Определите “действие строки”, как понято под Unix, кто управляет
tmpwatcher или "tmpreaper" в человечности.
http://linux.about.com/library/cmd/blcmdl8_tmpwatch.htm
используйте с-c
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
jferland pts/2 jferland:S.1 10:35 2.00s 0.18s 0.18s /bin/bash
jferland pts/3 jferland:S.2 10:35 45.00s 0.18s 0.00s sleep 30
jferland pts/1 jferland:S.0 10:35 0.00s 0.21s 0.00s w
S.0: The one I'm checking on, so definitely 0 time there.
S.1: I left a shell open. Two seconds before I pressed a key without pressing enter. So, any input received works even without a line return.
S.2: I ran while true; do echo "foo"; sleep 30; done. I even typed a character in the middle of it. Since the input was blocked (never read), I still appear idle there.
Conclusion
Idle time is reset when a character is read from the terminal input. Blocked input doesn't update idle time even if it does affect the screen display. Applications may update under different rules. For example, I used write which reads input by line, so it only updated my idle time upon pressing enter. The same was true for perl (literally executed as perl with no arguments).
Processes run all the time, and it doesnt matter for idle time.
If you do a:
while true; do w; sleep 0.1; done
in one terminal, and open another terminal, you will see that idle time of that other session is reset to zero, only when user inputs something (presses a key). If you run:
while true; do ls; done
in the other terminal the idle time will continue to rise.
So only when the session reads user input, the idle timer is reset.