internal virtual string DirectoryName(string filename)
{
filename = Backend.AbsName(filename);
if (string.IsNullOrEmpty(filename))
{
return(null);
}
var index = 0;
if (-1 == (index = filename.LastIndexOf('/')))
{
return(null);
}
if (0 == index || -1 == filename.LastIndexOf('/', index - 1))
{
return(null);
}
return(filename.Substring(0, index));
}
