Use unix style long options instead of / when running under mono.

3 files changed, 1414 insertions, 20 deletions

diff --git a/Options.cs b/Options.cs
new file mode 100644
index 0000000..5af7fe0
--- /dev/null
+++ b/Options.cs
@@ -0,0 +1,1366 @@
+//
+// Options.cs
+//
+// Authors:
+//  Jonathan Pryor <jpryor@novell.com>
+//  Federico Di Gregorio <fog@initd.org>
+//  Rolf Bjarne Kvinge <rolf@xamarin.com>
+//
+// Copyright (C) 2008 Novell (http://www.novell.com)
+// Copyright (C) 2009 Federico Di Gregorio.
+// Copyright (C) 2012 Xamarin Inc (http://www.xamarin.com)
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to
+// permit persons to whom the Software is furnished to do so, subject to
+// the following conditions:
+// 
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
+// Compile With:
+//   gmcs -debug+ -r:System.Core Options.cs -o:NDesk.Options.dll
+//   gmcs -debug+ -d:LINQ -r:System.Core Options.cs -o:NDesk.Options.dll
+//
+// The LINQ version just changes the implementation of
+// OptionSet.Parse(IEnumerable<string>), and confers no semantic changes.
+
+//
+// A Getopt::Long-inspired option parsing library for C#.
+//
+// NDesk.Options.OptionSet is built upon a key/value table, where the
+// key is a option format string and the value is a delegate that is 
+// invoked when the format string is matched.
+//
+// Option format strings:
+//  Regex-like BNF Grammar: 
+//    name: .+
+//    type: [=:]
+//    sep: ( [^{}]+ | '{' .+ '}' )?
+//    aliases: ( name type sep ) ( '|' name type sep )*
+// 
+// Each '|'-delimited name is an alias for the associated action.  If the
+// format string ends in a '=', it has a required value.  If the format
+// string ends in a ':', it has an optional value.  If neither '=' or ':'
+// is present, no value is supported.  `=' or `:' need only be defined on one
+// alias, but if they are provided on more than one they must be consistent.
+//
+// Each alias portion may also end with a "key/value separator", which is used
+// to split option values if the option accepts > 1 value.  If not specified,
+// it defaults to '=' and ':'.  If specified, it can be any character except
+// '{' and '}' OR the *string* between '{' and '}'.  If no separator should be
+// used (i.e. the separate values should be distinct arguments), then "{}"
+// should be used as the separator.
+//
+// Options are extracted either from the current option by looking for
+// the option name followed by an '=' or ':', or is taken from the
+// following option IFF:
+//  - The current option does not contain a '=' or a ':'
+//  - The current option requires a value (i.e. not a Option type of ':')
+//
+// The `name' used in the option format string does NOT include any leading
+// option indicator, such as '-', '--', or '/'.  All three of these are
+// permitted/required on any named option.
+//
+// Option bundling is permitted so long as:
+//   - '-' is used to start the option group
+//   - all of the bundled options are a single character
+//   - at most one of the bundled options accepts a value, and the value
+//     provided starts from the next character to the end of the string.
+//
+// This allows specifying '-a -b -c' as '-abc', and specifying '-D name=value'
+// as '-Dname=value'.
+//
+// Option processing is disabled by specifying "--".  All options after "--"
+// are returned by OptionSet.Parse() unchanged and unprocessed.
+//
+// Unprocessed options are returned from OptionSet.Parse().
+//
+// Examples:
+//  int verbose = 0;
+//  OptionSet p = new OptionSet ()
+//    .Add ("v", v => ++verbose)
+//    .Add ("name=|value=", v => Console.WriteLine (v));
+//  p.Parse (new string[]{"-v", "--v", "/v", "-name=A", "/name", "B", "extra"});
+//
+// The above would parse the argument string array, and would invoke the
+// lambda expression three times, setting `verbose' to 3 when complete.  
+// It would also print out "A" and "B" to standard output.
+// The returned array would contain the string "extra".
+//
+// C# 3.0 collection initializers are supported and encouraged:
+//  var p = new OptionSet () {
+//    { "h|?|help", v => ShowHelp () },
+//  };
+//
+// System.ComponentModel.TypeConverter is also supported, allowing the use of
+// custom data types in the callback type; TypeConverter.ConvertFromString()
+// is used to convert the value option to an instance of the specified
+// type:
+//
+//  var p = new OptionSet () {
+//    { "foo=", (Foo f) => Console.WriteLine (f.ToString ()) },
+//  };
+//
+// Random other tidbits:
+//  - Boolean options (those w/o '=' or ':' in the option format string)
+//    are explicitly enabled if they are followed with '+', and explicitly
+//    disabled if they are followed with '-':
+//      string a = null;
+//      var p = new OptionSet () {
+//        { "a", s => a = s },
+//      };
+//      p.Parse (new string[]{"-a"});   // sets v != null
+//      p.Parse (new string[]{"-a+"});  // sets v != null
+//      p.Parse (new string[]{"-a-"});  // sets v == null
+//
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Globalization;
+using System.IO;
+using System.Runtime.Serialization;
+using System.Security.Permissions;
+using System.Text;
+using System.Text.RegularExpressions;
+
+#if LINQ
+using System.Linq;
+#endif
+
+#if TEST
+using NDesk.Options;
+#endif
+
+#if NDESK_OPTIONS
+namespace NDesk.Options
+#else
+namespace Mono.Options
+#endif
+{
+	static class StringCoda {
+
+		public static IEnumerable<string> WrappedLines (string self, params int[] widths)
+		{
+			IEnumerable<int> w = widths;
+			return WrappedLines (self, w);
+		}
+
+		public static IEnumerable<string> WrappedLines (string self, IEnumerable<int> widths)
+		{
+			if (widths == null)
+				throw new ArgumentNullException ("widths");
+			return CreateWrappedLinesIterator (self, widths);
+		}
+
+		private static IEnumerable<string> CreateWrappedLinesIterator (string self, IEnumerable<int> widths)
+		{
+			if (string.IsNullOrEmpty (self)) {
+				yield return string.Empty;
+				yield break;
+			}
+			using (IEnumerator<int> ewidths = widths.GetEnumerator ()) {
+				bool? hw = null;
+				int width = GetNextWidth (ewidths, int.MaxValue, ref hw);
+				int start = 0, end;
+				do {
+					end = GetLineEnd (start, width, self);
+					char c = self [end-1];
+					if (char.IsWhiteSpace (c))
+						--end;
+					bool needContinuation = end != self.Length && !IsEolChar (c);
+					string continuation = "";
+					if (needContinuation) {
+						--end;
+						continuation = "-";
+					}
+					string line = self.Substring (start, end - start) + continuation;
+					yield return line;
+					start = end;
+					if (char.IsWhiteSpace (c))
+						++start;
+					width = GetNextWidth (ewidths, width, ref hw);
+				} while (start < self.Length);
+			}
+		}
+
+		private static int GetNextWidth (IEnumerator<int> ewidths, int curWidth, ref bool? eValid)
+		{
+			if (!eValid.HasValue || (eValid.HasValue && eValid.Value)) {
+				curWidth = (eValid = ewidths.MoveNext ()).Value ? ewidths.Current : curWidth;
+				// '.' is any character, - is for a continuation
+				const string minWidth = ".-";
+				if (curWidth < minWidth.Length)
+					throw new ArgumentOutOfRangeException ("widths",
+							string.Format ("Element must be >= {0}, was {1}.", minWidth.Length, curWidth));
+				return curWidth;
+			}
+			// no more elements, use the last element.
