diff options
Diffstat (limited to 'lib/kernel/src/os.erl')
-rw-r--r-- | lib/kernel/src/os.erl | 412 |
1 files changed, 196 insertions, 216 deletions
diff --git a/lib/kernel/src/os.erl b/lib/kernel/src/os.erl index 3330b38d84..29a26674ba 100644 --- a/lib/kernel/src/os.erl +++ b/lib/kernel/src/os.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1997-2013. All Rights Reserved. +%% Copyright Ericsson AB 1997-2018. 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. @@ -21,38 +21,40 @@ %% Provides a common operating system interface. --export([type/0, version/0, cmd/1, find_executable/1, find_executable/2]). +-export([type/0, version/0, cmd/1, cmd/2, find_executable/1, find_executable/2]). -include("file.hrl"). +-export_type([env_var_name/0, env_var_value/0, env_var_name_value/0]). + +-export([getenv/0, getenv/1, getenv/2, putenv/2, unsetenv/1]). + %%% BIFs --export([getenv/0, getenv/1, getenv/2, getpid/0, putenv/2, system_time/0, system_time/1, - timestamp/0, unsetenv/1]). +-export([get_env_var/1, getpid/0, list_env_vars/0, perf_counter/0, + perf_counter/1, set_env_var/2, set_signal/2, system_time/0, + system_time/1, timestamp/0, unset_env_var/1]). --spec getenv() -> [string()]. +-type os_command() :: atom() | io_lib:chars(). +-type os_command_opts() :: #{ max_size => non_neg_integer() | infinity }. -getenv() -> erlang:nif_error(undef). +-export_type([os_command/0, os_command_opts/0]). --spec getenv(VarName) -> Value | false when - VarName :: string(), - Value :: string(). +-type env_var_name() :: nonempty_string(). -getenv(_) -> - erlang:nif_error(undef). +-type env_var_value() :: string(). --spec getenv(VarName, DefaultValue) -> Value when - VarName :: string(), - DefaultValue :: string(), - Value :: string(). +-type env_var_name_value() :: nonempty_string(). -getenv(VarName, DefaultValue) -> - case os:getenv(VarName) of - false -> - DefaultValue; - Value -> - Value - end. +-spec list_env_vars() -> [{env_var_name(), env_var_value()}]. +list_env_vars() -> + erlang:nif_error(undef). + +-spec get_env_var(VarName) -> Value | false when + VarName :: env_var_name(), + Value :: env_var_value(). +get_env_var(_VarName) -> + erlang:nif_error(undef). -spec getpid() -> Value when Value :: string(). @@ -60,11 +62,22 @@ getenv(VarName, DefaultValue) -> getpid() -> erlang:nif_error(undef). --spec putenv(VarName, Value) -> true when - VarName :: string(), - Value :: string(). +-spec perf_counter() -> Counter when + Counter :: integer(). -putenv(_, _) -> +perf_counter() -> + erlang:nif_error(undef). + +-spec perf_counter(Unit) -> integer() when + Unit :: erlang:time_unit(). + +perf_counter(Unit) -> + erlang:convert_time_unit(os:perf_counter(), perf_counter, Unit). + +-spec set_env_var(VarName, Value) -> true when + VarName :: env_var_name(), + Value :: env_var_value(). +set_env_var(_, _) -> erlang:nif_error(undef). -spec system_time() -> integer(). @@ -84,16 +97,57 @@ system_time(_Unit) -> timestamp() -> erlang:nif_error(undef). --spec unsetenv(VarName) -> true when - VarName :: string(). +-spec unset_env_var(VarName) -> true when + VarName :: env_var_name(). +unset_env_var(_) -> + erlang:nif_error(undef). -unsetenv(_) -> +-spec set_signal(Signal, Option) -> 'ok' when + Signal :: 'sighup' | 'sigquit' | 'sigabrt' | 'sigalrm' | + 'sigterm' | 'sigusr1' | 'sigusr2' | 'sigchld' | + 'sigstop' | 'sigtstp', + Option :: 'default' | 'handle' | 