Problem with linked list

[Gwynbleidd]

Hi all, i have problem with linked list.
This is the code

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 100


struct Utenti{
char nome [20];
char cognome [20];
char username [20];
char email [20];
};




struct Profilo{
char username [20];
char email [20];
char titolo_video [20];
int durata_video;
int dimensione_video;
};




struct L_utenti{
char nome;
char cognome;
char nick;
char email;
struct nodo *next;
};


struct L_utenti *testa = NULL;
struct L_utenti *nodo;


struct Profilo profilo [N];
struct Utenti utenti [N];




void Lista_utenti(FILE *ptr_archivio);




int main (){


FILE *ptr_archivio;


ptr_archivio = fopen("Archivio.txt" , "r");


Lista_utenti(ptr_archivio);


return 0;


}


void Lista_utenti(FILE *ptr_archivio){


char archivio_array [N];
int i=0;


if (ptr_archivio == NULL){
    printf("Errore, file non trovato!");
}
else {


while(fgets(archivio_array, N, ptr_archivio)!= NULL){
    sscanf(archivio_array, "%s %s %s %s", utenti[i].nome, utenti[i].cognome, utenti[i].username, utenti[i].email);
    printf("Nome: %s\n" , utenti[i].nome);
    printf("Cognome: %s\n" , utenti[i].cognome);
    printf("Username: %s\n" , utenti[i].username);
    printf("Email: %s\n" , utenti[i].email);
    printf("\n\n");
    i++;
    }
    fclose(ptr_archivio);
}








for (i=0;i<3;i++){
nodo = malloc(sizeof(struct L_utenti));
nodo->nome = utenti[i].nome;
nodo->cognome = utenti[i].cognome;
nodo->nick = utenti[i].username;
nodo->email = utenti[i].email;
nodo->next=
testa;
testa=nodo;




}


while(testa!=NULL){
    printf("%s-->",testa->nome);
    printf("%s-->", testa->cognome);
    printf("%s-->", testa->nick);
    printf("%s-->", testa->email);
    testa=testa->next;
    }
    printf("NULL\n");


}

I have to create a linked list with the name,surname and username members, but the problem is that in the while condition the program crash.
Another question there is a method to read the file and put it into a linked list? whitout using a structure and then passing data in a linked list.

Sorry if my code isn't good but i'm a beginner

[_Viktor_]

One of your problems seems to be that the datatype 'struct L_utenti' has members of type 'char' instead of 'char*'.

This leads to problems in the second to last loop where you want to copy the adress of each item into a pointer to character but due to only using a character variable you're truncating the adress instead.
In the last loop('while(testa!=NULL) ... ') you feed these truncated pseudo adresses, stored in the char variables, to 'printf' and it rightfully implodes.

This is the most obvious unsound issue with this code - there may be much more of course.

You compiler was most likely issuing warnings aplenty... did you ignore them?