+			return curWidth;
+		}
+
+		private static bool IsEolChar (char c)
+		{
+			return !char.IsLetterOrDigit (c);
+		}
+
+		private static int GetLineEnd (int start, int length, string description)
+		{
+			int end = System.Math.Min (start + length, description.Length);
+			int sep = -1;
+			for (int i = start; i < end; ++i) {
+				if (description [i] == '\n')
+					return i+1;
+				if (IsEolChar (description [i]))
+					sep = i+1;
+			}
+			if (sep == -1 || end == description.Length)
+				return end;
+			return sep;
+		}
+	}
+
+	public class OptionValueCollection : IList, IList<string> {
+
+		List<string> values = new List<string> ();
+		OptionContext c;
+
+		internal OptionValueCollection (OptionContext c)
+		{
+			this.c = c;
+		}
+
+		#region ICollection
+		void ICollection.CopyTo (Array array, int index)  {(values as ICollection).CopyTo (array, index);}
+		bool ICollection.IsSynchronized                   {get {return (values as ICollection).IsSynchronized;}}
+		object ICollection.SyncRoot                       {get {return (values as ICollection).SyncRoot;}}
+		#endregion
+
+		#region ICollection<T>
+		public void Add (string item)                       {values.Add (item);}
+		public void Clear ()                                {values.Clear ();}
+		public bool Contains (string item)                  {return values.Contains (item);}
+		public void CopyTo (string[] array, int arrayIndex) {values.CopyTo (array, arrayIndex);}
+		public bool Remove (string item)                    {return values.Remove (item);}
+		public int Count                                    {get {return values.Count;}}
+		public bool IsReadOnly                              {get {return false;}}
+		#endregion
+
+		#region IEnumerable
+		IEnumerator IEnumerable.GetEnumerator () {return values.GetEnumerator ();}
+		#endregion
+
+		#region IEnumerable<T>
+		public IEnumerator<string> GetEnumerator () {return values.GetEnumerator ();}
+		#endregion
+
+		#region IList
+		int IList.Add (object value)                {return (values as IList).Add (value);}
+		bool IList.Contains (object value)          {return (values as IList).Contains (value);}
+		int IList.IndexOf (object value)            {return (values as IList).IndexOf (value);}
+		void IList.Insert (int index, object value) {(values as IList).Insert (index, value);}
+		void IList.Remove (object value)            {(values as IList).Remove (value);}
+		void IList.RemoveAt (int index)             {(values as IList).RemoveAt (index);}
+		bool IList.IsFixedSize                      {get {return false;}}
+		object IList.this [int index]               {get {return this [index];} set {(values as IList)[index] = value;}}
+		#endregion
+
+		#region IList<T>
+		public int IndexOf (string item)            {return values.IndexOf (item);}
+		public void Insert (int index, string item) {values.Insert (index, item);}
+		public void RemoveAt (int index)            {values.RemoveAt (index);}
+
+		private void AssertValid (int index)
+		{
+			if (c.Option == null)
+				throw new InvalidOperationException ("OptionContext.Option is null.");
+			if (index >= c.Option.MaxValueCount)
+				throw new ArgumentOutOfRangeException ("index");
+			if (c.Option.OptionValueType == OptionValueType.Required &&
+					index >= values.Count)
+				throw new OptionException (string.Format (
+							c.OptionSet.MessageLocalizer ("Missing required value for option '{0}'."), c.OptionName), 
+						c.OptionName);
+		}
+
+		public string this [int index] {
+			get {
+				AssertValid (index);
+				return index >= values.Count ? null : values [index];
+			}
+			set {
+				values [index] = value;
+			}
+		}
+		#endregion
+
+		public List<string> ToList ()
+		{
+			return new List<string> (values);
+		}
+
+		public string[] ToArray ()
+		{
+			return values.ToArray ();
+		}
+
+		public override string ToString ()
+		{
+			return string.Join (", ", values.ToArray ());
+		}
+	}
+
+	public class OptionContext {
+		private Option                option;
+		private string                name;
+		private int                   index;
+		private OptionSet             set;
+		private OptionValueCollection c;
+
+		public OptionContext (OptionSet set)
+		{
+			this.set = set;
+			this.c   = new OptionValueCollection (this);
+		}
+
+		public Option Option {
+			get {return option;}
+			set {option = value;}
+		}
+
+		public string OptionName { 
+			get {return name;}
+			set {name = value;}
+		}
+
+		public int OptionIndex {
+			get {return index;}
+			set {index = value;}
+		}
+
+		public OptionSet OptionSet {
+			get {return set;}
+		}
+
+		public OptionValueCollection OptionValues {
+			get {return c;}
+		}
+	}
+
+	public enum OptionValueType {
+		None, 
+		Optional,
+		Required,
+	}
+
+	public abstract class Option {
+		string prototype, description;
+		string[] names;
+		OptionValueType type;
+		int count;
+		string[] separators;
+		bool hidden;
+
+		protected Option (string prototype, string description)
+			: this (prototype, description, 1, false)
+		{
+		}
+
+		protected Option (string prototype, string description, int maxValueCount)
+			: this (prototype, description, maxValueCount, false)
+		{
+		}
+
+		protected Option (string prototype, string description, int maxValueCount, bool hidden)
+		{
+			if (prototype == null)
+				throw new ArgumentNullException ("prototype");
+			if (prototype.Length == 0)
+				throw new ArgumentException ("Cannot be the empty string.", "prototype");
+			if (maxValueCount < 0)
+				throw new ArgumentOutOfRangeException ("maxValueCount");
+
+			this.prototype   = prototype;
+			this.description = description;
+			this.count       = maxValueCount;
+			this.names       = (this is OptionSet.Category)
+				// append GetHashCode() so that "duplicate" categories have distinct
+				// names, e.g. adding multiple "" categories should be valid.
