%%%------------------------------------------------------------------- %%% @author Juan Jose Comellas %%% @copyright (C) 2009 Juan Jose Comellas %%% @doc Parses command line options with a format similar to that of GNU getopt. %%% @end %%% %%% This source file is subject to the New BSD License. You should have received %%% a copy of the New BSD license with this software. If not, it can be %%% retrieved from: http://www.opensource.org/licenses/bsd-license.php %%%------------------------------------------------------------------- -module(getopt). -author('juanjo@comellas.org'). -export([parse/2, usage/2, usage/3, usage/4]). -export_type([arg_type/0, arg_value/0, arg_spec/0, simple_option/0, compound_option/0, option/0, option_spec/0]). -define(TAB_LENGTH, 8). %% Indentation of the help messages in number of tabs. -define(INDENTATION, 3). %% Position of each field in the option specification tuple. -define(OPT_NAME, 1). -define(OPT_SHORT, 2). -define(OPT_LONG, 3). -define(OPT_ARG, 4). -define(OPT_HELP, 5). -define(IS_OPT_SPEC(Opt), (tuple_size(Opt) =:= ?OPT_HELP)). %% Atom indicating the data type that an argument can be converted to. -type arg_type() :: 'atom' | 'binary' | 'boolean' | 'float' | 'integer' | 'string'. %% Data type that an argument can be converted to. -type arg_value() :: atom() | binary() | boolean() | float() | integer() | string(). %% Argument specification. -type arg_spec() :: arg_type() | {arg_type(), arg_value()} | undefined. %% Option type and optional default argument. -type simple_option() :: atom(). -type compound_option() :: {atom(), arg_value()}. -type option() :: simple_option() | compound_option(). %% Command line option specification. -type option_spec() :: { Name :: atom(), Short :: char() | undefined, Long :: string() | undefined, ArgSpec :: arg_spec(), Help :: string() | undefined }. %% Output streams -type output_stream() :: 'standard_io' | 'standard_error'. %% @doc Parse the command line options and arguments returning a list of tuples %% and/or atoms using the Erlang convention for sending options to a %% function. -spec parse([option_spec()], string() | [string()]) -> {ok, {[option()], [string()]}} | {error, {Reason :: atom(), Data :: any()}}. parse(OptSpecList, CmdLine) -> try Args = if is_integer(hd(CmdLine)) -> string:tokens(CmdLine, " \t\n"); true -> CmdLine end, parse(OptSpecList, [], [], 0, Args) catch throw: {error, {_Reason, _Data}} = Error -> Error end. -spec parse([option_spec()], [option()], [string()], integer(), [string()]) -> {ok, {[option()], [string()]}}. %% Process the option terminator. parse(OptSpecList, OptAcc, ArgAcc, _ArgPos, ["--" | Tail]) -> %% Any argument present after the terminator is not considered an option. {ok, {lists:reverse(append_default_options(OptSpecList, OptAcc)), lists:reverse(ArgAcc, Tail)}}; %% Process long options. parse(OptSpecList, OptAcc, ArgAcc, ArgPos, ["--" ++ OptArg = OptStr | Tail]) -> parse_long_option(OptSpecList, OptAcc, ArgAcc, ArgPos, Tail, OptStr, OptArg); %% Process short options. parse(OptSpecList, OptAcc, ArgAcc, ArgPos, ["-" ++ ([_Char | _] = OptArg) = OptStr | Tail]) -> parse_short_option(OptSpecList, OptAcc, ArgAcc, ArgPos, Tail, OptStr, OptArg); %% Process non-option arguments. parse(OptSpecList, OptAcc, ArgAcc, ArgPos, [Arg | Tail]) -> case find_non_option_arg(OptSpecList, ArgPos) of {value, OptSpec} when ?IS_OPT_SPEC(OptSpec) -> parse(OptSpecList, add_option_with_arg(OptSpec, Arg, OptAcc), ArgAcc, ArgPos + 1, Tail); false -> parse(OptSpecList, OptAcc, [Arg | ArgAcc], ArgPos, Tail) end; parse(OptSpecList, OptAcc, ArgAcc, _ArgPos, []) -> %% Once we have completed gathering the options we add the ones that were %% not present