[SOLVED] TProcess doesn't output Carriage Returns before linebreaks

[MMarie]

I've been having this strange issue since ive moved to using readkey to get user input on console. I have not modified anything regarding the usage of TProcess and i write a CRLF after every press of enter. I'm not quite sure why this could be happening and have no clue what information is necessary.

Here is my unit where I get the user Input (also please excuse some of the messiness in my code, i will clean it up when im done with this issue :

Code: Pascal  [Select][+][-]

1. {$mode fpc}
2. unit uInteractiveMode;
3.  
4. { uInteractiveMode.pp ; Interactive Shell for DEASH }
5. { author: Marie Eckert                              }
6.  
7. {$H+}
8.  
9. interface
10.   uses Crt, Dos,
11. {$IF defined(UNIX)}
12.        BaseUnix,
13. {$ENDIF}
14.        SysUtils, StrUtils, Types, uDEASHConsts, uHelpers, uInternalProcs,
15.        uXDebug, uScriptEngine, uPathResolve, uTypes;
16.  
17.   procedure LaunchShell;
18.  
19.   const
20.     { INPUT ACTIONS }
21.     IA_ENTER  = 0;
22.     IA_CLEFT  = 1;
23.     IA_CRIGHT = 2;
24.  
25.   var
26.     history          : TextFile;
27.   {$IF defined(UNIX)}
28.     sig_int_handler  : PSigActionRec;
29.     sig_quit_handler : PSigActionRec;
30.   {$ENDIF}
31.     should_quit      : Boolean;
32. implementation
33. {$IF defined(UNIX)}
34.   procedure HandleSigInterrupt(sig: cint); cdecl;
35.   begin
36.   end;
37.  
38.   procedure HandleSigQuit(sig: cint); cdecl;
39.   begin
40.     should_quit := True;
41.   end;
42.  
43.   procedure InstallSignals;
44.   begin
45.     debugwriteln('Installing SIGINT handler...');
46.     new(sig_int_handler);
47.     sig_int_handler^.sa_Handler := SigActionHandler(@HandleSigInterrupt);
48.     fillchar(sig_int_handler^.Sa_Mask, sizeof(sig_int_handler^.sa_mask),#0);
49.     sig_int_handler^.Sa_Flags := 0;
50.  
51.   {$IF defined(LINUX)}
52.     sig_int_handler^.Sa_Restorer:=Nil;
53.   {$ENDIF}
54.  
55.     if fpSigAction(SIGINT, sig_int_handler, nil) <> 0 then
56.     begin
57.       deasherror('Error while installing SIGINT handler: '
58.                     + IntToStr(fpgeterrno) + '.');
59.       halt(1);
60.     end;
61.  
62.     debugwriteln('Installing SIGQUIT handler...');
63.     new(sig_quit_handler);
64.     sig_quit_handler^.sa_Handler := SigActionHandler(@HandleSigQuit);
65.     fillchar(sig_quit_handler^.Sa_Mask, sizeof(sig_quit_handler^.sa_mask), #0);
66.     sig_quit_handler^.Sa_Flags := 0;
67.  
68.   {$IF defined(LINUX)}
69.     sig_quit_handler^.Sa_Restorer:=Nil;
70.   {$ENDIF}
71.  
72.     if fpSigAction(SIGQUIT, sig_quit_handler, nil) <> 0 then
73.     begin
74.       deasherror('Error while installing SIGQUIT handler: '
75.                     + IntToStr(fpgeterrno) + '.');
76.       halt(1);
77.     end;
78.   end;
79. {$ENDIF}
80.  
81.   procedure HandleKeypress(AKey: Char; var AInputBuff: String;
82.                             var AAction: Integer);
83.   begin
84.     if AKey = #0 then AKey := readkey;
85.  
86.     case Integer(AKey) of
87.     13: AAction := IA_ENTER;
88.     else
89.     begin
90.       write(AKey);
91.       AInputBuff := AInputBuff + AKey;
92.     end; end;
93.   end;
94.  
95.   procedure HandleInputAction(const AAction: Integer; var AInputBuff: String);
96.   begin
97.     case AAction of
98.     IA_ENTER: write(#13#10);
99.     end;
100.   end;
101.  
102.   procedure LaunchShell;
103.   var
104.     eval_result: TEvalResult;
105.     script: TScript;
106.     inbuff: String;
107.     action: Integer;
108.     rchar: Char;
109.   begin
110.     should_quit := False;
111.  
112.     debugwriteln('Launching shell');
113.   {$IF defined(LINUX)}
114.     InstallSignals;
115.   {$ENDIF}
116.     DoScriptExec(ResolveEnvsInPath('$HOME/.deashrc'));
117.  
118.     script.scriptpath := ResolveEnvsInPath('$HOME/.deash_history');
119.     script.exited := False;
120.     script.nline := 1;
121.     script.incomment := False;
122.     SetLength(script.codeblocks, 1);
123.     script.codeblocks[0] := BLOCKTYPE_NONE;
124.     script.registering_proc := -1;
125.  
126.     Assign(history, script.scriptpath);
127.     if not FileExists(script.scriptpath) then
128.       ReWrite(history)
129.     else
130.       Append(history);
131.  
132.     while not script.exited and not should_quit do
133.     begin
134.       write('deash ', GetCurrentDir(), '> ');
135.  
136.       inbuff := '';
137.       repeat
138.         action := -1;
139.         if eof() then
140.         begin
141.           should_quit := True;
142.           break;
143.         end;
144.  
145.         rchar := readkey;
146.         HandleKeypress(rchar, inbuff, action);
147.         HandleInputAction(action, inbuff);
148.       until (action = IA_ENTER) or should_quit;
149.  
150.       if should_quit then break;
151.  
152.       script.cline := inbuff;
153.       write(history, script.cline);
154.  
155.       if script.cline = 'debug_cbtrace' then
156.         DoInternalCmd(script.cline, [], script)
157.       else
158.         eval_result := Eval(script);
159.  
160.       script.nline := script.nline + 1;
161.     end;
162.  
163.     Close(history);
164.   end;
165. end.
166.  