'ignore'. + +set_signal(_Signal, _Option) -> erlang:nif_error(undef). %%% End of BIFs +-spec getenv() -> [env_var_name_value()]. +getenv() -> + [lists:flatten([Key, $=, Value]) || {Key, Value} <- os:list_env_vars() ]. + +-spec getenv(VarName) -> Value | false when + VarName :: env_var_name(), + Value :: env_var_value(). +getenv(VarName) -> + os:get_env_var(VarName). + +-spec getenv(VarName, DefaultValue) -> Value when + VarName :: env_var_name(), + DefaultValue :: env_var_value(), + Value :: env_var_value(). +getenv(VarName, DefaultValue) -> + case os:getenv(VarName) of + false -> + DefaultValue; + Value -> + Value + end. + +-spec putenv(VarName, Value) -> true when + VarName :: env_var_name(), + Value :: env_var_value(). +putenv(VarName, Value) -> + os:set_env_var(VarName, Value). + +-spec unsetenv(VarName) -> true when + VarName :: env_var_name(). +unsetenv(VarName) -> + os:unset_env_var(VarName). + -spec type() -> {Osfamily, Osname} when - Osfamily :: unix | win32 | ose, + Osfamily :: unix | win32, Osname :: atom(). type() -> @@ -155,7 +209,7 @@ verify_executable(Name0, [Ext|Rest], OrigExtensions) -> end; verify_executable(Name, [], OrigExtensions) when OrigExtensions =/= [""] -> %% Windows %% Will only happen on windows, hence case insensitivity - case can_be_full_name(string:to_lower(Name),OrigExtensions) of + case can_be_full_name(string:lowercase(Name),OrigExtensions) of true -> verify_executable(Name,[""],[""]); _ -> @@ -209,206 +263,132 @@ extensions() -> %% Executes the given command in the default shell for the operating system. -spec cmd(Command) -> string() when - Command :: atom() | io_lib:chars(). + Command :: os_command(). cmd(Cmd) -> - validate(Cmd), - Bytes = case type() of - {unix, _} -> - unix_cmd(Cmd); - {win32, Wtype} -> - Command0 = case {os:getenv("COMSPEC"),Wtype} of - {false,windows} -> lists:concat(["command.com /c", Cmd]); - {false,_} -> lists:concat(["cmd /c", Cmd]); - {Cspec,_} -> lists:concat([Cspec," /c",Cmd]) - end, - %% open_port/2 awaits string() in Command, but io_lib:chars() can be - %% deep lists according to io_lib module description. - Command = lists:flatten(Command0), - Port = open_port({spawn, Command}, [stream, in, eof, hide]), - get_data(Port, []) - end, - String = unicode:characters_to_list(list_to_binary(Bytes)), + cmd(Cmd, #{ }). + +-spec cmd(Command, Options) -> string() when + Command :: os_command(), + Options :: os_command_opts(). +cmd(Cmd, Opts) -> + {SpawnCmd, SpawnOpts, SpawnInput, Eot} = mk_cmd(os:type(), validate(Cmd)), + Port = open_port({spawn, SpawnCmd}, [binary, stderr_to_stdout, + stream, in, hide | SpawnOpts]), + MonRef = erlang:monitor(port, Port), + true = port_command(Port, SpawnInput), + Bytes = get_data(Port, MonRef, Eot, [], 0, maps:get(max_size, Opts, infinity)), + demonitor(MonRef, [flush]), + String = unicode:characters_to_list(Bytes), if %% Convert to unicode list if possible otherwise return bytes is_list(String) -> String; - true -> Bytes + true -> binary_to_list(Bytes) end. -unix_cmd(Cmd) -> - Tag = make_ref(), - {Pid,Mref} = erlang:spawn_monitor( - fun() -> - process_flag(trap_exit, true), - Port = start_port(), - erlang:port_command(Port, mk_cmd(Cmd)), - exit({Tag,unix_get_data(Port)}) - end), - receive - {'DOWN',Mref,_,Pid,{Tag,Result}} -> - Result; - {'DOWN',Mref,_,Pid,Reason} -> - exit(Reason) +mk_cmd({win32,Wtype}, Cmd) -> + Command = case {os:getenv("COMSPEC"),Wtype} of + {false,windows} -> lists:concat(["command.com /c", Cmd]); + {false,_} -> lists:concat(["cmd /c", Cmd]); + {Cspec,_} -> lists:concat([Cspec," /c",Cmd]) + end, + {Command, [], [], <<>>}; +mk_cmd(_,Cmd) -> + %% Have to send command in like this in order to make sh commands like + %% cd and ulimit available + {"/bin/sh -s unix:cmd", [out], + %% We insert a new line after the command, in case the command + %% contains a comment character. + %% + %% The </dev/null closes stdin, which means that programs + %% that use a closed stdin as an termination indicator works. + %% An example of such a program is 'more'. + %% + %% The "echo ^D" is used to indicate that the program has executed + %% and we should return any output we have gotten. We cannot use + %% termination of the child or closing of stdin/stdout as then + %% starting background jobs from os:cmd will block os:cmd. + %% + %% I tried changing this to be "better", but got bombarded with + %% backwards incompatibility bug reports, so leave this as it is. + ["(", unicode:characters_to_binary(Cmd), "\n) </dev/null; echo \"\^D\"\n"], + <<$\^D>>}. + +validate(Atom) when is_atom(Atom) -> + validate(atom_to_list(Atom)); +validate(List) when is_list(List) -> + case validate1(List) of + false -> + List; + true -> + %% Had zeros at end; remove them... + string:trim(List, trailing, [0]) end. -%% The -s flag implies that only the positional parameters are set, -%% and the commands are read from standard input. We set the -%% $1 parameter for easy identification of the resident shell. -%% --define(ROOT, "/"). --define(ROOT_ANDROID, "/system"). --define(SHELL, "bin/sh -s unix:cmd 2>&1"). --define(PORT_CREATOR_NAME, os_cmd_port_creator). +validate1([0|Rest]) -> + validate2(Rest); +validate1([C|Rest]) when is_integer(C), C > 0 -> + validate1(Rest); +validate1([List|Rest]) when is_list(List) -> + validate1(List) or validate1(Rest); +validate1([]) -> + false. -%% -%% Serializing open_port through a process to avoid smp lock contention -%% when many concurrent os:cmd() want to do vfork (OTP-7890). -%% --spec start_port() -> port(). -start_port() -> - Ref = make_ref(), - Request = {Ref,self()}, - {Pid, Mon} = case whereis(?PORT_CREATOR_NAME) of - undefined -> - spawn_monitor(fun() -> - start_port_srv(Request) - end); - P -> - P ! Request, - M = erlang:monitor(process, P), - {P, M} - end, +%% Ensure that the rest is zero only... +validate2([]) -> + true; +validate2([0|Rest]) -> + validate2(Rest); +validate2([List|Rest]) when is_list(List) -> + validate2(List), + validate2(Rest). + +get_data(Port, MonRef, Eot, Sofar, Size, Max) -> receive - {Ref, Port} when is_port(Port) -> - erlang:demonitor(Mon, [flush]), - Port; - {Ref, Error} -> - erlang:demonitor(Mon, [flush]), - exit(Error); - {'DOWN', Mon, process, Pid, _Reason} -> - start_port() + {Port, {data, Bytes}} -> + case eot(Bytes, Eot, Size, Max) of + more -> + get_data(Port, MonRef, Eot, [Sofar, Bytes], + Size + byte_size(Bytes), Max); + Last -> + catch port_close(Port), + flush_until_down(Port, MonRef), + iolist_to_binary([Sofar, Last]) + end; + {'DOWN', MonRef, _, _, _} -> + flush_exit(Port), + iolist_to_binary(Sofar) end. -start_port_srv(Request) -> - %% We don't want a group leader of some random application. Use - %% kernel_sup's group leader. - {group_leader, GL} = process_info(whereis(kernel_sup), - group_leader), - true = group_leader(GL, self()), - process_flag(trap_exit, true), - StayAlive = try register(?PORT_CREATOR_NAME, self()) - catch - error:_ -> false - end, - start_port_srv_handle(Request), - case StayAlive of - true -> start_port_srv_loop(); - false -> exiting +eot(Bs, <<>>, Size, Max) when Size + byte_size(Bs) < Max -> + more; +eot(Bs, <<>>, Size, Max) -> + binary:part(Bs, {0, Max - Size}); +eot(Bs, Eot, Size, Max) -> + case binary:match(Bs, Eot) of + {Pos, _} when Size + Pos < Max -> + binary:part(Bs,{0, Pos}); + _ -> + eot(Bs, <<>>, Size, Max) end. -start_port_srv_handle({Ref,Client}) -> - Path = case lists:reverse(erlang:system_info(system_architecture)) of - % androideabi - "ibaediordna" ++ _ -> filename:join([?ROOT_ANDROID, ?SHELL]); - _ -> filename:join([?ROOT, ?SHELL]) - end, - Reply = try open_port({spawn, Path},[stream]) of - Port when is_port(Port) -> - (catch port_connect(Port, Client)), - unlink(Port), - Port - catch - error:Reason -> - {Reason,erlang:get_stacktrace()} - end, - Client ! {Ref,Reply}, - ok. - -start_port_srv_loop() -> - receive - {Ref, Client} = Request when is_reference(Ref), - is_pid(Client) -> - start_port_srv_handle(Request); - _Junk -> - ok - end, - start_port_srv_loop(). - -%% -%% unix_get_data(Port) -> Result -%% -unix_get_data(Port) -> - unix_get_data(Port, []). - -unix_get_data(Port, Sofar) -> +%% When port_close returns we know that all the +%% messages sent have been sent and that the +%% DOWN message is after them all. +flush_until_down(Port, MonRef) -> receive - {Port,{data, Bytes}} -> - case eot(Bytes) of - {done, Last} -> - lists:flatten([Sofar|Last]); - more -> - unix_get_data(Port, [Sofar|Bytes]) - end; - {'EXIT', Port, _} -> - lists:flatten(Sofar) + {Port, {data, _Bytes}} -> + flush_until_down(Port, MonRef); + {'DOWN', MonRef, _, _, _} -> + flush_exit(Port) end. -%% -%% eot(String) -> more | {done, Result} -%% -eot(Bs) -> - eot(Bs, []). - -eot([4| _Bs], As) -> - {done, lists:reverse(As)}; -eot([B| Bs], As) -> - eot(Bs, [B| As]); -eot([], _As) -> - more. - -%% -%% mk_cmd(Cmd) -> {ok, ShellCommandString} | {error, ErrorString} -%% -%% We do not allow any input to Cmd (hence commands that want -%% to read from standard input will return immediately). -%% Standard error is redirected to standard output. -%% -%% We use ^D (= EOT = 4) to mark the end of the stream. -%% -mk_cmd(Cmd) when is_atom(Cmd) -> % backward comp. - mk_cmd(atom_to_list(Cmd)); -mk_cmd(Cmd) -> - %% We insert a new line after the command, in case the command - %% contains a comment character. - [$(, unicode:characters_to_binary(Cmd), "\n) </dev/null; echo \"\^D\"\n"]. - - -validate(Atom) when is_atom(Atom) -> - ok; -validate(List) when is_list(List) -> - validate1(List). - -validate1([C|Rest]) when is_integer(C) -> - validate1(Rest); -validate1([List|Rest]) when is_list(List) -> - validate1(List), - validate1(Rest); -validate1([]) -> - ok. - -get_data(Port, Sofar) -> +%% The exit signal is always delivered before +%% the down signal, so we can be sure that if there +%% was an exit message sent, it will be in the +%% mailbox now. +flush_exit(Port) -> receive - {Port, {data, Bytes}} -> - get_data(Port, [Sofar|Bytes]); - {Port, eof} -> - Port ! {self(), close}, - receive - {Port, closed} -> - true - end, - receive - {'EXIT', Port, _} -> - ok - after 1 -> % force context switch - ok - end, - lists:flatten(Sofar) + {'EXIT', Port, _} -> + ok + after 0 -> + ok end. |