Just wanted to chime in, when I press E to end gracefully it doesn't terminate after the loop.
Unless of course it has to do it for each thread, I most likely got impatient and terminated it ungracefully.
'E' doesn't work, but 'e' should. It's required only once ("waiting for children..." is the message signalling that it takes care of the termination of all threads)
It really should work. Please try.
On some systems I observed some weird input buffer configuration i.e. buffered although I explicitly set the input buffer to unbuffered mode.
So I have the habit of pressing 'e' followed by 'Return'. As the 'Return' doesn't hurt anything with that combination I got LBC terminated gracefully on every Linux system.
I'd be very surprised if that didn't work for you so please check.
Rico
$ LBC -c 4 -p 127702249-127705448
Loop off! Work on blocks [127702249-127705448] (3355 Mkeys)
Best generator chosen: gen-hrdcore-avx2-linux64
PAGE-TO: 127705448 PAGE-FROM: 127702249
Estimated duration: 24m 1.2833s
END requested. (Ending this loop) Waiting for children to finish...
started up LBC and immediately pressed 'e' - now it will take24 minutes before the process ends. It's of course superfluous here, because the process would have ended in manual mode anyway, but it still works. As the blocks up to 128 000 000 are done, you can test this feature with no risk like this
$ LBC -c 4 -p 1000-1100
If it works, ok, if not, try 'e' + Return. If nothing works, please report. And you can terminate it ungracefully (Ctrl+C) with no risk.