Commands tagged ring (1)

  • pings a server once per second, and beeps when the server is unreachable. Basically the opposite of: ping -a server-or-ip.com which would beep when a server IS reachable. You could also substitute beep with any command, which makes this a powerful alternative to ping -a: while true; do [ "$(ping -c1W1w1 server-or-ip.com 2>/dev/null | awk '/received/ {print $4}')" = 1 ] && date || echo 'server is down!'; sleep 1; done which would output the date and time every sec until the ping failed, in which case it would echo. Notes: Requires beep package. May need to run as root (beep uses the system speaker) Tested on Ubuntu which doesn't have beep out of the box... sudo apt-get install beep


    14
    while true; do [ "$(ping -c1W1w1 server-or-ip.com | awk '/received/ {print $4}')" != 1 ] && beep; sleep 1; done
    sudopeople · 2009-03-31 20:47:56 4

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