+				? new[]{prototype + this.GetHashCode ()}
+				: prototype.Split ('|');
+
+			if (this is OptionSet.Category)
+				return;
+
+			this.type        = ParsePrototype ();
+			this.hidden      = hidden;
+
+			if (this.count == 0 && type != OptionValueType.None)
+				throw new ArgumentException (
+						"Cannot provide maxValueCount of 0 for OptionValueType.Required or " +
+							"OptionValueType.Optional.",
+						"maxValueCount");
+			if (this.type == OptionValueType.None && maxValueCount > 1)
+				throw new ArgumentException (
+						string.Format ("Cannot provide maxValueCount of {0} for OptionValueType.None.", maxValueCount),
+						"maxValueCount");
+			if (Array.IndexOf (names, "<>") >= 0 && 
+					((names.Length == 1 && this.type != OptionValueType.None) ||
+					 (names.Length > 1 && this.MaxValueCount > 1)))
+				throw new ArgumentException (
+						"The default option handler '<>' cannot require values.",
+						"prototype");
+		}
+
+		public string           Prototype       {get {return prototype;}}
+		public string           Description     {get {return description;}}
+		public OptionValueType  OptionValueType {get {return type;}}
+		public int              MaxValueCount   {get {return count;}}
+		public bool             Hidden          {get {return hidden;}}
+
+		public string[] GetNames ()
+		{
+			return (string[]) names.Clone ();
+		}
+
+		public string[] GetValueSeparators ()
+		{
+			if (separators == null)
+				return new string [0];
+			return (string[]) separators.Clone ();
+		}
+
+		protected static T Parse<T> (string value, OptionContext c)
+		{
+			Type tt = typeof (T);
+			bool nullable = tt.IsValueType && tt.IsGenericType && 
+				!tt.IsGenericTypeDefinition && 
+				tt.GetGenericTypeDefinition () == typeof (Nullable<>);
+			Type targetType = nullable ? tt.GetGenericArguments () [0] : typeof (T);
+			TypeConverter conv = TypeDescriptor.GetConverter (targetType);
+			T t = default (T);
+			try {
+				if (value != null)
+					t = (T) conv.ConvertFromString (value);
+			}
+			catch (Exception e) {
+				throw new OptionException (
+						string.Format (
+							c.OptionSet.MessageLocalizer ("Could not convert string `{0}' to type {1} for option `{2}'."),
+							value, targetType.Name, c.OptionName),
+						c.OptionName, e);
+			}
+			return t;
+		}
+
+		internal string[] Names           {get {return names;}}
+		internal string[] ValueSeparators {get {return separators;}}
+
+		static readonly char[] NameTerminator = new char[]{'=', ':'};
+
+		private OptionValueType ParsePrototype ()
+		{
+			char type = '\0';
+			List<string> seps = new List<string> ();
+			for (int i = 0; i < names.Length; ++i) {
+				string name = names [i];
+				if (name.Length == 0)
+					throw new ArgumentException ("Empty option names are not supported.", "prototype");
+
+				int end = name.IndexOfAny (NameTerminator);
+				if (end == -1)
+					continue;
+				names [i] = name.Substring (0, end);
+				if (type == '\0' || type == name [end])
+					type = name [end];
+				else 
+					throw new ArgumentException (
+							string.Format ("Conflicting option types: '{0}' vs. '{1}'.", type, name [end]),
+							"prototype");
+				AddSeparators (name, end, seps);
+			}
+
+			if (type == '\0')
+				return OptionValueType.None;
+
+			if (count <= 1 && seps.Count != 0)
+				throw new ArgumentException (
+						string.Format ("Cannot provide key/value separators for Options taking {0} value(s).", count),
+						"prototype");
+			if (count > 1) {
+				if (seps.Count == 0)
+					this.separators = new string[]{":", "="};
+				else if (seps.Count == 1 && seps [0].Length == 0)
+					this.separators = null;
+				else
+					this.separators = seps.ToArray ();
+			}
+
+			return type == '=' ? OptionValueType.Required : OptionValueType.Optional;
+		}
+
+		private static void AddSeparators (string name, int end, ICollection<string> seps)
+		{
+			int start = -1;
+			for (int i = end+1; i < name.Length; ++i) {
+				switch (name [i]) {
+					case '{':
+						if (start != -1)
+							throw new ArgumentException (
+									string.Format ("Ill-formed name/value separator found in \"{0}\".", name),
+									"prototype");
+						start = i+1;
+						break;
+					case '}':
+						if (start == -1)
+							throw new ArgumentException (
+									string.Format ("Ill-formed name/value separator found in \"{0}\".", name),
+									"prototype");
+						seps.Add (name.Substring (start, i-start));
+						start = -1;
+						break;
+					default:
+						if (start == -1)
