thread_server.cpp

#include <cstdio>
#include<sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <thread>

void handle_client(int c_fd){
        char rbuf[64] = {};
        int n = read(c_fd,&rbuf,sizeof(rbuf));
        if(n<0){
                perror("Couldn't read data from the client\n");
        }
        printf("Client says: %s\n",rbuf);

        char wbuf[64] = "Hello, from the server";
        n = write(c_fd,&wbuf,sizeof(wbuf));
        if(n<0){
                perror("Couldn't write data to the socket\n");
        }
}

static int on = 1;

int main(){
        int fd = socket(AF_INET, SOCK_STREAM,0);
        
        setsockopt(fd,SOL_SOCKET,SO_REUSEADDR, &on,sizeof(on));

        struct sockaddr_in addr = {};
        addr.sin_family = AF_INET;
        addr.sin_port = htons(1234);
        addr.sin_addr.s_addr = htonl(0);
        int n = bind(fd,(const struct sockaddr*)&addr,sizeof(addr));
        if(n){
                perror("Couldn't bind.\n");
        }

        n = listen(fd,10);
        if(n){
                perror("Couldn't start to listen.\n");
        }
        
        printf("Server is Listening!!\n");
        fflush(stdout);
        while(true){
                struct sockaddr_in c_addr = {};
                socklen_t len = sizeof(c_addr);
                int c_fd = accept(fd,(struct sockaddr*)&c_addr, &len);

                std::thread my_thread(handle_client,c_fd);
                my_thread.detach();
        }
}