#include <stdio.h>


#define	BLKSIZ	512
#define	SSZ	sizeof(short)


char	ibuf[BLKSIZ];
int	blksiz = BLKSIZ;


int	aflg = 0;
int	dflg = 0;
int	oflg = 0;


int	main(argc, argv)
	int	argc;
	char	*argv[];

{			char	*arg;
			char	*ifnm;
	register	FILE	*in;
			int	blkno, nblks, lstblk, eblksz;
			long	size;


	if (argc < 3) {
		printf("\ndumpf {-a} {-d} {-o} <ifile> <blkno>\n");
		exit(1);
		}

	argv++;
	argc--;
	

	for (;;) {
		arg = *argv;
		if (*arg++ != '-')
			break;

		argv++;
		argc--;

		switch (*arg) {

		  case 'a':	aflg++;
				break;

		  case 'd':	dflg++;
				break;

		  case 'o':	oflg++;
				break;

		  default:	printf("Bad flag: %c", *arg);
				exit(1);
		  }
		}


	ifnm = *argv++;
	argc--;
	
	in = fopen(ifnm, "rb");
	if (in == NULL) {
		printf("Error opening input file: '%s'\n", ifnm);
		exit(1);
		}


	arg = *argv++;
	argc--;

	blkno = atoi(arg);
	if (arg < 0) {
		printf("Bad block number: %\n", blkno);
		exit(1);
		}

	if (argc > 0) {
		printf("Unneeded extra arg '%s'", *argv);
		exit(1);		
		}


	if (fseek(in, 0, SEEK_END) != 0) {
		printf("Size seek failed\n");
		exit(1);
		}

	size = ftell(in);
	nblks = (size / BLKSIZ);
	eblksz = (size % BLKSIZ);

	if (eblksz == 0)
		eblksz = BLKSIZ;
	  else
		nblks++;

	lstblk = (nblks - 1);

	if (blkno == lstblk)
		blksiz = eblksz;

	if (blkno > lstblk) {
		printf("Block number too large\n");
		exit(1);
		}


	printf("\nBlock: %d %d %d\n", blkno, nblks, lstblk);
	printf("Size: %ld %d %d (%o) \n", size, eblksz, blksiz, blksiz);


	if (fseek(in, (blkno * BLKSIZ), SEEK_SET) != 0) {
		printf("Read seek failed\n");
		exit(1);
		}
	
	if (fread(&ibuf[0], sizeof(char), blksiz, in) != blksiz) {
		printf("Read failed\n");
		exit(1);
		}

	dumpblock();

	printf("\n");
}


dumpblock()

{	register	short	*loc;
			short	rowsiz, wd;
			int	wdloc, wdno;


	if (aflg)
		rowsiz = 4;
	  else
		rowsiz = 8;
	
	loc = ((short *) &ibuf[0]);
	wdloc = 0;

	for (;;) {
		if (oflg)
			printf("\n%03d:    ", wdloc);
		  else
			printf("\n%03o:    ", wdloc);

		for (wdno = 0; (wdno < rowsiz); wdno++) {
			if (aflg) {
				wd = *loc++;
				prchar(wd & 0377);
				prchar((wd >> 8) & 0377);
				}
			  else 
				printf(((dflg != 0) ? "%06hd " : "%06ho "),
					 *loc++);
			wdloc += SSZ;
			if (wdloc >= blksiz)
				return;
			}
		}
}


prchar(c)
char	c;

{	int	rlen = 0, i;

	if (c & 0200) {
		rlen = 2;
		printf("M-", (c + 0100));
		}
	c &= 0177;

	if (c < 040) {
		printf("^%c", (c + 0100));
		rlen += 2;
		}
	else if (c == ' ') {
		printf("' '");
		rlen += 3;
		}
	else if (c == 0177) {
		printf("DEL");
		rlen += 3;
		}
	else {
		printf("%c", c);
		rlen += 1;
		}
	for (i = rlen; (i < 6); i++)
		putchar(' ');
}