// bind.c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
int main(int argc, char *argv[])
{
int serv_sock;
int clnt_sock;
int str_len;
int client_count = 0;
struct sockaddr_in serv_addr;
struct sockaddr_in clnt_addr;
socklen_t clnt_addr_size;
char message[] = "Hello MUST! XueRenQianQian, 19098535i0110068";
char message_from_client[50];
char message_to_client[50];
if (argc != 2)
{
printf("Usage : %s <port>\n", argv[0]);
exit(1);
}
// new socket
serv_sock = socket(AF_INET, SOCK_STREAM, 0);
if (serv_sock == -1)
{
printf("socket error\n");
exit(1);
}
printf("socket id is %d\n", serv_sock);
memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
if (serv_addr.sin_addr.s_addr == INADDR_NONE)
{
printf("inet_aton error\n");
exit(1);
}
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(atoi(argv[1])); // port
// bind addr/ip to socket
if (bind(serv_sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1)
{
printf("bind() error");
exit(1);
}
if (listen(serv_sock, 10) == -1)
{
printf("listen() error");
exit(1);
}
while (client_count < 3)
{
clnt_addr_size = sizeof(clnt_addr);
clnt_sock = accept(serv_sock, (struct sockaddr *)&clnt_addr, &clnt_addr_size);
if (clnt_sock == -1)
{
printf("accept() error");
continue;
}
// get clnt address
char buff[INET_ADDRSTRLEN + 1] = {0}; // 不懂,查
inet_ntop(AF_INET, &clnt_addr.sin_addr, buff, INET_ADDRSTRLEN);
uint16_t port = ntohs(clnt_addr.sin_port);
printf("connection from %s, port %d\n", buff, port);
write(clnt_sock, message, sizeof(message));
for (int i = 0; i < 5; i++)
{
memset(message_from_client, 0, sizeof(message_from_client)); // 修改后
str_len = read(clnt_sock, message_from_client, sizeof(message_from_client) - 1);
message_from_client[str_len] = '\0';
if (str_len == -1)
{
printf("read() error!");
exit(1);
}
printf("Message from the client: %s \n", message_from_client);
if (strlen(message_from_client) == 1 && (message_from_client[0] == 'Q' || message_from_client[0] == 'q'))
break;
printf("Send message: ");
scanf("%[^\n]", message_to_client);
getchar();
write(clnt_sock, message_to_client, strlen(message_to_client));
if (strlen(message_to_client) == 1 && (message_to_client[0] == 'Q' || message_to_client[0] == 'q'))
break;
}
close(clnt_sock);
client_count++;
}
close(serv_sock);
return 0;
}
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
int sock;
struct sockaddr_in serv_addr;
char message[50];
char message_to_server[50];
char message_from_server[50];
int str_len;
if (argc != 3)
{
printf("Usage : %s <IP> <port> \n", argv[0]);
exit(1);
}
sock = socket(PF_INET, SOCK_STREAM, 0);
if (sock == -1)
{
printf("socket() error");
exit(1);
}
memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
serv_addr.sin_port = htons(atoi(argv[2]));
if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1)
{
printf("Connect() error!");
exit(1);
}
str_len = read(sock, message, sizeof(message) - 1);
if (str_len == -1)
{
printf("read() error!");
exit(1);
}
printf("From server: %s \n", message);
for (int i = 0; i < 5; i++)
{
printf("Type the message to server:");
scanf("%[^\n]", message_to_server);
getchar();
write(sock, message_to_server, strlen(message_to_server));
if (strlen(message_to_server) == 1 && (message_to_server[0] == 'Q' || message_to_server[0] == 'q'))
break;
memset(message_from_server, 0, sizeof(message_from_server)); // 修改后
str_len = read(sock, message_from_server, sizeof(message_from_server) - 1);
message_from_server[str_len] = '\0';
if (str_len == -1)
{
printf("read() error!");
exit(1);
}
printf("Message from the server: %s \n", message_from_server);
if (strlen(message_from_server) == 1 && (message_from_server[0] == 'Q' || message_from_server[0] == 'q'))
break;
}
close(sock);
return 0;
}
```