Here is one program that was born as a spin-off of Runner-QT. Meet CRunner: a program written with C++ and using Gtk+. The program is about 60 lines long and heavily commented -> you can easily follow the code.

CRunner accepts programs and programs with arguments. For example: firefox and firefox google.fi are both accepted. The later opens firefox window with google.fi in it.

/*CRunner v.1 Copyright (c) 2017 JJ Posti <techtimejourney.net>
#This program comes with ABSOLUTELY NO WARRANTY;
#for details see: http://www.gnu.org/copyleft/gpl.html.
#This is free software, and you are welcome to redistribute it under
#GPL Version 2, June 1991″)*/

Download CRunner.cpp(as a zip)

You need something along the lines of libgtk-3-dev and build-essential
installed in  order to compile CRunner. Also make sure that you have pkg-config installed.

Compile with the command:

g++ crunner.cpp -o crunner `pkg-config –cflags –libs gtk+-3.0`

-o crunner is the output file.  Adjust cflags and libs to match your system – if needed.

To clarify (due to WordPress formating errors): The command goes like this:

Run the program with this command: ./crunner . If needed make the progam executable with: chmod +x crunner .

Considerations.

Runner-QT and CRunner offer similar features. If any problems appear with Python+QT5 (Runner-QT) then CRunner becomes the default launcher dialog when PostX Gnu/Linux reaches Debian Stretch base.