%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(shell).
-export([start/0, start/1, start/2, server/1, server/2, history/1, results/1]).
-export([whereis_evaluator/0, whereis_evaluator/1]).
-export([start_restricted/1, stop_restricted/0]).
-export([local_allowed/3, non_local_allowed/3]).
-export([prompt_func/1]).
-define(LINEMAX, 30).
-define(CHAR_MAX, 60).
-define(DEF_HISTORY, 20).
-define(DEF_RESULTS, 20).
-define(DEF_CATCH_EXCEPTION, false).
-define(DEF_PROMPT_FUNC, default).
-define(RECORDS, shell_records).
-define(MAXSIZE_HEAPBINARY, 64).
%% When used as the fallback restricted shell callback module...
local_allowed(q,[],State) ->
{true,State};
local_allowed(_,_,State) ->
{false,State}.
non_local_allowed({init,stop},[],State) ->
{true,State};
non_local_allowed(_,_,State) ->
{false,State}.
-spec start() -> pid().
start() ->
start(false, false).
start(init) ->
start(false, true);
start(NoCtrlG) ->
start(NoCtrlG, false).
start(NoCtrlG, StartSync) ->
code:ensure_loaded(user_default),
spawn(fun() -> server(NoCtrlG, StartSync) end).
%% Find the pid of the current evaluator process.
-spec whereis_evaluator() -> 'undefined' | pid().
whereis_evaluator() ->
%% locate top group leader, always registered as user
%% can be implemented by group (normally) or user
%% (if oldshell or noshell)
case whereis(user) of
undefined ->
undefined;
User ->
%% get user_drv pid from group, or shell pid from user
case group:interfaces(User) of
[] -> % old- or noshell
case user:interfaces(User) of
[] ->
undefined;
[{shell,Shell}] ->
whereis_evaluator(Shell)
end;
[{user_drv,UserDrv}] ->
%% get current group pid from user_drv
case user_drv:interfaces(UserDrv) of
[] ->
undefined;
[{current_group,Group}] ->
%% get shell pid from group
GrIfs = group:interfaces(Group),
case lists:keyfind(shell, 1, GrIfs) of
{shell, Shell} ->
whereis_evaluator(Shell);
false ->
undefined
end
end
end
end.
-spec whereis_evaluator(pid()) -> 'undefined' | pid().
whereis_evaluator(Shell) ->
case process_info(Shell, dictionary) of
{dictionary,Dict} ->
case lists:keyfind(evaluator, 1, Dict) of
{_, Eval} when is_pid(Eval) ->
Eval;
_ ->
undefined
end;
_ ->
undefined
end.
%% Call this function to start a user restricted shell
%% from a normal shell session.
-spec start_restricted(Module) -> {'error', Reason} when
Module :: module(),
Reason :: code:load_error_rsn().
start_restricted(RShMod) when is_atom(RShMod) ->
case code:ensure_loaded(RShMod) of
{module,RShMod} ->
application:set_env(stdlib, restricted_shell, RShMod),
exit(restricted_shell_started);
{error,What} = Error ->
error_logger:error_report(
lists:flatten(
io_lib:fwrite(
"Restricted shell module ~w not found: ~"++cs_p() ++"\n",
[RShMod,What]))),
Error
end.
-spec stop_restricted() -> no_return().
stop_restricted() ->
application:unset_env(stdlib, restricted_shell),
exit(restricted_shell_stopped).
-spec server(boolean(), boolean()) -> 'terminated'.
server(NoCtrlG, StartSync) ->
put(no_control_g, NoCtrlG),
server(StartSync).
%%% The shell should not start until the system is up and running.
%%% We subscribe with init to get a notification of when.
%%% In older releases we didn't syncronize the shell with init, but let it
%%% start in parallell with other system processes. This was bad since
%%% accessing the shell too early could interfere with the boot procedure.
%%% Still, by means of a flag, we make it possible to start the shell the
%%% old way (for backwards compatibility reasons). This should however not
%%% be used unless for very special reasons necessary.
-spec server(boolean()) -> 'terminated'.
server(StartSync) ->
case init:get_argument(async_shell_start) of
{ok,_} ->
ok; % no sync with init
_ when not StartSync ->
ok;
_ ->
case init:notify_when_started(self()) of
started ->
ok;
_ ->
init:wait_until_started()
end
end,
%% Our spawner has fixed the process groups.
Bs = erl_eval:new_bindings(),
%% Use an Ets table for record definitions. It takes too long to
%% send a huge term to and from the evaluator. Ets makes it
%% possible to have thousands of record definitions.
RT = ets:new(?RECORDS, [public,ordered_set]),
_ = initiate_records(Bs, RT),
process_flag(trap_exit, true),
%% Check if we're in user restricted mode.
RShErr =
case application:get_env(stdlib, restricted_shell) of
{ok,RShMod} ->
io:fwrite(<<"Restricted ">>, []),
case code:ensure_loaded(RShMod) of
{module,RShMod} ->
undefined;
{error,What} ->
{RShMod,What}
end;
undefined ->
undefined
end,
case get(no_control_g) of
true ->
io:fwrite(<<"Eshell V~s\n">>, [erlang:system_info(version)]);
_undefined_or_false ->
io:fwrite(<<"Eshell V~s (abort with ^G)\n">>,
[erlang:system_info(version)])
end,
erase(no_control_g),
case RShErr of
undefined ->
ok;
{RShMod2,What2} ->
io:fwrite(
("Warning! Restricted shell module ~w not found: ~"
++cs_p()++".\n"
"Only the commands q() and init:stop() will be allowed!\n"),
[RShMod2,What2]),
application:set_env(stdlib, restricted_shell, ?MODULE)
end,
{History,Results} = check_and_get_history_and_results(),
server_loop(0, start_eval(Bs, RT, []), Bs, RT, [], History, Results).
server_loop(N0, Eval_0, Bs00, RT, Ds00, History0, Results0) ->
N = N0 + 1,
{Eval_1,Bs0,Ds0,Prompt} = prompt(N, Eval_0, Bs00, RT, Ds00),
{Res,Eval0} = get_command(Prompt, Eval_1, Bs0, RT, Ds0),
case Res of
{ok,Es0} ->
case expand_hist(Es0, N) of
{ok,Es} ->
{V,Eval,Bs,Ds} = shell_cmd(Es, Eval0, Bs0, RT, Ds0, cmd),
{History,Results} = check_and_get_history_and_results(),
add_cmd(N, Es, V),
HB1 = del_cmd(command, N - History, N - History0, false),
HB = del_cmd(result, N - Results, N - Results0, HB1),
%% The following test makes sure that large binaries
%% (outside of the heap) are garbage collected as soon
%% as possible.