+							seps.Add (name [i].ToString ());
+						break;
+				}
+			}
+			if (start != -1)
+				throw new ArgumentException (
+						string.Format ("Ill-formed name/value separator found in \"{0}\".", name),
+						"prototype");
+		}
+
+		public void Invoke (OptionContext c)
+		{
+			OnParseComplete (c);
+			c.OptionName  = null;
+			c.Option      = null;
+			c.OptionValues.Clear ();
+		}
+
+		protected abstract void OnParseComplete (OptionContext c);
+
+		public override string ToString ()
+		{
+			return Prototype;
+		}
+	}
+
+	public abstract class ArgumentSource {
+
+		protected ArgumentSource ()
+		{
+		}
+
+		public abstract string[] GetNames ();
+		public abstract string Description { get; }
+		public abstract bool GetArguments (string value, out IEnumerable<string> replacement);
+
+		public static IEnumerable<string> GetArgumentsFromFile (string file)
+		{
+			return GetArguments (File.OpenText (file), true);
+		}
+
+		public static IEnumerable<string> GetArguments (TextReader reader)
+		{
+			return GetArguments (reader, false);
+		}
+
+		// Cribbed from mcs/driver.cs:LoadArgs(string)
+		static IEnumerable<string> GetArguments (TextReader reader, bool close)
+		{
+			try {
+				StringBuilder arg = new StringBuilder ();
+
+				string line;
+				while ((line = reader.ReadLine ()) != null) {
+					int t = line.Length;
+
+					for (int i = 0; i < t; i++) {
+						char c = line [i];
+						
+						if (c == '"' || c == '\'') {
+							char end = c;
+							
+							for (i++; i < t; i++){
+								c = line [i];
+
+								if (c == end)
+									break;
+								arg.Append (c);
+							}
+						} else if (c == ' ') {
+							if (arg.Length > 0) {
+								yield return arg.ToString ();
+								arg.Length = 0;
+							}
+						} else
+							arg.Append (c);
+					}
+					if (arg.Length > 0) {
+						yield return arg.ToString ();
+						arg.Length = 0;
+					}
+				}
+			}
+			finally {
+				if (close)
+					reader.Close ();
+			}
+		}
+	}
+
+	public class ResponseFileSource : ArgumentSource {
+
+		public override string[] GetNames ()
+		{
+			return new string[]{"@file"};
+		}
+
+		public override string Description {
+			get {return "Read response file for more options.";}
+		}
+
+		public override bool GetArguments (string value, out IEnumerable<string> replacement)
+		{
+			if (string.IsNullOrEmpty (value) || !value.StartsWith ("@")) {
+				replacement = null;
+				return false;
+			}
+			replacement = ArgumentSource.GetArgumentsFromFile (value.Substring (1));
+			return true;
+		}
+	}
+
+	[Serializable]
+	public class OptionException : Exception {
+		private string option;
+
+		public OptionException ()
+		{
+		}
+
+		public OptionException (string message, string optionName)
+			: base (message)
+		{
+			this.option = optionName;
+		}
+
+		public OptionException (string message, string optionName, Exception innerException)
+			: base (message, innerException)
+		{
+			this.option = optionName;
+		}
+
+		protected OptionException (SerializationInfo info, StreamingContext context)
+			: base (info, context)
+		{
+			this.option = info.GetString ("OptionName");
+		}
+
+		public string OptionName {
+			get {return this.option;}
+		}
+
+		[SecurityPermission (SecurityAction.LinkDemand, SerializationFormatter = true)]
+		public override void GetObjectData (SerializationInfo info, StreamingContext context)
+		{
+			base.GetObjectData (info, context);
+			info.AddValue ("OptionName", option);
+		}
+	}
+
+	public delegate void OptionAction<TKey, TValue> (TKey key, TValue value);
+
+	public class OptionSet : KeyedCollection<string, Option>
+	{
+		public OptionSet ()
+			: this (delegate (string f) {return f;})
+		{
+		}
+
+		public OptionSet (Converter<string, string> localizer)
+		{
+			this.localizer = localizer;
+			this.roSources = new ReadOnlyCollection<ArgumentSource>(sources);
+		}
+
+		Converter<string, string> localizer;
+
+		public Converter<string, string> MessageLocalizer {
+			get {return localizer;}
+		}
+
+		List<ArgumentSource> sources = new List<ArgumentSource> ();
+		ReadOnlyCollection<ArgumentSource> roSources;
+
+		public ReadOnlyCollection<ArgumentSource> ArgumentSources {
+			get {return roSources;}
+		}
+
+
+		protected override string GetKeyForItem (Option item)
+		{
+			if (item == null)
+				throw new ArgumentNullException ("option");
+			if (item.Names != null && item.Names.Length > 0)
+				return item.Names [0];
+			// This should never happen, as it's invalid for Option to be
+			// constructed w/o any names.
