/* Richard A. DeVenezia
 * 1994
 */

#include <stdio.h>

int N=20; /* bytes in row */

void hex();

void main(argc, argv)
     int    argc;
     char **argv;
{
	int n;

	if (argc > 1 && argv[1][0]=='-')
	    N=atoi(argv[1]+1);

	if (N == 0) N=20;
	else
	if (N < 4) N=4;
	else
	if (N > 40) N=40;

	if (argc > 1) {
	    if (argc==2 && argv[1][0]=='-')
		hex ();
		/* change in bytes per row count only, input from stdin */
	    else
	        for (n=1;n<argc;n++) {
		    if (argv[n][0] != '-')
		    /* ignore -N option or filenames starting with - */

			if (freopen (argv[n], "r", stdin) == NULL)
		            fprintf (stderr, "could not open %s\n", argv[n]);
		    	else {
			    printf ("file: %s\n", argv[n]);
		   	    hex ();
		    	}
	        }
	}
	else
	    hex ();
	    /* input from stdin */
}

void hex()
{
	unsigned int c;
	long	i=0, j, offset=0, group=0;
	char    ch[40];

	for (c=getchar(); !feof(stdin); c=getchar()) {

		ch[i] = c;

/*		Use this to show offsets in hex
		if (i==0)	printf ("%h6x: ", offset);
 */
		if (i==0)	printf ("%8d: ", offset);

		if ((group++&3)==0 && i>0) putchar ('-');

		if (c < 0)	printf ("%h2x", c);
			   else printf ("%h2x", c);

		i++;

		if (i==N) {
			putchar (' ');
			for (j=0;j<N;j++)
				{ if (ch[j] >= 32) putchar (ch[j]);
					      else putchar ('.'); }
			putchar ('\n');
			offset+=N;
			i=group=0;
		}
	}

	if (i) {
		for (j=i;j<N;j++) printf ("  ");
		for (j=0;j<((N-1)/4-(i-1)/4);j++) putchar(' ');
		putchar (' ');
		for (j=0;j<i;j++)
			{ if (ch[j] >= 32) putchar (ch[j]);
				      else putchar ('.'); }
		putchar ('\n');
	}
}