Mono.Options 0.2.0.0 0.2.1.0 All public static members of this type are safe for multithreaded operations. The instance method is thread-safe if no concurrent modifying methods are invoked (, , etc.). System.Collections.ObjectModel.KeyedCollection<System.String,Mono.Options.Option> System.String Mono.Options.Option A class to parse program options.

A common requirement for command-line programs is option parsing. The command line consists of a sequence of . parses this argument sequence, invoking actions of registered s when a sequence of arguments matching the s requirements are encountered. 's are registered with and its overloads.

, returns a of all arguments which were not matched by a registered .

Three conditions must be met for a sequence of arguments to be considered as a match for an :

The must be matched. An has one or more names, as returned from . Matched names must start with a (even though the flag is not part of the ): -, --, or /. There are several different name matching algorithms:

names are matched when the argument consists solely of a flag followed by an option name.

Examples: -opt, --opt, and /opt are all simple names for the opt option.

names are matched when the argument consists of a flag, followed by an option name, followed by + or -. If a + follows the name, the option is enabled, otherwise the option is disabled.

Examples: -opt+ and -opt- enable and disble the opt option.

names are matched when the argument consists of a flag, followed by an option name, followed by a = or :, followed by an (optional) string.

Examples: -opt=A, --opt:B, and /opt=C all provide a value for the opt option.

names are matched only when simple, boolean, and assigned names are not matched, the flag is -, and the first character matches a registered option. Any number of (single-character) boolean options may be bundled in this fashion, and at most one or option (which will use all remaining characters within the argument as a value).

Examples: -xvfinput-file could match the boolean s x and v and the value-accepting option f, which will get the value input-file. (Other interpretations are also possible, depending upon which options are registered.)

As a fallback, a may be registered which will handle arguments which are not handled by any of the above matching algorithms. The default handler is designated by the name <> (which may be an alias for another named ).

Default handlers are useful for argument runs -- sequences of arguments that are not related to each other but are instead related to a prior option on the command line, and it isn't desirable to use named options for these. For example, mdoc-assemble --format=ecma DirA DirB --format=man FileC would process DirA and DirB with --format=ecma in effect, and then process FileC with --format=man in effect.

See for additional details regarding default option handlers.

The must be matched. specifies the option's type. See below for more information.
The must be matched. Whether an option takes any values is dependent upon the option's type (previous bullet), but the number of values the option either accepts or requires is specified by the property.

There are three types of s that can be parsed:

Boolean options, which correspond to a value of . When a matching argument is encountered, their registered action is invoked immediately. The value will be non- if the value is true, e.g. if -option or -option+ is specified, and the value will be if the value is false, e.g. if -option- is specified.

Optional value options, which correspond to a value of . Optional value options are not "greedy"; they will only get their value only from the current argument. If the value is not present, is provided to their corresponding .

Thus, -opt:value would pass value to the action registered for opt, while -opt value would pass to the action registered for opt and value would be an unparsed argument.

Required value options, which correspond to a value of . Required value options are "greedy" -- if the value is not found within the current argument, the following argument(s) will be used to supply the value(s). Once enough values have been parsed, their corresponding is invoked.

Thus, both -opt:value and -opt value would pass value to the action registered for opt.

If no value can be found, an is thrown from .

Use of OptionSet is split up into two parts:

Initialization.
Parsing.

During the phase, new instances are created and associated with an action to perform when the Option requirements are met (e.g. when a required value has been encountered). This phase is not thread safe. All options added during this phase are considered to have been .

`OptionSet p = new OptionSet () { { "option-a", v => { /* action to perform */ } }, };`

There are three ways to add s to the :

With C# collection initializers, as used above.
Explicitly by calling and the other Add overloads.
By creating a new subclass of and adding it via . This is not recommended, but is available if you require more direct option handling than the default implementation provides.

