/* Copyright 1996 Acorn Computers Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* File:     string32.c
 * Purpose:  strings terminated by char < 32
 * Author:   Timothy Roddis
 * History:  24-Jan-94: IDJ: created from original TGR sources
 */

#include "string32.h"


/* Strings passed to the toolbox might be terminated with any control character ... */

#define NULL 0

void string_copy (char *dst_txt, char *src_txt)
{
   /*
    * copy a ctrl-terminated string to a buffer big enough to
    * hold the result (no length checking).
    */

   if (!src_txt) src_txt = "";

   while ((*(dst_txt++)=*(src_txt++))>=32);
   *(--dst_txt) = '\0';
}



char *string_copy_chk (char *dst_txt, char *src_txt, int max_len)
{
   int i;

   /*
    * copy a ctrl-terminated string to a buffer checking it is big enough to
    * hold the result.  Return NULL and nul-terminate, if dst buffer not
    * big enough.
    */

   if (dst_txt == NULL || max_len == 0)
       return NULL;
   if (!src_txt) src_txt = "";

   for (i=1;(*dst_txt++=*src_txt++)>=32;i++)
      if (i>=max_len) {
         *(--dst_txt) = '\0';
         return NULL;
      }
   *(--dst_txt) = '\0';

   return dst_txt;
}


int string_length (char *txt)
{
   int i=0;

   /*
    * return length of ctrl-terminated string
    */

   if (!txt) return 0;
   while (*txt++>=32) i++;
   return i;
}


void string_to_buffer (char *dst_txt, char *src_txt, int *max_len)
{
    /*
     * general purpose routine to fill in a user-supplied buffer (and report
     * number of bytes written), or just report size of buffer needed.
     * If buffer is supplied (dst_txt != 0), then *max_len gives size of supplied
     * buffer; if this is not large enough, don't return an error, but return
     * size of bufer required!
     */

    int src_len = string_length (src_txt) + 1;

    if (dst_txt == NULL)
        *max_len = src_len;
    else   /* user-supplied buffer */
    {
        if (*max_len >= src_len)
            string_copy (dst_txt, src_txt);
        else
            string_copy_chk (dst_txt, src_txt, *max_len);

        *max_len = string_length (dst_txt) + 1;
    }
}