);
 	}
 	return 0;
}

Client Code:

#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
void str_echo(int s)
{
	char buf[2000],buf1[2000];
	puts("Enter the Message...");
	fgets(buf,2000,stdin);
	send(s,buf,2000,0); //sending data to server
	//receiving data from server
	recv(s,buf1,2000,0);
	puts("Message from Server...");
	//fputs(buf1,stdout);
	puts(buf1);
}
int main()
{
	int ls;
 	struct sockaddr_in cli;
 	puts("I am Client...");
	/*creating socket*/
 	ls=socket(AF_INET,SOCK_STREAM,0);
 	puts("Socket Created Successfully...");
	/*socket address structure*/
 	cli.sin_family=AF_INET;
 	cli.sin_addr.s_addr=inet_addr("127.0.0.1");
 	cli.sin_port=htons(6777);
	/*connecting to server*/
 	connect(ls,(struct sockaddr*)&cli,sizeof(cli));
 	puts("Connected with Server...");  
	str_echo(ls);
 	close(ls);
 	return 0;
}