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Diffstat (limited to 'src/rebar_prv_shell.erl')
-rw-r--r-- | src/rebar_prv_shell.erl | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/src/rebar_prv_shell.erl b/src/rebar_prv_shell.erl new file mode 100644 index 0000000..ef53518 --- /dev/null +++ b/src/rebar_prv_shell.erl @@ -0,0 +1,118 @@ +%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*- +%% ex: ts=4 sw=4 et +%% ------------------------------------------------------------------- +%% +%% rebar: Erlang Build Tools +%% +%% Copyright (c) 2011 Trifork +%% +%% 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. +%% ------------------------------------------------------------------- + +-module(rebar_prv_shell). +-author("Kresten Krab Thorup <krab@trifork.com>"). + +-behaviour(rebar_provider). + +-export([init/1, + do/1]). + +-include("rebar.hrl"). + +-define(PROVIDER, shell). +-define(DEPS, [compile]). + +%% =================================================================== +%% 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 shell", + short_desc = "", + desc = "", + opts = []}), + {ok, State1}. + +-spec do(rebar_state:t()) -> {ok, rebar_state:t()} | relx:error(). +do(Config) -> + shell(), + {ok, Config}. + +%% NOTE: +%% this is an attempt to replicate `erl -pa ./ebin -pa deps/*/ebin`. it is +%% mostly successful but does stop and then restart the user io system to get +%% around issues with rebar being an escript and starting in `noshell` mode. +%% it also lacks the ctrl-c interrupt handler that `erl` features. ctrl-c will +%% immediately kill the script. ctrl-g, however, works fine + +shell() -> + true = code:add_pathz(rebar_utils:ebin_dir()), + %% scan all processes for any with references to the old user and save them to + %% update later + NeedsUpdate = [Pid || Pid <- erlang:processes(), + proplists:get_value(group_leader, erlang:process_info(Pid)) == whereis(user) + ], + %% terminate the current user + ok = supervisor:terminate_child(kernel_sup, user), + %% start a new shell (this also starts a new user under the correct group) + _ = user_drv:start(), + %% wait until user_drv and user have been registered (max 3 seconds) + ok = wait_until_user_started(3000), + %% set any process that had a reference to the old user's group leader to the + %% new user process + _ = [erlang:group_leader(whereis(user), Pid) || Pid <- NeedsUpdate], + %% enable error_logger's tty output + ok = error_logger:swap_handler(tty), + %% disable the simple error_logger (which may have been added multiple + %% times). removes at most the error_logger added by init and the + %% error_logger added by the tty handler + ok = remove_error_handler(3), + %% this call never returns (until user quits shell) + timer:sleep(infinity). + +info(help, shell) -> + ?CONSOLE( + "Start a shell with project and deps preloaded similar to~n" + "'erl -pa ebin -pa deps/*/ebin'.~n", + [] + ). + +remove_error_handler(0) -> + ?WARN("Unable to remove simple error_logger handler~n", []); +remove_error_handler(N) -> + case gen_event:delete_handler(error_logger, error_logger, []) of + {error, module_not_found} -> ok; + {error_logger, _} -> remove_error_handler(N-1) + end. + +%% Timeout is a period to wait before giving up +wait_until_user_started(0) -> + ?ABORT("Timeout exceeded waiting for `user` to register itself~n", []), + erlang:error(timeout); +wait_until_user_started(Timeout) -> + case whereis(user) of + %% if user is not yet registered wait a tenth of a second and try again + undefined -> timer:sleep(100), wait_until_user_started(Timeout - 100); + _ -> ok + end. |