#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <pthread.h>
#define BUFFER_SIZE 1024
#define MAX_CLIENTS 5
void *client_handler(void *);
int main(int argc, char *argv[]) {
int server_socket, client_socket, port;
char buffer[BUFFER_SIZE];
struct sockaddr_in server_addr, client_addr;
socklen_t client_addr_len;
pthread_t threads[MAX_CLIENTS];
int thread_count = 0;
if (argc < 2) {
printf("Usage: %s <port>\n", argv[0]);
exit(EXIT_FAILURE);
}
// create server socket
server_socket = socket(AF_INET, SOCK_STREAM, 0);
if (server_socket < 0) {
perror("socket creation failed");
exit(EXIT_FAILURE);
}
// set server address and port
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY;
port = atoi(argv[1]);
server_addr.sin_port = htons(port);
// bind server socket to address and port
if (bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
perror("bind failed");
exit(EXIT_FAILURE);
}
// listen for incoming connections
if (listen(server_socket, MAX_CLIENTS) < 0) {
perror("listen failed");
exit(EXIT_FAILURE);
}
// print server address and port
printf("Server listening on %s:%d\n", inet_ntoa(server_addr.sin_addr), ntohs(server_addr.sin_port));
// accept incoming connections and spawn client threads
while (1) {
client_addr_len = sizeof(client_addr);
client_socket = accept(server_socket, (struct sockaddr *)&client_addr, &client_addr_len);
if (client_socket < 0) {
perror("accept failed");
break;
}
printf("Client connected from %s:%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
if (pthread_create(&threads[thread_count], NULL, client_handler, (void *)&client_socket) != 0) {
perror("thread creation failed");
break;
}
thread_count++;
if (thread_count >= MAX_CLIENTS) {
printf("Maximum number of clients reached\n");
break;
}
}
// join client threads and exit
for (int i = 0; i < thread_count; i++) {
pthread_join(threads[i], NULL);
}
close(server_socket);
exit(EXIT_SUCCESS);
}
void *client_handler(void *arg) {
int client_socket = *(int *)arg;
char buffer[BUFFER_SIZE];
pthread_t self = pthread_self();
// receive and print client strings until client disconnects or types "quit"
while (1) {
memset(buffer, 0, sizeof(buffer));
if (recv(client_socket, buffer, BUFFER_SIZE, 0) < 0) {
perror("recv failed");
break;
}
printf("Thread %lu received string: %s", self, buffer);
if (strcmp(buffer, "quit\n") == 0) {
break;
}
}
// close client socket and exit thread
printf("Thread %lu exiting\n", self);