1%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*- 2%% ex: ts=4 sw=4 et 3%% ------------------------------------------------------------------- 4%% 5%% rebar: Erlang Build Tools 6%% 7%% Copyright (c) 2011 Trifork 8%% 9%% Permission is hereby granted, free of charge, to any person obtaining a copy 10%% of this software and associated documentation files (the "Software"), to deal 11%% in the Software without restriction, including without limitation the rights 12%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 13%% copies of the Software, and to permit persons to whom the Software is 14%% furnished to do so, subject to the following conditions: 15%% 16%% The above copyright notice and this permission notice shall be included in 17%% all copies or substantial portions of the Software. 18%% 19%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 20%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 21%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 22%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 23%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 24%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 25%% THE SOFTWARE. 26%% ------------------------------------------------------------------- 27 28-module(rebar_shell). 29-author("Kresten Krab Thorup <krab@trifork.com>"). 30 31-include("rebar.hrl"). 32 33-export([shell/2, info/2]). 34 35%% NOTE: 36%% this is an attempt to replicate `erl -pa ./ebin -pa deps/*/ebin`. it is 37%% mostly successful but does stop and then restart the user io system to get 38%% around issues with rebar being an escript and starting in `noshell` mode. 39%% it also lacks the ctrl-c interrupt handler that `erl` features. ctrl-c will 40%% immediately kill the script. ctrl-g, however, works fine 41 42shell(_Config, _AppFile) -> 43 true = code:add_pathz(rebar_utils:ebin_dir()), 44 %% scan all processes for any with references to the old user and save them to 45 %% update later 46 NeedsUpdate = [Pid || Pid <- erlang:processes(), 47 proplists:get_value(group_leader, erlang:process_info(Pid)) == whereis(user) 48 ], 49 %% terminate the current user 50 ok = supervisor:terminate_child(kernel_sup, user), 51 %% start a new shell (this also starts a new user under the correct group) 52 _ = user_drv:start(), 53 %% wait until user_drv and user have been registered (max 3 seconds) 54 ok = wait_until_user_started(3000), 55 %% set any process that had a reference to the old user's group leader to the 56 %% new user process 57 _ = [erlang:group_leader(whereis(user), Pid) || Pid <- NeedsUpdate], 58 %% enable error_logger's tty output 59 ok = error_logger:swap_handler(tty), 60 %% disable the simple error_logger (which may have been added multiple 61 %% times). removes at most the error_logger added by init and the 62 %% error_logger added by the tty handler 63 ok = remove_error_handler(3), 64 %% this call never returns (until user quits shell) 65 timer:sleep(infinity). 66 67info(help, shell) -> 68 ?CONSOLE( 69 "Start a shell with project and deps preloaded similar to~n" 70 "'erl -pa ebin -pa deps/*/ebin'.~n", 71 [] 72 ). 73 74remove_error_handler(0) -> 75 ?WARN("Unable to remove simple error_logger handler~n", []); 76remove_error_handler(N) -> 77 case gen_event:delete_handler(error_logger, error_logger, []) of 78 {error, module_not_found} -> ok; 79 {error_logger, _} -> remove_error_handler(N-1) 80 end. 81 82%% Timeout is a period to wait before giving up 83wait_until_user_started(0) -> 84 ?ABORT("Timeout exceeded waiting for `user` to register itself~n", []), 85 erlang:error(timeout); 86wait_until_user_started(Timeout) -> 87 case whereis(user) of 88 %% if user is not yet registered wait a tenth of a second and try again 89 undefined -> timer:sleep(100), wait_until_user_started(Timeout - 100); 90 _ -> ok 91 end.