During the phase, an is enumerated, looking for arguments which match a registered option, and invoking the corresponding action when an option and associated (optional) value is encountered. During this phase, the instance itself is thread safe, but full thread safety depends upon thread-safety of the registered actions. Any option-like strings for names that haven't been registered, e.g. --this-was-never-registered=false, and all arguments that are not used as option values are returned from or processed by the default handler <>, if registered.

`List<string> extra = p.Parse (new string[]{"-option-a"});`

Subclasses can override the following methods to customize option parsing behavior:

The following example demonstrates some simple usage of .

`using System; using System.Collections.Generic; using Mono.Options; class Test { static int verbosity; public static void Main (string[] args) { bool show_help = false; List<string> names = new List<string> (); int repeat = 1; var p = new OptionSet () { { "n|name=", "the {NAME} of someone to greet.", v => names.Add (v) }, { "r|repeat=", "the number of {TIMES} to repeat the greeting.\n" + "this must be an integer.", (int v) => repeat = v }, { "v", "increase debug message verbosity", v => { if (v != null) ++verbosity; } }, { "h|help", "show this message and exit", v => show_help = v != null }, }; List<string> extra; try { extra = p.Parse (args); } catch (OptionException e) { Console.Write ("greet: "); Console.WriteLine (e.Message); Console.WriteLine ("Try `greet --help' for more information."); return; } if (show_help) { ShowHelp (p); return; } string message; if (extra.Count > 0) { message = string.Join (" ", extra.ToArray ()); Debug ("Using new message: {0}", message); } else { message = "Hello {0}!"; Debug ("Using default message: {0}", message); } foreach (string name in names) { for (int i = 0; i < repeat; ++i) Console.WriteLine (message, name); } } static void ShowHelp (OptionSet p) { Console.WriteLine ("Usage: greet [OPTIONS]+ message"); Console.WriteLine ("Greet a list of individuals with an optional message."); Console.WriteLine ("If no message is specified, a generic greeting is used."); Console.WriteLine (); Console.WriteLine ("Options:"); p.WriteOptionDescriptions (Console.Out); } static void Debug (string format, params object[] args) { if (verbosity > 0) { Console.Write ("# "); Console.WriteLine (format, args); } } }`

The output (under the influence of different command-line arguments) is:

`$ mono greet.exe --help Usage: greet [OPTIONS]+ message Greet a list of individuals with an optional message. If no message is specified, a generic greeting is used. Options: -n, --name=NAME the NAME of someone to greet. -r, --repeat=TIMES the number of TIMES to repeat the greeting. this must be an integer. -v increase debug message verbosity -h, --help show this message and exit $ mono greet.exe -v- -n A -name=B --name=C /name D -nE Hello A! Hello B! Hello C! Hello D! Hello E! $ mono greet.exe -v -n E custom greeting for: {0} # Using new message: custom greeting for: {0} custom greeting for: E $ mono greet.exe -r 3 -n A Hello A! Hello A! Hello A! $ mono greet.exe -r not-an-int greet: Could not convert string `not-an-int' to type Int32 for option `-r'. Try `greet --help' for more information.`

Notice how the output produced by --help uses the descriptions provided during OptionSet initialization. Notice that the requiring a value (n|name=) can use multiple different forms of invocation, including: -n value, -n=value, -name value, -name=value, --name value, --name=value, /name value, and /name=value.

Notice also that the boolean v option can take three separate forms: -v and -v+, which both enable the option, and -v-, which disables the option. (The second greet invocation uses -v-, which is why no debug messages are shown.)

Finally, note that the action can specify a type to use. If no type is provided, the action parameter will be a . If a type is provided, then will be used to convert a string to the specified type.

The following example shows how options and values can be bundled together.

