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shell.erl
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shell.erl
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%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2024. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(shell).
-moduledoc({file, "../doc/src/shell.md"}).
-export([start/0, start/1, start/2, server/1, server/2, history/1, results/1]).
-export([get_state/0, get_function/2]).
-export([start_restricted/1, stop_restricted/0]).
-export([local_func/0, local_func/1, local_allowed/3, non_local_allowed/3]).
-export([catch_exception/1, prompt_func/1, multiline_prompt_func/1, strings/1]).
-export([format_shell_func/1, erl_pp_format_func/1]).
-export([start_interactive/0, start_interactive/1]).
-export([read_and_add_records/5]).
-export([default_multiline_prompt/1, inverted_space_prompt/1]).
-export([prompt_width/1, prompt_width/2]).
-export([whereis/0]).
-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(DEF_STRINGS, true).
-define(RECORDS, shell_records).
-define(MAXSIZE_HEAPBINARY, 64).
-record(shell_state,{
bindings = [],
records = [],
functions = []
}).
%% When used as the fallback restricted shell callback module...
-doc false.
local_allowed(q,[],State) ->
{true,State};
local_allowed(_,_,State) ->
{false,State}.
-doc false.
non_local_allowed({init,stop},[],State) ->
{true,State};
non_local_allowed(_,_,State) ->
{false,State}.
-doc """
Starts the interactive shell if it has not already been started. It can be used
to programatically start the shell from an escript or when erl is started with
the -noinput or -noshell flags.
""".
-doc(#{since => <<"OTP 26.0">>}).
-spec start_interactive() -> ok | {error, already_started}.
start_interactive() ->
user_drv:start_shell().
-doc """
Starts the interactive shell if it has not already been started. It can be used
to programatically start the shell from an [`escript`](`e:erts:escript_cmd.md`)
or when [`erl`](`e:erts:erl_cmd.md`) is started with the
[`-noinput`](`e:erts:erl_cmd.md#noinput`) or
[`-noshell`](`e:erts:erl_cmd.md#noshell`) flags. The following options are
allowed:
- **noshell** - Starts the interactive shell as if
[`-noshell`](`e:erts:erl_cmd.md#noshell`) was given to
[`erl`](`e:erts:erl_cmd.md`). This is only useful when erl is started with
[`-noinput`](`e:erts:erl_cmd.md#noinput`) and the system want to read input
data.
- **[mfa()](`t:erlang:mfa/0`)** - Starts the interactive shell using
[`mfa()`](`t:erlang:mfa/0`) as the default shell.
- **\{[node()](`t:erlang:node/0`), [mfa()](`t:erlang:mfa/0`)\}** - Starts the
interactive shell using [`mfa()`](`t:erlang:mfa/0`) on
[`node()`](`t:erlang:node/0`) as the default shell.
- **\{remote, [`string()`](`t:erlang:string/0`)\}** - Starts the interactive
shell using as if [`-remsh`](`e:erts:erl_cmd.md#remsh`) was given to
[`erl`](`e:erts:erl_cmd.md`).
- **\{remote, [`string()`](`t:erlang:string/0`),
[`mfa()`](`t:erlang:mfa/0`)\}** - Starts the interactive shell using as if
[`-remsh`](`e:erts:erl_cmd.md#remsh`) was given to
[`erl`](`e:erts:erl_cmd.md`) but with an alternative shell implementation.
On error this function will return:
- **already_started** - if an interactive shell is already started.
- **noconnection** - if a remote shell was requested but it could not be
connected to.
- **badfile | nofile | on_load_failure** - if a remote shell was requested with
a custom [mfa()](`t:erlang:mfa/0`), but the module could not be loaded. See
[Error Reasons for Code-Loading Functions](`m:code#error_reasons`) for a
description of the error reasons.
""".
-doc(#{since => <<"OTP 26.0">>}).
