Embedding resources into binary with C

note, Jun 19, 2024, on Mitja Felicijan's blog

Binary resource inclusion preprocessor has been put into the C23 standard but has not yet been implemented by the compilers.

Until then a workaround with xxd is possible without spending time on rolling out your own.

xxd has an option to export to C header file which makes this much easier. This works for all files be that text files or binary ones such as images, etc.

Convert text.txt into a C header file with xxd -i test.txt > test.h. This creates the following file and uses the filename for variable names.

// test.h
unsigned char test_txt[] = {
  0x54, 0x68, 0x65, 0x20, 0x66, 0x69, 0x72, 0x73, 0x74, 0x20, 0x72, 0x75,
  0x6c, 0x65, 0x20, 0x69, 0x73, 0x20, 0x74, 0x79, 0x70, 0x69, 0x63, 0x61,
  0x6c, 0x20, 0x6f, 0x66, 0x20, 0x71, 0x75, 0x61, 0x6e, 0x74, 0x75, 0x6d,
unsigned int test_txt_len = 547;

Then use it in C in this manner.

// main.c
#include <stdio.h>
#include "test.h"

int main(void) {
  printf("Testing embedding of files into binary.\n");

  for (unsigned int i = 0; i < test_txt_len; i++) {
    printf("%02x ", test_txt[i]);

  for (unsigned int i = 0; i < test_txt_len; i++) {
    printf("%c", test_txt[i]);

  return 0;

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