And here is the unit which handles Process Execution:

Code: Pascal  [Select][+][-]

1. {$mode fpc}
2. unit uExecutor;
3.  
4. { uExectuor.pp ; Invoke execution handler for deash }
5. { Author: Marie Eckert                              }
6.  
7. interface
8.   uses Classes, StrUtils, SysUtils, Types, Process, uDEASHConsts, uHelpers;
9.  
10.   type
11.     TInvoke = record
12.       invoketype : Integer;
13.       location   : String;
14.       parameters : TStringDynArray;
15.     end;
16.  
17.     TInvokeResult = record
18.       code: Integer;
19.       message: String;
20.     end;
21.  
22.   function ExecBin(const ABinaryLocation: String; const AParameters: TStringDynArray): TInvokeResult;
23.  
24.   const
25.     BUF_SIZE = 2048;
26. implementation
27.   function ExecBin(const ABinaryLocation: String; const AParameters: TStringDynArray): TInvokeResult;
28.   var
29.     process: TProcess;
30.     parameter: String;
31.   begin
32.     ExecBin.code := 0;
33.     ExecBin.message := '';
34.  
35.     writeln;
36.     process := TProcess.Create(nil);
37.     process.executable := ABinaryLocation;
38.     for parameter in AParameters do
39.       process.parameters.add(parameter);
40.  
41.     process.options := [poPassInput];
42.     process.execute;
43.  
44.     while process.running do
45.     begin
46.     end;
47.  
48.     process.free;
49.   end;
50. end.
51.  

Also here is sample output of what happens:

Code: Text  [Select][+][-]

1.  
2.       /\               USER marie@thinkarch
3.                                                 /  \                OS "Arch Linux"
4.                                                                                        /\   \             PKGS 1409
5.                                                                                                                       /      \          KERNEL 6.2.12-arch1-1
6.                                                                                                                                                                /   ,,   \          SHELL /bin/bash
7.                          /   |  |  -\        UPTIME 43 minutes
8.                                                               /_-''    ''-_\          CPU Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz
9.                                                                                                                                                           MEM 4958528 / 65486528 kB
10.  
11.  
12. I hope those containment parameters are still nominal.
13.                                                       deash /home/felix/workspace/deash>
14.  

[marcov]

TProcess is just relays binary data. It doesn't implement any text level filtering. Maybe Crt eats it as it intercepts stdin and -out

[MMarie]

I've tried this fix i found in https://forum.lazarus.freepascal.org/index.php?topic=44149.0 where I just reassign output to '', but this completly strips the return carriage, so i think the only valid options are:
  1. Create my own interception which forces a CR before a LF
  2. Copy Crt to my inc/ directory and patch out the reassignment

I'm not totally happy with both options. Is there another unit that has a readkey equivalent which does not redirect stdout?

[marcov]

Maybe ncrt works for you.

Afaik some forms of input/output trapping puts the console in raw mode, with different lf characteristics.

[Fred vS]

Hello.

Maybe you will have more luck using keyboard unit ( vs crt ):

Here one of the example: https://forum.lazarus.freepascal.org/index.php/topic,57682.msg429176.html#msg429176

[MMarie]

Hello.

Maybe you will have more luck using keyboard unit ( vs crt ):

Here one of the example: https://forum.lazarus.freepascal.org/index.php/topic,57682.msg429176.html#msg429176

It works with the keyboard unit, thanks Only was a bit confused in the beginning because I didnt realise that i'd have to call DoneKeyboard before i start writing to stdout again…