stopped job (SIGTSTP)

What Ctrl+Z produces: [2]+ Stopped in the shell, state T in ps. Ctrl+Z sends SIGTSTP to the foreground job, and a stopped process executes nothing at all — not a line, not a timer, no progress. That is the trap, because Stopped gets read as "it went to the background". Putting the two side by side settles it: after a minute the same script started with & has written sixty more lines to /tmp/export.log, and the stopped one is still on line five. bg %2 sends it SIGCONT and resumes it where it froze; fg %2 does the same and keeps the terminal. Leaving one stopped is not harmless: push past the There are stopped jobs. warning by typing exit again and that work is terminated where it stands.