stdlib: Add shell:start_interactive/0,1

erlang · Aug 10, 2022 · 080996d · 080996d
1 parent 1d43051
commit 080996d
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Showing 6 changed files with 138 additions and 10 deletions.
diff --git a/erts/doc/src/erl_cmd.xml b/erts/doc/src/erl_cmd.xml
@@ -537,12 +537,12 @@ $ <input>erl \
           to implement an Alternative Carrier for the Erlang
           Distribution</seeguide>.</p>
       </item>
-      <tag><c><![CDATA[-noinput]]></c></tag>
+      <tag><marker id="noinput"/><c><![CDATA[-noinput]]></c></tag>
       <item>
         <p>Ensures that the Erlang runtime system never tries to read
           any input. Implies <c><![CDATA[-noshell]]></c>.</p>
       </item>
-      <tag><c><![CDATA[-noshell]]></c></tag>
+      <tag><marker id="noshell"/><c><![CDATA[-noshell]]></c></tag>
       <item>
         <p>Starts an Erlang runtime system with no shell. This flag
           makes it possible to have the Erlang runtime system as a

diff --git a/lib/kernel/src/prim_tty.erl b/lib/kernel/src/prim_tty.erl
@@ -235,6 +235,8 @@ init_term(State = #state{ tty = TTY, options = Options }) ->
             {true, undefined} ->
                 {ok, Reader} = proc_lib:start_link(?MODULE, reader, [[State#state.tty, self()]]),
                 WriterState#state{ reader = Reader };
+            {true, _} ->
+                WriterState;
             {false, undefined} ->
                 WriterState
         end,
@@ -336,12 +338,17 @@ unicode(State) ->
     State#state.unicode.
 
 -spec unicode(state(), boolean()) -> state().
-unicode(#state{ reader = {ReaderPid, _} } = State, Bool) ->
-    MonRef = erlang:monitor(process, ReaderPid),
-    ReaderPid ! {self(), set_unicode_state, Bool},
-    receive
-        {ReaderPid, set_unicode_state, _} -> ok;
-        {'DOWN',MonRef,_,_,_} -> ok
+unicode(#state{ reader = Reader } = State, Bool) ->
+    case Reader of
+        {ReaderPid, _} ->
+            MonRef = erlang:monitor(process, ReaderPid),
+            ReaderPid ! {self(), set_unicode_state, Bool},
+            receive
+                {ReaderPid, set_unicode_state, _} -> ok;
+                {'DOWN',MonRef,_,_,_} -> ok
+            end;
+        undefined ->
+            ok
     end,
     State#state{ unicode = Bool }.
 

diff --git a/lib/kernel/src/user_drv.erl b/lib/kernel/src/user_drv.erl
@@ -69,7 +69,7 @@
         {requests, [request()]}.
 
 -export_type([message/0]).
--export([start/0, start/1, start_shell/0]).
+-export([start/0, start/1, start_shell/0, start_shell/1]).
 
 %% gen_statem state callbacks
 -export([init/3,server/3,switch_loop/3]).
@@ -283,8 +283,11 @@ server({call, From}, {start_shell, Args},
         true ->
             try prim_tty:reinit(TTY, #{input => maps:get(input, Args, true) }) of
                 NewTTY ->
+                    #{ read := ReadHandle, write := WriteHandle } = prim_tty:handles(NewTTY),
                     gen_statem:reply(From, ok),
-                    NewState = State#state{ tty = NewTTY },
+                    NewState = State#state{ tty = NewTTY,
+                                            read = ReadHandle,
+                                            write = WriteHandle },
                     case Args of
                         #{ initial_shell := noshell } ->
                             init_noshell(NewState);

diff --git a/lib/stdlib/doc/src/shell.xml b/lib/stdlib/doc/src/shell.xml
@@ -956,6 +956,60 @@ q                 - quit erlang
       </desc>
     </func>
 
+    <func>
+      <name name="start_interactive" arity="0" since="OTP-12345"/>
+      <fsummary>Start the interactive shell</fsummary>
+      <desc>
+        <p>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.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="start_interactive" arity="1" since="OTP-12345"/>
+      <fsummary>Start the interactive shell</fsummary>
+      <desc>
+        <p>Starts the interactive shell if it has not already been started.
+        It can be used to programatically start the shell from an
+        <seecom marker="erts:escript"><c>escript</c></seecom> or when
+        <seecom marker="erts:erl"><c>erl</c></seecom> is started with the
+        <seecom marker="erts:erl#noinput"><c>-noinput</c></seecom> or
+        <seecom marker="erts:erl#noshell"><c>-noshell</c></seecom> flags.
+        The following options are allowed:</p>
+        <taglist>
+          <tag>noshell</tag>
+          <item>
+              <p>Starts the interactive shell as if <seecom marker="erts:erl#noshell">
+                <c>-noshell</c></seecom> was given to <seecom marker="erts:erl"><c>erl</c></seecom>.
+                This is only useful when erl is started with
+                <seecom marker="erts:erl#noinput"><c>-noinput</c></seecom> and the
+                system want to read input data.
+              </p>
+          </item>
+          <tag><seetype marker="erts:erlang#mfa">mfa()</seetype></tag>
+          <item>
+              <p>Starts the interactive shell using
+                <seetype marker="erts:erlang#mfa"><c>mfa()</c></seetype>
+                as the default shell.</p>
+          </item>
+          <tag>{<seetype marker="erts:erlang#node">node()</seetype>,
+                <seetype marker="erts:erlang#mfa">mfa()</seetype>}</tag>
+          <item>
+              <p>Starts the interactive shell using
+              <seetype marker="erts:erlang#mfa"><c>mfa()</c></seetype> on
+              <seetype marker="erts:erlang#node"><c>node()</c></seetype> as the default shell.</p>
+          </item>
+          <tag>{remote, <seetype marker="erts:erlang#string"><c>string()</c></seetype>}</tag>
+          <item>
+              <p>Starts the interactive shell using as if
+                <seecom marker="erts:erl#remsh"><c>-remsh</c></seecom>
+                was given to <seecom marker="erts:erl"><c>erl</c></seecom>.</p>
+          </item>
+        </taglist>
+      </desc>
+    </func>
+
     <func>
       <name name="start_restricted" arity="1" since=""/>
       <fsummary>Exit a normal shell and starts a restricted shell.</fsummary>

