server16.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>

void main()
{
	int ssock,csock;
	int t = 0;     // creating server and clinet socket discriptor
	char s1[30], s2[30], c[30], h[30];
	unsigned int len;
	strcpy(s2, "oyeoye");
	struct sockaddr_in server,client;   // creating server & client socket object

	if((ssock=socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		perror("socket: is not created");
		exit(-1);
	}

	server.sin_family=AF_INET;
	server.sin_port=htons(10000);       // initializing server socket parameters..
	server.sin_addr.s_addr=INADDR_ANY;
	//inet_addr("127.0.0.1");
	bzero(&server.sin_zero,0); //appending 8 byte zeroes to 'struct sockaddr_in', to make it equal in size with 'struct sockaddr'..


	len=sizeof(struct sockaddr_in);

	if((bind(ssock,(struct sockaddr *)&server,len))==-1)
	{  // binding port & IP
		perror("bind: ");
		exit(-1);
	}

	if((listen(ssock,5))==-1)
	{     // listening for client
		perror("listen: ");
		exit(-1);
	}


	if((csock=accept(ssock,(struct sockaddr *)&client,&len))==-1)
	{  // accepting connectn
		perror("accept: ");
		exit(-1);
	}
	while(1)
	{
		recv(csock,s1,sizeof(s1),0);
		if((strcmp(s1, s2) == 0))
		{
			t = 1;
			send(csock,&t,sizeof(t),0);
			recv(csock,h,sizeof(h),0);
			strcpy(c, "Hello");
			send(csock,c,sizeof(c),0);
		}
		else
		{
			send(csock,&t,sizeof(t),0);
			strcpy(c, "IncorrectPassword");
			send(csock,c,sizeof(c),0);
		}	            // sending data to client...
		printf("\nsent value=: %s\n",c);
	}
	close(ssock);
}