What is the output of this program?

#include<stdio.h>
#include<stdlib.h>
#include<netinet/in.h>
#include<sys/types.h>
#include<sys/socket.h>
 
int main()
{
    int fd_server, fd_client, len, len_client;
    struct sockaddr_in add_server, add_client;
    char buff[10];
    fd_server = socket(AF_INET,SOCK_STREAM,0);
    if (fd_server == -1)
    {
        perror("fd_sock");
        exit(1);   
    }
    len = sizeof(add_server);
    len_client = sizeof(add_client);
    if( bind(fd_server,(struct sockaddr*)&add_server,len) != 0)
        perror("bind");
    fd_client = accept(fd_server,(struct sockaddr*)&add_client,len_client);
    if(fd_client == -1)
        perror("accept");
    read(fd_client,buff,10);
    return 0;
}