utility.c

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static BOOLEAN RemoveCPFunction(name,head)
  char *name;
  struct cleanupFunction **head;
  {
   struct cleanupFunction *currentPtr, *lastPtr;

   lastPtr = NULL;
   currentPtr = *head;

   while (currentPtr != NULL)
     {
      if (strcmp(name,currentPtr->name) == 0)
        {
         if (lastPtr == NULL)
           { *head = currentPtr->next; }
         else
           { lastPtr->next = currentPtr->next; }
         rtn_struct(cleanupFunction,currentPtr);
         return(CLIPS_TRUE);
        }
      lastPtr = currentPtr;
      currentPtr = currentPtr->next;
     }

   return(CLIPS_FALSE);
  }

/*****************************************************/
/* StringPrintForm: Generates printed representation */
/*   of a string. Replaces / with // and " with /".  */
/*****************************************************/
globle char *StringPrintForm(str)
  char *str;
  {
   int i = 0, pos = 0, max = 0;
   char *theString = NULL;
   VOID *thePtr;

   theString = ExpandStringWithChar('"',theString,&pos,&max,max+80);
   while (str[i] != EOS)
     {
      if ((str[i] == '"') || (str[i] == '\\'))
        {
         theString = ExpandStringWithChar('\\',theString,&pos,&max,max+80);
         theString = ExpandStringWithChar(str[i],theString,&pos,&max,max+80);
        }
      else
        { theString = ExpandStringWithChar(str[i],theString,&pos,&max,max+80); }
      i++;
     }

   theString = ExpandStringWithChar('"',theString,&pos,&max,max+80);

   thePtr = AddSymbol(theString);
   rm(theString,max);
   return(ValueToString(thePtr));
  }

/***********************************************************/
/* AppendStrings: Appends two strings together. The string */
/*   created is added to the SymbolTable, so it is not     */
/*   necessary to deallocate the string returned.          */
/***********************************************************/
globle char *AppendStrings(str1,str2)
  char *str1, *str2;
  {
   int pos = 0, max = 0;
   char *theString = NULL;
   VOID *thePtr;

   theString = AppendToString(str1,theString,&pos,&max);
   theString = AppendToString(str2,theString,&pos,&max);

   thePtr = AddSymbol(theString);
   rm(theString,max);
   return(ValueToString(thePtr));
  }

/******************************************************/
/* AppendToString: Appends a string to another string */
/*   (expanding the other string if necessary).       */
/******************************************************/
globle char *AppendToString(appendStr,oldStr,oldPos,oldMax)
  char *appendStr, *oldStr;
  int *oldPos, *oldMax;
  {
   int length;

   /*=========================================*/
   /* Expand the old string so it can contain */
   /* the new string (if necessary).          */
   /*=========================================*/
   
   length = strlen(appendStr);
   if (length + *oldPos + 1 > *oldMax)
     {
      oldStr = genrealloc(oldStr,(unsigned) *oldMax,(unsigned) length + *oldPos + 1);
      *oldMax = length + *oldPos + 1;
     }

   /*==============================================================*/
   /* Return NULL if the old string was not successfully expanded. */
   /*==============================================================*/
   
   if (oldStr == NULL) { return(NULL); }

   /*===============================================*/
   /* Append the new string to the expanded string. */
   /*===============================================*/
   
   strcpy(&oldStr[*oldPos],appendStr);
   *oldPos += length;

   /*============================================================*/
   /* Return the expanded string containing the appended string. */
   /*============================================================*/
   
   return(oldStr);
  }

/*******************************************************/
/* AppendNToString: Appends a string to another string */
/*   (expanding the other string if necessary). Only a */
/*   specified number of characters are appended from  */
/*   the string.                                       */
/*******************************************************/
globle char *AppendNToString(appendStr,oldStr,length,oldPos,oldMax)
  char *appendStr, *oldStr;
  int length;
  int *oldPos, *oldMax;
  {
   int lengthWithEOS;

   /*====================================*/
   /* Determine the number of characters */
   /* to be appended from the string.    */
   /*====================================*/
   
   if (appendStr[length-1] != '\0') lengthWithEOS = length + 1;
   else lengthWithEOS = length;
   
