1.TCP
服务端程序:
int main()
{
/* delete the socket file */
unlink("server_socket");
/* create a socket */
int server_sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
struct sockaddr_un server_addr;
server_addr.sun_family = AF_UNIX;
strcpy(server_addr.sun_path, "server_socket");
/* bind with the local file */
bind(server_sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr));
/* listen */
listen(server_sockfd, 5);
char ch;
int client_sockfd;
struct sockaddr_un client_addr;
socklen_t len = sizeof(client_addr);
while(1)
{
printf("server waiting:\n");
/* accept a connection */
client_sockfd = accept(server_sockfd, (struct sockaddr *)&client_addr, &len);
/* exchange data */
read(client_sockfd, &ch, 1);
printf("get char from client: %c\n", ch);
++ch;
write(client_sockfd, &ch, 1);
/* close the socket */
close(client_sockfd);
}
return 0;
}
客户端程序:
int main()
{
/* create a socket */
int sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
struct sockaddr_un address;
address.sun_family = AF_UNIX;
strcpy(address.sun_path, "server_socket");
/* connect to the server */
int result = connect(sockfd, (struct sockaddr *)&address, sizeof(address));
if(result == -1)
{
perror("connect failed: ");
exit(1);
}
/* exchange data */
char ch = 'A';
write(sockfd, &ch, 1);
read(sockfd, &ch, 1);
printf("get char from server: %c\n", ch);
/* close the socket */
close(sockfd);
return 0;
}
2.UDP
服务端:
#define SERV_PORT 8000
int main()
{
/* socket文件描述符 */
int sock_fd;
/* 建立udp socket */
sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
if(sock_fd < 0)
{
perror("socket");
exit(1);
}
/* 设置address */
struct sockaddr_in addr_serv;
int len;
memset(&addr_serv, 0, sizeof(struct sockaddr_in));
addr_serv.sin_family = AF_INET;
addr_serv.sin_port = htons(SERV_PORT);
/* INADDR_ANY表示不管是哪个网卡接收到数据,只要目的端口是SERV_PORT,就会被该应用程序接收到 */
addr_serv.sin_addr.s_addr = htonl(INADDR_ANY);
len = sizeof(addr_serv);
/* 绑定socket */
if(bind(sock_fd, (struct sockaddr *)&addr_serv, sizeof(addr_serv)) < 0)
{
perror("bind error:");
exit(1);
}
int recv_num;
int send_num;
char send_buf[20] = "i am server!";
char recv_buf[20];
struct sockaddr_in addr_client;
while(1)
{
printf("server wait:\n");
recv_num = recvfrom(sock_fd, recv_buf, sizeof(recv_buf), 0, (struct sockaddr *)&addr_client, (socklen_t *)&len);
if(recv_num < 0)
{
perror("recvfrom error:");
exit(1);
}
recv_buf[recv_num] = '\0';
printf("server receive %d bytes: %s\n", recv_num, recv_buf);
send_num = sendto(sock_fd, send_buf, recv_num, 0, (struct sockaddr *)&addr_client, len);
if(send_num < 0)
{
perror("sendto error:");
exit(1);
}
}
close(sock_fd);
return 0;
}
客户端:
#define DEST_PORT 8000
#define DSET_IP_ADDRESS "127.0.0.1"
int main()
{
/* socket文件描述符 */
int sock_fd;
/* 建立udp socket */
sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
if(sock_fd < 0)
{
perror("socket");
exit(1);
}
/* 设置address */
struct sockaddr_in addr_serv;
int len;
memset(&addr_serv, 0, sizeof(addr_serv));
addr_serv.sin_family = AF_INET;
addr_serv.sin_addr.s_addr = inet_addr(DSET_IP_ADDRESS);
addr_serv.sin_port = htons(DEST_PORT);
len = sizeof(addr_serv);
int send_num;
int recv_num;
char send_buf[20] = "hey, who are you?";
char recv_buf[20];
printf("client send: %s\n", send_buf);
send_num = sendto(sock_fd, send_buf, strlen(send_buf), 0, (struct sockaddr *)&addr_serv, len);
if(send_num < 0)
{
perror("sendto error:");
exit(1);
}
recv_num = recvfrom(sock_fd, recv_buf, sizeof(recv_buf), 0, (struct sockaddr *)&addr_serv, (socklen_t *)&len);
if(recv_num < 0)
{
perror("recvfrom error:");
exit(1);
}
recv_buf[recv_num] = '\0';
printf("client receive %d bytes: %s\n", recv_num, recv_buf);
close(sock_fd);
return 0;
}