#include <stdio.h>

int write_one_by_one(char *filename, const char *text){

    FILE *file = fopen(filename, "w");
    if(!file) return 1;

    int index = 0;
    while(*(text + index) != '\0'){
        fputc(*(text + index ), file);
        index ++;
    }
    //fputc(*text, file);
    fputc('\0', file);
    fclose(file);
    return 0;
}

int main()
{
    // does_exist.txt contains: "something which will be replaced"
    int a = write_one_by_one("does_exist.txt", "Hello World!");
    // does_exist.txt contains: "Hello World!"

    // does_not_exist.txt... does not exist.
    int b = write_one_by_one("does_not_exist.txt", "Now I exist");
    // does_not_exist.txt... now exists and contains: "Now I exist"

    printf("%d %d\n", a, b); // 0 0
    // The opening should succeed as it creates the file if needed
    // However it can fail if the file's access is forbidden

    return 0;
}