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

struct option longopts[] =
{
    { "byte", 0, 0, 'b' },
    { "short", 0, 0, 's' },
    { "long", 0, 0, 'l' },
    { "big_endian", 0, 0, 'E' },
    { "little_endian", 0, 0, 'e' },
    { "ascii", 0, 0, 'a' },
    { "8bit", 0, 0, '8' },
    { "width", 1 , 0, 'w' },
    { "help", 0, 0, 'h' },
    { 0, 0, 0, 0 }
};

void usage(FILE *fp, char *name)
{
    fprintf(fp, "Usage: %s [-bslEea8h] [-w<width>] [FILE]\n", name);
}

void help(char *name)
{
    usage(stdout, name);
    printf("\n\t-b --byte\t\t1 byte format\n");
    printf("\t-s --short\t\t2 byte format\n");
    printf("\t-l --long\t\t4 byte format\n");
    printf("\t-E --big_endian\t\tbig endian format\n");
    printf("\t-e --little_endian\tlittle endian format\n");
    printf("\t-a --ascii\t\tinclude ascii column\n");
    printf("\t-8 --8bit\t\tuse 8 bit characters in ascii column\n");
    printf("\t-w --width=BYTES\toutput BYTES per output line\n");
    printf("\t-h --help\t\tdisplay this help and exit\n");
}

char opt_size = 1;
char opt_endian = 0;
char opt_ascii = 0;
char opt_8bit = 0;
int opt_width = 16;
unsigned char *buffer;

void dump_file(FILE *fp)
{
    int i, j, k, count;

    for(count = 0; (k = fread(buffer, 1, opt_width, fp)); count += k)
    {
	for(i = k; i < opt_width; i++)
	    buffer[i] = 0;

	printf("%08X: ", count);
	for(i = 0; i < k; i += opt_size)
	{
	    putchar(' ');
	    for(j = 1; j <= opt_size; j++)
	    {
		printf("%02X", buffer[i + (opt_endian ? j - 1: opt_size - j)]);
	    }
	}
	if(opt_ascii)
	{
	    for(; i < opt_width; i += opt_size)
		fputs("         "+(8-(opt_size+opt_size)), stdout);
	    printf("  \"");
	    for(i = 0; i < opt_width; i++)
	    {
		j = buffer[i];
		putchar((j >= 32 && j < 127) || (opt_8bit && j >= 160) ?
			j : '.');
	    }
	    putchar('"');
	}
	putchar('\n');
    }
}

int main(int argc, char **argv)
{
    FILE *fp;
    int c;

    while((c = getopt_long(argc, argv, "bslEea8w:h", longopts, 0)) != -1)
    {
	switch(c)
	{
	case 'b':
	    opt_size = 1;
	    break;
	case 's':
	    opt_size = 2;
	    break;
	case 'l':
	    opt_size = 4;
	    break;
	case 'a':
	    opt_ascii = 1;
	    break;
	case 'E':
	    opt_endian = 1;
	    break;
	case 'e':
	    opt_endian = 0;
	    break;
	case '8':
	    opt_8bit = 1;
	    break;
	case 'h':
	    help(argv[0]);
	    return 0;
	case 'w':
	    if((opt_width = atoi(optarg)))
		break;
	default:
	    usage(stderr, argv[0]);
	    return 1;
	}
    }

    if(opt_width % opt_size)
    {
	fprintf(stderr, "%s: width must be a multiple of the output size\n", argv[0]);
	return 1;
    }

    if(!(buffer = malloc(opt_width)))
    {
	perror(argv[0]);
	return 1;
    }

    if(optind < argc)
    {
	do
	{
	    if(!(fp = fopen(argv[optind], "r")))
	    {
		perror(argv[optind]);
		return 1;
	    }
	    dump_file(fp);
	    fclose(fp);
	}
	while(++optind < argc);
    }
    else
    {
	dump_file(stdin);
    }

    return 0;
}