`using System; using System.Linq; using System.Collections.Generic; using Mono.Options; class Test { public static void Main (string[] args) { var show_help = false; var macros = new Dictionary<string, string>(); bool create = false, extract = false, list = false; string output = null, input = null; string color = null; var p = new OptionSet () { // gcc-like options { "D:", "Predefine a macro with an (optional) value.", (m, v) => { if (m == null) throw new OptionException ("Missing macro name for option -D.", "-D"); macros.Add (m, v); } }, { "d={-->}{=>}", "Alternate macro syntax.", (m, v) => macros.Add (m, v) }, { "o=", "Specify the output file", v => output = v }, // tar-like options { "f=", "The input file", v => input = v }, { "x", "Extract the file", v => extract = v != null }, { "c", "Create the file", v => create = v != null }, { "t", "List the file", v => list = v != null }, // ls-like optional values { "color:", "control whether and when color is used", v => color = v }, // other... { "h|help", "show this message and exit", v => show_help = v != null }, // default { "<>", v => Console.WriteLine ("def handler: color={0}; arg={1}", color, v)}, }; try { p.Parse (args); } catch (OptionException e) { Console.Write ("bundling: "); Console.WriteLine (e.Message); Console.WriteLine ("Try `greet --help' for more information."); return; } if (show_help) { ShowHelp (p); return; } Console.WriteLine ("Macros:"); foreach (var m in (from k in macros.Keys orderby k select k)) { Console.WriteLine ("\t{0}={1}", m, macros [m] ?? "<null>"); } Console.WriteLine ("Options:"); Console.WriteLine ("\t Input File: {0}", input); Console.WriteLine ("\tOuptut File: {0}", output); Console.WriteLine ("\t Create: {0}", create); Console.WriteLine ("\t Extract: {0}", extract); Console.WriteLine ("\t List: {0}", list); Console.WriteLine ("\t Color: {0}", color ?? "<null>"); } static void ShowHelp (OptionSet p) { Console.WriteLine ("Usage: bundling [OPTIONS]+"); Console.WriteLine ("Demo program to show the effects of bundling options and their values"); Console.WriteLine (); Console.WriteLine ("Options:"); p.WriteOptionDescriptions (Console.Out); } }`

The output (under the influence of different command-line arguments) is:

`$ mono bundling.exe --help Usage: bundling [OPTIONS]+ Demo program to show the effects of bundling options and their values Options: -D[=VALUE1:VALUE2] Predefine a macro with an (optional) value. -d=VALUE1-->VALUE2 Alternate macro syntax. -o=VALUE Specify the output file -f=VALUE The input file -x Extract the file -c Create the file -t List the file --color[=VALUE] control whether and when color is used -h, --help show this message and exit $ mono bundling.exe -D bundling: Missing macro name for option -D. Try `greet --help' for more information. $ mono bundling.exe -DA -DB=C "-dD-->E" "-dF=>G" -d "H=>I" -cf input --color -ooutput Macros: A=<null> B=C D=E F=G H=I Options: Input File: input Ouptut File: output Create: True Extract: False List: False Color: <null> $ mono bundling.exe -cfv input def handler: color=; arg=input Macros: Options: Input File: v Ouptut File: Create: True Extract: False List: False Color: <null> $ mono bundling.exe -xctf input Macros: Options: Input File: input Ouptut File: Create: True Extract: True List: True Color: <null> $ mono bundling.exe --color=auto -o output -finput Macros: Options: Input File: input Ouptut File: output Create: False Extract: False List: False Color: auto $ mono bundling.exe --color=on A B --color=off C D def handler: color=on; arg=A def handler: color=on; arg=B def handler: color=off; arg=C def handler: color=off; arg=D Macros: Options: Input File: Ouptut File: Create: False Extract: False List: False Color: off`

The following example shows a custom OptionSet subclass with the following additional functionality:

