How to scan string from file and store it on an array of strings (two-dimensional array)?

Question

I am scanning a string from a file and storing it into an array of strings. When I compile my program, it does not produce any error but when I run it, it says Segmentation fault (core dumped). I know that the error is in the fscanf statement, but I can't figure out what's wrong.

My code looks like this:

 FILE    *stringsIn = fopen("strings.txt", "rt");
 char    *strings[INPUT_STRINGS];

    for (int i = 0; i < INPUT_STRINGS; i++)
            fscanf(stringsIn, "%s ", &strings[i][0]);

Answer 1

You have an array of pointers but you didn't allocate space for each string. In this case what you can do is preallocate a big enough buffer or read in a preallocated buffer, see how many characters were read and allocate a string of that size.

FILE    *stringsIn = fopen("strings.txt", "rt");
char    *strings[INPUT_STRINGS];

for (int i = 0; i < INPUT_STRINGS; i++) {
   strings[i] = (char*)malloc(2048); //allocate a big enough buffer
   fscanf(stringsIn, "%2047s ", &strings[i][0]);
}

The second version is something like:

FILE    *stringsIn = fopen("strings.txt", "rt");
char    *strings[INPUT_STRINGS];
char temp[2048];

for (int i = 0; i < INPUT_STRINGS; i++) {
   fscanf(stringsIn, "%2047s ", &temp);
   size_t len = strlen(temp);
   strings[i] = (char*)malloc(len + 1);
   strncpy(strings[i], temp, len);
}