Terminal based QR code generator

qrcurses.c

/*
 * gcc -lqrencode -Wall -Wextra -std=c99 -O3 -o qrcurses qrcurses.c
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <qrencode.h>

#define BLOCK "\x1b[47m  \x1b[0m"
#define LINE(z) for (int y = 0; y < qr->width + z; y++) printf("%s", BLOCK); printf("\n")

static void qr_print(QRcode *qr)
{
	if (!qr)
		return;
	LINE(2);
	printf("%s", BLOCK);
	for (int y = 0; y < qr->width; y += (printf("%s\n%s", BLOCK, BLOCK), 1))
		for (int x = 0; x < qr->width; x++)
			printf("%s", qr->data[y * qr->width + x] & 0x01 ? "  " : BLOCK);
	LINE(1);
	return;
}

int main(int argc, char **argv)
{
	char data[7089] = { 0x0 };
	QRcode *qr = NULL;

	if (argc > 1)
	{
		for (int i = 1; i < argc; i += (strcat(data, argv[i]), 1))
			if (i > 1)
				strcat(data, " ");
		qr = QRcode_encodeString(data, 0, QR_ECLEVEL_L, QR_MODE_8, 1);
	}
	else
		qr = QRcode_encodeData(read(STDIN_FILENO, data, sizeof data), (unsigned char *)data, 0, QR_ECLEVEL_L);

	qr_print(qr);
	QRcode_free(qr);

	return EXIT_SUCCESS;
}