if
HB ->
garb(self());
true ->
ok
end,
server_loop(N, Eval, Bs, RT, Ds, History, Results);
{error,E} ->
fwrite_severity(benign, <<"~ts">>, [E]),
server_loop(N0, Eval0, Bs0, RT, Ds0, History0, Results0)
end;
{error,{Line,Mod,What}} ->
fwrite_severity(benign, <<"~w: ~ts">>,
[Line, Mod:format_error(What)]),
server_loop(N0, Eval0, Bs0, RT, Ds0, History0, Results0);
{error,terminated} -> %Io process terminated
exit(Eval0, kill),
terminated;
{error,interrupted} -> %Io process interrupted us
exit(Eval0, kill),
{_,Eval,_,_} = shell_rep(Eval0, Bs0, RT, Ds0),
server_loop(N0, Eval, Bs0, RT, Ds0, History0, Results0);
{error,tokens} -> %Most probably character > 255
fwrite_severity(benign, <<"~w: Invalid tokens.">>,
[N]),
server_loop(N0, Eval0, Bs0, RT, Ds0, History0, Results0);
eof ->
fwrite_severity(fatal, <<"Terminating erlang (~w)">>, [node()]),
halt()
end.
get_command(Prompt, Eval, Bs, RT, Ds) ->
Parse =
fun() ->
exit(
case
io:scan_erl_exprs(group_leader(), Prompt, 1, [unicode])
of
{ok,Toks,_EndPos} ->
erl_parse:parse_exprs(Toks);
{eof,_EndPos} ->
eof;
{error,ErrorInfo,_EndPos} ->
%% Skip the rest of the line:
_ = io:get_line(''),
{error,ErrorInfo};
Else ->
Else
end
)
end,
Pid = spawn_link(Parse),
get_command1(Pid, Eval, Bs, RT, Ds).
get_command1(Pid, Eval, Bs, RT, Ds) ->
receive
{'EXIT', Pid, Res} ->
{Res, Eval};
{'EXIT', Eval, {Reason,Stacktrace}} ->
report_exception(error, {Reason,Stacktrace}, RT),
get_command1(Pid, start_eval(Bs, RT, Ds), Bs, RT, Ds);
{'EXIT', Eval, Reason} ->
report_exception(error, {Reason,[]}, RT),
get_command1(Pid, start_eval(Bs, RT, Ds), Bs, RT, Ds)
end.
prompt(N, Eval0, Bs0, RT, Ds0) ->
case get_prompt_func() of
{M,F} ->
L = [{history,N}],
C = {call,1,{remote,1,{atom,1,M},{atom,1,F}},[{value,1,L}]},
{V,Eval,Bs,Ds} = shell_cmd([C], Eval0, Bs0, RT, Ds0, pmt),
{Eval,Bs,Ds,case V of
{pmt,Val} ->
Val;
_ ->
bad_prompt_func({M,F}),
default_prompt(N)
end};
default ->
{Eval0,Bs0,Ds0,default_prompt(N)}
end.
get_prompt_func() ->
case application:get_env(stdlib, shell_prompt_func) of
{ok,{M,F}=PromptFunc} when is_atom(M), is_atom(F) ->
PromptFunc;
{ok,default=Default} ->
Default;
{ok,Term} ->
bad_prompt_func(Term),
default;
undefined ->
default
end.
bad_prompt_func(M) ->
fwrite_severity(benign, "Bad prompt function: ~"++cs_p(), [M]).
default_prompt(N) ->
%% Don't bother flattening the list irrespective of what the
%% I/O-protocol states.
case is_alive() of
true -> io_lib:format(<<"(~s)~w> ">>, [node(), N]);
false -> io_lib:format(<<"~w> ">>, [N])
end.
%% expand_hist(Expressions, CommandNumber)
%% Preprocess the expression list replacing all history list commands
%% with their expansions.
expand_hist(Es, C) ->
catch {ok,expand_exprs(Es, C)}.
expand_exprs([E|Es], C) ->
[expand_expr(E, C)|expand_exprs(Es, C)];
expand_exprs([], _C) ->
[].
expand_expr({cons,L,H,T}, C) ->
{cons,L,expand_expr(H, C),expand_expr(T, C)};
expand_expr({lc,L,E,Qs}, C) ->
{lc,L,expand_expr(E, C),expand_quals(Qs, C)};
expand_expr({bc,L,E,Qs}, C) ->
{bc,L,expand_expr(E, C),expand_quals(Qs, C)};
expand_expr({tuple,L,Elts}, C) ->
{tuple,L,expand_exprs(Elts, C)};
expand_expr({record_index,L,Name,F}, C) ->
{record_index,L,Name,expand_expr(F, C)};
expand_expr({record,L,Name,Is}, C) ->
{record,L,Name,expand_fields(Is, C)};
expand_expr({record_field,L,R,Name,F}, C) ->
{record_field,L,expand_expr(R, C),Name,expand_expr(F, C)};
expand_expr({record,L,R,Name,Ups}, C) ->
{record,L,expand_expr(R, C),Name,expand_fields(Ups, C)};
expand_expr({record_field,L,R,F}, C) -> %This is really illegal!
{record_field,L,expand_expr(R, C),expand_expr(F, C)};
expand_expr({block,L,Es}, C) ->
{block,L,expand_exprs(Es, C)};
expand_expr({'if',L,Cs}, C) ->
{'if',L,expand_cs(Cs, C)};
expand_expr({'case',L,E,Cs}, C) ->
{'case',L,expand_expr(E, C),expand_cs(Cs, C)};
expand_expr({'try',L,Es,Scs,Ccs,As}, C) ->
{'try',L,expand_exprs(Es, C),expand_cs(Scs, C),
expand_cs(Ccs, C),expand_exprs(As, C)};
expand_expr({'receive',L,Cs}, C) ->
{'receive',L,expand_cs(Cs, C)};
expand_expr({'receive',L,Cs,To,ToEs}, C) ->
{'receive',L,expand_cs(Cs, C), expand_expr(To, C), expand_exprs(ToEs, C)};
expand_expr({call,L,{atom,_,e},[N]}, C) ->
case get_cmd(N, C) of
{undefined,_,_} ->
no_command(N);
{[Ce],_V,_CommandN} ->
Ce;
{Ces,_V,_CommandN} when is_list(Ces) ->
{block,L,Ces}
end;
expand_expr({call,_L,{atom,_,v},[N]}, C) ->
case get_cmd(N, C) of
{_,undefined,_} ->
no_command(N);
{Ces,V,CommandN} when is_list(Ces) ->
{value,CommandN,V}
end;
expand_expr({call,L,F,Args}, C) ->
{call,L,expand_expr(F, C),expand_exprs(Args, C)};
expand_expr({'catch',L,E}, C) ->
{'catch',L,expand_expr(E, C)};
expand_expr({match,L,Lhs,Rhs}, C) ->
{match,L,Lhs,expand_expr(Rhs, C)};
expand_expr({op,L,Op,Arg}, C) ->
{op,L,Op,expand_expr(Arg, C)};
expand_expr({op,L,Op,Larg,Rarg}, C) ->
{op,L,Op,expand_expr(Larg, C),expand_expr(Rarg, C)};
expand_expr({remote,L,M,F}, C) ->
{remote,L,expand_expr(M, C),expand_expr(F, C)};
expand_expr({'fun',L,{clauses,Cs}}, C) ->
{'fun',L,{clauses,expand_exprs(Cs, C)}};
expand_expr({clause,L,H,G,B}, C) ->
%% Could expand H and G, but then erl_eval has to be changed as well.
