Flicker-free OSD display of system information

I know it's an old post, but I found it was the only one when searching online.

What you can do is print the elements that don't change first, like CPU % C

Then with another process of osd_cat you print the values that do change.

I found using the popular example of piping the output of a loop that has a sleep to osd_cat causes them to go out of sync and even more flicker.

Here's how I did it for example: https://github.com/kevinlekiller/shell_scripts/blob/main/misc/osd_stats.sh

Edit: With the solution I provided, there's no flicker, but there's a transition between when osd_cat prints on the screen, this is because the osd_cat process terminates, then the string has to be computed and osd_cat is called again, the transition we see, is that in between time.

We can get rid of this transition time by forking the call to osd_cat in the loop, then we use sleep inside the loop, with a slightly lower delay than the time we for osd_cat, this might cause a bit of a overlap for a few milliseconds, but we don't see the transition. I'll edit the script I linked above and add these changes.