Option name lookup is done in a case insensitive fashion, so --name and --NAME are identical.
Option-like strings cannot be used as values to options, so --name --repeat is an error.
A key/value parser is provided, to show the use of custom and subclasses.
`// Case-Insensitive and Concatenating OptionSet using System; using System.Collections.Generic; using Mono.Options; class DemoOptionSet : OptionSet { protected override void InsertItem (int index, Option item) { if (item.Prototype.ToLower () != item.Prototype) throw new ArgumentException ("prototypes must be lower-case!"); base.InsertItem (index, item); } protected override OptionContext CreateOptionContext () { return new OptionContext (this); } protected override bool Parse (string option, OptionContext c) { string f, n, s, v; bool haveParts = GetOptionParts (option, out f, out n, out s, out v); Option nextOption = null; string newOption = option; if (haveParts) { string nl = n.ToLower (); nextOption = Contains (nl) ? this [nl] : null; newOption = f + n.ToLower () + (v != null ? s + v : ""); } if (c.Option != null) { // Prevent --a --b if (c.Option != null && haveParts) { if (nextOption == null) { // ignore } else throw new OptionException ( string.Format ("Found option `{0}' as value for option `{1}'.", option, c.OptionName), c.OptionName); } // have a option w/ required value; try to concat values. if (AppendValue (option, c)) { if (!option.EndsWith ("\\") && c.Option.MaxValueCount == c.OptionValues.Count) { c.Option.Invoke (c); } return true; } else base.Parse (newOption, c); } if (!haveParts || v == null) { // Not an option; let base handle as a non-option argument. return base.Parse (newOption, c); } if (nextOption.OptionValueType != OptionValueType.None && v.EndsWith ("\\")) { c.Option = nextOption; c.OptionValues.Add (v); c.OptionName = f + n; return true; } return base.Parse (newOption, c); } private bool AppendValue (string value, OptionContext c) { bool added = false; string[] seps = c.Option.GetValueSeparators (); foreach (var o in seps.Length != 0 ? value.Split (seps, StringSplitOptions.None) : new string[]{value}) { int idx = c.OptionValues.Count-1; if (idx == -1 || !c.OptionValues [idx].EndsWith ("\\")) { c.OptionValues.Add (o); added = true; } else { c.OptionValues [idx] += value; added = true; } } return added; } } class Demo { public static void Main (string[] args) { List<string> names = new List<string> (); Dictionary<string,string> map = new Dictionary<string,string> (); int repeat = 1; OptionSet p = new DemoOptionSet () { { "n|name=", v => names.Add (v) }, { "r|repeat:", (int v) => repeat = v }, { "m|map=", (k,v) => map.Add (k, v) }, }; List<string> extra; try { extra = p.Parse (args); } catch (OptionException e) { Console.Write ("subclass: "); Console.WriteLine (e.Message); return; } string message; if (extra.Count > 0) { message = string.Join (" ", extra.ToArray ()); } else { message = "Hello {0}!"; } foreach (string name in names) { for (int i = 0; i < repeat; ++i) Console.WriteLine (message, name); } List<string> keys = new List<string>(map.Keys); keys.Sort (); foreach (string key in keys) { Console.WriteLine ("Key: {0}={1}", key, map [key]); } } }`

The output (under the influence of different command-line arguments) is:

`$ mono subclass.exe -n A -Name=B --NAME=C /nAMe D Hello A! Hello B! Hello C! Hello D! $ mono subclass.exe --Repeat -name A $ mono subclass.exe -Name --Repeat 3 subclass: Found option `--Repeat' as value for option `-name'. $ mono subclass.exe --Map a b -mAp c=d /maP=e=f Key: a=b Key: c=d Key: e=f $ mono subclass.exe --map 'a\' 'b\' c 'd\' 'e\' f Key: a\b\c=d\e\f`

Notice:

That --name is treated in a case-insensitive fashion.
That repeat has an optional value, so with --Repeat -name A the default int value is passed (0), so no message is printed.
That name has a required value, so -Name --Repeat 3 generates an error.
The DemoOptionSet.Add() method provides appropriate key/value option pairs to the callback method.
- Constructor
  0.2.0.0
  0.2.1.0
  Creates and initializes a new class instance.