diff --git a/lib/stdlib/src/shell.erl b/lib/stdlib/src/shell.erl
@@ -23,6 +23,7 @@
 -export([start_restricted/1, stop_restricted/0]).
 -export([local_allowed/3, non_local_allowed/3]).
 -export([catch_exception/1, prompt_func/1, strings/1]).
+-export([start_interactive/0, start_interactive/1]).
 
 -define(LINEMAX, 30).
 -define(CHAR_MAX, 60).
@@ -47,6 +48,16 @@ non_local_allowed({init,stop},[],State) ->
 non_local_allowed(_,_,State) ->
     {false,State}.
 
+-spec start_interactive() -> ok | {error, already_started | enottty}.
+start_interactive() ->
+    user_drv:start_shell().
+-spec start_interactive(noshell | mfa() | {node(), mfa()} | {remote, string()}) ->
+          ok | {error, already_started | enottty}.
+start_interactive({Node, {_M,_F,_A}}) ->
+    start_interactive({Node, _M,_F,_A});
+start_interactive(InitialShell) ->
+    user_drv:start_shell(#{ initial_shell => InitialShell }).
+
 -spec start() -> pid().
 
 start() ->

diff --git a/lib/stdlib/test/shell_SUITE.erl b/lib/stdlib/test/shell_SUITE.erl
@@ -36,6 +36,8 @@
 -export([ start_restricted_from_shell/1, 
 	  start_restricted_on_command_line/1,restricted_local/1]).
 
+-export([ start_interactive/1 ]).
+
 %% Internal export.
 -export([otp_5435_2/0, prompt1/1, prompt2/1, prompt3/1, prompt4/1,
 	 prompt5/1]).
@@ -3014,6 +3016,57 @@ otp_14296(Config) when is_list(Config) ->
     {error, {_,_,"bad term"}} = TF("1, 2"),
     ok.
 
+start_interactive(_Config) ->
+    rtnode:run(
+      [{expect, "test"},
+       {putline, "test."},
+       {eval, fun() -> shell:start_interactive() end},
+       {expect, "1>"},
+       {expect, "2>"}
+      ],[],"",["-noinput","-eval","io:format(\"test~n\")"]),
+
+    rtnode:run(
+      [{expect, "test"},
+       {putline, "test."},
+       {eval, fun() -> shell:start_interactive({shell,start,[]}) end},
+       {expect, "1>"},
+       {expect, "2>"}
+      ],[],"",["-noinput","-eval","io:format(\"test~n\")"]),
+
+    rtnode:run(
+      [{expect, "test"},
+       {putline, "test."},
+       {eval, fun() -> shell:start_interactive(noshell) end},
+       {eval, fun() -> io:format(user,"~ts",[io:get_line(user, "")]) end},
+       {expect, "test\\."},
+       {putline, "test."},
+       {eval, fun() -> shell:start_interactive() end},
+       {expect, "1>"},
+       {expect, "2>"}
+      ],[],"",["-noinput","-eval","io:format(\"test~n\")"]),
+
+    {ok, RPeer, RNode} = ?CT_PEER(),
+    unlink(RPeer),
+    SRNode = atom_to_list(RNode),
+    rtnode:run(
+      [{expect, "test"},
+       {putline, "test."},
+       {eval, fun() -> shell:start_interactive({remote, SRNode}) end},
+       {expect, "\\Q("++SRNode++")\\E2>"}
+      ],[],"",["-noinput","-eval","io:format(\"test~n\")"]),
+
+    {ok, Peer, Node} = ?CT_PEER(),
+    unlink(Peer),
+    SNode = atom_to_list(Node),
+    rtnode:run(
+      [{expect, "test"},
+       {putline, "test."},
+       {eval, fun() -> shell:start_interactive({Node, {shell,start,[]}}) end},
+       {expect, "\\Q("++SNode++")\\E2>"}
+      ],[],"",["-noinput","-eval","io:format(\"test~n\")"]),
+
+    ok.
+
 term_to_string(T) ->
     lists:flatten(io_lib:format("~w", [T])).