Returning strings from the DLL to the application is always performed by returning a pointer to a memory area and, as a further parameter, an integer value for the length. The buffer size (in characters) must be passed so that buffer overflows are impossible. The string is always \0-terminated. If, for example, the buffer is too short, the returned string will be shortened and may result in incomplete return values. This is indicated by the API function's return value. LL_ERR_BUFFERTOOSMALL will be returned in these cases.
The parameters are checked for correctness as far as possible. While developing a program it is therefore worth switching on the debug mode (see LlSetDebug()) and checking the return values. You can switch off the parameter check later using LL_OPTION_NOPARAMETERCHECK.
Please note that with Delphi the routines require "\0"-terminated strings just like the Windows API functions. It may be necessary to use the Pascal-string to C-string conversion routines.
Please note with C or C++ the C convention in source texts of having to enter, for example, the '\' in path entries twice: "c:\\temp.lbl" instead of "c:\temp.lbl".
Example:
INT nSize = 16000;
LPWSTR pszBuffer = new TCHAR[nSize];
INT nResult = <API>(hJob,...,pszBuffer,nSize);
if (nResult == LL_ERR_BUFFERTOOSMALL)
{
nSize = <API>(hJob,...,NULL,0);
ASSERT(nSize > 0);
delete[] pszBuffer;
pszBuffer = new TCHAR[nSize];
nResult = <API>(hJob,...,pszBuffer,nSize);
}
...
delete[] pszBuffer;