  This constructor causes the created instance to perform no translation of string messages; consequently, no localization is performed.

- Constructor
  0.2.0.0
  0.2.1.0
  A instance that will be used to translate strings.
  Creates and initializes a new class instance.

  This constructor initializes the property of the new instance using .

  Use this constructor when you want to perform some form of localization or internationalization on text strings generated from the class. Generated strings include:

  The written by , but not the option names themselves.
  Message format strings used when an error is encountered.

  See the following example, which demonstrates how different localizers alter the program output.

  // Localization with Mono.Options.OptionSet. // // Compile as: // gmcs -r:Mono.Posix.dll -r:Mono.Options.dll code-localization.cs using System; using System.IO; using Mono.Unix; using Mono.Options;

  class LocalizationDemo { public static void Main (string[] args) { bool with_gettext = false; string useLocalizer = null; var p = new OptionSet () { { "with-gettext", v => { useLocalizer = "gettext"; } }, { "with-hello", v => { useLocalizer = "hello"; } }, { "with-default", v => { /* do nothing */ } }, }; p.Parse (args);

  Converter<string, string> localizer = f => f; switch (useLocalizer) { case "gettext": Catalog.Init ("localization", Path.Combine (AppDomain.CurrentDomain.BaseDirectory, "locale")); localizer = f => { return Catalog.GetString (f); }; break; case "hello": localizer = f => { return "hello:" + f; };; break; }

  bool help = false; int verbose = 0; bool version = false; p = new OptionSet (localizer) { { "h|?|help", "show this message and exit.", v => help = v != null }, { "v|verbose", "increase message verbosity.", v => { ++verbose; } }, { "n=", "must be an int", (int n) => { /* ignore */ } }, { "V|version", "output version information and exit.", v => version = v != null }, }; try { p.Parse (args); } catch (OptionException e) { Console.Write ("localization: "); Console.WriteLine (e.Message); return; } if (help) p.WriteOptionDescriptions (Console.Out); if (version) Console.WriteLine ("Mono.Options Localizer Demo 1.0"); if (verbose > 0) Console.WriteLine ("Message level: {0}", verbose); } }

  The output (under the influence of different command-line arguments) is:

  $ mono localization.exe --help --version -h, -?, --help show this message and exit. -v, --verbose increase message verbosity. -n=VALUE must be an int -V, --version output version information and exit. Mono.Options Localizer Demo 1.0

  $ LANGUAGE=es mono localization.exe --with-gettext --help --version -h, -?, --help A mostrar este mensaje y salir. -v, --verbose Aumento mensaje verbosidad. -n=VALUE Debe ser un int -V, --version Salida de información de versión y sale. Mono.Options Localizer Demo 1.0

  $ mono localization.exe --with-hello --help --version -h, -?, --help hello:show this message and exit. -v, --verbose hello:increase message verbosity. -nhello:=VALUE hello:must be an int -V, --version hello:output version information and exit. Mono.Options Localizer Demo 1.0

  $ mono localization.exe -n not-an-int localization: Could not convert string `not-an-int' to type Int32 for option `-n'.

  $ mono localization.exe --with-hello -n not-an-int localization: hello:Could not convert string `not-an-int' to type Int32 for option `-n'.

  Notice:

  The --with-gettext parser uses to translate all messages
  The -with-hello parser prefixes all descriptions with hello:.
  Only the descriptions are translated, and not the command-line arguments themselves. Only error messages and option descriptions are translated, not the options themselves.
- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` The to register. Registers so that any options matching will be treated specially by . The current instance. This is to permit method chaining. Registers each option name returned by , ensuring that any option with a matching name will be handled by the instance. has an alias (as returned from ) that conflicts with a previously registered . is .
- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining. Calls with a value of . has an alias (as returned from ) that conflicts with a previously registered .

  is

  -or-

  is

- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining. Calls with a value of . has an alias (as returned from ) that conflicts with a previously registered .

  is

  -or-

  is

- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` `` A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A to be used to initialize the property. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining.