{clause,L,H, G, expand_exprs(B, C)};
expand_expr({bin,L,Fs}, C) ->
{bin,L,expand_bin_elements(Fs, C)};
expand_expr(E, _C) -> % Constants.
E.
expand_cs([{clause,L,P,G,B}|Cs], C) ->
[{clause,L,P,G,expand_exprs(B, C)}|expand_cs(Cs, C)];
expand_cs([], _C) ->
[].
expand_fields([{record_field,L,F,V}|Fs], C) ->
[{record_field,L,expand_expr(F, C),expand_expr(V, C)}|
expand_fields(Fs, C)];
expand_fields([], _C) -> [].
expand_quals([{generate,L,P,E}|Qs], C) ->
[{generate,L,P,expand_expr(E, C)}|expand_quals(Qs, C)];
expand_quals([{b_generate,L,P,E}|Qs], C) ->
[{b_generate,L,P,expand_expr(E, C)}|expand_quals(Qs, C)];
expand_quals([E|Qs], C) ->
[expand_expr(E, C)|expand_quals(Qs, C)];
expand_quals([], _C) -> [].
expand_bin_elements([], _C) ->
[];
expand_bin_elements([{bin_element,L,E,Sz,Ts}|Fs], C) ->
[{bin_element,L,expand_expr(E, C),Sz,Ts}|expand_bin_elements(Fs, C)].
no_command(N) ->
throw({error,
io_lib:fwrite(<<"~ts: command not found">>,
[erl_pp:expr(N, enc())])}).
%% add_cmd(Number, Expressions, Value)
%% get_cmd(Number, CurrentCommand)
%% del_cmd(Number, NewN, OldN, HasBin0) -> bool()
add_cmd(N, Es, V) ->
put({command,N}, Es),
put({result,N}, V).
getc(N) ->
{get({command,N}), get({result,N}), N}.
get_cmd(Num, C) ->
case catch erl_eval:expr(Num, erl_eval:new_bindings()) of
{value,N,_} when N < 0 -> getc(C+N);
{value,N,_} -> getc(N);
_Other -> {undefined,undefined,undefined}
end.
del_cmd(_Type, N, N0, HasBin) when N < N0 ->
HasBin;
del_cmd(Type, N, N0, HasBin0) ->
T = erase({Type,N}),
HasBin = HasBin0 orelse has_binary(T),
del_cmd(Type, N-1, N0, HasBin).
has_binary(T) ->
try has_bin(T), false
catch true=Thrown -> Thrown
end.
has_bin(T) when is_tuple(T) ->
has_bin(T, tuple_size(T));
has_bin([E | Es]) ->
has_bin(E),
has_bin(Es);
has_bin(B) when byte_size(B) > ?MAXSIZE_HEAPBINARY ->
throw(true);
has_bin(T) ->
T.
has_bin(T, 0) ->
T;
has_bin(T, I) ->
has_bin(element(I, T)),
has_bin(T, I - 1).
%% shell_cmd(Sequence, Evaluator, Bindings, RecordTable, Dictionary, What)
%% shell_rep(Evaluator, Bindings, RecordTable, Dictionary) ->
%% {Value,Evaluator,Bindings,Dictionary}
%% Send a command to the evaluator and wait for the reply. Start a new
%% evaluator if necessary.
%% What = pmt | cmd. When evaluating a prompt ('pmt') the evaluated value
%% must not be displayed, and it has to be returned.
shell_cmd(Es, Eval, Bs, RT, Ds, W) ->
Eval ! {shell_cmd,self(),{eval,Es}, W},
shell_rep(Eval, Bs, RT, Ds).
shell_rep(Ev, Bs0, RT, Ds0) ->
receive
{shell_rep,Ev,{value,V,Bs,Ds}} ->
{V,Ev,Bs,Ds};
{shell_rep,Ev,{command_error,{Line,M,Error}}} ->
fwrite_severity(benign, <<"~w: ~ts">>,
[Line, M:format_error(Error)]),
{{'EXIT',Error},Ev,Bs0,Ds0};
{shell_req,Ev,get_cmd} ->
Ev ! {shell_rep,self(),get()},
shell_rep(Ev, Bs0, RT, Ds0);
{shell_req,Ev,exit} ->
Ev ! {shell_rep,self(),exit},
exit(normal);
{shell_req,Ev,{update_dict,Ds}} -> % Update dictionary
Ev ! {shell_rep,self(),ok},
shell_rep(Ev, Bs0, RT, Ds);
{ev_exit,{Ev,Class,Reason0}} -> % It has exited unnaturally
receive {'EXIT',Ev,normal} -> ok end,
report_exception(Class, Reason0, RT),
Reason = nocatch(Class, Reason0),
{{'EXIT',Reason},start_eval(Bs0, RT, Ds0), Bs0, Ds0};
{ev_caught,{Ev,Class,Reason0}} -> % catch_exception is in effect
report_exception(Class, benign, Reason0, RT),
Reason = nocatch(Class, Reason0),
{{'EXIT',Reason},Ev,Bs0,Ds0};
{'EXIT',_Id,interrupt} -> % Someone interrupted us
exit(Ev, kill),
shell_rep(Ev, Bs0, RT, Ds0);
{'EXIT',Ev,{Reason,Stacktrace}} ->
report_exception(exit, {Reason,Stacktrace}, RT),
{{'EXIT',Reason},start_eval(Bs0, RT, Ds0), Bs0, Ds0};
{'EXIT',Ev,Reason} ->
report_exception(exit, {Reason,[]}, RT),
{{'EXIT',Reason},start_eval(Bs0, RT, Ds0), Bs0, Ds0};
{'EXIT',_Id,R} ->
exit(Ev, R),
exit(R);
_Other -> % Ignore everything else
shell_rep(Ev, Bs0, RT, Ds0)
end.
