mt5-manager/docs/publish/code/04_cpp.txt

string InstanceFolder()
  {
   string path = TerminalInfoString(TERMINAL_DATA_PATH);
   StringReplace(path, "\\", "/");

   int len = StringLen(path);
   if(len > 0 && StringGetCharacter(path, len - 1) == '/')
      path = StringSubstr(path, 0, len - 1);

   int pos = FindLast(path, "/");
   return (pos >= 0) ? StringSubstr(path, pos + 1) : path;
  }