  Use this method when should accept two values, generally a key and a value.

  If specifies a option, then it's possible that both the key and the value will be in the callback function. has an alias (as returned from ) that conflicts with a previously registered .

  is

  -or-

  is

- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` `` A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A containing to used to initialize the property. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining. has an alias (as returned from ) that conflicts with a previously registered .

  is

  -or-

  is

- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` The type of the option to parse and provide to the callback. A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining. Calls with a value of . has an alias (as returned from ) that conflicts with a previously registered .
- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` `` The type of the option to parse and provide to the callback. A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A containing to used to initialize the property. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining.

  Use this typed overload when you want strongly typed option values that correspond to a managed type. is used to lookup the to use when performing the string-to-type conversion.

  Special support is provided for types; doesn't currently support their use, but if is a nullable type, then this method will instead use the for the type. This allows straightforward use of nullable types, identical to using any other strongly typed value.

  If specifies an value and the value is not provided, then default(T) is provided as the value to .

  has an alias (as returned from ) that conflicts with a previously registered .

  is

  -or-

  is

- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` The type of the first argument to parse and provide to the callback. The type of the second argument to parse and provide to the callback. A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining. Calls with a value of . has an alias (as returned from ) that conflicts with a previously registered .

  is

  -or-

  is

- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionSet `` `` `` The type of the first argument to parse and provide to the callback. The type of the second argument to parse and provide to the callback. A containing all option aliases to register, an (optional) type specifier, and an (optional) value separator list; see for details. A to be used to initialize the property. A to invoke when an option is parsed. Registers each alias within so that any options matching the aliases in will be handled by during any subsequent calls. The current instance. This is to permit method chaining.

  Use this method when should accept two typed values, generally a key and a value.

  If specifies an value and the value is not provided, then default(TKey) and default(TValue) may be provided as the values to .

  has an alias (as returned from ) that conflicts with a previously registered .

  is

  -or-

  is

- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.OptionContext Creates an instance. A instance to be used when parsing all options during the current call.

  This method can be overridden if is overridden and requires access to an subclass to store additional information during the current invocation.

- Method
  0.2.1.0
  System.String `` An to return the key of. Returns .GetNames()[0]. A containing the first alias returned by .

  This is to support the infrastructure. assumes only one key per item, so we arbitrarily choose the first item in the option alias list.

  All aliases returned by are still registered with even though will never return them. Consequently, and will both correctly use all aliases returned by .
- Method
  0.2.0.0
  0.2.1.0
  Mono.Options.Option `` System.Obsolete("Use KeyedCollection.this[string]") A containing the option name to lookup. Looks up the registered to handle the option name . The instance registered to handle the option name . If there is no registered handler for , then is returned.

  Subclasses can use this function to perform lookup when overriding .

  is .
- Method
  0.2.0.0
  0.2.1.0
  System.Boolean `` `` `` `` `` A containing the option to parse into its constituent parts. A reference which will be set to if the method returns , or set to the flag the option starts with if the method returns . Valid flags include: -, --, and /. A reference which will be set to if the method returns , or set to the option name following a valid flag if the method returns . No lookup is made to determine that flag has been registered via a prior call to or related overload. A reference which will be set to if either the method returns or if = or : was not found within ; if the method returns and contains a = or :, then will contain either = or :, whichever was found within . A reference which will be set to if either the method returns or if is null; if the method returns and is not , then will contain all text after . Splits into its constituent parts. if could be split into its constituent parts, and and are set ( and may not be set, depending on whether or not they are present within ); if is not the possible start of a valid option.

  Subclasses can call this method from their method to determine whether a given string is an option, and to split the option up for further processing.