-spec start_interactive(noshell | {module(), atom(), [term()]}) ->
ok | {error, already_started};
({remote, string()}) ->
ok | {error, already_started | noconnection};
({node(), {module(), atom(), [term()]}} | {remote, string(), {module(), atom(), [term()]}}) ->
ok | {error, already_started | noconnection | badfile | nofile | on_load_failure}.
start_interactive({Node, {M, F, A}}) ->
user_drv:start_shell(#{ initial_shell => {Node, M, F ,A} });
start_interactive(InitialShell) ->
user_drv:start_shell(#{ initial_shell => InitialShell }).
-doc """
Returns the current shell process on the node where the calling process'
group_leader is located. If that node has no shell this function will return
undefined.
""".
-doc(#{since => <<"OTP 26.0">>}).
-spec whereis() -> pid() | undefined.
whereis() ->
group:whereis_shell().
-doc false.
-spec start() -> pid().
start() ->
start(false, false).
-doc false.
start(init) ->
start(false, true);
start(NoCtrlG) ->
start(NoCtrlG, false).
-doc false.
start(NoCtrlG, StartSync) ->
_ = code:ensure_loaded(user_default),
Ancestors = [self() | case get('$ancestors') of
undefined -> [];
Anc -> Anc
end],
spawn(fun() ->
put('$ancestors', Ancestors),
server(NoCtrlG, StartSync)
end).
%% Call this function to start a user restricted shell
%% from a normal shell session.
-doc """
Exits a normal shell and starts a restricted shell. `Module` specifies the
callback module for the functions `local_allowed/3` and `non_local_allowed/3`.
The function is meant to be called from the shell.
If the callback module cannot be loaded, an error tuple is returned. The
`Reason` in the error tuple is the one returned by the code loader when trying
to load the code of the callback module.
""".
-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: ~tp\n",
[RShMod,What]))),
Error
end.
-doc """
Exits a restricted shell and starts a normal shell. The function is meant to be
called from the shell.
""".
-spec stop_restricted() -> no_return().
stop_restricted() ->
application:unset_env(stdlib, restricted_shell),
exit(restricted_shell_stopped).
-doc false.
-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.
-doc false.
-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),
%% Store local definitions of functions, records and types in an ets table.
%% {function_def, {M,F,A}},string()} i.e. "func(X) -> X."
%% {function, {M,F,A}},fun()} i.e. rewrite of the function_def with the same MFA into a fun "fun(X)-> X end."
%% {function_type_def, {M,F,A}},string()} i.e. "-spec func(X :: integer()) -> X."
%% {{function_type, {M,F,A}}, attr_form()} i.e. The intermediate representation of the spec, used for type traversal in edlin_type_suggestion.erl
%% {type_def, {M,F,A}},string()} i.e. "-type foo() :: bar() | baz()"
%% {type, {M,F,A}}, attr_form()} i.e. The intermediate representation of the type, used for type traversal in edlin_type_suggestion.erl
%% {record_def, {M,F,A}},string()} i.e. "-record(foo, {bar :: baz()})."
%% The attr_form() of the record is saved in the RT table.
FT = ets:new(user_functions, [public,ordered_set]),
%% Check if we're in user restricted mode.
RShErr =
case application:get_env(stdlib, restricted_shell) of
{ok,RShMod} when is_atom(RShMod) ->
io:fwrite(<<"Restricted ">>, []),
case code:ensure_loaded(RShMod) of
{module,RShMod} ->
undefined;
{error,What} ->
{RShMod,What}
end;
{ok, Term} ->
{Term,not_an_atom};
undefined ->
undefined
end,
JCL =
case get(no_control_g) of
true -> " (type help(). for help)";
_ -> " (press Ctrl+G to abort, type help(). for help)"
end,
DefaultSessionSlogan =
io_lib:format(<<"Eshell V~s">>, [erlang:system_info(version)]),
SessionSlogan =
case application:get_env(stdlib, shell_session_slogan, DefaultSessionSlogan) of
SloganFun when is_function(SloganFun, 0) ->
SloganFun();
Slogan ->
Slogan
end,
try
io:fwrite("~ts~ts\n",[unicode:characters_to_list(SessionSlogan),JCL])
catch _:_ ->
io:fwrite("Warning! The slogan \"~p\" could not be printed.\n",[SessionSlogan])
end,
erase(no_control_g),
case RShErr of
undefined ->
ok;
{RShMod2,What2} ->
io:fwrite(
("Warning! Restricted shell module ~w not found: ~tp.\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, FT, []), Bs, RT, FT, [], History, Results).
