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

int
main(int argc, char** argv)
{
	if (argc != 5)
	{
		fprintf(stderr, "extractor [usage]: input_file output_file size offset");
		return EXIT_FAILURE;
	}

	char* in = argv[1];
	char* out = argv[2];
	int size = atoi(argv[3]);
	int offset = atoi(argv[4]);
	char* data = (char*)malloc(size + 1 * sizeof(char));
	FILE* fin = fopen(in, "r");
	fseek(fin, offset, SEEK_SET);
	fread(data, sizeof(char), size, fin);
	data[size + 1] = 0;
	fclose(fin);
	FILE* fout = fopen(out, "w");
	fwrite(data, sizeof(char), size, fout);
	fclose(fout);
	free(data);
	return EXIT_SUCCESS;
}