#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>

// fputc vs. fwrite
//
// fputc(…) writes one byte at a time.
// fwrite(…) writes any number of bytes.

typedef unsigned char uchar;

int main(int argc, char* argv[]) {
    FILE* fp = fopen("b.txt", "w");  // "w" means write (and replace file if it exists).

    // Write one byte ('A' == 0x41 == 65 == 01000001₂) using fputc(…).
    fputc(0x41, fp);

    // Write one byte ('B' == 0x42 == 66 == 01000010₂) using fwrite(…).
    uchar src_data[] = { 0x42 };
    fwrite(src_data, sizeof(src_data[0]), 1, fp);  // too much risk of getting it wrong
    // fwrite(src_data, 1, 1, fp);              // BOO!!!!!!!
    // fwrite(src_data, sizeof(uchar), 1, fp);  // BOO!!!!!!!
    // fwrite(src_data, sizeof(0x42), 1, fp);   // WRONG!!!!!
    
    // LESSON:  Use fputc(…)

    fclose(fp);
    
    return EXIT_SUCCESS;
}
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