nocatch(throw, {Term,Stack}) ->
{{nocatch,Term},Stack};
nocatch(error, Reason) ->
Reason;
nocatch(exit, Reason) ->
Reason.
report_exception(Class, Reason, RT) ->
report_exception(Class, serious, Reason, RT).
report_exception(Class, Severity, {Reason,Stacktrace}, RT) ->
Tag = severity_tag(Severity),
I = iolist_size(Tag) + 1,
PF = fun(Term, I1) -> pp(Term, I1, RT) end,
SF = fun(M, _F, _A) -> (M =:= erl_eval) or (M =:= ?MODULE) end,
Enc = encoding(),
Str = lib:format_exception(I, Class, Reason, Stacktrace, SF, PF, Enc),
io:requests([{put_chars, latin1, Tag},
{put_chars, unicode, Str},
nl]).
start_eval(Bs, RT, Ds) ->
Self = self(),
Eval = spawn_link(fun() -> evaluator(Self, Bs, RT, Ds) end),
put(evaluator, Eval),
Eval.
%% evaluator(Shell, Bindings, RecordTable, ProcessDictionary)
%% Evaluate expressions from the shell. Use the "old" variable bindings
%% and dictionary.
evaluator(Shell, Bs, RT, Ds) ->
init_dict(Ds),
case application:get_env(stdlib, restricted_shell) of
undefined ->
eval_loop(Shell, Bs, RT);
{ok,RShMod} ->
case get(restricted_shell_state) of
undefined -> put(restricted_shell_state, []);
_ -> ok
end,
put(restricted_expr_state, []),
restricted_eval_loop(Shell, Bs, RT, RShMod)
end.
eval_loop(Shell, Bs0, RT) ->
receive
{shell_cmd,Shell,{eval,Es},W} ->
Ef = {value,
fun(MForFun, As) -> apply_fun(MForFun, As, Shell) end},
Lf = local_func_handler(Shell, RT, Ef),
Bs = eval_exprs(Es, Shell, Bs0, RT, Lf, Ef, W),
eval_loop(Shell, Bs, RT)
end.
restricted_eval_loop(Shell, Bs0, RT, RShMod) ->
receive
{shell_cmd,Shell,{eval,Es}, W} ->
{LFH,NLFH} = restrict_handlers(RShMod, Shell, RT),
put(restricted_expr_state, []),
Bs = eval_exprs(Es, Shell, Bs0, RT, {eval,LFH}, {value,NLFH}, W),
restricted_eval_loop(Shell, Bs, RT, RShMod)
end.
eval_exprs(Es, Shell, Bs0, RT, Lf, Ef, W) ->
try
{R,Bs2} = exprs(Es, Bs0, RT, Lf, Ef, W),
Shell ! {shell_rep,self(),R},
Bs2
catch
exit:normal ->
exit(normal);
Class:Reason ->
Stacktrace = erlang:get_stacktrace(),
M = {self(),Class,{Reason,Stacktrace}},
case do_catch(Class, Reason) of
true ->
Shell ! {ev_caught,M},
Bs0;
false ->
%% We don't want the ERROR REPORT generated by the
%% emulator. Note: exit(kill) needs nothing special.
{links,LPs} = process_info(self(), links),
ER = nocatch(Class, {Reason,Stacktrace}),
lists:foreach(fun(P) -> exit(P, ER) end, LPs--[Shell]),
Shell ! {ev_exit,M},
exit(normal)
end
end.
do_catch(exit, restricted_shell_stopped) ->
false;
do_catch(exit, restricted_shell_started) ->
false;
do_catch(_Class, _Reason) ->
case application:get_env(stdlib, shell_catch_exception) of
{ok, true} ->
true;
_ ->
false
end.
exprs(Es, Bs0, RT, Lf, Ef, W) ->
exprs(Es, Bs0, RT, Lf, Ef, Bs0, W).
exprs([E0|Es], Bs1, RT, Lf, Ef, Bs0, W) ->
UsedRecords = used_record_defs(E0, RT),
RBs = record_bindings(UsedRecords, Bs1),
case check_command(prep_check([E0]), RBs) of
ok ->
E1 = expand_records(UsedRecords, E0),
{value,V0,Bs2} = expr(E1, Bs1, Lf, Ef),
Bs = orddict:from_list([VV || {X,_}=VV <- erl_eval:bindings(Bs2),
not is_expand_variable(X)]),
if
Es =:= [] ->
VS = pp(V0, 1, RT),
[io:requests([{put_chars, unicode, VS}, nl]) ||
W =:= cmd],
%% Don't send the result back if it will be
%% discarded anyway.
V = if
W =:= pmt ->
{W,V0};
true -> case result_will_be_saved() of
true -> V0;
false -> ignored
end
end,
{{value,V,Bs,get()},Bs};
true ->
exprs(Es, Bs, RT, Lf, Ef, Bs0, W)
end;
{error,Error} ->
{{command_error,Error},Bs0}
end.
is_expand_variable(V) ->
case catch atom_to_list(V) of
"rec" ++ _Integer -> true;
_ -> false
end.
result_will_be_saved() ->
case get_history_and_results() of
{_, 0} -> false;
_ -> true
end.
used_record_defs(E, RT) ->
%% Be careful to return a list where used records come before
%% records that use them. The linter wants them ordered that way.
UR = case used_records(E, [], RT) of
[] ->
[];
L0 ->
L1 = lists:zip(L0, lists:seq(1, length(L0))),
L2 = lists:keysort(2, lists:ukeysort(1, L1)),
[R || {R, _} <- L2]
end,
record_defs(RT, UR).
used_records(E, U0, RT) ->
case used_records(E) of
{name,Name,E1} ->
U = used_records(ets:lookup(RT, Name), [Name | U0], RT),
used_records(E1, U, RT);
{expr,[E1 | Es]} ->
used_records(Es, used_records(E1, U0, RT), RT);
_ ->
U0
end.