but had default arguments in the specification. {ok, {lists:reverse(append_default_options(OptSpecList, OptAcc)), lists:reverse(ArgAcc)}}. %% @doc Parse a long option, add it to the option accumulator and continue %% parsing the rest of the arguments recursively. %% A long option can have the following syntax: %% --foo Single option 'foo', no argument %% --foo=bar Single option 'foo', argument "bar" %% --foo bar Single option 'foo', argument "bar" -spec parse_long_option([option_spec()], [option()], [string()], integer(), [string()], string(), string()) -> {ok, {[option()], [string()]}}. parse_long_option(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptStr, OptArg) -> case split_assigned_arg(OptArg) of {Long, Arg} -> %% Get option that has its argument within the same string %% separated by an equal ('=') character (e.g. "--port=1000"). parse_long_option_assigned_arg(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptStr, Long, Arg); Long -> case lists:keyfind(Long, ?OPT_LONG, OptSpecList) of {Name, _Short, Long, undefined, _Help} -> parse(OptSpecList, [Name | OptAcc], ArgAcc, ArgPos, Args); {_Name, _Short, Long, _ArgSpec, _Help} = OptSpec -> %% The option argument string is empty, but the option requires %% an argument, so we look into the next string in the list. %% e.g ["--port", "1000"] parse_long_option_next_arg(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptSpec); false -> throw({error, {invalid_option, OptStr}}) end end. %% @doc Parse an option where the argument is 'assigned' in the same string using %% the '=' character, add it to the option accumulator and continue parsing the %% rest of the arguments recursively. This syntax is only valid for long options. -spec parse_long_option_assigned_arg([option_spec()], [option()], [string()], integer(), [string()], string(), string(), string()) -> {ok, {[option()], [string()]}}. parse_long_option_assigned_arg(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptStr, Long, Arg) -> case lists:keyfind(Long, ?OPT_LONG, OptSpecList) of {_Name, _Short, Long, ArgSpec, _Help} = OptSpec -> case ArgSpec of undefined -> throw({error, {invalid_option_arg, OptStr}}); _ -> parse(OptSpecList, add_option_with_assigned_arg(OptSpec, Arg, OptAcc), ArgAcc, ArgPos, Args) end; false -> throw({error, {invalid_option, OptStr}}) end. %% @doc Split an option string that may contain an option with its argument %% separated by an equal ('=') character (e.g. "port=1000"). -spec split_assigned_arg(string()) -> {Name :: string(), Arg :: string()} | string(). split_assigned_arg(OptStr) -> split_assigned_arg(OptStr, OptStr, []). split_assigned_arg(_OptStr, "=" ++ Tail, Acc) -> {lists:reverse(Acc), Tail}; split_assigned_arg(OptStr, [Char | Tail], Acc) -> split_assigned_arg(OptStr, Tail, [Char | Acc]); split_assigned_arg(OptStr, [], _Acc) -> OptStr. %% @doc Retrieve the argument for an option from the next string in the list of %% command-line parameters or set the value of the argument from the argument %% specification (for boolean and integer arguments), if possible. parse_long_option_next_arg(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, {Name, _Short, _Long, ArgSpec, _Help} = OptSpec) -> ArgSpecType = arg_spec_type(ArgSpec), case Args =:= [] orelse is_implicit_arg(ArgSpecType, hd(Args)) of true -> parse(OptSpecList, add_option_with_implicit_arg(OptSpec, OptAcc), ArgAcc, ArgPos, Args); false -> [Arg | Tail] = Args, try parse(OptSpecList, [{Name, to_type(ArgSpecType, Arg)} | OptAcc], ArgAcc, ArgPos, Tail) catch error:_ -> throw({error, {invalid_option_arg, {Name, Arg}}}) end end. %% @doc Parse a short option, add it to the option accumulator and continue %% parsing the