+			throw new InvalidOperationException ("Option has no names!");
+		}
+
+		[Obsolete ("Use KeyedCollection.this[string]")]
+		protected Option GetOptionForName (string option)
+		{
+			if (option == null)
+				throw new ArgumentNullException ("option");
+			try {
+				return base [option];
+			}
+			catch (KeyNotFoundException) {
+				return null;
+			}
+		}
+
+		protected override void InsertItem (int index, Option item)
+		{
+			base.InsertItem (index, item);
+			AddImpl (item);
+		}
+
+		protected override void RemoveItem (int index)
+		{
+			Option p = Items [index];
+			base.RemoveItem (index);
+			// KeyedCollection.RemoveItem() handles the 0th item
+			for (int i = 1; i < p.Names.Length; ++i) {
+				Dictionary.Remove (p.Names [i]);
+			}
+		}
+
+		protected override void SetItem (int index, Option item)
+		{
+			base.SetItem (index, item);
+			AddImpl (item);
+		}
+
+		private void AddImpl (Option option)
+		{
+			if (option == null)
+				throw new ArgumentNullException ("option");
+			List<string> added = new List<string> (option.Names.Length);
+			try {
+				// KeyedCollection.InsertItem/SetItem handle the 0th name.
+				for (int i = 1; i < option.Names.Length; ++i) {
+					Dictionary.Add (option.Names [i], option);
+					added.Add (option.Names [i]);
+				}
+			}
+			catch (Exception) {
+				foreach (string name in added)
+					Dictionary.Remove (name);
+				throw;
+			}
+		}
+
+		public OptionSet Add (string header)
+		{
+			if (header == null)
+				throw new ArgumentNullException ("header");
+			Add (new Category (header));
+			return this;
+		}
+
+		internal sealed class Category : Option {
+
+			// Prototype starts with '=' because this is an invalid prototype
+			// (see Option.ParsePrototype(), and thus it'll prevent Category
+			// instances from being accidentally used as normal options.
+			public Category (string description)
+				: base ("=:Category:= " + description, description)
+			{
+			}
+
+			protected override void OnParseComplete (OptionContext c)
+			{
+				throw new NotSupportedException ("Category.OnParseComplete should not be invoked.");
+			}
+		}
+
+
+		public new OptionSet Add (Option option)
+		{
+			base.Add (option);
+			return this;
+		}
+
+		sealed class ActionOption : Option {
+			Action<OptionValueCollection> action;
+
+			public ActionOption (string prototype, string description, int count, Action<OptionValueCollection> action)
+				: this (prototype, description, count, action, false)
+			{
+			}
+
+			public ActionOption (string prototype, string description, int count, Action<OptionValueCollection> action, bool hidden)
+				: base (prototype, description, count, hidden)
+			{
+				if (action == null)
+					throw new ArgumentNullException ("action");
+				this.action = action;
+			}
+
+			protected override void OnParseComplete (OptionContext c)
+			{
+				action (c.OptionValues);
+			}
+		}
+
+		public OptionSet Add (string prototype, Action<string> action)
+		{
+			return Add (prototype, null, action);
+		}
+
+		public OptionSet Add (string prototype, string description, Action<string> action)
+		{
+			return Add (prototype, description, action, false);
+		}
+
+		public OptionSet Add (string prototype, string description, Action<string> action, bool hidden)
+		{
+			if (action == null)
+				throw new ArgumentNullException ("action");
+			Option p = new ActionOption (prototype, description, 1, 
+					delegate (OptionValueCollection v) { action (v [0]); }, hidden);
+			base.Add (p);
+			return this;
+		}
+
+		public OptionSet Add (string prototype, OptionAction<string, string> action)
+		{
+			return Add (prototype, null, action);
+		}
+
+		public OptionSet Add (string prototype, string description, OptionAction<string, string> action)
+		{
+			return Add (prototype, description, action, false);
+		}
+
+		public OptionSet Add (string prototype, string description, OptionAction<string, string> action, bool hidden)	{
+			if (action == null)
+				throw new ArgumentNullException ("action");
+			Option p = new ActionOption (prototype, description, 2, 
+					delegate (OptionValueCollection v) {action (v [0], v [1]);}, hidden);
+			base.Add (p);
+			return this;
+		}
+
+		sealed class ActionOption<T> : Option {
+			Action<T> action;
+
+			public ActionOption (string prototype, string description, Action<T> action)
+				: base (prototype, description, 1)
+			{
+				if (action == null)
+					throw new ArgumentNullException ("action");
+				this.action = action;
+			}
+
+			protected override void OnParseComplete (OptionContext c)
+			{
+				action (Parse<T> (c.OptionValues [0], c));
+			}
+		}
+
+		sealed class ActionOption<TKey, TValue> : Option {
+			OptionAction<TKey, TValue> action;
+
+			public ActionOption (string prototype, string description, OptionAction<TKey, TValue> action)
+				: base (prototype, description, 2)
+			{
+				if (action == null)