used_records({record_index,_,Name,F}) ->
{name, Name, F};
used_records({record,_,Name,Is}) ->
{name, Name, Is};
used_records({record_field,_,R,Name,F}) ->
{name, Name, [R | F]};
used_records({record,_,R,Name,Ups}) ->
{name, Name, [R | Ups]};
used_records({record_field,_,R,F}) -> % illegal
{expr, [R | F]};
used_records({call,_,{atom,_,record},[A,{atom,_,Name}]}) ->
{name, Name, A};
used_records({call,_,{atom,_,is_record},[A,{atom,_,Name}]}) ->
{name, Name, A};
used_records({call,_,{remote,_,{atom,_,erlang},{atom,_,is_record}},
[A,{atom,_,Name}]}) ->
{name, Name, A};
used_records({call,_,{atom,_,record_info},[A,{atom,_,Name}]}) ->
{name, Name, A};
used_records({call,Line,{tuple,_,[M,F]},As}) ->
used_records({call,Line,{remote,Line,M,F},As});
used_records(T) when is_tuple(T) ->
{expr, tuple_to_list(T)};
used_records(E) ->
{expr, E}.
fwrite_severity(Severity, S, As) ->
io:fwrite(<<"~ts\n">>, [format_severity(Severity, S, As)]).
format_severity(Severity, S, As) ->
add_severity(Severity, io_lib:fwrite(S, As)).
add_severity(Severity, S) ->
[severity_tag(Severity), S].
severity_tag(fatal) -> <<"*** ">>;
severity_tag(serious) -> <<"** ">>;
severity_tag(benign) -> <<"* ">>.
restrict_handlers(RShMod, Shell, RT) ->
{ fun(F,As,Binds) ->
local_allowed(F, As, RShMod, Binds, Shell, RT)
end,
fun(MF,As) ->
non_local_allowed(MF, As, RShMod, Shell)
end }.
-define(BAD_RETURN(M, F, V),
try erlang:error(reason)
catch _:_ -> erlang:raise(exit, {restricted_shell_bad_return,V},
[{M,F,3} | erlang:get_stacktrace()])
end).
local_allowed(F, As, RShMod, Bs, Shell, RT) when is_atom(F) ->
{LFH,NLFH} = restrict_handlers(RShMod, Shell, RT),
case not_restricted(F, As) of % Not restricted is the same as builtin.
% variable and record manipulations local
% to the shell process. Those are never
% restricted.
true ->
local_func(F, As, Bs, Shell, RT, {eval,LFH}, {value,NLFH});
false ->
{AsEv,Bs1} = expr_list(As, Bs, {eval,LFH}, {value,NLFH}),
case RShMod:local_allowed(F, AsEv, {get(restricted_shell_state),
get(restricted_expr_state)}) of
{Result,{RShShSt,RShExprSt}} ->
put(restricted_shell_state, RShShSt),
put(restricted_expr_state, RShExprSt),
if not Result ->
shell_req(Shell, {update_dict,get()}),
exit({restricted_shell_disallowed,{F,AsEv}});
true -> % This is never a builtin,
% those are handled above.
non_builtin_local_func(F,AsEv,Bs1)
end;
Unexpected -> % The user supplied non conforming module
?BAD_RETURN(RShMod, local_allowed, Unexpected)
end
end.
non_local_allowed(MForFun, As, RShMod, Shell) ->
case RShMod:non_local_allowed(MForFun, As, {get(restricted_shell_state),
get(restricted_expr_state)}) of
{Result,{RShShSt,RShExprSt}} ->
put(restricted_shell_state, RShShSt),
put(restricted_expr_state, RShExprSt),
case Result of
false ->
shell_req(Shell, {update_dict,get()}),
exit({restricted_shell_disallowed,{MForFun,As}});
{redirect, NewMForFun, NewAs} ->
apply_fun(NewMForFun, NewAs, Shell);
_ ->
apply_fun(MForFun, As, Shell)
end;
Unexpected -> % The user supplied non conforming module
?BAD_RETURN(RShMod, non_local_allowed, Unexpected)
end.
%% The commands implemented in shell should not be checked if allowed
%% This *has* to correspond to the function local_func/7!
%% (especially true for f/1, the argument must not be evaluated).
not_restricted(f, []) ->
true;
not_restricted(f, [_]) ->
true;
not_restricted(h, []) ->
true;
not_restricted(b, []) ->
true;
not_restricted(history, [_]) ->
true;
not_restricted(results, [_]) ->
true;
not_restricted(catch_exception, [_]) ->
true;
not_restricted(exit, []) ->
true;
not_restricted(rd, [_,_]) ->
true;
not_restricted(rf, []) ->
true;
not_restricted(rf, [_]) ->
true;
not_restricted(rl, []) ->
true;
not_restricted(rl, [_]) ->
true;
not_restricted(rp, [_]) ->
true;
not_restricted(rr, [_]) ->
true;
not_restricted(rr, [_,_]) ->
true;
not_restricted(rr, [_,_,_]) ->
true;
not_restricted(_, _) ->
false.
%% When erlang:garbage_collect() is called from the shell,
%% the shell process process that spawned the evaluating
%% process is garbage collected as well.
%% To garbage collect the evaluating process only the command
%% garbage_collect(self()). can be used.
apply_fun({erlang,garbage_collect}, [], Shell) ->
garb(Shell);
apply_fun({M,F}, As, _Shell) ->
apply(M, F, As);
apply_fun(MForFun, As, _Shell) ->
apply(MForFun, As).
prep_check({call,Line,{atom,_,f},[{var,_,_Name}]}) ->
%% Do not emit a warning for f(V) when V is unbound.
{atom,Line,ok};
prep_check({value,_CommandN,_Val}) ->
%% erl_lint cannot handle the history expansion {value,_,_}.
{atom,0,ok};
prep_check(T) when is_tuple(T) ->
list_to_tuple(prep_check(tuple_to_list(T)));
prep_check([E | Es]) ->
[prep_check(E) | prep_check(Es)];
prep_check(E) ->
E.
expand_records([], E0) ->
E0;
expand_records(UsedRecords, E0) ->
RecordDefs = [Def || {_Name,Def} <- UsedRecords],
L = 1,
E = prep_rec(E0),
Forms = RecordDefs ++ [{function,L,foo,0,[{clause,L,[],[],[E]}]}],
[{function,L,foo,0,[{clause,L,[],[],[NE]}]}] =
erl_expand_records:module(Forms, [strict_record_tests]),
prep_rec(NE).
prep_rec({value,_CommandN,_V}=Value) ->
%% erl_expand_records cannot handle the history expansion {value,_,_}.
{atom,Value,ok};
prep_rec({atom,{value,_CommandN,_V}=Value,ok}) ->
%% Undo the effect of the previous clause...
Value;
prep_rec(T) when is_tuple(T) -> list_to_tuple(prep_rec(tuple_to_list(T)));
prep_rec([E | Es]) -> [prep_rec(E) | prep_rec(Es)];
prep_rec(E) -> E.
init_dict([{K,V}|Ds]) ->
put(K, V),
init_dict(Ds);
init_dict([]) -> true.