rest of the arguments recursively. %% A short option can have the following syntax: %% -a Single option 'a', no argument or implicit boolean argument %% -a foo Single option 'a', argument "foo" %% -afoo Single option 'a', argument "foo" %% -abc Multiple options: 'a'; 'b'; 'c' %% -bcafoo Multiple options: 'b'; 'c'; 'a' with argument "foo" %% -aaa Multiple repetitions of option 'a' (only valid for options with integer arguments) -spec parse_short_option([option_spec()], [option()], [string()], integer(), [string()], string(), string()) -> {ok, {[option()], [string()]}}. parse_short_option(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptStr, OptArg) -> parse_short_option(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptStr, first, OptArg). parse_short_option(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptStr, OptPos, [Short | Arg]) -> case lists:keyfind(Short, ?OPT_SHORT, OptSpecList) of {Name, Short, _Long, undefined, _Help} -> parse_short_option(OptSpecList, [Name | OptAcc], ArgAcc, ArgPos, Args, OptStr, first, Arg); {_Name, Short, _Long, ArgSpec, _Help} = OptSpec -> %% The option has a specification, so it requires an argument. case Arg of [] -> %% The option argument string is empty, but the option requires %% an argument, so we look into the next string in the list. parse_short_option_next_arg(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, OptSpec, OptPos); _ -> case is_valid_arg(ArgSpec, Arg) of true -> parse(OptSpecList, add_option_with_arg(OptSpec, Arg, OptAcc), ArgAcc, ArgPos, Args); _ -> NewOptAcc = case OptPos of first -> add_option_with_implicit_arg(OptSpec, OptAcc); _ -> add_option_with_implicit_incrementable_arg(OptSpec, OptAcc) end, parse_short_option(OptSpecList, NewOptAcc, ArgAcc, ArgPos, Args, OptStr, next, Arg) end end; false -> throw({error, {invalid_option, OptStr}}) end; parse_short_option(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, _OptStr, _OptPos, []) -> parse(OptSpecList, OptAcc, ArgAcc, ArgPos, Args). %% @doc Retrieve the argument for an option from the next string in the list of %% command-line parameters or set the value of the argument from the argument %% specification (for boolean and integer arguments), if possible. parse_short_option_next_arg(OptSpecList, OptAcc, ArgAcc, ArgPos, Args, {Name, _Short, _Long, ArgSpec, _Help} = OptSpec, OptPos) -> case Args =:= [] orelse is_implicit_arg(ArgSpec, hd(Args)) of true when OptPos =:= first -> parse(OptSpecList, add_option_with_implicit_arg(OptSpec, OptAcc), ArgAcc, ArgPos, Args); true -> parse(OptSpecList, add_option_with_implicit_incrementable_arg(OptSpec, OptAcc), ArgAcc, ArgPos, Args); false -> [Arg | Tail] = Args, try parse(OptSpecList, [{Name, to_type(ArgSpec, Arg)} | OptAcc], ArgAcc, ArgPos, Tail) catch error:_ -> throw({error, {invalid_option_arg, {Name, Arg}}}) end end. %% @doc Find the option for the discrete argument in position specified in the %% Pos argument. -spec find_non_option_arg([option_spec()], integer()) -> {value, option_spec()} | false. find_non_option_arg([{_Name, undefined, undefined, _ArgSpec, _Help} = OptSpec | _Tail], 0) -> {value, OptSpec}; find_non_option_arg([{_Name, undefined, undefined, _ArgSpec, _Help} | Tail], Pos) -> find_non_option_arg(Tail, Pos - 1); find_non_option_arg([_Head | Tail], Pos) -> find_non_option_arg(Tail, Pos); find_non_option_arg([], _Pos) -> false. %% @doc Append options that were not present in the command line arguments with %% their default arguments. -spec append_default_options([option_spec()], [option()]) -> [option()]. append_default_options([{Name, _Short, _Long, {_Type, DefaultArg}, _Help} | Tail], OptAcc) -> append_default_options(Tail, case