//TCPServer.c
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#define SERVER_PORT 5555
main()
{int serverSocket;struct sockaddr_in server_addr;struct sockaddr_in clientAddr;int addr_len = sizeof(clientAddr);int client;char buffer[1024];int iDataNum ;if((serverSocket = socket(AF_INET,SOCK_STREAM,0)) < 0){perror("socket");exit(1);}bzero(&server_addr,sizeof(server_addr));server_addr.sin_family =AF_INET;server_addr.sin_port = htons(SERVER_PORT);server_addr.sin_addr.s_addr = htonl(INADDR_ANY);if(bind(serverSocket,(struct sockaddr *)&server_addr,sizeof(server_addr)) < 0){perror("connect");exit(1);}if(listen(serverSocket,5)<0){perror("listen");exit(1);}while(1){client = accept(serverSocket,(struct sockaddr *)&clientAddr,(socklen_t*)&addr_len);if(client < 0){perror("accept");continue;}iDataNum = recv(client,buffer,1024,0);if(iDataNum < 0){perror("Recv");continue;}printf("\nRecv client data.......\n");printf("IP is %s\n",inet_ntoa(clientAddr.sin_addr));printf("Port is %d\n",htons(clientAddr.sin_port));printf("Recv Data is %s\n",buffer);send(client,buffer,sizeof(buffer),0);}
}

//TCPClient.c
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
main()
{struct sockaddr_in serverAddr;int clientSocket;char sendbuf[200];char recvbuf[200];if((clientSocket=socket(AF_INET,SOCK_STREAM,0)) < 0){perror( "socket error" );return -1;}serverAddr.sin_family=AF_INET;serverAddr.sin_port=htons(5555);serverAddr.sin_addr.s_addr=inet_addr("127.0.0.1");if(connect(clientSocket,( struct sockaddr * )&serverAddr,sizeof(serverAddr)) < 0){perror("connect");exit(1);}printf("connect with destination host.....\n");while(1){printf("Input your World:>");scanf("%s",sendbuf);printf("\n");if(strcmp(sendbuf,"quit") == 0)break;send(clientSocket,sendbuf,sizeof(sendbuf),0);recv(clientSocket,recvbuf,200,0);printf("recv data of my world is: %s\n",recvbuf);}close(clientSocket);return 0;
}