int main(int argc, char** argv) {


    char command[80], words[3][MAX_SIZE];
    //char username[MAX_SIZE];
    //char password[MAX_SIZE];

    printf("<<<<<<<<<<<<Server>>>>>>>>>>>>\n\n\n");

    do {

        printf("> Input commands as you wish :)\n");
        printf("> ");

        fgets(command, sizeof (command), stdin);
        sscanf(command, "%s %s %s", words[0], words[1], words[2]);


        if (strcmp(words[0], "add") == 0)
            add(words[1], words[2]);

    } while (1);

    return (EXIT_SUCCESS);
}

void add(char *username, char *password) {
    int file;
    char *f_username, *f_password;
    char buffer[80];

    file = open("utilizadores.txt", O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);

    if (file == -1) {
        printf("> Error opening file.\n");
        return;
    }
    while (read(file, buffer, strlen(buffer)) != 0) {
        f_username = strtok(buffer,":");
        f_password = strtok(NULL, ":");

        if (strcmp(f_username, username) == 0) {
            printf("> This username already exists!\n");
            close(file);
            return;

        }

    }
    sprintf(buffer, "%s:%s:\n", username, password);

    if (write(file, buffer, strlen(buffer)) < 0) {
        printf("> Error writing to file");
        return;
    }

    printf("> User added!\n");
    close(file);
}