  For example, GetOptionParts("foo", ...) would return , while GetOptionParts("--foo=bar", ...) would result in containing --, containing foo, containing =, and containing bar.

  is .
- Method
  0.2.0.0
  0.2.1.0
  System.Void `` `` A specifying the index to insert into. The to insert. Inserts at the specified .
- Property
  0.2.0.0
  0.2.1.0
  System.Converter<System.String,System.String> Permits access to the message localization facility. A that can be used to localize messages.

  subclasses can use this property (via ) to perform message localization for their own exception messages.

- Method
  0.2.0.0
  0.2.1.0
  System.Collections.Generic.List<System.String> `` A containing all arguments to parse. Parses each within , invoking any registered if a registered option is encountered. A containing all unhandled arguments.

  An argument is unhandled if:

  There is no default handler registered (the <> handler). If there is a default handler registered, then the default handler is invoked for otherwise-unhandled arguments.
  The option starts with a flag such as -, --, /, and the option name following the flag is unregistered.
  Or, the option does not start with a flag, and there is no prior parsed option that accepts a value that would use the argument as its value.

  Furthermore, argument parsing (including default handler invocation) stops whenever the -- option is encountered. This is in accordance with GNU conventions, and is frequently used to permit users to provide option-like filenames, e.g. ls -lF -- -l to view the file -l instead of needing to use ls -lF ./-l.

  A value was not found for an requiring a value.

  -or-

  An attempt was made to bundle together an option requiring a value.

  -or-

  An exception was generated when trying to convert the value to the type , for options added with and related methods. The originating exception is provided via the property.

  The following example demonstrates some simple usage of .

  `using System; using System.Collections.Generic; using Mono.Options; class Test { static int verbosity; public static void Main (string[] args) { bool show_help = false; List<string> names = new List<string> (); int repeat = 1; var p = new OptionSet () { { "n|name=", "the {NAME} of someone to greet.", v => names.Add (v) }, { "r|repeat=", "the number of {TIMES} to repeat the greeting.\n" + "this must be an integer.", (int v) => repeat = v }, { "v", "increase debug message verbosity", v => { if (v != null) ++verbosity; } }, { "h|help", "show this message and exit", v => show_help = v != null }, }; List<string> extra; try { extra = p.Parse (args); } catch (OptionException e) { Console.Write ("greet: "); Console.WriteLine (e.Message); Console.WriteLine ("Try `greet --help' for more information."); return; } if (show_help) { ShowHelp (p); return; } string message; if (extra.Count > 0) { message = string.Join (" ", extra.ToArray ()); Debug ("Using new message: {0}", message); } else { message = "Hello {0}!"; Debug ("Using default message: {0}", message); } foreach (string name in names) { for (int i = 0; i < repeat; ++i) Console.WriteLine (message, name); } } static void ShowHelp (OptionSet p) { Console.WriteLine ("Usage: greet [OPTIONS]+ message"); Console.WriteLine ("Greet a list of individuals with an optional message."); Console.WriteLine ("If no message is specified, a generic greeting is used."); Console.WriteLine (); Console.WriteLine ("Options:"); p.WriteOptionDescriptions (Console.Out); } static void Debug (string format, params object[] args) { if (verbosity > 0) { Console.Write ("# "); Console.WriteLine (format, args); } } }`
- Method
  0.2.0.0
  0.2.1.0
  System.Boolean `` `` A containing the current option to parse. A containing the current parser context. Parses and invokes if appropriate. A specifying whether or not was handled. If , then will return as an unhandled option.

  This method is called for each within the provided to , which thus gives this method a chance to parse a single option, or chain together multiple options to form a single option (as is necessary when an option and its value are separated, e.g. with -option value).

  The default implementation will check , which is assumed to be a in need of a value. If is non-, then is ed to and is invoked.

  Next, is invoked. If GetOptionParts returns , then is returned from Parse.

  Finally, check to see if the returned from GetOptionParts is registered; if it is, handle it appropriately. If it isn't, check to see if is a bundled option or a boolean option. If isn't any registered option, then is returned. Otherwise, is returned.

  Inheriting types can override this method if they want to customize the per-option parsing within the containing invocation.

