The functions fprintf() and fscanf() are similar to printf() and scanf() except that these functions operate on files and require one additional and first argument to be a file pointer
Example of fscanf() and fprintf() function
#include <stdio.h>
main ()
{
FILE *fp;
float total;
fp = fopen("data.txt", "w+");
if (fp == NULL) {
printf("data.txt does not exist, please check!\n");
exit (1);
}
fprintf(fp, 100);
fscanf(fp, "%f", &total);
fclose(fp);
printf("Value of total is %f\n", total);
}