server_loop(N0, Eval_0, Bs00, RT, FT, Ds00, History0, Results0) ->
N = N0 + 1,
{Eval_1,Bs0,Ds0,Prompt} = prompt(N, Eval_0, Bs00, RT, FT, Ds00),
{Res,Eval0} = get_command(Prompt, Eval_1, Bs0, RT, FT, Ds0),
case Res of
{ok,Es0} ->
case expand_hist(Es0, N) of
{ok,Es} ->
{V,Eval,Bs,Ds} = shell_cmd(Es, Eval0, Bs0, RT, FT, 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());
Results < Results0 ->
garb(self());
true ->
ok
end,
server_loop(N, Eval, Bs, RT, FT, Ds, History, Results);
{error,E} ->
fwrite_severity(benign, <<"~ts">>, [E]),
server_loop(N0, Eval0, Bs0, RT, FT, Ds0, History0, Results0)
end;
{error,{Location,Mod,What}} ->
fwrite_severity(benign, <<"~s: ~ts">>,
[pos(Location), Mod:format_error(What)]),
server_loop(N0, Eval0, Bs0, RT, FT, 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, FT, Ds0),
server_loop(N0, Eval, Bs0, RT, FT, Ds0, History0, Results0);
{error,tokens} -> %Most probably character > 255
fwrite_severity(benign, <<"~w: Invalid tokens.">>,
[N]),
server_loop(N0, Eval0, Bs0, RT, FT, Ds0, History0, Results0);
eof ->
fwrite_severity(fatal, <<"Terminating erlang (~w)">>, [node()]),
halt()
end.
get_command(Prompt, Eval, Bs, RT, FT, Ds) ->
Ancestors = [self() | get('$ancestors')],
ResWordFun = fun erl_scan:reserved_word/1,
Parse =
fun() ->
put('$ancestors', Ancestors),
exit(
case
io:scan_erl_exprs(group_leader(), Prompt, {1,1},
[text,{reserved_word_fun,ResWordFun}])
of
{ok,Toks,_EndPos} ->
%% NOTE: we can handle function definitions, records and type declarations
%% but this cannot be handled by the function which only expects erl_parse:abstract_expressions()
%% for now just pattern match against those types and pass the string to shell local func.
case Toks of
[{'-', _}, {atom, _, Atom}|_] ->
SpecialCase = fun(LocalFunc) ->
FakeLine = begin
case erl_parse:parse_form(Toks) of
{ok, Def} -> lists:flatten(erl_pp:form(Def));
E ->
exit(E)
end
end,
{done, {ok, FakeResult, _}, _} = erl_scan:tokens(
[], atom_to_list(LocalFunc) ++ "(\""++FakeLine++"\").\n",
{1,1}, [text,{reserved_word_fun,fun erl_scan:reserved_word/1}]),
erl_eval:extended_parse_exprs(FakeResult)
end,
case Atom of
record -> SpecialCase(rd);
spec -> SpecialCase(ft);
type -> SpecialCase(td);
_ -> erl_eval:extended_parse_exprs(Toks)
end;
[{atom, _, FunName}, {'(', _}|_] ->
case erl_parse:parse_form(Toks) of
{ok, FunDef} ->
FunName1 = lists:flatten(io_lib:fwrite("~tw",[FunName])),
case {edlin_expand:shell_default_or_bif(FunName1), shell:local_func(FunName1)} of
{"user_defined", false} ->
FunDef1 = lists:flatten(escape_quotes(lists:flatten(erl_pp:form(FunDef)))),
FakeLine = reconstruct(FunDef, FunName),
{done, {ok, FakeResult, _}, _} = erl_scan:tokens(
[], "fd("++ FunName1 ++ ", " ++ FakeLine ++ ", \"" ++ FunDef1 ++ "\").\n",
{1,1}, [text,{reserved_word_fun,fun erl_scan:reserved_word/1}]),
erl_eval:extended_parse_exprs(FakeResult);
_ -> erl_eval:extended_parse_exprs(Toks)
end;
_ -> erl_eval:extended_parse_exprs(Toks)
end;
_ ->
erl_eval:extended_parse_exprs(Toks)
end;
{eof,_EndPos} ->
eof;
{error,ErrorInfo,_EndPos} ->
%% Skip the rest of the line:
Opts = io:getopts(),
TmpOpts = lists:keyreplace(echo, 1, Opts,
{echo, false}),
_ = io:setopts(TmpOpts),
_ = io:get_line(''),
_ = io:setopts(Opts),
{error,ErrorInfo};
Else ->
Else
end
)
end,
Pid = spawn_link(Parse),
get_command1(Pid, Eval, Bs, RT, FT, Ds).