%% local_func(Function, Args, Bindings, Shell, RecordTable,
%% LocalFuncHandler, ExternalFuncHandler) -> {value,Val,Bs}
%% Evaluate local functions, including shell commands.
%%
%% Note that the predicate not_restricted/2 has to correspond to what's
%% handled internally - it should return 'true' for all local functions
%% handled in this module (i.e. those that are not eventually handled by
%% non_builtin_local_func/3 (user_default/shell_default).
local_func(h, [], Bs, Shell, RT, _Lf, _Ef) ->
Cs = shell_req(Shell, get_cmd),
Cs1 = lists:filter(fun({{command, _},_}) -> true;
({{result, _},_}) -> true;
(_) -> false
end,
Cs),
Cs2 = lists:map(fun({{T, N}, V}) -> {{N, T}, V} end,
Cs1),
Cs3 = lists:keysort(1, Cs2),
{value,list_commands(Cs3, RT),Bs};
local_func(b, [], Bs, _Shell, RT, _Lf, _Ef) ->
{value,list_bindings(erl_eval:bindings(Bs), RT),Bs};
local_func(f, [], _Bs, _Shell, _RT, _Lf, _Ef) ->
{value,ok,erl_eval:new_bindings()};
local_func(f, [{var,_,Name}], Bs, _Shell, _RT, _Lf, _Ef) ->
{value,ok,erl_eval:del_binding(Name, Bs)};
local_func(f, [_Other], _Bs, _Shell, _RT, _Lf, _Ef) ->
erlang:raise(error, function_clause, [{shell,f,1}]);
local_func(rd, [{atom,_,RecName},RecDef0], Bs, _Shell, RT, _Lf, _Ef) ->
RecDef = expand_value(RecDef0),
RDs = lists:flatten(erl_pp:expr(RecDef)),
Attr = lists:concat(["-record('", RecName, "',", RDs, ")."]),
{ok, Tokens, _} = erl_scan:string(Attr, 1, [unicode]),
case erl_parse:parse_form(Tokens) of
{ok,AttrForm} ->
[RN] = add_records([AttrForm], Bs, RT),
{value,RN,Bs};
{error,{_Line,M,ErrDesc}} ->
ErrStr = io_lib:fwrite(<<"~ts">>, [M:format_error(ErrDesc)]),
exit(lists:flatten(ErrStr))
end;
local_func(rd, [_,_], _Bs, _Shell, _RT, _Lf, _Ef) ->
erlang:raise(error, function_clause, [{shell,rd,2}]);
local_func(rf, [], Bs, _Shell, RT, _Lf, _Ef) ->
true = ets:delete_all_objects(RT),
{value,initiate_records(Bs, RT),Bs};
local_func(rf, [A], Bs0, _Shell, RT, Lf, Ef) ->
{[Recs],Bs} = expr_list([A], Bs0, Lf, Ef),
if '_' =:= Recs ->
true = ets:delete_all_objects(RT);
true ->
lists:foreach(fun(Name) -> true = ets:delete(RT, Name)
end, listify(Recs))
end,
{value,ok,Bs};
local_func(rl, [], Bs, _Shell, RT, _Lf, _Ef) ->
{value,list_records(ets:tab2list(RT)),Bs};
local_func(rl, [A], Bs0, _Shell, RT, Lf, Ef) ->
{[Recs],Bs} = expr_list([A], Bs0, Lf, Ef),
{value,list_records(record_defs(RT, listify(Recs))),Bs};
local_func(rp, [A], Bs0, _Shell, RT, Lf, Ef) ->
{[V],Bs} = expr_list([A], Bs0, Lf, Ef),
Cs = io_lib_pretty:print(V, ([{column, 1},
{line_length, columns()},
{depth, -1},
{max_chars, ?CHAR_MAX},
{record_print_fun, record_print_fun(RT)}]
++ enc())),
io:requests([{put_chars, unicode, Cs}, nl]),
{value,ok,Bs};
local_func(rr, [A], Bs0, _Shell, RT, Lf, Ef) ->
{[File],Bs} = expr_list([A], Bs0, Lf, Ef),
{value,read_and_add_records(File, '_', [], Bs, RT),Bs};
local_func(rr, [_,_]=As0, Bs0, _Shell, RT, Lf, Ef) ->
{[File,Sel],Bs} = expr_list(As0, Bs0, Lf, Ef),
{value,read_and_add_records(File, Sel, [], Bs, RT),Bs};
local_func(rr, [_,_,_]=As0, Bs0, _Shell, RT, Lf, Ef) ->
{[File,Sel,Options],Bs} = expr_list(As0, Bs0, Lf, Ef),
{value,read_and_add_records(File, Sel, Options, Bs, RT),Bs};
local_func(history, [{integer,_,N}], Bs, _Shell, _RT, _Lf, _Ef) ->
{value,history(N),Bs};
local_func(history, [_Other], _Bs, _Shell, _RT, _Lf, _Ef) ->
erlang:raise(error, function_clause, [{shell,history,1}]);
local_func(results, [{integer,_,N}], Bs, _Shell, _RT, _Lf, _Ef) ->
{value,results(N),Bs};
local_func(results, [_Other], _Bs, _Shell, _RT, _Lf, _Ef) ->
erlang:raise(error, function_clause, [{shell,results,1}]);
local_func(catch_exception, [{atom,_,Bool}], Bs, _Shell, _RT, _Lf, _Ef)
when Bool; not Bool ->
{value,catch_exception(Bool),Bs};
local_func(catch_exception, [_Other], _Bs, _Shell, _RT, _Lf, _Ef) ->
erlang:raise(error, function_clause, [{shell,catch_exception,1}]);
local_func(exit, [], _Bs, Shell, _RT, _Lf, _Ef) ->
shell_req(Shell, exit), %This terminates us
exit(normal);
local_func(F, As0, Bs0, _Shell, _RT, Lf, Ef) when is_atom(F) ->
{As,Bs} = expr_list(As0, Bs0, Lf, Ef),
non_builtin_local_func(F,As,Bs).
non_builtin_local_func(F,As,Bs) ->
Arity = length(As),
case erlang:function_exported(user_default, F, Arity) of
true ->
{eval,erlang:make_fun(user_default, F, Arity),As,Bs};
false ->
shell_default(F,As,Bs)
end.
shell_default(F,As,Bs) ->
M = shell_default,
A = length(As),
case code:ensure_loaded(M) of
{module, _} ->
case erlang:function_exported(M,F,A) of
true ->
{eval,erlang:make_fun(M, F, A),As,Bs};
false ->
shell_undef(F,A)
end;
{error, _} ->
shell_undef(F,A)
end.
