issue with the /dev/stdout redirection into a file

[pavel1murat]

• Checked for duplicates

Describe the bug

Dear ROOT developers,

since, I believe, introduction of ROOT v6, after one redirects /dev/stdout to a file, by typing, for example,
".> a.txt", one can no longer see what he is typing on the command line - the typed characters are saved
to a.txt, but are not duplicated on the screen.

Moreover, pressing the up-arrow key brings to the screen usual escape characters (as shown in the example below -
"^[[A" corresponds to me pressing up-arrow) and a user has to remember the contents of the command stack till he finally
types ".>" and gets visibility of the command prompt back.

-- many thanks for taking time and looking into it, Pasha

Expected behavior

The desired (a'la ROOT 5) behavior is that after the redirection, the output of the compiled code is redirected
to the specified file, everything coming from /usr/stdin is also sent to that file, but also duplicated on the screen,
so the command line is fully visible and editable at any time.

To Reproduce

murat@mu2e01:/data/murat/mu2e_dev>root.exe
   ------------------------------------------------------------------
  | Welcome to ROOT 6.22/06                        https://root.cern |
  | (c) 1995-2020, The ROOT Team; conception: R. Brun, F. Rademakers |
  | Built for linuxx8664gcc on Nov 27 2020, 15:14:08                 |
  | From tags/v6-22-06@v6-22-06                                      |
  | Try '.help', '.demo', '.license', '.credits', '.quit'/'.q'       |
   ------------------------------------------------------------------

root [0] .> a.txt
.?
^[[A
.>
root [4] 

Setup

1. ROOT version : v6xx - I believe, any will do
2. Operating system : Linux
3. How you obtained ROOT: via centralized Fermilab code management

Additional context

https://root-forum.cern.ch/t/back-to-redirecting-the-command-line-output-to-a-file-how-to-use-the-command-line-history-buffer/39886
https://its.cern.ch/jira/browse/ROOT-10842

[pavel1murat]

dear ROOT developers, this bug has been reporter two years ago and not yeat fixed in 6.28/04.

in the early days of ROOT development bugs like this were fixed by Rene within a day, so let me ask -
what is going on?

I'd appreciate a response.

-- regards, Pavel Murat

[Axel-Naumann]

Hi Pavel,

Apologies for that - it's pretty bad that your didn't receive any reaction from us, I should have as a minimum responded with the following:

Sorry, that's indeed annoying and sadly far from trivial to fix. I will see what to do here (and what CINT did).

Currently, redirection really means redirection; I agree that's not as useful as copying at least the terminal input.

[pavel1murat]

thank you , Axel. I understand that properly redirecting output of the interpreter may not be trivial.
A quick suggestion: the syntax

a() ; .> a.log

which assumes that the "dot" commands are allowed on the same line with the C++ statements may be easier
to implement correctly than the current one
.> a.log
a()
.>
-- regards, Pavel Murat

[dpiparo]

Another example

As reported [on the forum|https://root-forum.cern.ch/t/back-to-redirecting-the-command-line-output-to-a-file-how-to-use-the-command-line-history-buffer/39886], and after testing on different platforms, the ROOT command prompt doesn't work properly when redirecting it in a file. For example, on Windows:

root [0] .> a.txt
root [1] .!dir
root [2] .ls
root [3] .>
root [4]

While on Linux (and most probably on Mac too):

root [0] .> blah.txt

.!ls
.>
root [3]