#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char* get_header(FILE* file, char* sep){
char *header = NULL;
size_t len = 0;
getline(&header, &len, file);
header = strtok(header, sep);
return header;
}
int main(void) {
const char* filename = "input.txt";
FILE* input_file = fopen(filename, "r");
if (!input_file)
exit(EXIT_FAILURE);
char *contents = NULL;
size_t len = 0;
char* sep =",";
char* header = get_header(input_file, sep);
while(header!=NULL){