I want a really easy thing to happen, I want the bash to open a picture with QuickPictureViewer (qpv) and then some seconds or after a if function with some specific value that this process is terminated. The problem is, that the bash opens the picture and the script doesn´t go on (because the terminal is now for controlling the application) until i manually terminate the process showing the picture. How do I resolve that? Do I need 2 scripts for that?
You may start qpv in background with & suffix:
qpv someimage.png &
qpv_pid=$!
# do_something here ...
kill $qpv_pid
Did you consider running that qpv process in background?