  Inheriting types should consider overriding if they want to store extra information for use and retrieval during each Parse invocation.

- Method
  0.2.0.0
  0.2.1.0
  System.Void `` A containing the index of the to remove. Removes the at the specified .
- Method
  0.2.0.0
  0.2.1.0
  System.Void `` `` A containing the index of the to change. The new to set at . Removes the current at and sets as the value for the value.
- Method
  0.2.0.0
  0.2.1.0
  System.Void `` The to write option descriptions to. Writes documentation to .

  For each previously added to the current instance, this method writes out a comma-separated list of all followed by the .

  The is automatically wrapped so that output will flow nicely across multiple lines. Wrapping is preferred at explicit embedded newline characters (\n) or spaces, but words will be split (by adding a -) if necessary.

  Options requiring a value have =VALUE appended to their last name, while options with an optional value have [=VALUE] appended to their last name. The VALUE string can be changed by using a format specifier-like string within the .

  For s accepting one value, the string {VALUE} or {0:VALUE} can be used to explicitly provide the value name. For Options accepting more than one value, the leading number is used to specify which value the string is for.

  The following example initializes a instance to accept a variety of parameters and provides a description for each parameter:

  `using System; using System.Collections.Generic; using Mono.Options; class Test { static int verbosity; public static void Main (string[] args) { bool show_help = false; List<string> names = new List<string> (); int repeat = 1; var p = new OptionSet () { { "n|name=", "the {NAME} of someone to greet.", v => names.Add (v) }, { "r|repeat=", "the number of {TIMES} to repeat the greeting.\n" + "this must be an integer.", (int v) => repeat = v }, { "v", "increase debug message verbosity", v => { if (v != null) ++verbosity; } }, { "h|help", "show this message and exit", v => show_help = v != null }, }; List<string> extra; try { extra = p.Parse (args); } catch (OptionException e) { Console.Write ("greet: "); Console.WriteLine (e.Message); Console.WriteLine ("Try `greet --help' for more information."); return; } if (show_help) { ShowHelp (p); return; } string message; if (extra.Count > 0) { message = string.Join (" ", extra.ToArray ()); Debug ("Using new message: {0}", message); } else { message = "Hello {0}!"; Debug ("Using default message: {0}", message); } foreach (string name in names) { for (int i = 0; i < repeat; ++i) Console.WriteLine (message, name); } } static void ShowHelp (OptionSet p) { Console.WriteLine ("Usage: greet [OPTIONS]+ message"); Console.WriteLine ("Greet a list of individuals with an optional message."); Console.WriteLine ("If no message is specified, a generic greeting is used."); Console.WriteLine (); Console.WriteLine ("Options:"); p.WriteOptionDescriptions (Console.Out); } static void Debug (string format, params object[] args) { if (verbosity > 0) { Console.Write ("# "); Console.WriteLine (format, args); } } }`

  Notice that when the above program is invoked with the --help parameter, is used to generate the description, that the --repeat description spans multiple lines, and that format specifiers such as {NAME} are used to provide a description for the option value:

  `$ mono greet.exe --help Usage: greet [OPTIONS]+ message Greet a list of individuals with an optional message. If no message is specified, a generic greeting is used. Options: -n, --name=NAME the NAME of someone to greet. -r, --repeat=TIMES the number of TIMES to repeat the greeting. this must be an integer. -v increase debug message verbosity -h, --help show this message and exit $ mono greet.exe -v- -n A -name=B --name=C /name D -nE Hello A! Hello B! Hello C! Hello D! Hello E! $ mono greet.exe -v -n E custom greeting for: {0} # Using new message: custom greeting for: {0} custom greeting for: E $ mono greet.exe -r 3 -n A Hello A! Hello A! Hello A! $ mono greet.exe -r not-an-int greet: Could not convert string `not-an-int' to type Int32 for option `-r'. Try `greet --help' for more information.`