lists:keymember(Name, 1, OptAcc) of false -> [{Name, DefaultArg} | OptAcc]; _ -> OptAcc end); %% For options with no default argument. append_default_options([_Head | Tail], OptAcc) -> append_default_options(Tail, OptAcc); append_default_options([], OptAcc) -> OptAcc. %% @doc Add an option with argument converting it to the data type indicated by the %% argument specification. -spec add_option_with_arg(option_spec(), string(), [option()]) -> [option()]. add_option_with_arg({Name, _Short, _Long, ArgSpec, _Help} = OptSpec, Arg, OptAcc) -> case is_valid_arg(ArgSpec, Arg) of true -> try [{Name, to_type(ArgSpec, Arg)} | OptAcc] catch error:_ -> throw({error, {invalid_option_arg, {Name, Arg}}}) end; false -> add_option_with_implicit_arg(OptSpec, OptAcc) end. %% @doc Add an option with argument that was part of an assignment expression %% (e.g. "--verbose=3") converting it to the data type indicated by the %% argument specification. -spec add_option_with_assigned_arg(option_spec(), string(), [option()]) -> [option()]. add_option_with_assigned_arg({Name, _Short, _Long, ArgSpec, _Help}, Arg, OptAcc) -> try [{Name, to_type(ArgSpec, Arg)} | OptAcc] catch error:_ -> throw({error, {invalid_option_arg, {Name, Arg}}}) end. %% @doc Add an option that required an argument but did not have one. Some data %% types (boolean, integer) allow implicit or assumed arguments. -spec add_option_with_implicit_arg(option_spec(), [option()]) -> [option()]. add_option_with_implicit_arg({Name, _Short, _Long, ArgSpec, _Help}, OptAcc) -> case arg_spec_type(ArgSpec) of boolean -> %% Special case for boolean arguments: if there is no argument we %% set the value to 'true'. [{Name, true} | OptAcc]; integer -> %% Special case for integer arguments: if the option had not been set %% before we set the value to 1. This is needed to support options like %% "-v" to return something like {verbose, 1}. [{Name, 1} | OptAcc]; _ -> throw({error, {missing_option_arg, Name}}) end. %% @doc Add an option with an implicit or assumed argument. -spec add_option_with_implicit_incrementable_arg(option_spec() | arg_spec(), [option()]) -> [option()]. add_option_with_implicit_incrementable_arg({Name, _Short, _Long, ArgSpec, _Help}, OptAcc) -> case arg_spec_type(ArgSpec) of boolean -> %% Special case for boolean arguments: if there is no argument we %% set the value to 'true'. [{Name, true} | OptAcc]; integer -> %% Special case for integer arguments: if the option had not been set %% before we set the value to 1; if not we increment the previous value %% the option had. This is needed to support options like "-vvv" to %% return something like {verbose, 3}. case OptAcc of [{Name, Count} | Tail] -> [{Name, Count + 1} | Tail]; _ -> [{Name, 1} | OptAcc] end; _ -> throw({error, {missing_option_arg, Name}}) end. %% @doc Retrieve the data type form an argument specification. -spec arg_spec_type(arg_spec()) -> arg_type() | undefined. arg_spec_type({Type, _DefaultArg}) -> Type; arg_spec_type(Type) when is_atom(Type) -> Type. %% @doc Convert an argument string to its corresponding data type. -spec to_type(arg_spec() | arg_type(), string()) -> arg_value(). to_type({Type, _DefaultArg}, Arg) -> to_type(Type, Arg); to_type(binary, Arg) -> list_to_binary(Arg); to_type(atom, Arg) -> list_to_atom(Arg); to_type(integer, Arg) -> list_to_integer(Arg); to_type(float, Arg) -> list_to_float(Arg); to_type(boolean, Arg) -> LowerArg = string:to_lower(Arg), case is_arg_true(LowerArg) of true -> true; _ -> case is_arg_false(LowerArg) of true -> false; false -> erlang:error(badarg) end end; to_type(_Type, Arg) -> Arg. -spec is_arg_true(string()) -> boolean(). is_arg_true(Arg) -> (Arg =:= "true") orelse (Arg =:= "t") orelse (Arg =:= "yes") orelse (Arg =:= "y") orelse (Arg =:= "on") orelse (Arg =:= "enabled") orelse (Arg =:= "1"). -spec is_arg_false(string()) -> boolean(). is_arg_false(Arg) -> (Arg =:= "false") orelse (Arg =:= "f") orelse (Arg =:= "no") orelse (Arg =:= "n") orelse (Arg =:= "off") orelse (Arg =:= "disabled") orelse (Arg =:= "0"). -spec is_valid_arg(arg_spec(), nonempty_string()) -> boolean(). is_valid_arg({Type, _DefaultArg}, Arg) -> is_valid_arg(Type, Arg); is_valid_arg(boolean, Arg) -> is_boolean_arg(Arg); is_valid_arg(integer, Arg) -> is_non_neg_integer_arg(Arg); is_valid_arg(float, Arg) -> is_non_neg_float_arg(Arg); is_valid_arg(_Type, _Arg) -> true. -spec is_implicit_arg(arg_spec(), nonempty_string()) -> boolean(). is_implicit_arg({Type, _DefaultArg}, Arg) -> is_implicit_arg(Type, Arg); is_implicit_arg(boolean, Arg) -> not is_boolean_arg(Arg); is_implicit_arg(integer, Arg) -> not is_integer_arg(Arg); is_implicit_arg(_Type, _Arg) -> false. -spec is_boolean_arg(string()) -> boolean(). is_boolean_arg(Arg) -> LowerArg = string:to_lower(Arg), is_arg_true(LowerArg) orelse is_arg_false(LowerArg). -spec is_integer_arg(string()) -> boolean(). is_integer_arg([$- | Tail]) -> is_non_neg_integer_arg(Tail); is_integer_arg(Arg) -> is_non_neg_integer_arg(Arg). -spec is_non_neg_integer_arg(string()) -> boolean(). is_non_neg_integer_arg([Head | Tail]) when Head >= $0, Head =< $9 -> is_non_neg_integer_arg(Tail); is_non_neg_integer_arg([_Head | _Tail]) -> false; is_non_neg_integer_arg([]) -> true. -spec is_non_neg_float_arg(string()) -> boolean(). is_non_neg_float_arg([Head | Tail]) when (Head >= $0 andalso Head =< $9) orelse Head =:= $. -> is_non_neg_float_arg(Tail); is_non_neg_float_arg([_Head | _Tail]) -> false; is_non_neg_float_arg([]) -> true. %% @doc Show a message on standard_error indicating the command line options and %% arguments that are supported by the program. -spec usage([option_spec()], string()) -> ok. usage(OptSpecList, ProgramName) -> usage(OptSpecList, ProgramName, standard_error). %% @doc Show a message on standard_error or standard_io indicating the command line options and %% arguments that are supported by the program. -spec usage([option_spec()], string(), output_stream() | string()) -> ok. usage(OptSpecList, ProgramName, OutputStream) when is_atom(OutputStream) -> io:format(OutputStream, "Usage: ~s~s~n~n~s~n", [ProgramName, usage_cmd_line(OptSpecList), usage_options(OptSpecList)]); %% @doc Show a message on standard_error indicating the command line options and %% arguments that are supported by the program. The CmdLineTail argument %% is a string that is added to the end of the usage command line. usage(OptSpecList, ProgramName, CmdLineTail) -> usage(OptSpecList, ProgramName, CmdLineTail, standard_error). %% @doc Show a message on standard_error or standard_io indicating the command line options and %% arguments that are supported by the program. The CmdLineTail argument %% is a string that is added to the end of the usage command line. -spec usage([option_spec()], string(), string(), output_stream() | [{string(), string()}]) -> ok. usage(OptSpecList, ProgramName, CmdLineTail, OutputStream) when is_atom(OutputStream) -> io:format(OutputStream, "Usage: ~s~s ~s~n~n~s~n", [ProgramName, usage_cmd_line(OptSpecList), CmdLineTail, usage_options(OptSpecList)]); %% @doc Show a message on standard_error indicating the command line options and %% arguments that are supported by the program. The CmdLineTail and OptionsTail %% arguments are a string that is added to the end of the usage command line %% and a list of tuples that are added to the end of the options' help