i need help with understanding this file function in c

Question

I need to calculate the number of letter in a text per average but i cant figure out how to use this file function (which is mandatory) .
#include <stdio.h>

void writeToFile() {
FILE *f = fopen("text.txt", "w");
char c;
while((c = getchar()) != '#') {
fputc(c, f);
}
fclose(f);
}

int main() {
writeToFile();

// your code here
}

Answer 1

the 'writeToFile' function write the user input in 'text.txt' file and stop when the character '#' is typed.

so in the main function, you should open that 'text.txt' file in reading mode and then read it with 'fgetc' to do what your asked to do.