asked on

Again, In 16-bit, how do I check whether Drive A is formatted or not?"

I asked this question just days before.
(Programming : Languages : C : Q.10236627 )
I accepted one of the answers, which is not correct after testing. So, I have to ask again.

In my program, I try to write sth to Drive A, so I need to check the status of A drive, the first is whether Drive A is formatted.
I think _bios_disk can't work, this one always work no matter the drive A is formatted or not. _dos_open also can't. when I use this one to access A drive, it will give me the Abort, Retry, and Fail, if it's not formatted. I don't want my end user to see this message. besides, I will lose control.

Any idea to detect whether A is formatted or how to disable the Abort, Retry, and Fail, or and a handler?

Thanks
Wenfeng

mmessuri

wenfeng:

Here is a quick example on how to install your own error handler. This will allow you override the the Abort, Retry, and Fail error:

#include <stdio.h>
#include <dos.h>
#include <dir.h>
#include <process.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>

// globals

char tempdir[144];
int diskErr;

// prototypes

int diskErrorHandler(int errval, int ax, int bp, int si);
int restoreDir(char *s);

/* critical error handler for drive change - not working yet */

int testDisk(int n)
{
      void interrupt (*oldHarderr)();
      FILE *fp;
      char buffer[32];

      oldHarderr=getvect(0x24);
       harderr(diskErrorHandler);
      diskErr=0;
      getcwd(tempdir,80);
      sprintf(buffer,"%c:\\TEMP.DAT",n+'A');
clearerr(fp);
      if((fp=fopen(buffer,"r")) != NULL) fclose(fp);
      setvect(0x24,oldHarderr);
      return(diskErr);
}

int diskErrorHandler(int errval, int ax, int bp, int si)
{
      unsigned di;
      int errorno;

      if(ax >=0) {
            di = _DI;
            errorno = di & 0x00FF;
            diskErr = di & 0x00FF;;
            restoreDir(tempdir);
      }
      hardretn(2);
      return 0;
}

int restoreDir(char *s)       /* restore a saved directory path */
{
      strupr(s);
      if(isalpha(s[0]) && s[1]==':') setdisk(s[0]-'A');
      chdir(s);
return 0;
}

imladris

Also note that normally you are not expected to grade an answer until you have tried it.

KangaRoo

I mentioned using the access() function in that question. See if your compiler supports it.

ASKER CERTIFIED SOLUTION

KangaRoo

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

AlexVirochovsky

Hi, i hope, next programmm is a reply to you Q:
/*==========================================================*/
/* Name : GetStatusDriveInt */
/* Descript : Get Status of Drive                    */
/* Parameters : nDrive: 0-> A:, 1: B: , */
/* Return : -2: Disket not formatted,-1: not ready,0:OK */
/*==========================================================*/
int GetStatusDriveInt(int nDrive)
{
int nRet = -1;
struct SREGS sregs;
union REGS regs;
char szTemp[512];
int block[5];
                              //clear all
memset(&sregs , 0, sizeof(sregs));
memset(&regs , 0, sizeof(regs));
memset(szTemp , 0, sizeof(szTemp));
memset(block, 0, sizeof(block));

block[2] = 1;
block[3] = FP_OFF(szTemp);
block[4] = FP_SEG(szTemp);

sregs.ds = FP_SEG(block);
regs.x.bx = FP_OFF(block);
//        absread(as Interruption, vers 4.0 and more)
regs.h.al = nDrive;                  //disk a/b
regs.x.cx = -1;                  //data in block
regs.x.dx = 0;                  //1-st Sector

int86x(0x25, &regs, &regs, &sregs);      //read
if (regs.h.ah == 0)                  //ok?
{
int nErr = 0;
for (int i = 0, i < 512; i++)
      if (szTemp[i] != -10)
       break;
nRet = i < 512 ? 0: -2; //not formatted!
}
return nRet;
}
Alex

Again, In 16-bit, how do I check whether Drive A is formatted or not?&quot;

Again, In 16-bit, how do I check whether Drive A is formatted or not?"