cerror,h

• cerror_close
• cerror_open

cerror_close

Header

cerror.h

Prototype

void __cdecl cerror_close(void);

Description

Removes a user supplied critical handler. The handler should have previously been installed by cerror_open().

Compatibility

DOS Windows 3.x Phar Lap DOSX Win32

See Also

cerror_open

Example

See cerror_open

cerror_open

Header

cerror.h

Prototype

void __cdecl cerror_open(void);

Description

Installs a user supplied critical handler. This function, which you must write, uses the following prototype:

void __cdecl _cerror_handler(unsigned short *ax, unsigned short *di);

After a call to cerror_open, this routine begins receiving critical errors. It stops receiving them with a call to cerror_close.

Critical errors can occur under MS-DOS during attempts to access floppy disk drives or while using a parallel printer. They can cause the Abort, Retry, Ignore, Fail messages. Normally you have to write and debug a critical error handler for MS-DOS, and for each DOS extended platform you want to support.

The cerror_open and cerror_close functions provide a solution to this problem. They are portable across all platforms Digital Mars C++ supports.

Compatibility

DOS Windows 3.x Phar Lap DOSX Win32

See Also

cerror_close

Example

/* 	Example for cerror_open 
	Also demonstrates cerror_close 
*/ 

#include <cerror.h> 
#include <stdio.h> 
#include <windows.h>

static unsigned short ax_value, di_value; 

void _cerror_handler (unsigned short *ax, 
		       unsigned short *di) 
{   
  ax_value = *ax; 
  di_value = *di; 
} 

void main () 
{   
  printf (" Be sure there is no disk in A:\n"); 
  getch (); 
  cerror_open (); 

  ax_value = di_value = 0; 
  fopen ("a:anything", "r"); 
  printf ("After trying to open A:ANYTHING, ax = %x, di = %x\n",
	ax_value, di_value); 

  ax_value = di_value = 0;
  fopen ("c:anything", "r"); 
  printf ("After trying to open C:ANYTHING, ax = %x, di = %x\n",
	ax_value, di_value);

  cerror_close (); 
}

Output

Be sure there is no disk in A:

After trying to open A:ANYTHING, ax = 1a00, di = 2

After trying to open C:ANYTHING, ax = 0, di = 0