escape_quotes(String) -> escape_quotes(String, []).
escape_quotes([], Acc) ->
% When we've processed all characters, reverse the accumulator
% because we've been prepending for efficiency reasons.
lists:reverse(Acc);
escape_quotes([$\\, $\" | Rest], Acc) ->
% If we find an escaped quote (\"),
% we escape the backslash and the quote (\\\") and continue.
escape_quotes(Rest, [$\", $\\, $\\, $\\ | Acc]);
escape_quotes([$\" | Rest], Acc) ->
% If we find a quote ("),
% we escape it (\\") and continue.
escape_quotes(Rest, [$\", $\\ | Acc]);
escape_quotes([Char | Rest], Acc) ->
% In case of any other character, we keep it as is.
escape_quotes(Rest, [Char | Acc]).
reconstruct(Fun, Name) ->
lists:flatten(erl_pp:expr(reconstruct1(Fun, Name))).
reconstruct1({function, Anno, Name, Arity, Clauses}, Name) ->
{named_fun, Anno, 'RecursiveFuncVar', reconstruct1(Clauses, Name, Arity)}.
reconstruct1([{call, Anno, {atom, Anno1, Name}, Args}|Body], Name, Arity) when length(Args) =:= Arity ->
[{call, Anno, {var, Anno1, 'RecursiveFuncVar'}, reconstruct1(Args, Name, Arity)}| reconstruct1(Body, Name, Arity)];
reconstruct1([{call, Anno, {atom, Anno1, Name}, Args}|Body], Name, Arity) -> % arity not the same
[{call, Anno, {remote, Anno1, {atom, Anno1, shell_default}, {atom, Anno1, Name}}, reconstruct1(Args, Name, Arity)}|
reconstruct1(Body, Name, Arity)];
reconstruct1([{call, Anno, {atom, Anno1, Fun}, Args}|Body], Name, Arity) -> % Name not the same
case {edlin_expand:shell_default_or_bif(atom_to_list(Fun)), shell:local_func(Fun)} of
{"user_defined", false} ->
[{call, Anno, {remote, Anno1, {atom, Anno1, shell_default}, {atom, Anno1, Fun}}, reconstruct1(Args, Name, Arity)}|
reconstruct1(Body, Name, Arity)];
{"shell_default", false} ->
[{call, Anno, {remote, Anno1, {atom, Anno1, shell_default}, {atom, Anno1, Fun}}, reconstruct1(Args, Name, Arity)}| reconstruct1(Body, Name, Arity)];
{"erlang", false} ->
[{call, Anno, {remote, Anno1, {atom, Anno1, erlang}, {atom, Anno1, Fun}}, reconstruct1(Args, Name, Arity)}| reconstruct1(Body, Name, Arity)];
{_, true} ->
[{call, Anno, {atom, Anno1, Fun}, reconstruct1(Args, Name, Arity)}| reconstruct1(Body, Name, Arity)]
end;
reconstruct1([E|Body], Name, Arity) when is_tuple(E) ->
[list_to_tuple(reconstruct1(tuple_to_list(E), Name, Arity))|reconstruct1(Body, Name, Arity)];
reconstruct1([E|Body], Name, Arity) when is_list(E) ->
[reconstruct1(E, Name, Arity)|reconstruct1(Body, Name, Arity)];
reconstruct1([E|Body], Name, Arity) ->
[E|reconstruct1(Body, Name, Arity)];
reconstruct1([], _, _) -> [].
