Re: List of lists code example

g*****ca <pg*****ca@[EMAIL PROTECTED]
> wrote:

>Everytime I try to search for "how mem.exe works" or something like
>that I end up with "you need to use int21h/52h to get list-of-lists
>and walk through the MCB chain"...  Well, I tried this:

This works for me:

/*----------------------------------------------------------------------------
Displays DOS MCB chain
Compile with Turbo C, Borland C, or Watcom C
----------------------------------------------------------------------------*/
#include <stdio.h>
#include <dos.h>

typedef unsigned short	uint16_t;

/* mcb_t must be a packed struct: */
#pragma pack(1)

/* That doesn't work for Turbo C++ 1.0, so do this: */
#if defined(__TURBOC__)
#if __TURBOC__==0x296
#pragma option -a-
#endif
#endif

typedef struct
{
	char type;
	uint16_t owner_psp;
	uint16_t size; /* in paragraphs */
	char unused[3];
	char owner_name[8];
} mcb_t;
/*****************************************************************************
*****************************************************************************/
static void wrstr(char far *s)
{
	int i;

	for(i = 0; i < 8; i++)
	{
		putchar(*s < ' ' ? '.' : *s);
		s++;
	}
}
/*****************************************************************************
debug function
*****************************************************************************/
#define BPERL		16	/* byte/line for dump */

void dump(void far *data_p, unsigned count)
{
	unsigned char far *data = (unsigned char far *)data_p;
	unsigned byte1, byte2;

	while(count != 0)
	{
		for(byte1 = 0; byte1 < BPERL; byte1++)
		{
			if(count == 0)
				break;
			printf("%02X ", data[byte1]);
			count--;
		}
		printf("\t");
		for(byte2 = 0; byte2 < byte1; byte2++)
		{
			if(data[byte2] < ' ')
				printf(".");
			else
				printf("%c", data[byte2]);
		}
		printf("\n");
		data += BPERL;
	}
}
/*****************************************************************************
*****************************************************************************/
int main(void)
{
	struct SREGS sregs;
	union REGS regs;
	mcb_t far *mcb;
	unsigned s;

	regs.x.ax = 0x5200;
	int86x(0x21, &regs, &regs, &sregs);
/* segment of MCB list entry
Watcom C has no 'peek'
	s = peek(sregs.es - 1, regs.x.bx + 14); */
	s = *(uint16_t far *)MK_FP(sregs.es - 1, regs.x.bx + 14);
	while(1)
	{
		mcb = (mcb_t far *)MK_FP(s, 0);
/*dump(mem, sizeof(mcb_t));*/
		printf("adr=%04X, owner_psp=%04X, size=%6lu, owner=",
			FP_SEG(mcb), mcb->owner_psp, mcb->size * 16uL);
		wrstr(mcb->owner_name);
		printf(", contents=");
		wrstr(&((char far *)mcb)[16]);
		printf("\n");
		if(mcb->type == 0x5A)
			break;
		s += (1 + mcb->size);
	}
	printf("adr=%04X\n", FP_SEG(mcb));
	return 0;
}