1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
---
title: "Embedding resources into binary with C"
url: embedding-resources-into-binary-with-c.html
date: 2024-06-19T16:13:13+02:00
type: note
draft: false
tags: [c]
---
[Binary resource inclusion](https://en.cppreference.com/w/c/preprocessor/embed)
preprocessor has been put into the C23 standard but has not yet been
implemented by the compilers.
Until then a workaround with
[`xxd`](https://en.cppreference.com/w/c/preprocessor/embed) 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.
```c
// 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.
```c
// 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]);
}
printf("\n\n");
for (unsigned int i = 0; i < test_txt_len; i++) {
printf("%c", test_txt[i]);
}
printf("\n\n");
return 0;
}
```
|
