Reading strings from file and copying them in an Array - C

Question

I'm trying to read some strings from a file, and copy them into a string array. I can't understand why I manage to read properly just the first of the strings in the file, before getting a segmentation fault. I know that each string in the file has up to 50 characters.

...

int i = 0;
char s[50]; 
int N=0;
FILE *fp;

//Figures out how many strings are stored in the file
while(fgets(s, 50, fp)!=NULL){N++}  

rewind(fp);

char *strings[N];  //This is the array where I want to store strings

for(i=0;i<N;i++){

    fgets(s, 50, fp);
    strcpy(strings[i], s);
    printf("%s", s );
}

Why I can't store succesfully strings into the array ?

Answer 1

You are making two mistakes:

1- when copying strings, you have to allocate memory for the destination, inyour case the destination is strings[i] for which you haven't allocated any memory

2-your strings must be null terminated

This code should work:

   #define MAX_STRINGS 100
   int i = 0;
   char s[50]; 
   int N=0;
   while(fgets(s, 50, fp)!=NULL){N++;}
   char strings[MAX_STRINGS][50];

   rewind(fp);
    for(i=0;i<N && i<MAX_STRINGS;i++){

        fgets(s, 50, fp);
        strcpy(strings[i], s);
        printf("%s", s );
    }

Note that if you are not using vectors, you have to pre-define the size of your array, basically the size of the array must be a constant