Char problem * and fgets()

Question

I have a struct with a vector type field of char and I have a file .txt with several lines in this format with song names.

text 1
text2
text 3
text4

I need to read the entire file row by row and store each row in a vector position of struct. I made this code here, but it stores the last line in all the positions of this vector struct.

    #include <iostream>
    #include <cstring>
    #include <fstream>

    using namespace std;

    struct musica2{
       char *musica;
    };

    int main(){
       FILE *arquivo;
       musica2 *z = new musica2[12];
       char a[255];
       arquivo = fopen("teste.dat", "r");
       int i=0;
       if(arquivo == NULL)
           cout << "Erro ao abrir arquivo." << endl;
       else{
        while(!feof(arquivo)){
        z[i].musica = fgets(a,255,arquivo);
        i++;
       }
      }
    cout << z[3].musica;
    fclose(arquivo);
    return 0;
    } 

What can it be?

Answer 1

The problem is on this line:

z[i].musica = fgets(a,255,arquivo);

Here you are doing two things:

1. Overwriting the a every line read

2. Pointing all vectors to a

This way, when iterating the vectors, you will have the same return for all.

The solution would be to copy the value of a to the vector, or to eliminate the a completely point directly to the item of the vector in the fgets, as in this example:

struct musica2{
   char musica[255];
};

...

fgets( z[i].musica, 255, arquivo);

See working on IDEONE.

I was just trying to figure out the main problem. Then you need to put the proper protections to check the fgets return, and ensure that the string is properly formatted.