get_command1(Pid, Eval, Bs, RT, FT, Ds) ->
receive
{shell_state, From} ->
From ! {shell_state, Bs, RT, FT},
get_command1(Pid, Eval, Bs, RT, FT, Ds);
{'EXIT', Pid, Res} ->
{Res, Eval};
{'EXIT', Eval, {Reason,Stacktrace}} ->
report_exception(error, {Reason,Stacktrace}, RT),
get_command1(Pid, start_eval(Bs, RT, FT, Ds), Bs, RT, FT, Ds);
{'EXIT', Eval, Reason} ->
report_exception(error, {Reason,[]}, RT),
get_command1(Pid, start_eval(Bs, RT, FT, Ds), Bs, RT, FT, Ds)
end.
prompt(N, Eval0, Bs0, RT, FT, Ds0) ->
case get_prompt_func() of
{M,F} ->
A = erl_anno:new(1),
L = {cons,A,{tuple,A,[{atom,A,history},{integer,A,N}]},{nil,A}},
C = {call,A,{remote,A,{atom,A,M},{atom,A,F}},[L]},
{V,Eval,Bs,Ds} = shell_cmd([C], Eval0, Bs0, RT, FT, 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, default) of
{M,F}=PromptFunc when is_atom(M), is_atom(F) ->
PromptFunc;
default=Default ->
Default;
Term ->
bad_prompt_func(Term),
default
end.
bad_prompt_func(M) ->
fwrite_severity(benign, "Bad prompt function: ~tp", [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,A,H,T}, C) ->
{cons,A,expand_expr(H, C),expand_expr(T, C)};
expand_expr({lc,A,E,Qs}, C) ->
{lc,A,expand_expr(E, C),expand_quals(Qs, C)};
expand_expr({bc,A,E,Qs}, C) ->
{bc,A,expand_expr(E, C),expand_quals(Qs, C)};
expand_expr({tuple,A,Elts}, C) ->
{tuple,A,expand_exprs(Elts, C)};
expand_expr({map,A,Es}, C) ->
{map,A,expand_exprs(Es, C)};
expand_expr({map,A,Arg,Es}, C) ->
{map,A,expand_expr(Arg, C),expand_exprs(Es, C)};
expand_expr({map_field_assoc,A,K,V}, C) ->
{map_field_assoc,A,expand_expr(K, C),expand_expr(V, C)};
expand_expr({map_field_exact,A,K,V}, C) ->
{map_field_exact,A,expand_expr(K, C),expand_expr(V, C)};
expand_expr({record_index,A,Name,F}, C) ->
{record_index,A,Name,expand_expr(F, C)};
expand_expr({record,A,Name,Is}, C) ->
{record,A,Name,expand_fields(Is, C)};
expand_expr({record_field,A,R,Name,F}, C) ->
{record_field,A,expand_expr(R, C),Name,expand_expr(F, C)};
expand_expr({record,A,R,Name,Ups}, C) ->
{record,A,expand_expr(R, C),Name,expand_fields(Ups, C)};
expand_expr({record_field,A,R,F}, C) -> %This is really illegal!
