Error copying array of strings in C

Question

I have two to arrays of pointers that contains strings. The first one reads from a file line by line and gets populated. I want to copy the strings from the first to the second but at some point with some changes.The odd thing is that when I used the code to remove a person (some lines) from the file with the same methods in an earlier function it worked.... .

Here is the code below:

void verificare() {
    int nrInt = 0, linieInt = 0;
    system("cls");
    FILE *fisier, *fisier2;
    char buffer[1000];
    char* v[100], w[100], c[100], nume[100];
    char numeFisier[100], rasp[100];
    int i = 0, j = 0, k = 0, k1 = 0, k2 = 0, l = 0, cont = 1, pozVal;

    printf("Enter the name of the file: ");
    scanf("%s", numeFisier);

    fisier = fopen(numeFisier, "rt");


    while(!feof(fisier))
    {
        while(fgets(nume, sizeof nume, fisier))
        {
            v[i] = (char*) malloc(100);
            v[i] = strdup(nume);
            i++;
        }
    }

    //Checking and reviewing the array with some formatting in the console:
    for (j = 0; j < i; j+=4)
    {
        printf("\n");
        printf("Record Nr.: %d \n", cont);
        printf("Name: %s", v[j] );
        printf("Surname: %s", v[j + 1] );
        printf("Age: %s", v[j + 2] );
        printf("\n");
        cont++;
    }

    //Copying the from array1( v[] ) to array2( c[] )

    for (k = 0; k < i; k++)
    {
        c[k] = (char*) malloc(1000);
        strncpy(c[k],v[k],100);
    } // this for loop works in another earlier function ......


}

I also tryed to use these methods :

    strcpy(c[k], v[k]);
    memcpy(c[k], v[k], 1000);
    snprintf(c[k], 1000, "%s", v[k]);

    // Or 
    calloc() istead of malloc()

I really don't understand where i get it wrong....

[`while (!feof(file))` is always wrong](http://stackoverflow.com/questions/5431941/while-feof-file-is-always-wrong) — Barmar, Aug 27 '16 at 08:17
`strdup()` calls `malloc()` itself. You should use `strcpy()` if you have already allocated memory for the string. — Barmar, Aug 27 '16 at 08:18
Why are you allocating 1000 when the original strings are at most 100? — Barmar, Aug 27 '16 at 08:21
Thanks Barmar for the advices :D, there was a little error when I copied 1000 with 100 ... — Philipos D., Aug 27 '16 at 08:36

rheber · Accepted Answer · 2016-08-27T21:51:15.403

1

Try changing your declaration:

char *v[100], *w[100], *c[100], *nume[100];

Edit: The point is that when you declare multiple pointers on the same line, each variable needs an asterisk. For example

char *a, *b;

declares two char pointers, whereas

char *a, b;

declares a as a char pointer but b as a char.

edited Aug 27 '16 at 21:51

answered Aug 27 '16 at 08:23

rheber

24
4

Thanks Robert Herber that really helped, the thing is that I tried: `char *name[100]` method but not with all of them... But i was wondering how in an earlier function the same method worked ? I had the same variable declaration `char* name` – Philipos D. Aug 27 '16 at 08:40
A bit of explanation exactly why this change is required would suite the answer well. – alk Aug 27 '16 at 16:11

Error copying array of strings in C

1 Answers1