open-or-bring-to-front is a command line script to be run with some custom keybinding attached to it. It launches the application passed as <launch-command> (see Usage below) if the application hasn't already a window open, which matches with <search-string>. If it does, it brings all the windows of said application to front.

open-or-bring-to-front

#!/bin/bash

# open-or-bring-to-front
# 
# open-or-bring-to-front is a command line script to be run with
# some custom keybinding attached to it. It launches the application
# passed as <launch-command> (see Usage below) if the application hasn't
# already a window open, which matches with <search-string>.
# If it does, it brings all the windows of said application to front.
# 
# The difference with other versions I found is that it supports
# having a name to search for that is different from the "terminal"
# command to be run.
# 
# It depends on "xdotool" so be sure to have it installed and somewhere
# in your path. An installation command using Ubuntu could be: 
# 
# sudo apt install xdotool
# 
# That said, open-or-bring-to-front works as follows:
# 
# open-or-bring-to-front <search-string> <launch-command>
# 
# Examples (yes, same name works too):
#
# - open-or-bring-to-front terminal gnome-terminal
# - open-or-bring-to-front edge-beta microsoft-edge-beta
# - open-or-bring-to-front spotify spotify 

prog="$1"
launch="$2"

activate_all_windows() {
	for pid in $windows; do
		xdotool windowactivate $pid
	done
}

logic_with_server() {
    number_windows="$(echo $windows | wc -w)"
    if [[ $number_windows -lt 2 ]]; then
	    $launch &
        windows="$(xdotool search --desktop 0 $prog)"
    fi
    activate_all_windows
    exit
}

windows="$(xdotool search --desktop 0 $prog)"
case $prog in

emacs)
    logic_with_server
	;;
spotify)
    logic_with_server
	;;
*)
    if [ -z "$windows" ]; then
	    $launch &
        windows="$(xdotool search --desktop 0 $prog)"
    fi
    activate_all_windows
	exit
	;;
esac