🚀 go-pugleaf

News wrote:

> I need some help for string manipulation (without CString class).
> I know basics of C++, but never used strings.
> For example I need a function for appending a backslash after a directory
> name:
>
> VOID WINAPI AppendSlash(LPTSTR *lpFileName)
> {
>  len = lstrlen(*lpFileName) + 1;

You realize that len will never be 0 now.  Even when lpFileName is "" len
will be 1.

>  if (len > 0 && szBuffer[len] != '\\')

The first test, len>0 will always be true.  What is szBuffer?  If it
duplicates what lpFileName is pointing at, then looking at [len] is probably
not what you want to do.  Suppose lpFileName points to "foo.txt" then strlen
will return 7.  Now, lpFileName[6] is 't' and lpFileName[7] is the
terminating NULL.  You've got len set to point at in-effect lpFileName[8]
which is undefined.

>  {
>   // Modify string by adding a backsslash
>  }
> }

If you know lpFileName points to memory that is long enough to accept the
additional character, why not just do something like:

int n = strlen(lpFileName);
if( n && ( lpFileName[n-1] != '\\' ) )
  strcat( lpFileName, "\\" );