How to run a command within a previously opened terminal with gnome-terminal command in a shell script?

I want to run a source code that needs four terminal A, B, C and D. There are some commands for source code running in Ubuntu. These commands must be run in order in terminals A, B, C, D, A, B and C. Indeed these commands are interconnected and must be executed in this specific order.

I want to automatically run the source code with shell scripting. I already have wrote a shell script that opens multiple terminals with gnome-terminal and it works well so far:

gnome-terminal --title="A" -- bash -c "cd ~; ./myscript1; exec bash"
gnome-terminal --title="B" -- bash -c "cd ~; ./myscript2; exec bash"
gnome-terminal --title="C" -- bash -c "cd ~; ./myscript3; exec bash"
gnome-terminal --title="D" -- bash -c "cd ~; ./myscript4; exec bash"

Now I want back to terminal A and run another command within it.

The following statement does not work fine, it opens a new terminal!

gnome-terminal --title="A" -- bash -c "cd ~; command; exec bash"

I did not understand how to do this after reading man pages of Gnome-terminal and searching in the web.

You can't, except perhaps on a hackish way using keypress simulation. e.g. xdotool to switch back to the first window, then paste some commands.

There may be better ways to do what you want. However, in order for us to give better suggestions, we need to know what you really want to achieve.

Try with the following demo running A and B

A master script creates a temporary file (in /tmp) and starts a-script and b-script in xterm windows.

Install

sudo apt install xterm

Put all the scripts into a dedicated directory, make them executable and run

./master

master:

#!/bin/bash

echo "$0 start"

b4a=$(mktemp)

nohup xterm -fa default -e ./a-script "$b4a" 2> /dev/null &
nohup xterm -fa default -e ./b-script "$b4a" 2> /dev/null &

if test -f "$b4a"
then
 rm "$b4a"
fi
echo "$0 finish"

a-script:

#!/bin/bash

echo "$0 start"
echo "$0 can do things here ..."
while ! test -f "$1"
do
 sleep 1
 echo -n "."
done
echo ""
echo "$0 can do things here ..."
rm "$1"
read -p "$0: Press enter to finish "

b-script:

#!/bin/bash

echo "$0 start"
echo "$0 can do things here ..."
sleep 5
touch "$1"
read -p "$0: Press enter to finish "