lines. usage(OptSpecList, ProgramName, CmdLineTail, OptionsTail) -> usage(OptSpecList, ProgramName, CmdLineTail, OptionsTail, standard_error). %% @doc Show a message on standard_error or standard_io indicating the command line options and %% arguments that are supported by the program. The CmdLineTail and OptionsTail %% arguments are a string that is added to the end of the usage command line %% and a list of tuples that are added to the end of the options' help lines. -spec usage([option_spec()], string(), string(), [{string(), string()}], output_stream()) -> ok. usage(OptSpecList, ProgramName, CmdLineTail, OptionsTail, OutputStream) -> UsageOptions = lists:foldl( fun ({Prefix, Help}, Acc) -> add_option_help(Prefix, Help, Acc) end, usage_options_reverse(OptSpecList, []), OptionsTail), io:format(OutputStream, "Usage: ~s~s ~s~n~n~s~n", [ProgramName, usage_cmd_line(OptSpecList), CmdLineTail, lists:flatten(lists:reverse(UsageOptions))]). %% @doc Return a string with the syntax for the command line options and %% arguments. -spec usage_cmd_line([option_spec()]) -> string(). usage_cmd_line(OptSpecList) -> usage_cmd_line(OptSpecList, []). usage_cmd_line([{Name, Short, Long, ArgSpec, _Help} | Tail], Acc) -> CmdLine = case ArgSpec of undefined -> if %% For options with short form and no argument. Short =/= undefined -> [$\s, $[, $-, Short, $]]; %% For options with only long form and no argument. Long =/= undefined -> [$\s, $[, $-, $-, Long, $]]; true -> [] end; _ -> if %% For options with short form and argument. Short =/= undefined -> [$\s, $[, $-, Short, $\s, $<, atom_to_list(Name), $>, $]]; %% For options with only long form and argument. Long =/= undefined -> [$\s, $[, $-, $-, Long, $\s, $<, atom_to_list(Name), $>, $]]; %% For options with neither short nor long form and argument. true -> [$\s, $<, atom_to_list(Name), $>] end end, usage_cmd_line(Tail, [CmdLine | Acc]); usage_cmd_line([], Acc) -> lists:flatten(lists:reverse(Acc)). %% @doc Return a string with the help message for each of the options and %% arguments. -spec usage_options([option_spec()]) -> string(). usage_options(OptSpecList) -> lists:flatten(lists:reverse(usage_options_reverse(OptSpecList, []))). usage_options_reverse([{Name, Short, Long, _ArgSpec, Help} | Tail], Acc) -> Prefix = case Long of undefined -> case Short of %% Neither short nor long form (non-option argument). undefined -> [$<, atom_to_list(Name), $>]; %% Only short form. _ -> [$-, Short] end; _ -> case Short of %% Only long form. undefined -> [$-, $- | Long]; %% Both short and long form. _ -> [$-, Short, $,, $\s, $-, $- | Long] end end, usage_options_reverse(Tail, add_option_help(Prefix, Help, Acc)); usage_options_reverse([], Acc) -> Acc. %% @doc Add the help message corresponding to an option specification to a list %% with the correct indentation. -spec add_option_help(Prefix :: string(), Help :: string(), Acc :: string()) -> string(). add_option_help(Prefix, Help, Acc) when is_list(Help), Help =/= [] -> FlatPrefix = lists:flatten(Prefix), case ((?INDENTATION * ?TAB_LENGTH) - 2 - length(FlatPrefix)) of TabSize when TabSize > 0 -> Tab = lists:duplicate(ceiling(TabSize / ?TAB_LENGTH), $\t), [[$\s, $\s, FlatPrefix, Tab, Help, $\n] | Acc]; _ -> % The indentation for the option description is 3 tabs (i.e. 24 characters) % IMPORTANT: Change the number of tabs below if you change the % value of the INDENTATION macro. [[$\t, $\t, $\t, Help, $\n], [$\s, $\s, FlatPrefix, $\n] | Acc] end; add_option_help(_Opt, _Prefix, Acc) -> Acc. %% @doc Return the smallest integral value not less than the argument. -spec ceiling(float()) -> integer(). ceiling(X) -> T = erlang:trunc(X), case (X - T) of % Neg when Neg < 0 -> % T; Pos when Pos > 0 -> T + 1; _ -> T end.