+					throw new ArgumentNullException ("action");
+				this.action = action;
+			}
+
+			protected override void OnParseComplete (OptionContext c)
+			{
+				action (
+						Parse<TKey> (c.OptionValues [0], c),
+						Parse<TValue> (c.OptionValues [1], c));
+			}
+		}
+
+		public OptionSet Add<T> (string prototype, Action<T> action)
+		{
+			return Add (prototype, null, action);
+		}
+
+		public OptionSet Add<T> (string prototype, string description, Action<T> action)
+		{
+			return Add (new ActionOption<T> (prototype, description, action));
+		}
+
+		public OptionSet Add<TKey, TValue> (string prototype, OptionAction<TKey, TValue> action)
+		{
+			return Add (prototype, null, action);
+		}
+
+		public OptionSet Add<TKey, TValue> (string prototype, string description, OptionAction<TKey, TValue> action)
+		{
+			return Add (new ActionOption<TKey, TValue> (prototype, description, action));
+		}
+
+		public OptionSet Add (ArgumentSource source)
+		{
+			if (source == null)
+				throw new ArgumentNullException ("source");
+			sources.Add (source);
+			return this;
+		}
+
+		protected virtual OptionContext CreateOptionContext ()
+		{
+			return new OptionContext (this);
+		}
+
+		public List<string> Parse (IEnumerable<string> arguments)
+		{
+			if (arguments == null)
+				throw new ArgumentNullException ("arguments");
+			OptionContext c = CreateOptionContext ();
+			c.OptionIndex = -1;
+			bool process = true;
+			List<string> unprocessed = new List<string> ();
+			Option def = Contains ("<>") ? this ["<>"] : null;
+			ArgumentEnumerator ae = new ArgumentEnumerator (arguments);
+			foreach (string argument in ae) {
+				++c.OptionIndex;
+				if (argument == "--") {
+					process = false;
+					continue;
+				}
+				if (!process) {
+					Unprocessed (unprocessed, def, c, argument);
+					continue;
+				}
+				if (AddSource (ae, argument))
+					continue;
+				if (!Parse (argument, c))
+					Unprocessed (unprocessed, def, c, argument);
+			}
+			if (c.Option != null)
+				c.Option.Invoke (c);
+			return unprocessed;
+		}
+
+		class ArgumentEnumerator : IEnumerable<string> {
+			List<IEnumerator<string>> sources = new List<IEnumerator<string>> ();
+
+			public ArgumentEnumerator (IEnumerable<string> arguments)
+			{
+				sources.Add (arguments.GetEnumerator ());
+			}
+
+			public void Add (IEnumerable<string> arguments)
+			{
+				sources.Add (arguments.GetEnumerator ());
+			}
+
+			public IEnumerator<string> GetEnumerator ()
+			{
+				do {
+					IEnumerator<string> c = sources [sources.Count-1];
+					if (c.MoveNext ())
+						yield return c.Current;
+					else {
+						c.Dispose ();
+						sources.RemoveAt (sources.Count-1);
+					}
+				} while (sources.Count > 0);
+			}
+
+			IEnumerator IEnumerable.GetEnumerator ()
+			{
+				return GetEnumerator ();
+			}
+		}
+
+		bool AddSource (ArgumentEnumerator ae, string argument)
+		{
+			foreach (ArgumentSource source in sources) {
+				IEnumerable<string> replacement;
+				if (!source.GetArguments (argument, out replacement))
+					continue;
+				ae.Add (replacement);
+				return true;
+			}
+			return false;
+		}
+
+		private static bool Unprocessed (ICollection<string> extra, Option def, OptionContext c, string argument)
+		{
+			if (def == null) {
+				extra.Add (argument);
+				return false;
+			}
+			c.OptionValues.Add (argument);
+			c.Option = def;
+			c.Option.Invoke (c);
+			return false;
+		}
+
+		private readonly Regex ValueOption = new Regex (
+			@"^(?<flag>--|-|/)(?<name>[^:=]+)((?<sep>[:=])(?<value>.*))?$");
+
+		protected bool GetOptionParts (string argument, out string flag, out string name, out string sep, out string value)
+		{
+			if (argument == null)
+				throw new ArgumentNullException ("argument");
+
+			flag = name = sep = value = null;
+			Match m = ValueOption.Match (argument);
+			if (!m.Success) {
+				return false;
+			}
+			flag  = m.Groups ["flag"].Value;
+			name  = m.Groups ["name"].Value;
+			if (m.Groups ["sep"].Success && m.Groups ["value"].Success) {
+				sep   = m.Groups ["sep"].Value;
+				value = m.Groups ["value"].Value;
+			}
+			return true;
+		}
+
+		protected virtual bool Parse (string argument, OptionContext c)
+		{
+			if (c.Option != null) {
+				ParseValue (argument, c);
+				return true;
+			}
+
+			string f, n, s, v;
+			if (!GetOptionParts (argument, out f, out n, out s, out v))
+				return false;
+
+			Option p;
+			if (Contains (n)) {
+				p = this [n];
+				c.OptionName = f + n;
+				c.Option     = p;
+				switch (p.OptionValueType) {
+					case OptionValueType.None:
+						c.OptionValues.Add (n);
+						c.Option.Invoke (c);
+						break;
+					case OptionValueType.Optional:
+					case OptionValueType.Required: 
+						ParseValue (v, c);
+						break;
+				}
+				return true;
+			}
+			// no match; is it a bool option?
+			if (ParseBool (argument, n, c))
+				return true;
+			// is it a bundled option?
