Make imagemagick's `display` exit at terminal, preserving the window (single instance mode)

Question

When I use imagemagick's display from command line, say:

$ display -density 150 test1.pdf 

... then display locks in the command line, until you exit the window (or press CTRL+C in terminal).

However, what I'd like to do, is when the above command is ran in terminal, then display would both start the window, and at the same time exit; then I could quickly press up arrow in terminal, and edit the settings (like -density), and repeat the now modified command line - which would likewise now exit, and the window would show the newly requested image.

This is similar to how scite has a "single instance mode" (see How to load new documents in a single instance of SciTE): when it is set up, you can say scite filename on the command line; scite then exits in terminal - while it opens the file as new tab (so you can quickly open files on command line by using bash history and up arrow). Now, I wouldn't expect display's GUI to have tabs, but I think it should be possible to somehow have display's window replace the content it displays upon a command...

Is what I want possible with imagemagick's display - and if so, how?

Many thanks in advance for any answers,
Cheers!

Answer 1

Well, just came up with a (very crude - no mouse interaction, no anything) script example using ImageMagick's Perl API, which demonstrates what I wanted done with display - so I thought I may just as well post about it here. The example is given in this answer: ImageMagick API for command-line GUI application interface to display - Stack Overflow.

Hope I get to eventually read about how to do this with ImageMagick's display, though :)

Cheers!