{record_field,A,expand_expr(R, C),expand_expr(F, C)};
expand_expr({block,A,Es}, C) ->
{block,A,expand_exprs(Es, C)};
expand_expr({'if',A,Cs}, C) ->
{'if',A,expand_cs(Cs, C)};
expand_expr({'case',A,E,Cs}, C) ->
{'case',A,expand_expr(E, C),expand_cs(Cs, C)};
expand_expr({'try',A,Es,Scs,Ccs,As}, C) ->
{'try',A,expand_exprs(Es, C),expand_cs(Scs, C),
expand_cs(Ccs, C),expand_exprs(As, C)};
expand_expr({'receive',A,Cs}, C) ->
{'receive',A,expand_cs(Cs, C)};
expand_expr({'receive',A,Cs,To,ToEs}, C) ->
{'receive',A,expand_cs(Cs, C), expand_expr(To, C), expand_exprs(ToEs, C)};
expand_expr({call,A,{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,A,Ces}
end;
expand_expr({call,CA,{atom,VA,v},[N]}, C) ->
case get_cmd(N, C) of
{undefined,_,_} ->
no_command(N);
{Ces,_V,CommandN} when is_list(Ces) ->
{call,CA,{atom,VA,v},[{integer,VA,CommandN}]}
end;
expand_expr({call,A,F,Args}, C) ->
{call,A,expand_expr(F, C),expand_exprs(Args, C)};
expand_expr({'catch',A,E}, C) ->
{'catch',A,expand_expr(E, C)};
expand_expr({match,A,Lhs,Rhs}, C) ->
{match,A,Lhs,expand_expr(Rhs, C)};
expand_expr({op,A,Op,Arg}, C) ->
{op,A,Op,expand_expr(Arg, C)};
expand_expr({op,A,Op,Larg,Rarg}, C) ->
{op,A,Op,expand_expr(Larg, C),expand_expr(Rarg, C)};
expand_expr({remote,A,M,F}, C) ->
{remote,A,expand_expr(M, C),expand_expr(F, C)};
expand_expr({'fun',A,{clauses,Cs}}, C) ->
{'fun',A,{clauses,expand_exprs(Cs, C)}};
expand_expr({named_fun,A,Name,Cs}, C) ->
{named_fun,A,Name,expand_exprs(Cs, C)};
expand_expr({clause,A,H,G,B}, C) ->
%% Could expand H and G, but then erl_eval has to be changed as well.
{clause,A,H, G, expand_exprs(B, C)};
expand_expr({bin,A,Fs}, C) ->
{bin,A,expand_bin_elements(Fs, C)};
%expand_expr({'-'})
expand_expr(E, _C) -> % Constants.
E.
expand_cs([{clause,A,P,G,B}|Cs], C) ->
[{clause,A,P,G,expand_exprs(B, C)}|expand_cs(Cs, C)];
expand_cs([], _C) ->
[].
expand_fields([{record_field,A,F,V}|Fs], C) ->
[{record_field,A,expand_expr(F, C),expand_expr(V, C)}|
expand_fields(Fs, C)];
expand_fields([], _C) -> [].
expand_quals([{generate,A,P,E}|Qs], C) ->
[{generate,A,P,expand_expr(E, C)}|expand_quals(Qs, C)];
expand_quals([{b_generate,A,P,E}|Qs], C) ->
[{b_generate,A,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,A,E,Sz,Ts}|Fs], C) ->
[{bin_element,A,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).
-doc false.
get_state() ->
whereis() ! {shell_state, self()},
receive
{shell_state, Bs, RT, FT} ->
#shell_state{bindings = Bs, records = ets:tab2list(RT), functions = ets:tab2list(FT)}
end.
-doc false.
get_function(Func, Arity) ->
{shell_state, _Bs, _RT, FT} = get_state(),
try
{value, {_, Fun}} = lists:keysearch({function, {shell_default,Func,Arity}}, 1, FT),
Fun
catch _:_ ->
undefined
end.
