matherr_handler

Syntax

  #include <math.h> 
   
  int matherr_handler (
     int (*newFunc)(_FP_EXCEPTION   *err_info));
  

Parameters

newFunc

(IN) Points to the function to be used as the matherr function.

Return Values

If successful, returns 0. If a nonzero value is returned, an error occurred and no error handler was registered.

Remarks

If a routine has already been registered, matherr_handler returns a nonzero value.

The following unregisters a previously registered matherr handler:

     matherr_handler(NULL);
  

The routine that is registered must meet the requirements of matherr.

For more information on developing a matherr handler, see Section 17.1, Writing a Math Error Handler.

See Also

• matherr
• exception

Example

The following code is more or less what LibC does when no matherr handler is registered.

  #include <math.h>
  
  int mymatherr
  (
     __FP_EXCEPTION *exc
  )
  {
        char  *msg;
  /*
  ** Protect against a bad calling parameter which could cause
  ** us to index beyond the valid messages or foul up a user
  ** error handler. We don’t permit any localization of these
  ** strings because they are fixed though in English.
  */
        if (exc->type < DOMAIN ||  exc->type > PLOSS)
           exc->type = DOMAIN;
  
        switch (exc->type)
        {
           default :
              break;
           case DOMAIN :
              msg = "Domain error";
              break;
           case SING :
              msg = "Argument singularity";
              break;
           case OVERFLOW :
              msg = "Overflow range error";
              break;
           case UNDERFLOW :
              msg = "Underflow range error";
              break;
           case TLOSS :
              msg = "Total loss of significance";
              break;
           case PLOSS :
              msg = "Partial loss of significance";
              break;
        }
  
  #define ERR_PROMPT   "MyNLM-1.0-100: %s in %s\n"
  
        fprintf(stderr, ERR_PROMPT, msg, exc->name);
  
     return exc->retval;
  }