After pausing the process with ctrl-z, I attempted to send it to background with
bg command. Unfortunately, the process isn't sent to the background, and reappear to be running foreground. Then, I do a ctrl-z again in order to pause it again. Unfortunately, the key combination is no longer responding and the process is still ongoing. To make matters worst, the command is a
for loop on many items. If I hit ctrl-c, the job will resume on the next iteration, and until the last iteration.
Running on tmux inside iTerm on macOS.