shell_undef(F,A) ->
erlang:error({shell_undef,F,A,[]}).
local_func_handler(Shell, RT, Ef) ->
H = fun(Lf) ->
fun(F, As, Bs) ->
local_func(F, As, Bs, Shell, RT, {eval,Lf(Lf)}, Ef)
end
end,
{eval,H(H)}.
record_print_fun(RT) ->
fun(Tag, NoFields) ->
case ets:lookup(RT, Tag) of
[{_,{attribute,_,record,{Tag,Fields}}}]
when length(Fields) =:= NoFields ->
record_fields(Fields);
_ ->
no
end
end.
record_fields([{record_field,_,{atom,_,Field}} | Fs]) ->
[Field | record_fields(Fs)];
record_fields([{record_field,_,{atom,_,Field},_} | Fs]) ->
[Field | record_fields(Fs)];
record_fields([]) ->
[].
initiate_records(Bs, RT) ->
RNs1 = init_rec(shell_default, Bs, RT),
RNs2 = case code:is_loaded(user_default) of
{file,_File} ->
init_rec(user_default, Bs, RT);
false ->
[]
end,
lists:usort(RNs1 ++ RNs2).
init_rec(Module, Bs, RT) ->
case read_records(Module, []) of
RAs when is_list(RAs) ->
case catch add_records(RAs, Bs, RT) of
{'EXIT',_} ->
[];
RNs ->
RNs
end;
_Error ->
[]
end.
read_and_add_records(File, Selected, Options, Bs, RT) ->
case read_records(File, Selected, Options) of
RAs when is_list(RAs) ->
add_records(RAs, Bs, RT);
Error ->
Error
end.
read_records(File, Selected, Options) ->
case read_records(File, listify(Options)) of
Error when is_tuple(Error) ->
Error;
RAs when Selected =:= '_' ->
RAs;
RAs ->
Sel = listify(Selected),
[RA || {attribute,_,_,{Name,_}}=RA <- RAs,
lists:member(Name, Sel)]
end.
add_records(RAs, Bs0, RT) ->
Recs = [{Name,D} || {attribute,_,_,{Name,_}}=D <- RAs],
Bs1 = record_bindings(Recs, Bs0),
case check_command([], Bs1) of
{error,{_Line,M,ErrDesc}} ->
%% A source file that has not been compiled.
ErrStr = io_lib:fwrite(<<"~ts">>, [M:format_error(ErrDesc)]),
exit(lists:flatten(ErrStr));
ok ->
true = ets:insert(RT, Recs),
lists:usort([Name || {Name,_} <- Recs])
end.
listify(L) when is_list(L) ->
L;
listify(E) ->
[E].
check_command(Es, Bs) ->
erl_eval:check_command(Es, Bs).
expr(E, Bs, Lf, Ef) ->
erl_eval:expr(E, Bs, Lf, Ef).
expr_list(Es, Bs, Lf, Ef) ->
erl_eval:expr_list(Es, Bs, Lf, Ef).
%% Note that a sequence number is used here to make sure that if a
%% record is used by another record, then the first record is parsed
%% before the second record. (erl_eval:check_command() calls the
%% linter which needs the records in a proper order.)
record_bindings([], Bs) ->
Bs;
record_bindings(Recs0, Bs0) ->
{Recs1, _} = lists:mapfoldl(fun ({Name,Def}, I) -> {{Name,I,Def},I+1}
end, 0, Recs0),
Recs2 = lists:keysort(2, lists:ukeysort(1, Recs1)),
lists:foldl(fun ({Name,I,Def}, Bs) ->
erl_eval:add_binding({record,I,Name}, Def, Bs)
end, Bs0, Recs2).
%%% Read record information from file(s)
read_records(FileOrModule, Opts0) ->
Opts = lists:delete(report_warnings, Opts0),
case find_file(FileOrModule) of
{files,[File]} ->
read_file_records(File, Opts);
{files,Files} ->
lists:flatmap(fun(File) ->
case read_file_records(File, Opts) of
RAs when is_list(RAs) -> RAs;
_ -> []
end
end, Files);
Error ->
Error
end.
-include_lib("kernel/include/file.hrl").
find_file(Mod) when is_atom(Mod) ->
case code:which(Mod) of
File when is_list(File) ->
{files,[File]};
preloaded ->
{_M,_Bin,File} = code:get_object_code(Mod),
{files,[File]};
_Else -> % non_existing, interpreted, cover_compiled
{error,nofile}
end;
find_file(File) ->
case catch filelib:wildcard(File) of
{'EXIT',_} ->
{error,invalid_filename};
Files ->
{files,Files}
end.
read_file_records(File, Opts) ->
case filename:extension(File) of
".beam" ->
case beam_lib:chunks(File, [abstract_code,"CInf"]) of
{ok,{_Mod,[{abstract_code,{Version,Forms}},{"CInf",CB}]}} ->
case record_attrs(Forms) of
[] when Version =:= raw_abstract_v1 ->
[];
[] ->
%% If the version is raw_X, then this test
%% is unnecessary.
try_source(File, CB);
Records ->
Records
end;
{ok,{_Mod,[{abstract_code,no_abstract_code},{"CInf",CB}]}} ->
try_source(File, CB);
Error ->
%% Could be that the "Abst" chunk is missing (pre R6).
Error
end;
_ ->
parse_file(File, Opts)
end.
%% This is how the debugger searches for source files. See int.erl.
try_source(Beam, CB) ->
Os = case lists:keyfind(options, 1, binary_to_term(CB)) of
false -> [];
{_, Os0} -> Os0
end,
Src0 = filename:rootname(Beam) ++ ".erl",
case is_file(Src0) of
true -> parse_file(Src0, Os);
false ->
EbinDir = filename:dirname(Beam),
Src = filename:join([filename:dirname(EbinDir), "src",
filename:basename(Src0)]),
case is_file(Src) of
true -> parse_file(Src, Os);
false -> {error, nofile}
end
end.
is_file(Name) ->
case filelib:is_file(Name) of
true ->
not filelib:is_dir(Name);
false ->
false
end.
parse_file(File, Opts) ->
Cwd = ".",
Dir = filename:dirname(File),
IncludePath = [Cwd,Dir|inc_paths(Opts)],
case epp:parse_file(File, IncludePath, pre_defs(Opts)) of
{ok,Forms} ->
record_attrs(Forms);
Error ->
Error
end.
pre_defs([{d,M,V}|Opts]) ->
[{M,V}|pre_defs(Opts)];
pre_defs([{d,M}|Opts]) ->
[M|pre_defs(Opts)];
pre_defs([_|Opts]) ->
pre_defs(Opts);
pre_defs([]) -> [].
inc_paths(Opts) ->
[P || {i,P} <- Opts, is_list(P)].
record_attrs(Forms) ->
[A || A = {attribute,_,record,_D} <- Forms].
