mnist.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

static const char *urls[] = {
	"http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz",
	"http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz",
	"http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz",
	"http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz"
};

int main() {
	struct stat st = {0};
	if(stat(".local/", &st) == -1) {
		mkdir(".local/", 0755);
	}

	FILE *trainImages = fopen(".local/train-images-idx3-ubyte", "rb");
	if(trainImages == NULL) {
		printf("Couldn't open file");
		return 1;
	}

	int magicNumber;
	int numItems;
	int sizeRow;
	int sizeColumn;

	size_t ret = fread(&magicNumber, 4, 1, trainImages);

	if(1 != ret) {
		printf("Could not read the file");
		fclose(trainImages);
		return 1;
	}


	if( magicNumber != 0x00000308) {
		printf("Incorrect magic number. Expected 0x00000308, got 0x%x\n", magicNumber);
		fclose(trainImages);
		return 1;
	}

	fclose(trainImages);
}