from input file to array using malloc and realloc

Question

I am trying to read input from a file and put each string in an array using malloc and realloc. So if the input file is :

alex
john
jane
smith

Answer 1

you would want to allocate an array of pointers first with an initial size say 10:

int size = 10;
char **inputFile= malloc(sizeof*inputFile*size);

Then for each word you read you allocate more memory for it and insert it into the array:

char line[100];
fscanf(file, "%s", line);
inputFile[index++] = strdup(line);

Now check if you need more words then you realloc the array:

if (index==size) {
   size += 10;
   inputFile = realloc(inputFile, sizeof*inputFile*size);
}

So you end up with something like this:

[0]->"alex"
[1]->"john"
[2]->"jane"
[3]->"smith"

When you're done you need to loop over the array and free each string and then free the array, this part is left as an exercise :)