/* hex.c
 * D. Brylow    2010 Sep 03    COSC 3300
 * Demo #1 - Hex dump utility demonstrates command line arguments,
 *  file I/O, output specifiers for examining data.
 */
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

int main(int argc, char **argv)
{
	int i, count = 0, total = 0;
	FILE *input;
	char contents[16];


//	printf("Number of arguments = %d\n", argc);
//	for (i = 0 ; i < argc; i++)
//	{
//		printf("ArgV[%d] = %s\n", i, argv[i]);
//	}

	if (argc != 2)
	{
		printf("Error: Expected filename!\n");
		exit(-1);
	}

	input = fopen(argv[1], "r");
	if (NULL == input)
	{
		printf("Error: Could not open file %s!\n", argv[1]);
		exit(-2);
	}


	while (0 < (count = fread(contents, 1, 16, input)))
	{
		printf("%08X  ", total);
		total += count;
		for (i = 0; i < count; i++)
		{
			printf("%02X ", contents[i]);
			if (7 == (i % 8)) { printf(" "); }
		}
		if (count < 16)
		{
			for (i = 0; i < 16 - count; i++)
			{
				printf("   ");
				if (7 == (i % 8)) { printf(" "); }
			}
			printf(" ");
		}
		printf("|");
		for (i = 0; i < count; i++)
		{
			if (isprint(contents[i]))
			{   printf("%c", contents[i]);  }
			else
			{   printf(".");  }
		}
		printf("|\n");
	}
	printf("%08X\n", total);
         
	fclose(input);
}