#pragma inline

#include "dos.h"

struct INTERRUPT

{

unsigned bp,di,si,ds,es,dx,cx,bx,ax,ip,cs,fl;

};

void interrupt nodel(struct INTERRUPT);

void interrupt (*prev)();

main()

{

//AIM : to deactivate the dos del command using int21 tsr

void interrupt nodel(struct INTERRUPT);

unsigned long far *int21ptr;

int21ptr=(unsigned long far*)(0x21*4);

prev=(void (interrupt far*)())*int21ptr;

*int21ptr=(unsigned long)nodel;

keep(0,1000);

return 0;

}

void interrupt nodel(struct INTERRUPT r)

{

// if((_AH==19)|(_AH==65)) // if delete attempted on a file

// {

// r.fl=r.fl&0xfffe; //make LSB of flag register on stack as 0

// return;

// }

if (_AH==0x41)

{

r.fl=r.fl&0xfffe;

return;

}

asm pop bp;

asm pop di;

asm pop si;

asm pop ds;

asm pop es;

asm pop dx;

asm pop cx;

asm pop bx;

asm pop ax;

asm jmp cs:_prev;

}