countf.c

来自「汇编源代码大全」· C语言 代码 · 共 40 行

/***************************************************************
 *     COUNTF.C - Jim Kyle
 *  Last change : 13 August 1990
 ***************************************************************/
#include <stdio.h>
#include <dos.h>
#include <stdlib.h>

#ifndef MK_FP
#define MK_FP( s, o ) (void far *)(((long)(s) << 16) | \
	(unsigned)(o))
#endif

unsigned files(void)
{ union REGS regs;
  struct SREGS sregs;
  unsigned int far *ptr;
  int n = 0;

  if ( _osmajor < 2 )
    { puts( "FILES not supported in this DOS version.");
      exit(0);
    }
  regs.h.ah = 0x52;
  intdosx( &regs, &regs, &sregs );
  ptr = (unsigned int far *) MK_FP( sregs.es, regs.x.bx + 4 );
  ptr = (unsigned int far *) MK_FP( ptr[1], ptr[0] );
  while ( FP_OFF(ptr) != 0xFFFF )
    { n += ptr[2];
      ptr = (unsigned int far *) MK_FP( ptr[1], ptr[0] );
    }
  return n;
}

#ifdef TESTING
void main( void )
{   printf("FILES=%d\n", files());
}
#endif