%% 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, FT, Ds, W) ->
Eval ! {shell_cmd,self(),{eval,Es}, W},
shell_rep(Eval, Bs, RT, FT, Ds).
shell_rep(Ev, Bs0, RT, FT, Ds0) ->
receive
{shell_rep,Ev,{value,V,Bs,Ds}} ->
{V,Ev,Bs,Ds};
{shell_rep,Ev,{command_error,{Location,M,Error}}} ->
fwrite_severity(benign, <<"~s: ~ts">>,
[pos(Location), M:format_error(Error)]),
{{'EXIT',Error},Ev,Bs0,Ds0};
{shell_req,Ev,{get_cmd,N}} ->
Ev ! {shell_rep,self(),getc(N)},
shell_rep(Ev, Bs0, RT, FT, Ds0);
{shell_req,Ev,get_cmd} ->
Ev ! {shell_rep,self(),get()},
shell_rep(Ev, Bs0, RT, FT, 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, FT, Ds);
{shell_state, From} ->
From ! {shell_state, Bs0, RT, FT},
shell_rep(Ev, Bs0, RT, FT, Ds0);
{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, FT, 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, FT, Ds0);
{'EXIT',Ev,{Reason,Stacktrace}} ->
report_exception(exit, {Reason,Stacktrace}, RT),
{{'EXIT',Reason},start_eval(Bs0, RT, FT, Ds0), Bs0, Ds0};
{'EXIT',Ev,Reason} ->
report_exception(exit, {Reason,[]}, RT),
{{'EXIT',Reason},start_eval(Bs0, RT, FT, Ds0), Bs0, Ds0};
{'EXIT',_Id,R} ->
exit(Ev, R),
exit(R);
_Other -> % Ignore everything else
io:format("Throwing ~p~n", [_Other]),
shell_rep(Ev, Bs0, RT, FT, 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 = erl_error:format_exception(I, Class, Reason, Stacktrace, SF, PF, Enc),
io:requests([{put_chars, latin1, Tag},
{put_chars, unicode, Str},
nl]).
start_eval(Bs, RT, FT, Ds) ->
Self = self(),
Ancestors = [self() | get('$ancestors')],
Eval = spawn_link(fun() ->
put('$ancestors', Ancestors),
evaluator(Self, Bs, RT, FT, 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, FT, Ds) ->
init_dict(Ds),
case application:get_env(stdlib, restricted_shell) of
undefined ->
eval_loop(Shell, Bs, RT, FT);
{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, FT, RShMod)
end.
eval_loop(Shell, Bs0, RT, FT) ->
receive
{shell_cmd,Shell,{eval,Es},W} ->
Ef = {value,
fun(MForFun, As) -> apply_fun(MForFun, As, Shell) end},
Lf = local_func_handler(Shell, RT, FT, Ef),
Bs = eval_exprs(Es, Shell, Bs0, RT, Lf, Ef, W),
eval_loop(Shell, Bs, RT, FT)
end.
restricted_eval_loop(Shell, Bs0, RT, FT, RShMod) ->
receive
{shell_cmd,Shell,{eval,Es}, W} ->
{LFH,NLFH} = restrict_handlers(RShMod, Shell, RT, FT),
put(restricted_expr_state, []),
Bs = eval_exprs(Es, Shell, Bs0, RT, {eval,LFH}, {value,NLFH}, W),
restricted_eval_loop(Shell, Bs, RT, FT, 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 ->
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, false) of
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),
case W of
cmd -> io:requests([{put_chars, unicode, VS}, nl]);
pmt -> ok
end,
%% 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 ->
erlang:garbage_collect(),
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, Skip) ->
case used_records(E) of
{name,Name,E1} ->
U = case lists:member(Name, Skip) of
true ->
U0;
false ->
R = ets:lookup(RT, Name),
used_records(R, [Name | U0], RT, [Name | Skip])
end,
used_records(E1, U, RT, Skip);
{expr,[E1 | Es]} ->
used_records(Es, used_records(E1, U0, RT, Skip), RT, Skip);
_ ->
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,A,{tuple,_,[M,F]},As}) ->
used_records({call,A,{remote,A,M,F},As});
used_records({type,_,record,[{atom,_,Name}|Fs]}) ->
{name, Name, Fs};
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].