utils.c

/*
 * dabpi_ctl - raspberry pi fm/fmhd/dab receiver board control interface
 * Copyright (C) 2014  Bjoern Biesenbach <bjoern@bjoern-b.de>
 * Copyright (C) 2016  Heiko Jehmlich <hje@jecons.de>
 *
 * http://stackoverflow.com/questions/7775991/how-to-get-hexdump-of-a-structure-data
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

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

void hexDump(char *desc, void *addr, int len) {
	int i;
	unsigned char buff[17];
	unsigned char *pc = (unsigned char*) addr;

	// Output description if given.
	if (desc != 0)
		printf("%s:\n", desc);

	if (len == 0) {
		printf("  ZERO LENGTH\n");
		return;
	}
	if (len < 0) {
		printf("  NEGATIVE LENGTH: %i\n", len);
		return;
	}

	// Process every byte in the data.
	for (i = 0; i < len; i++) {
		// Multiple of 16 means new line (with line offset).

		if ((i % 16) == 0) {
			// Just don't print ASCII for the zeroth line.
			if (i != 0)
				printf("  %s\n", buff);

			// Output the offset.
			printf("  %04x ", i);
		}

		// Now the hex code for the specific character.
		printf(" %02x", pc[i]);

		// And store a printable ASCII character for later.
		if ((pc[i] < 0x20) || (pc[i] > 0x7e))
			buff[i % 16] = '.';
		else
			buff[i % 16] = pc[i];
		buff[(i % 16) + 1] = '\0';
	}

	// Pad out last line if not exactly 16 characters.
	while ((i % 16) != 0) {
		printf("   ");
		i++;
	}

	// And print the final ASCII bit.
	printf("  %s\n", buff);
}