Feature: virtual terminal

[milahu]

Feature

add a virtual terminal widget, so we can show the live stdout and stderr of the run function

Is your feature request related to a problem? Please describe

problem: when running the app without a terminal, then stdout/stderr are not visible

Describe the solution you'd like

challenges:

• capture stdout and stderr → function call to run_function or subprocess
• correctly interleave stdout and stderr
• render terminal control commands → virtual terminal (tty) / pseudo terminal (pty)
  • https://github.com/Saadmairaj/tkterminal
  • https://stackoverflow.com/questions/10239965/giving-a-command-in-a-embedded-terminal
  • https://stackoverflow.com/questions/7253448/how-to-embed-a-terminal-in-a-tkinter-application
  • https://stackoverflow.com/questions/62335989/redirect-terminal-output-to-tkinter

example: capture stdout with io.TextIOBase
https://stackoverflow.com/questions/51527750/capture-print-output-from-multiple-threads-in-python

import threading
import time
import sys
import io

class demo_copy_stdout():

  def __init__(self):

    def run_function():
      for i in range(0, 100):
        print(*sys.argv, i)
        time.sleep(1)

    self.run_function = run_function

    def main_function_wrapper(*argv):
        sys.argv = argv # set arguments
        # note: run_function takes no arguments
        return self.run_function()

    print("main_thread create")
    self.main_thread = threading.Thread(target=main_function_wrapper, args=("toy.py", "hello",))

    class CopyStdout(io.TextIOBase):
        def __init__(self, target):
            self.target = target
            #self.stringio = io.StringIO()
        def write(self, s):
            writecount = self.target.write(s)
            written = s[:writecount]
            #self.stringio.write(written)
            # TODO send to GUI
            with open("stdout.txt", "a") as f:
                f.write(written)
            return writecount
    print("copying stdout to tee.txt")
    original_stdout = sys.stdout
    sys.stdout = CopyStdout(sys.stdout)

    print("main_thread start")
    self.main_thread.start() # run

    if True:
        print("main_thread wait ...")
        self.main_thread.join() # wait
        print("main_thread done")
        sys.stdout = original_stdout # stop copying stdout

x = demo_copy_stdout()

Describe alternatives you've considered

Additional context

[milahu]

ps. im working on this : )

the input tab is the old interface with all the input elements, to set arguments

the output tab is a fully-featured bash terminal (todo: on windows run busybox-w32)

when the user hits start, the GUI switches to the output tab
and shows all output from the process

[FredHappyface]

Wow that looks awesome thanks for making a start on it. I was going to add it to the backlog as there's a couple other projects I'm focusing on right now

I'm assuming this is compatible with pysimplegui?

Cheers 😊

[milahu]

I'm assuming this is compatible with pysimplegui?

yes, this is implemented in psg

[FredHappyface]

Closing for the following reasons:

1. Challenges implementing this in a cross-platform way add terminal widget [DRAFT] #9 (comment)
2. Probably out of scope. I'd encourage an end user to use their fav terminal to start the process in the first place (though there are drawbacks to this)