linux tcp通讯demo

linux tcp通讯demo代码。通过用chatgpt生成的代码。做一个代码记录。

一、基本的通讯demo

server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>#define PORT 8080int main() {int server_fd, new_socket, valread;struct sockaddr_in address;int opt = 1;int addrlen = sizeof(address);char buffer[1024] = {0};char *hello = "Hello from server";// Creating socket file descriptorif ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {perror("socket failed");exit(EXIT_FAILURE);}// Forcefully attaching socket to the port 8080if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {perror("setsockopt");exit(EXIT_FAILURE);}address.sin_family = AF_INET;address.sin_addr.s_addr = INADDR_ANY;address.sin_port = htons(PORT);// Binding the socket to the portif (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {perror("bind failed");exit(EXIT_FAILURE);}// Listening for incoming connectionsif (listen(server_fd, 3) < 0) {perror("listen");exit(EXIT_FAILURE);}// Accept an incoming connectionif ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {perror("accept");exit(EXIT_FAILURE);}// Receive the client's messagevalread = read(new_socket, buffer, 1024);printf("%s\n", buffer);// Send a response to the clientsend(new_socket, hello, strlen(hello), 0);printf("Hello message sent\n");return 0;
}

client.c

#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>#define PORT 8080int main(int argc, char const *argv[]) {int sock = 0, valread;struct sockaddr_in serv_addr;char *hello = "Hello from client";char buffer[1024] = {0};// Creating socket file descriptorif ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {printf("\n Socket creation error \n");return -1;}serv_addr.sin_family = AF_INET;serv_addr.sin_port = htons(PORT);// Convert IPv4 and IPv6 addresses from text to binary formif (inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr) <= 0) {printf("\nInvalid address/ Address not supported \n");return -1;}// Connect to the serverif (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {printf("\nConnection Failed \n");return -1;}// Send a message to the serversend(sock, hello, strlen(hello), 0);printf("Hello message sent\n");// Receive a response from the servervalread = read(sock, buffer, 1024);printf("%s\n", buffer);return 0;
}

client 代码能重复用

二、server的thread方式实现

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <pthread.h>#define PORT 8080void *handle_client(void *arg) {int new_socket = (int)arg;char buffer[1024] = {0};char *hello = "Hello from server";// Receive the client's messageint valread = read(new_socket, buffer, 1024);printf("Client message: %s\n", buffer);// Send a response to the clientsend(new_socket, hello, strlen(hello), 0);printf("Hello message sent\n");close(new_socket);pthread_exit(NULL);
}int main() {int server_fd, new_socket, valread;struct sockaddr_in address;int opt = 1;int addrlen = sizeof(address);// Creating socket file descriptorif ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {perror("socket failed");exit(EXIT_FAILURE);}// Forcefully attaching socket to the port 8080if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {perror("setsockopt");exit(EXIT_FAILURE);}address.sin_family = AF_INET;address.sin_addr.s_addr = INADDR_ANY;address.sin_port = htons(PORT);// Binding the socket to the portif (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {perror("bind failed");exit(EXIT_FAILURE);}// Listening for incoming connectionsif (listen(server_fd, 3) < 0) {perror("listen");exit(EXIT_FAILURE);}printf("Server listening on port %d\n", PORT);while (1) {// Accept an incoming connectionif ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {perror("accept");exit(EXIT_FAILURE);}pthread_t tid;if (pthread_create(&tid, NULL, handle_client, (void *)new_socket) != 0) {perror("pthread_create");exit(EXIT_FAILURE);}}return 0;
}

三、server 的process方式实现

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/wait.h>#define PORT 8080void handle_client(int new_socket) {char buffer[1024] = {0};char *hello = "Hello from server";// Receive the client's messageint valread = read(new_socket, buffer, 1024);printf("Client message: %s\n", buffer);// Send a response to the clientsend(new_socket, hello, strlen(hello), 0);printf("Hello message sent\n");close(new_socket);exit(EXIT_SUCCESS);
}int main() {int server_fd, new_socket, valread;struct sockaddr_in address;int opt = 1;int addrlen = sizeof(address);// Creating socket file descriptorif ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {perror("socket failed");exit(EXIT_FAILURE);}// Forcefully attaching socket to the port 8080if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {perror("setsockopt");exit(EXIT_FAILURE);}address.sin_family = AF_INET;address.sin_addr.s_addr = INADDR_ANY;address.sin_port = htons(PORT);// Binding the socket to the portif (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {perror("bind failed");exit(EXIT_FAILURE);}// Listening for incoming connectionsif (listen(server_fd, 3) < 0) {perror("listen");exit(EXIT_FAILURE);}printf("Server listening on port %d\n", PORT);while (1) {// Accept an incoming connectionif ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {perror("accept");exit(EXIT_FAILURE);}pid_t pid = fork();if (pid == 0) {// Child processhandle_client(new_socket);} else if (pid > 0) {// Parent processclose(new_socket);while (waitpid(-1, NULL, WNOHANG) > 0);} else {perror("fork");exit(EXIT_FAILURE);}}return 0;
}

