Replace a string, in a string function

HMmmm. The general case is probably going to be quite messy. If you have to deal with a newWord that can be more characters than the srcWord, then you would either have to guarantee that oRgLine "has" sufficient memory to contain the new expanded string (and relying on the caller to do that is not ideal), or you have allocate a buffer to hold the new string (and then you have to rely on the caller to free it; also not ideal).

Do you need the general case? Or are there some limitations/assumptions/specifications about what parameters the caller will be handing in.

the newWord is fixed (fixed length), so are the srcWord, and in this case it's simple to calculate how many chars that are added to the string, since I know how many words it needs to change. (even though it wont be the most ideal way to do it).

the newWord is fixed (fixed length), so are the srcWord, and in this case it's simple to calculate how many chars that are added to the string, since I know how many words it needs to change. (even though it wont be the most ideal way to do it).

Ok, I got it working, but for everyone else who wants to know how to do this, this is it :-)


char *ReplaceString(char *innString, char *forekomst, char *nyforekomst, const int strlength)
{
  char *resString;
  char *resString2;

  char *newstring;
  char *inStr;

  inStr = (char *)malloc(strlength);
  newstring = (char *)malloc(strlength);
  resString = (char *)malloc(strlength);
  resString2 = (char *)malloc(strlength);
  strcpy(inStr, innString);
  while (1)
    {
      if (strstr(inStr, forekomst) != NULL)
        {
          strcpy(newstring, strstr(inStr,forekomst));
          strcpy(resString, &newstring[7]);
          strncpy(resString2, inStr, strlen(inStr)-strlen(newstring) );

          strcat(resString2, nyforekomst);
          strcat(resString2, resString);


          memset(inStr,0,strlength);
          memset(resString,0,strlength);
          memset(newstring, 0, strlength);
          memcpy(inStr, resString2, strlength);
          memset(resString2,0, strlength);

        }else
          {
            break;
          }
    }
 
  return inStr;
  free(inStr);
  free(resString);
  free(resString2);
  free(newstring);
}

-- cPix.

Just to end the thread :)