   /*=========================================*/
   /* Expand the old string so it can contain */
   /* the new string (if necessary).          */
   /*=========================================*/

   if (lengthWithEOS + *oldPos > *oldMax)
     {
      oldStr = genrealloc(oldStr,(unsigned) *oldMax,(unsigned) *oldPos + lengthWithEOS);
      *oldMax = *oldPos + lengthWithEOS;
     }

   /*==============================================================*/
   /* Return NULL if the old string was not successfully expanded. */
   /*==============================================================*/
   
   if (oldStr == NULL) { return(NULL); }
   
   /*==================================*/
   /* Append N characters from the new */
   /* string to the expanded string.   */
   /*==================================*/

   strncpy(&oldStr[*oldPos],appendStr,(CLIPS_STD_SIZE) length);
   *oldPos += (lengthWithEOS - 1);
   oldStr[*oldPos] = '\0';
   
   /*============================================================*/
   /* Return the expanded string containing the appended string. */
   /*============================================================*/

   return(oldStr);
  }

/*******************************************************/
/* ExpandStringWithChar: Adds a character to a string, */
/*   reallocating space for the string if it needs to  */
/*   be enlarged. The backspace character causes the   */
/*   size of the string to reduced if it is "added" to */
/*   the string.                                       */
/*******************************************************/
globle char *ExpandStringWithChar(inchar,str,pos,max,newSize)
  int inchar;
  char *str;
  int *max, *pos, newSize;
  {
   if (*pos >= (*max - 1))
     {
      str = genrealloc(str,(unsigned) *max,(unsigned) newSize);
      *max = newSize;
     }

  if (inchar != '\b')
    {
     str[*pos] = (char) inchar;
     (*pos)++;
     str[*pos] = '\0';
    }
  else
    {
     if (*pos > 0) (*pos)--;
     str[*pos] = '\0';
    }

   return(str);
  }

/*****************************************************************/
/* AddFunctionToCallList: Adds a function to a list of functions */
/*   which are called to perform certain operations (e.g. clear, */
/*   reset, and bload functions).                                */
/*****************************************************************/
globle struct callFunctionItem *AddFunctionToCallList(name,priority,func,head)
  char *name;
  int priority;
#if ANSI_COMPILER
  VOID (*func)(void);
#else
  VOID (*func)();
#endif
  struct callFunctionItem *head;
  {
   struct callFunctionItem *newPtr, *currentPtr, *lastPtr = NULL;

   newPtr = get_struct(callFunctionItem);

   newPtr->name = name;
   newPtr->func = func;
   newPtr->priority = priority;

   if (head == NULL)
     {
      newPtr->next = NULL;
      return(newPtr);
     }

   currentPtr = head;
   while ((currentPtr != NULL) ? (priority < currentPtr->priority) : CLIPS_FALSE)
     {
      lastPtr = currentPtr;
      currentPtr = currentPtr->next;
     }

   if (lastPtr == NULL)
     {
      newPtr->next = head;
      head = newPtr;
     }
   else
     {
      newPtr->next = currentPtr;
      lastPtr->next = newPtr;
     }
     
   return(head);
  }
  
/*****************************************************************/
/* RemoveFunctionFromCallList: Removes a function from a list of */
/*   functions which are called to perform certain operations    */
/*   (e.g. clear, reset, and bload functions).                   */
/*****************************************************************/
globle struct callFunctionItem *RemoveFunctionFromCallList(name,head,found)
  char *name;
  struct callFunctionItem *head;
  int *found;
  {
   struct callFunctionItem *currentPtr, *lastPtr;

   *found = CLIPS_FALSE;
   lastPtr = NULL;
   currentPtr = head;

   while (currentPtr != NULL)
     {
      if (strcmp(name,currentPtr->name) == 0)
        {
         *found = CLIPS_TRUE;
         if (lastPtr == NULL)
           { head = currentPtr->next; }
         else
           { lastPtr->next = currentPtr->next; }
           
         rtn_struct(callFunctionItem,currentPtr);
         return(head);
        }
        
      lastPtr = currentPtr;
      currentPtr = currentPtr->next;
     }

   return(head);
  }
  
/********************************************/
/* YieldTime: Yields time to a user-defined */
/*   function. Intended to allow foreground */
/*   application responsiveness when CLIPS  */
/*   is running in the background.          */
/********************************************/
void YieldTime()
  {
   if (YieldTimeFunction != NULL)
     { (*YieldTimeFunction)(); }
  }