protected override Variable Evaluate(ParsingScript script)
{
if (script.Substr().StartsWith(" .."))
{
script.Forward();
}
string newDir = Utils.GetItem(script).AsString();
try
{
if (newDir == "..")
{
string pwd = Directory.GetCurrentDirectory();
DirectoryInfo parent = Directory.GetParent(pwd);
if (parent == null)
{
throw new ArgumentException("No parent exists.");
}
newDir = parent.FullName;
}
if (newDir.Length == 0)
{
newDir = Environment.GetEnvironmentVariable("HOME");
}
Directory.SetCurrentDirectory(newDir);
newDir = Directory.GetCurrentDirectory();
}
catch (Exception exc)
{
throw new ArgumentException("Couldn't change directory: " + exc.Message);
}
return(new Variable(newDir));
}