using System.IO;

string[] arguments;
if(args.Length == 0)
	arguments = ["."];
else
	arguments = args;
foreach(var arg in arguments) {
	if(!Path.Exists(arg))
		Console.WriteLine($"'{arg}: does not exist");
	if(File.Exists(arg))
		Console.WriteLine($"'{arg}: is file");

	var children = Directory.GetFileSystemEntries(arg);

	var line = "";
	var longest = children.OrderByDescending(s => Path.GetFileName(s).Length).First().Length;
	var columns = Console.WindowWidth / (longest + 2);
	var position = -1;

	if(args.Length > 1)
		Console.WriteLine($"{arg}:");
	foreach(var child in children) {
		var name = Path.GetFileName(child);

		if(
			name.StartsWith('.') ||
			( File.GetAttributes(child) & FileAttributes.Hidden ) == FileAttributes.Hidden
		)
			continue;

		if(++position >= columns) {
			position = -1;
			Console.WriteLine(line);
			line = "";
		}
		line += name + "  ";

	}

	Console.WriteLine(line);
}