embedding blobs into executable

demo.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>

extern char _binary_resources_tar_start;
extern char _binary_resources_tar_end;

#define BLOCK_SIZE 512

typedef struct {
  char name[100];
  char mode[8];
  char uid[8];
  char gid[8];
  char size[12];
} header_t;

int main(void) {
  char *offset = &_binary_resources_tar_start;
  while (*offset != '\0') {
    header_t *entry = (header_t*)offset;
    long int size = strtol(entry->size, NULL, 8);
    printf("%s: %ld bytes\n", entry->name, size);
    for (int i = 0; i < size; ++i) {
      fputc(offset[BLOCK_SIZE + i], stdout);
    }
    int blocks = size <= 512 ? 1 : ceil(size / 512.0);
    offset += BLOCK_SIZE * (blocks + 1);
  }
  return 0;
}

foobar.txt

foobar

lorem.txt

lorem
ipsum
dolor

Makefile

override CFLAGS += -Wall -Wextra -std=c99 -pedantic

.PHONY: all
all: demo

.PHONY: clean
clean:
  rm *.o *.tar demo

demo.o: demo.c
demo: resources.o -lm

resources.o: resources.tar
	ld -r -b binary -o $@ $^

resources.tar: foobar.txt lorem.txt
	tar -cf $@ $^