/// <summary>
/// Shows help.
/// </summary>
public void PrintHelp(TextWriter output)
{
const int ArgHelpLineLength = 100;
const int ArgHelpIndent = 30;
string prefix = string.Format("usage: {0} ", this.AppName);
output.Write(prefix);
int indent = prefix.Length;
var wrapper = new WordWrapper(output, indent, ArgHelpLineLength);
foreach (var name in this.PositionalNames)
{
var arg = this.Arguments[name];
string text = arg.LongSyntax;
if (arg.DependsOn != null)
{
text = "[" + text + "]";
}
wrapper.WriteWord(text);
}
foreach (var name in this.LongNames)
{
var arg = this.Arguments[name];
if (arg.IsHidden)
{
continue;
}
string text = arg.LongSyntaxAndDataType;
if (!arg.IsRequired)
{
text = "[" + text + "]";
}
wrapper.WriteWord(text);
}
output.WriteLine();
output.WriteLine();
wrapper = new WordWrapper(output, 0, ArgHelpLineLength);
wrapper.Write(this.AppDescription);
output.WriteLine();
output.WriteLine();
var visitedOptions = new HashSet <string>();
foreach (var name in this.GroupNames)
{
CommandLineGroup g = this.Groups[name];
if (g.IsHidden)
{
continue;
}
output.WriteLine(g.Description + ":");
output.WriteLine(new string('-', g.Description.Length + 1));
foreach (var option in this.PositionalNames.Concat(this.LongNames))
{
var arg = this.Arguments[option];
if (arg.IsHidden)
{
continue;
}
if (arg.Group == name)
{
visitedOptions.Add(option);
string syntax = " ";
if (!string.IsNullOrEmpty(arg.ShortName))
{
syntax += string.Format("{0}, ", arg.ShortSyntax);
}
syntax += string.Format("{0} ", arg.LongSyntaxAndDataType);
output.Write(syntax);
if (syntax.Length < ArgHelpIndent)
{
output.Write(new string(' ', ArgHelpIndent - syntax.Length));
}
else
{
output.WriteLine();
output.Write(new string(' ', ArgHelpIndent));
}
if (!string.IsNullOrEmpty(arg.Description))
{
output.Write(": ");
wrapper = new WordWrapper(output, ArgHelpIndent + 2, ArgHelpLineLength);
wrapper.Write(arg.Description);
}
output.WriteLine();
}
}
output.WriteLine();
}
bool optionalHeader = false;
foreach (var option in this.PositionalNames.Concat(this.LongNames))
{
var arg = this.Arguments[option];
if (arg.IsHidden)
{
continue;
}
if (!visitedOptions.Contains(arg.LongName))
{
if (!optionalHeader)
{
optionalHeader = true;
const string optionalBanner = "Optional Arguments:";
output.WriteLine(optionalBanner);
output.WriteLine(new string('-', optionalBanner.Length));
}
string syntax = " ";
if (!string.IsNullOrEmpty(arg.ShortName))
{
syntax += string.Format("{0}, ", arg.ShortSyntax);
}
syntax += string.Format("{0} ", arg.LongSyntax);
output.Write(syntax);
if (syntax.Length < ArgHelpIndent)
{
output.Write(new string(' ', ArgHelpIndent - syntax.Length));
}
else
{
output.WriteLine();
output.Write(new string(' ', ArgHelpIndent));
}
if (!string.IsNullOrEmpty(arg.Description))
{
wrapper = new WordWrapper(output, ArgHelpIndent, ArgHelpLineLength);
wrapper.Write(arg.Description);
}
output.WriteLine();
}
}
}