+			if (ParseBundledValue (f, string.Concat (n + s + v), c))
+				return true;
+
+			return false;
+		}
+
+		private void ParseValue (string option, OptionContext c)
+		{
+			if (option != null)
+				foreach (string o in c.Option.ValueSeparators != null 
+						? option.Split (c.Option.ValueSeparators, c.Option.MaxValueCount - c.OptionValues.Count, StringSplitOptions.None)
+						: new string[]{option}) {
+					c.OptionValues.Add (o);
+				}
+			if (c.OptionValues.Count == c.Option.MaxValueCount || 
+					c.Option.OptionValueType == OptionValueType.Optional)
+				c.Option.Invoke (c);
+			else if (c.OptionValues.Count > c.Option.MaxValueCount) {
+				throw new OptionException (localizer (string.Format (
+								"Error: Found {0} option values when expecting {1}.", 
+								c.OptionValues.Count, c.Option.MaxValueCount)),
+						c.OptionName);
+			}
+		}
+
+		private bool ParseBool (string option, string n, OptionContext c)
+		{
+			Option p;
+			string rn;
+			if (n.Length >= 1 && (n [n.Length-1] == '+' || n [n.Length-1] == '-') &&
+					Contains ((rn = n.Substring (0, n.Length-1)))) {
+				p = this [rn];
+				string v = n [n.Length-1] == '+' ? option : null;
+				c.OptionName  = option;
+				c.Option      = p;
+				c.OptionValues.Add (v);
+				p.Invoke (c);
+				return true;
+			}
+			return false;
+		}
+
+		private bool ParseBundledValue (string f, string n, OptionContext c)
+		{
+			if (f != "-")
+				return false;
+			for (int i = 0; i < n.Length; ++i) {
+				Option p;
+				string opt = f + n [i].ToString ();
+				string rn = n [i].ToString ();
+				if (!Contains (rn)) {
+					if (i == 0)
+						return false;
+					throw new OptionException (string.Format (localizer (
+									"Cannot bundle unregistered option '{0}'."), opt), opt);
+				}
+				p = this [rn];
+				switch (p.OptionValueType) {
+					case OptionValueType.None:
+						Invoke (c, opt, n, p);
+						break;
+					case OptionValueType.Optional:
+					case OptionValueType.Required: {
+						string v     = n.Substring (i+1);
+						c.Option     = p;
+						c.OptionName = opt;
+						ParseValue (v.Length != 0 ? v : null, c);
+						return true;
+					}
+					default:
+						throw new InvalidOperationException ("Unknown OptionValueType: " + p.OptionValueType);
+				}
+			}
+			return true;
+		}
+
+		private static void Invoke (OptionContext c, string name, string value, Option option)
+		{
+			c.OptionName  = name;
+			c.Option      = option;
+			c.OptionValues.Add (value);
+			option.Invoke (c);
+		}
+
+		private const int OptionWidth = 29;
+		private const int Description_FirstWidth  = 80 - OptionWidth;
+		private const int Description_RemWidth    = 80 - OptionWidth - 2;
+
+		public void WriteOptionDescriptions (TextWriter o)
+		{
+			foreach (Option p in this) {
+				int written = 0;
+
+				if (p.Hidden)
+					continue;
+
+				Category c = p as Category;
+				if (c != null) {
+					WriteDescription (o, p.Description, "", 80, 80);
+					continue;
+				}
+
+				if (!WriteOptionPrototype (o, p, ref written))
+					continue;
+
+				if (written < OptionWidth)
+					o.Write (new string (' ', OptionWidth - written));
+				else {
+					o.WriteLine ();
+					o.Write (new string (' ', OptionWidth));
+				}
+
+				WriteDescription (o, p.Description, new string (' ', OptionWidth+2),
+						Description_FirstWidth, Description_RemWidth);
+			}
+
+			foreach (ArgumentSource s in sources) {
+				string[] names = s.GetNames ();
+				if (names == null || names.Length == 0)
+					continue;
+
+				int written = 0;
+
+				Write (o, ref written, "  ");
+				Write (o, ref written, names [0]);
+				for (int i = 1; i < names.Length; ++i) {
+					Write (o, ref written, ", ");
+					Write (o, ref written, names [i]);
+				}
+
+				if (written < OptionWidth)
+					o.Write (new string (' ', OptionWidth - written));
+				else {
+					o.WriteLine ();
+					o.Write (new string (' ', OptionWidth));
+				}
+
+				WriteDescription (o, s.Description, new string (' ', OptionWidth+2),
+						Description_FirstWidth, Description_RemWidth);
+			}
+		}
+
+		void WriteDescription (TextWriter o, string value, string prefix, int firstWidth, int remWidth)
+		{
+			bool indent = false;
+			foreach (string line in GetLines (localizer (GetDescription (value)), firstWidth, remWidth)) {
+				if (indent)
+					o.Write (prefix);
+				o.WriteLine (line);
+				indent = true;
+			}
+		}
+
+		bool WriteOptionPrototype (TextWriter o, Option p, ref int written)
+		{
+			string[] names = p.Names;
+
+			int i = GetNextOptionIndex (names, 0);
+			if (i == names.Length)
+				return false;
+
+			if (names [i].Length == 1) {
+				Write (o, ref written, "  -");
+				Write (o, ref written, names [0]);
+			}
+			else {
+				Write (o, ref written, "      --");
+				Write (o, ref written, names [0]);
+			}
+
+			for ( i = GetNextOptionIndex (names, i+1); 
+					i < names.Length; i = GetNextOptionIndex (names, i+1)) {
+				Write (o, ref written, ", ");
+				Write (o, ref written, names [i].Length == 1 ? "-" : "--");
+				Write (o, ref written, names [i]);
+			}
+
+			if (p.OptionValueType == OptionValueType.Optional ||
+					p.OptionValueType == OptionValueType.Required) {
+				if (p.OptionValueType == OptionValueType.Optional) {
+					Write (o, ref written, localizer ("["));
+				}
+				Write (o, ref written, localizer ("=" + GetArgumentName (0, p.MaxValueCount, p.Description)));
+				string sep = p.ValueSeparators != null && p.ValueSeparators.Length > 0 
+					? p.ValueSeparators [0]
+					: " ";
+				for (int c = 1; c < p.MaxValueCount; ++c) {
+					Write (o, ref written, localizer (sep + GetArgumentName (c, p.MaxValueCount, p.Description)));
+				}
+				if (p.OptionValueType == OptionValueType.Optional) {
+					Write (o, ref written, localizer ("]"));
+				}
+			}
+			return true;
+		}
+
+		static int GetNextOptionIndex (string[] names, int i)
+		{
+			while (i < names.Length && names [i] == "<>") {
+				++i;
+			}
+			return i;
+		}
+
+		static void Write (TextWriter o, ref int n, string s)
+		{
+			n += s.Length;
+			o.Write (s);
+		}
+
+		private static string GetArgumentName (int index, int maxIndex, string description)
+		{
+			if (description == null)
+				return maxIndex == 1 ? "VALUE" : "VALUE" + (index + 1);
+			string[] nameStart;
+			if (maxIndex == 1)
