rebar3/src/rebar_prv_help.erl

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3.1 KiB
Erlang
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2021-12-27 19:09:21 +00:00
%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
%% ex: ts=4 sw=4 et
-module(rebar_prv_help).
-behaviour(provider).
-export([init/1,
do/1,
format_error/1]).
-include("rebar.hrl").
-define(PROVIDER, help).
-define(DEPS, []).
%% ===================================================================
%% Public API
%% ===================================================================
-spec init(rebar_state:t()) -> {ok, rebar_state:t()}.
init(State) ->
State1 = rebar_state:add_provider(State, providers:create([{name, ?PROVIDER},
{module, ?MODULE},
{bare, true},
{deps, ?DEPS},
{example, "rebar3 help <task>"},
{short_desc, "Display a list of tasks or help for a given task or subtask."},
{desc, "Display a list of tasks or help for a given task or subtask."},
{opts, [
{help_task, undefined, undefined, string, "Task to print help for."}
]}])),
{ok, State1}.
-spec do(rebar_state:t()) -> {ok, rebar_state:t()} | {error, string()}.
do(State) ->
case rebar_state:command_args(State) of
[] ->
help(State),
{ok, State};
[Name] -> % default namespace
task_help(default, list_to_atom(Name), State);
[Namespace, Name] ->
task_help(list_to_atom(Namespace), list_to_atom(Name), State);
_ ->
{error, "Too many arguments given. " ++
"Usage: rebar3 help [<namespace>] <task>"}
end.
-spec format_error(any()) -> iolist().
format_error(Reason) ->
io_lib:format("~p", [Reason]).
%%
%% print help/usage string
%%
help(State) ->
?CONSOLE("Rebar3 is a tool for working with Erlang projects.~n", []),
OptSpecList = rebar3:global_option_spec_list(),
getopt:usage(OptSpecList, "rebar3", "", []),
?CONSOLE(" Set the environment variable DEBUG=1 for detailed output.~n", []),
?CONSOLE("Several tasks are available:~n", []),
providers:help(rebar_state:providers(State)),
?CONSOLE("~nRun 'rebar3 help <TASK>' for details.", []).
task_help(Namespace, Name, State) ->
Providers = rebar_state:providers(State),
case providers:get_provider(Name, Providers, Namespace) of
not_found ->
case providers:get_providers_by_namespace(Name, Providers) of
[] ->
{error, io_lib:format("Unknown task ~p", [Name])};
NSProviders ->
providers:help(NSProviders),
{ok, State}
end;
Provider ->
providers:help(Provider),
{ok, State}
end.