my program does not open a socket - c

Question

This is the server part of a chat client server program i wrote. I create a pool of thread and the server must associated a a connected client to a thread. The thread function gestisci() receives commands from clients and sends messages from client1 to client2. But, once i run it, there is nothing appearing on the terminal. Can someone help me?
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include<sys/wait.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<pthread.h>
#define BACKLOG_SIZE 5
#define SA struct sockaddr
void* gestisci_richiesta(void*dati)
int main(int argc, char* argv[]) {
printf("in main function\n");
struct sockaddr_in srv_addr, cl_addr;
int ret, sock, cn_sk, porta, t;
struct argomenti{
int sock_cl,stato;
struct sockaddr_in cl_addr;
int index;}
struct argomenti mess[BACKLOG_SIZE];
int arg_cont[BACKLOG_SIZE];
socklen_t len;
int t_free[BACKLOG_SIZE];
pthread_t tid[BACKLOG_SIZE];
if (argc < 2)
printf("errore:inserire numero porta\n");
porta = atoi(argv[1]);
printf(" %d\n", porta);
sock = socket(PF_INET, SOCK_STREAM, 0);
if (sock == -1) {
printf("server: impossibile creare un nuovo socket.\n");
return 0;
}
memset(&srv_addr, 0, sizeof(srv_addr));
srv_addr.sin_family = AF_INET;
srv_addr.sin_addr.s_addr = htonl(INADDR_ANY );/* il server si mette in ascolto suqualsiasi delle sueinerfacce di rete*/
srv_addr.sin_port = htons(porta);
ret = bind(sock, (SA*) &srv_addr, sizeof(srv_addr));
if (ret == -1) {
printf("server : impossibile eseguire il bind sul socket.\n");
return 0;
}
printf("bind con successo\n");
listen(sock, BACKLOG_SIZE);
for (t = 0; t < BACKLOG_SIZE; t++) {
t_free[t] = 0;
client[t] = 0;
}
t= 0;
while (1) {
while (t_free[t] != 0)
t = (t + 1) % BACKLOG_SIZE;
t_free[t] = 1;
len = (socklen_t) sizeof(mess[t].cl_addr);
cn_sk = accept(sock, (SA*) &mess[t].cl_addr, &len);
mess[t].sock_cl = cn_sk;
mess[t].index = t;
printf("client:%d connesso\n", t);
if (cn_sk == -1) {
printf("SERVER: errore in attesa di connessione\n");
return 0;
}
if (pthread_create(&tid[t], 0, gestisci_richiesta, (void*) &mess[t])) {
printf("server:impossibile avviare un thread dal pool\n");
return 0;
}
}
}

Answer 1

You are missing \n's on several of those printfs, which will cause them to be buffered instead of printing out immediately.
Other problems exist. Your error message where you call socket() is misleading. There has been no attempt yet to use the port specified. That happens at the bind(). There is no reason to assume the number of clients will equal the backlog size. The size of a sockaddr_in is always the same: no need to recalculate it each time.

Answer 2

you should move t = 0; before while(1).