%%% End of reading record information from file(s)
shell_req(Shell, Req) ->
Shell ! {shell_req,self(),Req},
receive
{shell_rep,Shell,Rep} -> Rep
end.
list_commands([{{N,command},Es0}, {{N,result}, V} |Ds], RT) ->
Es = prep_list_commands(Es0),
VS = pp(V, 4, RT),
Ns = io_lib:fwrite(<<"~w: ">>, [N]),
I = iolist_size(Ns),
io:requests([{put_chars, latin1, Ns},
{format,<<"~ts\n">>,[erl_pp:exprs(Es, I, enc())]},
{format,<<"-> ">>,[]},
{put_chars, unicode, VS},
nl]),
list_commands(Ds, RT);
list_commands([{{N,command},Es0} |Ds], RT) ->
Es = prep_list_commands(Es0),
Ns = io_lib:fwrite(<<"~w: ">>, [N]),
I = iolist_size(Ns),
io:requests([{put_chars, latin1, Ns},
{format,<<"~ts\n">>,[erl_pp:exprs(Es, I, enc())]}]),
list_commands(Ds, RT);
list_commands([_D|Ds], RT) ->
list_commands(Ds, RT);
list_commands([], _RT) -> ok.
list_bindings([{Name,Val}|Bs], RT) ->
case erl_eval:fun_data(Val) of
{fun_data,_FBs,FCs0} ->
FCs = expand_value(FCs0), % looks nicer
F = {'fun',0,{clauses,FCs}},
M = {match,0,{var,0,Name},F},
io:fwrite(<<"~ts\n">>, [erl_pp:expr(M, enc())]);
false ->
Namel = io_lib:fwrite(<<"~s = ">>, [Name]),
Nl = iolist_size(Namel)+1,
ValS = pp(Val, Nl, RT),
io:requests([{put_chars, latin1, Namel},
{put_chars, unicode, ValS},
nl])
end,
list_bindings(Bs, RT);
list_bindings([], _RT) ->
ok.
list_records(Records) ->
lists:foreach(fun({_Name,Attr}) ->
io:fwrite(<<"~ts">>, [erl_pp:attribute(Attr, enc())])
end, Records).
record_defs(RT, Names) ->
lists:flatmap(fun(Name) -> ets:lookup(RT, Name)
end, Names).
expand_value(E) ->
substitute_v1(fun({value,CommandN,V}) -> try_abstract(V, CommandN)
end, E).
%% There is no abstract representation of funs.
try_abstract(V, CommandN) ->
try erl_parse:abstract(V)
catch _:_ -> {call,0,{atom,0,v},[{integer,0,CommandN}]}
end.
%% Rather than listing possibly huge results the calls to v/1 are shown.
prep_list_commands(E) ->
substitute_v1(fun({value,CommandN,_V}) ->
{call,0,{atom,0,v},[{integer,0,CommandN}]}
end, E).
substitute_v1(F, {value,_,_}=Value) ->
F(Value);
substitute_v1(F, T) when is_tuple(T) ->
list_to_tuple(substitute_v1(F, tuple_to_list(T)));
substitute_v1(F, [E | Es]) ->
[substitute_v1(F, E) | substitute_v1(F, Es)];
substitute_v1(_F, E) ->
E.
check_and_get_history_and_results() ->
check_env(shell_history_length),
check_env(shell_saved_results),
get_history_and_results().
get_history_and_results() ->
History = get_env(shell_history_length, ?DEF_HISTORY),
Results = get_env(shell_saved_results, ?DEF_RESULTS),
{History, erlang:min(Results, History)}.
pp(V, I, RT) ->
pp(V, I, RT, enc()).
pp(V, I, RT, Enc) ->
io_lib_pretty:print(V, ([{column, I}, {line_length, columns()},
{depth, ?LINEMAX}, {max_chars, ?CHAR_MAX},
{record_print_fun, record_print_fun(RT)}]
++ Enc)).
%% Control sequence 'p' possibly with Unicode translation modifier
cs_p() ->
case encoding() of
latin1 -> "p";
unicode -> "tp"
end.
columns() ->
case io:columns() of
{ok,N} -> N;
_ -> 80
end.
encoding() ->
[{encoding, Encoding}] = enc(),
Encoding.
enc() ->
case lists:keyfind(encoding, 1, io:getopts()) of
false -> [{encoding,latin1}]; % should never happen
Enc -> [Enc]
end.
garb(Shell) ->
erlang:garbage_collect(Shell),
catch erlang:garbage_collect(whereis(user)),
catch erlang:garbage_collect(whereis(group)),
catch erlang:garbage_collect(group_leader()),
erlang:garbage_collect().
get_env(V, Def) ->
case application:get_env(stdlib, V) of
{ok, Val} when is_integer(Val), Val >= 0 ->
Val;
_ ->
Def
end.
check_env(V) ->
case application:get_env(stdlib, V) of
undefined ->
ok;
{ok, Val} when is_integer(Val), Val >= 0 ->
ok;
{ok, Val} ->
Txt = io_lib:fwrite(
("Invalid value of STDLIB configuration parameter ~w: ~"
++cs_p()++"\n"),
[V, Val]),
error_logger:info_report(lists:flatten(Txt))
end.
set_env(App, Name, Val, Default) ->
Prev = case application:get_env(App, Name) of
undefined ->
Default;
{ok, Old} ->
Old
end,
application_controller:set_env(App, Name, Val),
Prev.
-spec history(N) -> non_neg_integer() when
N :: non_neg_integer().
history(L) when is_integer(L), L >= 0 ->
set_env(stdlib, shell_history_length, L, ?DEF_HISTORY).
-spec results(N) -> non_neg_integer() when
N :: non_neg_integer().
results(L) when is_integer(L), L >= 0 ->
set_env(stdlib, shell_saved_results, L, ?DEF_RESULTS).
-spec catch_exception(Bool) -> Bool when
Bool :: boolean().
catch_exception(Bool) ->
set_env(stdlib, shell_catch_exception, Bool, ?DEF_CATCH_EXCEPTION).
-spec prompt_func(PromptFunc) -> PromptFunc when
PromptFunc :: 'default' | {module(),atom()}.
prompt_func(String) ->
set_env(stdlib, shell_prompt_func, String, ?DEF_PROMPT_FUNC).
