initial commit

src/main.c

@@ -0,0 +1,126 @@
+#include <arpa/inet.h>
+#include <asm-generic/socket.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#define PORT 5555
+#define MAX_CLIENTS 10
+#define BUFFER_SIZE 1024
+
+struct client_t {
+  int sock;
+  char username[50];
+};
+
+int main() {
+  int server_fd;
+  struct client_t clients[MAX_CLIENTS];
+  struct sockaddr_in address;
+  int addrlen = sizeof(address);
+  fd_set readfds;
+  char buffer[BUFFER_SIZE];
+
+  for (int i = 0; i < MAX_CLIENTS; i++) {
+    clients[i].sock = 0;
+    bzero(clients[i].username, sizeof(clients[i].username));
+  }
+
+  server_fd = socket(AF_INET, SOCK_STREAM, 0);
+  if (server_fd < 0) {
+    perror("socket");
+    exit(EXIT_FAILURE);
+  }
+
+  int opt = 1;
+  if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
+    perror("setsockopt");
+    exit(EXIT_FAILURE);
+  }
+
+  address.sin_family = AF_INET;
+  address.sin_addr.s_addr = INADDR_ANY;
+  address.sin_port = htons(PORT);
+
+  if (bind(server_fd, (struct sockaddr *) &address, sizeof(address)) < 0) {
+    perror("bind");
+    exit(EXIT_FAILURE);
+  }
+
+  if (listen(server_fd, 5) < 0) {
+    perror("listen");
+    exit(EXIT_FAILURE);
+  }
+
+  printf("Chat server started on port %d\n", PORT);
+
+  while (1) {
+    FD_ZERO(&readfds);
+    FD_SET(server_fd, &readfds);
+    int max_sd = server_fd;
+
+    for (int i = 0; i < MAX_CLIENTS; i++) {
+      int sd = clients[i].sock;
+      if (sd > 0) FD_SET(sd, &readfds);
+      if (sd > max_sd) max_sd = sd;
+    }
+
+    if (select(max_sd + 1, &readfds, NULL, NULL, NULL) < 0) {
+      perror("select");
+      exit(EXIT_FAILURE);
+    }
+
+    // Новое подключение
+    if (FD_ISSET(server_fd, &readfds)) {
+      int new_socket = accept(server_fd, (struct sockaddr *) &address,
+                              (socklen_t *) &addrlen);
+
+      printf("New connection: socket %d\n", new_socket);
+      read(new_socket, buffer, BUFFER_SIZE);
+
+      for (int i = 0; i < MAX_CLIENTS; i++) {
+        if (clients[i].sock == 0) {
+          clients[i].sock = new_socket;
+          strcpy(clients[i].username, buffer);
+          break;
+        }
+      }
+    }
+
+    // Сообщения от клиентов
+    for (int i = 0; i < MAX_CLIENTS; i++) {
+      int sd = clients[i].sock;
+      char sd_username[50];
+      bzero(sd_username, sizeof(sd_username));
+      strcpy(sd_username, clients[i].username);
+
+      if (FD_ISSET(sd, &readfds)) {
+        int valread = read(sd, buffer, BUFFER_SIZE);
+
+        if (valread == 0) {
+          printf("Client disconnected: socket %d\n", sd);
+          close(sd);
+          clients[i].sock = 0;
+          bzero(clients[i].username, sizeof(clients[i].username));
+        } else {
+          buffer[valread] = '\0';
+          printf("from_socket: %d\n", sd);
+          printf("from_username: %s\n", sd_username);
+          printf("Message: %s\n", buffer);
+
+          // Рассылка всем другим
+          for (int j = 0; j < MAX_CLIENTS; j++) {
+            if (clients[j].sock != 0 && clients[j].sock != sd) {
+              send(clients[j].sock, buffer, strlen(buffer), 0);
+            }
+          }
+        }
+      }
+    }
+  }
+
+  return 0;
+}