user/ping_offline.sh

   1 #!/bin/bash
   2 # Desc:Marks the time when a remote server can be pinged.
   3 # Depends: GNU Coreutils 8.32 (date, sleep), iputils-ping 3:20211215-1 (ping)
   4 # Version: 0.1.0
   5
   6 delay=10;
   7 domain="google.com"
   8
   9 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
  10 die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
  11 must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
  12
  13 if [[ -n "$1" ]]; then domain="$1"; fi;
  14
  15 SECONDS=0;
  16 printf "%s:STATUS:Starting ping...\n" "$(date -Is)";
  17 while [[ ! noPing == "true" ]]; do
  18     printf "%s:" "$(date -Is)"; # prepend line with date
  19     ping -c1 "$domain"; pingExitCode="$?"; # perform ping
  20
  21     if [[ "$pingExitCode" -eq 0 ]]; then
  22         # Case if ping succeeded
  23         printf "%s:Ping resolved after $SECONDS seconds.\n" "$(date -Is)";
  24         exit 0;
  25     elif [[ "$pingExitCode" -eq 1 ]]; then
  26         sleep "$delay";
  27         continue;
  28     else
  29         die "FATAL:Unknown error.";
  30         exit 1;
  31     fi;
  32 done;
  33
  34 yell "ERROR:Here be dragons.";
  35 exit 1;