server_test.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include <unistd.h>

// sockets
#include <netdb.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/select.h>

// #include "./includes/socket_functions.h"

int SOCKET_Create(int _domain, int _type, int _port, char* _addr, int _n_listen){
    int err = 0;

    // create socket
    int sock = socket(_domain, _type, 0);
    if (sock < 0){
        perror("Socket creation");
        return sock;
    }

    // re use socket
    int opt_val = 1;
    err = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &opt_val, sizeof(int));
    if ( err < 0 ){
        perror("Sock reuse option failed");
        return err;
    }

    // sock addr
    struct sockaddr_in sock_addr_info;
    struct in_addr addr;
    inet_aton(_addr, &addr);
    sock_addr_info.sin_family = _domain;
    sock_addr_info.sin_addr.s_addr = addr.s_addr; 
    sock_addr_info.sin_port = htons( (uint16_t)_port );

    // bind
    err = bind(sock, (struct sockaddr*) &sock_addr_info, sizeof(sock_addr_info)); 
    if ( err < 0 ){
        perror("Bind failed");
        return err;
    }

    // listen 
    err = listen(sock, _n_listen);
    if ( err < 0 ){
        perror("Listen failed");
        return err;
    }

    // return socket fd
    return sock;

}

// connect to a socket and return thee file descriptor
int SOCKET_Connect(int _domain, int _type, int _port, char* _addr){
    int err = 0;

    // create socket
    int sock = socket(_domain, _type, 0);
    if (sock < 0){
        perror("Socket creation");
        return sock;
    }

    // sock addr
    struct sockaddr_in sock_addr_info;
    struct in_addr addr;
    inet_aton(_addr, &addr);
    sock_addr_info.sin_family = _domain;
    sock_addr_info.sin_addr.s_addr = addr.s_addr; 
    sock_addr_info.sin_port = htons( (uint16_t)_port );



    // connect to server
    err = connect(sock, (struct sockaddr*) &sock_addr_info, sizeof(sock_addr_info));
    if ( err < 0 ){
        perror("Connection failed");
        return err;
    }

    return sock;
}
int SOCKET_Close(int socket){

    shutdown(socket, SHUT_RDWR);

    char buffer[1];
    int bytes_read = 0;
    // while( (bytes_read = read(socket, buffer, 1)) == 0 ){
    //     printf("bytes read -> %d",bytes_read);
    // }
    // printf("bytes read ---> %d",bytes_read);

    close(socket);
}

int main(void){


    // int sock = socket(AF_INET, SOCK_STREAM, 0);
    // bind(sock, &local, sizeof(local));
    // listen(sock, 128);

    int sock = SOCKET_Create(AF_INET, SOCK_STREAM, 10000, "0.0.0.0", 100);
    struct sockaddr_in connection_addres;
    socklen_t connection_addres_len = sizeof(connection_addres);

    int client= accept(sock, (struct sockaddr*) &connection_addres, &connection_addres_len);

    
    char buffer[4096];

    int bytesRead=0, res;
    for(;;) {
        usleep(100);
        res = read(client, buffer, 4096);
        printf(  "b -> %d %d\n" , bytesRead, res);
        if(res < 0)  {
            perror("read");
            exit(1);
        }
        if(!res)
            break;
        bytesRead += res;
        // usleep(10);
    }
    // sleep(1);
    // close(client);
    printf("%d %d\n", bytesRead, write(client, "220 Welcome\r\n", 13));
    
    SOCKET_Close(client);
}