1 files changed, 48 insertions, 0 deletions
diff --git a/src/rebar_prv_help.erl b/src/rebar_prv_help.erl
new file mode 100644
index 0000000..a9949e7
--- /dev/null
+++ b/src/rebar_prv_help.erl
@@ -0,0 +1,48 @@
+%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
+%% ex: ts=4 sw=4 et
+
+-module(rebar_prv_help).
+
+-behaviour(rebar_provider).
+
+-export([init/1,
+         do/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, #provider{name = ?PROVIDER,
+                                                       provider_impl = ?MODULE,
+                                                       bare = false,
+                                                       deps = ?DEPS,
+                                                       example = "rebar help <task>",
+                                                       short_desc = "Display a list of tasks or help for a given task or subtask.",
+                                                       desc = "",
+                                                       opts = []}),
+    {ok, State1}.
+
+-spec do(rebar_state:t()) -> {ok, rebar_state:t()} | relx:error().
+do(State) ->
+    help(State),
+    {ok, State}.
+
+%%
+%% print help/usage string
+%%
+help(State) ->
+    ?CONSOLE("Rebar is a tool for working with Erlang projects.~n~n", []),
+    OptSpecList = rebar3:option_spec_list(),
+    getopt:usage(OptSpecList, "rebar", "", []),
+    ?CONSOLE("~nSeveral tasks are available:~n", []),
+
+    rebar_provider:help(State),
+
+    ?CONSOLE("~nRun 'rebar help <TASK>' for details.~n~n", []).