四、server的select方式实现

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/time.h>
#include <sys/select.h>#define PORT 8080
#define MAX_CLIENTS 10
#define BUFFER_SIZE 1024int main() {int server_fd, new_socket, client_sockets[MAX_CLIENTS], max_sd, sd, activity, i, valread;fd_set rd_set;struct sockaddr_in address;int opt = 1;int addrlen = sizeof(address);char buffer[BUFFER_SIZE] = {0};char *hello = "Hello from server";// Initialize all client sockets to 0for (i = 0; i < MAX_CLIENTS; i++) {client_sockets[i] = 0;}// Creating socket file descriptorif ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {perror("socket failed");exit(EXIT_FAILURE);}// Forcefully attaching socket to the port 8080if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {perror("setsockopt");exit(EXIT_FAILURE);}address.sin_family = AF_INET;address.sin_addr.s_addr = INADDR_ANY;address.sin_port = htons(PORT);// Binding the socket to the portif (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {perror("bind failed");exit(EXIT_FAILURE);}// Listening for incoming connectionsif (listen(server_fd, 3) < 0) {perror("listen");exit(EXIT_FAILURE);}printf("Server listening on port %d\n", PORT);while (1) {// Clear the socket setFD_ZERO(&(rd_set));// Add the server socket to the setFD_SET(server_fd, &(rd_set));max_sd = server_fd;// Add child sockets to the setfor (i = 0; i < MAX_CLIENTS; i++) {sd = client_sockets[i];if (sd > 0) {FD_SET(sd, &(rd_set));}if (sd > max_sd) {max_sd = sd;}}// Wait for an activity on the socketsactivity = select(max_sd + 1, &(rd_set), NULL, NULL, NULL);if ((activity < 0) && (errno != EINTR)) {printf("select error");}// If something happened on the server socket, accept new connectionif (FD_ISSET(server_fd, &(rd_set))) {if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {perror("accept");exit(EXIT_FAILURE);}// Add the new socket to the array of socketsfor (i = 0; i < MAX_CLIENTS; i++) {if (client_sockets[i] == 0) {client_sockets[i] = new_socket;printf("New connection, socket fd is %d, ip is : %s, port : %d\n", new_socket, inet_ntoa(address.sin_addr), ntohs(address.sin_port));break;}}}// Else, it's some IO operation on some other socketfor (i = 0; i < MAX_CLIENTS; i++) {sd = client_sockets[i];if (FD_ISSET(sd, &(rd_set))) {// Check if it was for closing, and also read the incoming messageif ((valread = read(sd, buffer, BUFFER_SIZE)) == 0) {// Somebody disconnected, get his details and printgetpeername(sd, (struct sockaddr *)&address, (socklen_t *)&addrlen);printf("Host disconnected, ip %s, port %d\n", inet_ntoa(address.sin_addr), ntohs(address.sin_port));// Close the socket and mark as 0 in list for reuseclose(sd);client_sockets[i] = 0;} else {// Echo the message back to the clientbuffer[valread] = '\0';printf("Received message: %s\n", buffer);send(sd, hello, strlen(hello), 0);printf("Hello message sent\n");}}}}return 0;
}

五、server的poll 方式

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/poll.h>#define PORT 8080
#define MAX_CLIENTS 10
#define BUFFER_SIZE 1024int main() {int server_fd, new_socket, client_sockets[MAX_CLIENTS], i, valread;struct sockaddr_in address;int opt = 1;int addrlen = sizeof(address);char buffer[BUFFER_SIZE] = {0};char *hello = "Hello from server";struct pollfd pollfds[MAX_CLIENTS + 1];int nfds = 1;// Creating socket file descriptorif ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {perror("socket failed");exit(EXIT_FAILURE);}// Forcefully attaching socket to the port 8080if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {perror("setsockopt");exit(EXIT_FAILURE);}address.sin_family = AF_INET;address.sin_addr.s_addr = INADDR_ANY;address.sin_port = htons(PORT);// Binding the socket to the portif (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {perror("bind failed");exit(EXIT_FAILURE);}// Listening for incoming connectionsif (listen(server_fd, 3) < 0) {perror("listen");exit(EXIT_FAILURE);}// Add the server socket to the pollfd arraypollfds[0].fd = server_fd;pollfds[0].events = POLLIN;printf("Server listening on port %d\n", PORT);while (1) {// Wait for an activity on the socketsint ready = poll(pollfds, nfds, -1);if (ready == -1) {perror("poll");exit(EXIT_FAILURE);}// If something happened on the server socket, accept new connectionif (pollfds[0].revents & POLLIN) {if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {perror("accept");exit(EXIT_FAILURE);}// Add the new socket to the pollfd arrayfor (i = 1; i < MAX_CLIENTS + 1; i++) {if (pollfds[i].fd == 0) {pollfds[i].fd = new_socket;pollfds[i].events = POLLIN;nfds++;printf("New connection, socket fd is %d, ip is : %s, port : %d\n", new_socket, inet_ntoa(address.sin_addr), ntohs(address.sin_port));break;}}}// Else, it's some IO operation on some other socketfor (i = 1; i < nfds; i++) {if (pollfds[i].revents & POLLIN) {// Check if it was for closing, and also read the incoming messageif ((valread = read(pollfds[i].fd, buffer, BUFFER_SIZE)) == 0) {// Somebody disconnected, get his details and printgetpeername(pollfds[i].fd, (struct sockaddr *)&address, (socklen_t *)&addrlen);printf("Host disconnected, ip %s, port %d\n", inet_ntoa(address.sin_addr), ntohs(address.sin_port));// Close the socket and remove it from the pollfd arrayclose(pollfds[i].fd);pollfds[i].fd = 0;nfds--;} else {// Echo the message back to the clientbuffer[valread] = '\0';printf("Received message: %s\n", buffer);send(pollfds[i].fd, hello, strlen(hello), 0);printf("Hello message sent\n");}}}}return 0;
}