utils/watchcat/files/watchcat.sh

   1 #!/bin/sh
   2
   3 mode="$1"
   4
   5 shutdown_now() {
   6         local forcedelay="$1"
   7
   8         reboot &
   9
  10         [ "$forcedelay" -ge 1 ] && {
  11                 sleep "$forcedelay"
  12
  13                 echo b > /proc/sysrq-trigger # Will immediately reboot the system without syncing or unmounting your disks.
  14         }
  15 }
  16
  17 watchcat_allways() {
  18         local period="$1"; local forcedelay="$2"
  19
  20         sleep "$period" && shutdown_now "$forcedelay"
  21 }
  22
  23 watchcat_ping() {
  24         local period="$1"; local forcedelay="$2"; local pinghosts="$3"; local pingperiod="$4"
  25
  26         time_now="$(cat /proc/uptime)"
  27         time_now="${time_now%%.*}"
  28         time_lastcheck="$time_now"
  29         time_lastcheck_withinternet="$time_now"
  30
  31         while true
  32         do
  33                 # account for the time ping took to return. With a ping time of 5s, ping might take more than that, so it is important to avoid even more delay.
  34                 time_now="$(cat /proc/uptime)"
  35                 time_now="${time_now%%.*}"
  36                 time_diff="$((time_now-time_lastcheck))"
  37
  38                 [ "$time_diff" -lt "$pingperiod" ] && {
  39                         sleep_time="$((pingperiod-time_diff))"
  40                         sleep "$sleep_time"
  41                 }
  42
  43                 time_now="$(cat /proc/uptime)"
  44                 time_now="${time_now%%.*}"
  45                 time_lastcheck="$time_now"
  46
  47                 for host in "$pinghosts"
  48                 do
  49                         if ping -c 1 "$host" &> /dev/null
  50                         then
  51                                 time_lastcheck_withinternet="$time_now"
  52                         else
  53                                 time_diff="$((time_now-time_lastcheck_withinternet))"
  54                                 logger -p daemon.info -t "watchcat[$$]" "no internet connectivity for $time_diff seconds. Reseting when reaching $period"
  55                         fi
  56                 done
  57
  58                 time_diff="$((time_now-time_lastcheck_withinternet))"
  59                 [ "$time_diff" -ge "$period" ] && shutdown_now "$forcedelay"
  60
  61         done
  62 }
  63
  64         if [ "$mode" = "allways" ]
  65         then
  66                 watchcat_allways "$2" "$3"
  67         else
  68                 watchcat_ping "$2" "$3" "$4" "$5"
  69         fi