+				nameStart = new string[]{"{0:", "{"};
+			else
+				nameStart = new string[]{"{" + index + ":"};
+			for (int i = 0; i < nameStart.Length; ++i) {
+				int start, j = 0;
+				do {
+					start = description.IndexOf (nameStart [i], j);
+				} while (start >= 0 && j != 0 ? description [j++ - 1] == '{' : false);
+				if (start == -1)
+					continue;
+				int end = description.IndexOf ("}", start);
+				if (end == -1)
+					continue;
+				return description.Substring (start + nameStart [i].Length, end - start - nameStart [i].Length);
+			}
+			return maxIndex == 1 ? "VALUE" : "VALUE" + (index + 1);
+		}
+
+		private static string GetDescription (string description)
+		{
+			if (description == null)
+				return string.Empty;
+			StringBuilder sb = new StringBuilder (description.Length);
+			int start = -1;
+			for (int i = 0; i < description.Length; ++i) {
+				switch (description [i]) {
+					case '{':
+						if (i == start) {
+							sb.Append ('{');
+							start = -1;
+						}
+						else if (start < 0)
+							start = i + 1;
+						break;
+					case '}':
+						if (start < 0) {
+							if ((i+1) == description.Length || description [i+1] != '}')
+								throw new InvalidOperationException ("Invalid option description: " + description);
+							++i;
+							sb.Append ("}");
+						}
+						else {
+							sb.Append (description.Substring (start, i - start));
+							start = -1;
+						}
+						break;
+					case ':':
+						if (start < 0)
+							goto default;
+						start = i + 1;
+						break;
+					default:
+						if (start < 0)
+							sb.Append (description [i]);
+						break;
+				}
+			}
+			return sb.ToString ();
+		}
+
+		private static IEnumerable<string> GetLines (string description, int firstWidth, int remWidth)
+		{
+			return StringCoda.WrappedLines (description, firstWidth, remWidth);
+		}
+	}
+}
+
diff --git a/Program.cs b/Program.cs
index baf2172..d0e4308 100644
--- a/Program.cs
+++ b/Program.cs
@@ -26,30 +26,50 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.IO;
+using Mono.Options;
 
 namespace Ildasm
 {
     class Program
     {
-        static void Main(string[] args)
+        static int Main(string[] args)
         {
             string outputFile = null;
             string inputFile = null;
             var compatLevel = CompatLevel.None;
             var flags = Flags.None;
-            foreach (var arg in args)
-            {
-                if (arg.StartsWith("-", StringComparison.Ordinal) || arg.StartsWith("/", StringComparison.Ordinal))
-                {
-                    string value;
-                    if (TryMatchOption(arg, "out", out value))
-                    {
-                        outputFile = value;
-                    }
-                    else if (TryMatchOption(arg, "compat", out value))
-                    {
-                        switch (value)
-                        {
+
+			if (typeof (int).Assembly.GetType ("Mono.Runtime") != null) {
+				bool printUsage = false;
+
+				var p = new OptionSet () {
+						{ "help", v => printUsage = true },
+						{ "out", v => outputFile = v }
+					};
+				args = p.Parse (args).ToArray ();
+				if (printUsage) {
+					PrintUsage ();
+					return 0;
+				}
+				if (args.Length < 1) {
+					PrintUsage ();
+					return 1;
+				}
+				inputFile = args [0];
+			} else {
+				foreach (var arg in args)
+				{
+					if (arg.StartsWith("-", StringComparison.Ordinal) || arg.StartsWith("/", StringComparison.Ordinal))
+					{
+						string value;
+						if (TryMatchOption(arg, "out", out value))
+						{
+							outputFile = value;
+						}
+						else if (TryMatchOption(arg, "compat", out value))
+						{
+							switch (value)
+							{
                             case "2.0":
                                 compatLevel = CompatLevel.V20;
                                 break;
@@ -95,10 +115,11 @@ namespace Ildasm
                     }
                 }
             }
+
             if (inputFile == null)
             {
                 PrintUsage();
-                return;
+                return 1;
             }
             var disassembler = new Disassembler(inputFile, outputFile, compatLevel, flags);
             if (outputFile != null)
@@ -128,6 +149,7 @@ namespace Ildasm
             {
                 disassembler.Save(Console.Out);
             }
+			return 0;
         }
 
         static bool TryMatchOption(string arg, string key, out string value)
@@ -155,11 +177,16 @@ namespace Ildasm
             Console.WriteLine("Usage: ikdasm [options] <file_name> [options]");
             Console.WriteLine();
             Console.WriteLine("Options:");
-            Console.WriteLine("  /OUT=<file name>    Direct output to file rather than to stdout.");
-            Console.WriteLine("  /COMPAT=<version>   Match ildasm behavior. (<version> = 2.0 | 4.0 | 4.5)");
-            Console.WriteLine("  /DIFFMODE           Remove superficial differences to allow assembly comparisons");
-            Console.WriteLine("  /CAVERBAL           Try to decode custom attribute blobs");
-            Console.WriteLine("  /PROJECT            Project WinMD metadata into .NET format");
+			if (typeof (int).Assembly.GetType ("Mono.Runtime") != null) {
+				Console.WriteLine ("  --out=<file name>   Direct output to file rather than stdout.");
+				Console.WriteLine ("  --help              Print this help.");
+			} else {
+				Console.WriteLine("  /OUT=<file name>    Direct output to file rather than to stdout.");
+				Console.WriteLine("  /COMPAT=<version>   Match ildasm behavior. (<version> = 2.0 | 4.0 | 4.5)");
+				Console.WriteLine("  /DIFFMODE           Remove superficial differences to allow assembly comparisons");
+				Console.WriteLine("  /CAVERBAL           Try to decode custom attribute blobs");
+                Console.WriteLine("  /PROJECT            Project WinMD metadata into .NET format");
+			}
         }
     }
 }
diff --git a/ikdasm.csproj b/ikdasm.csproj
index 4d558e2..327eae5 100644
--- a/ikdasm.csproj
+++ b/ikdasm.csproj
@@ -63,6 +63,7 @@
     <Compile Include="Program.cs" />
     <Compile Include="Util.cs" />
     <Compile Include="VTableFixups.cs" />
+    <Compile Include="Options.cs" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="Properties\" />