how to tokenize string to array of int in c?

Question

Anyone got anything about reading a sequential number from text file per line and parsing it to an array in C?

What I have in a file:

12 3 45 6 7 8
3         


        

Answer 1

What I would do is to make a function like this:

size_t read_em(FILE *f, int **a);

In the function, allocate some memory to the pointer *a, then start reading numbers from the f and storing them in *a. When you encounter a newline character, simply return the number of elements you've stored in *a. Then, call it like this:

int *a = NULL;
FILE *f = fopen("Somefile.txt", "r");
size_t len = read_em(f, &a);
// now a is an array, and len is the number of elements in that array

Useful functions:

• malloc() to allocate an array.
• realloc() to extend a malloc()ed array
• fgets() to read a line of text (or as much as can be stored).
• sscanf() to read data from a string (such as a string returned by fgets()) into other variables (such as an int array created by malloc() - hint hint)