read a file with three tab separated columns. Ignore the first column, the second column is a string, the third column is a number.

read_data.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_LINE_LENGTH 1024

typedef struct
{
  char *SKU;
  long *count;
} Data;

void free_data(Data *data, int nrows);
Data *read_data(const char *filename, int *nrows);

int main(void)
{
  int nrows;
  int i = 0;
  Data *data = read_data("C:\\data.txt", &nrows);
  system("cls");
  if (data == NULL)
  {
    return 1;
  }

  for (i = 0; i < nrows; i++)
  {
    printf("%s, %ld\n", data[i].SKU, *data[i].count);
  }

  free_data(data, nrows);

  return 0;
}

void free_data(Data *data, int nrows)
{
  int i;
  for (i = 0; i < nrows; i++)
  {
    free(data[i].SKU);
    free(data[i].count);
  }
  free(data);
}

Data *read_data(const char *filename, int *nrows)
{
  FILE *fp = fopen(filename, "r");
  Data *data = NULL;
  char line[MAX_LINE_LENGTH];
  int n = 0;
  int i = 0;
  long *count = NULL;
  if (fp == NULL)
  {
    perror("Error opening file");
    return NULL;
  }

  while (fgets(line, MAX_LINE_LENGTH, fp) != NULL)
  {
    n++;
  }
  rewind(fp);

  if (n > 0)
  {
    data = (Data *)malloc(n * sizeof(Data) + 1);
    if (data == NULL)
    {
      perror("Error allocating memory");
      fclose(fp);
      return NULL;
    }
  }

  while (fgets(line, MAX_LINE_LENGTH, fp) != NULL)
  {
    data[i].SKU = (char *)malloc((strlen(line) + 1) * sizeof(char));
    count = (long *)malloc(sizeof(long));
    if (data[i].SKU == NULL)
    {
      perror("Error allocating memory");
      fclose(fp);
      free_data(data, n);
      return NULL;
    }
    if (count == NULL)
    {
      perror("Error allocating memory");
      fclose(fp);
      free_data(data, n);
    }
    sscanf(line, "%*d %s %ld", data[i].SKU, count);
    data[i].count = count;
    i++;
  }

  fclose(fp);
  *nrows = n;
  return data;
}