A simple internet connectivity test script

test_inet

#!/usr/bin/env zsh
#!/usr/bin/env bash
#Configure these as needed
host="google.com"
ping="ping -c1 -W1000 $host > /dev/null"
#Status update interval (In seconds)
statusinterval=300
dndstart="23:50"
dndend="09:30"
#reset wifi script - change this for a quick connection fix
resetwifi=~/reset_wifi.sh
maxwifiresets=3
retries=3
wifialreadyreset=0
#Init variables
scrname=$0
declare {SECONDS,RET,statustimer,pingfailures,internetlosses,keeprunning,_logtofile,usednd,verbose}=0


#log config
[[ -n "$TMP" ]] && log=$TMP/${scrname:t}.log || { [[ -d /tmp ]] && log=/tmp/${scrname:t}.log || log=~/${scrname:t}.log ; }

#Colors
blue='\033[0;34m'
green='\033[0;32m'
red='\033[0;31m'
white='\033[0m'

# positional arguments init
_arg_log="$log"

die()
{
  local _ret=$2
  test -n "$_ret" || _ret=1
  test "$_PRINT_HELP" = yes && print_help >&2
  echo "$1" >&2
  exit ${_ret}
}

begins_with_short_option()
{
  local first_option all_short_options='lvdch'
  first_option="${1:0:1}"
  test "$all_short_options" = "${all_short_options/$first_option/}" && return 1 || return 0
}

print_help()
{
  printf '%s\n' "Test internet connection"
  printf 'Usage: %s [-l|--log=<logfile>] [-c|--(no-)continue] [-d|--dnd=[<dndstart>-<dndend>]] [-v|--verbose] [-h|--help]\n' "$scrname"
  printf '\t%s\n' "-l=<logfile>, --log=<logfile>: log  to file (default: $log)"
  printf '\t%s\n' "-c, --continue, --no-continue: continue running on internet failure (off by default)"
  printf '\t%s\n' "-d=[<dndstart>-<dndend>], --dnd=[<dndstart>-<dndend>]: Define a do not disturb time period for silent notifications (default: $dndstart-$dndend)"
  printf '\t%s\n' "-v, --verbose: Prints verbose output"
  printf '\t%s\n' "-h, --help: Prints help"
}

parse_commandline()
{
  while test $# -gt 0
  do
    _key="$1"
    case "$_key" in
      -l|--log)
        _logtofile=1
        ;;
      --log=*)
        _logtofile=1
        _arg_log="${_key##--log=}"
        ;;
      -l=*)
        _logtofile=1
        _arg_log="${_key##-l=}"
        ;;
      -l*)
        _logtofile=1
        _next="${_key##-l}"
        if test -n "$_next" -a "$_next" != "$_key"
        then
          { begins_with_short_option "$_next" && shift && set -- "-l" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
        fi
        ;;
      -d|--dnd)
        usednd=1
        ;;
      --dnd=*)
        usednd=1
        _arg_dnd="${_key##--dnd=}"
        dndstart="${_arg_dnd%%-*}"
        dndend="${_arg_dnd##*-}"
        ;;
      -d=*)
        usednd=1
        _arg_dnd="${_key##-d=}"
        dndstart="${_arg_dnd%%-*}"
        dndend="${_arg_dnd##*-}"
        ;;
      -d*)
        usednd=1
        _next="${_key##-d}"
        if test -n "$_next" -a "$_next" != "$_key"
        then
          { begins_with_short_option "$_next" && shift && set -- "-d" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
        fi
        ;;
      -v|--verbose)
        verbose=1
        test "${1:0:5}" = "--no-" &&  verbose=0
        ;;
      -v*)
        verbose=1
        _next="${_key##-v}"
        if test -n "$_next" -a "$_next" != "$_key"
        then
          { begins_with_short_option "$_next" && shift && set -- "-v" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
        fi
        ;;
      -c|--no-continue|--continue)
        keeprunning=1
        test "${1:0:5}" = "--no-" &&  keeprunning=0
        ;;
      -c*)
        keeprunning=1
        _next="${_key##-c}"
        if test -n "$_next" -a "$_next" != "$_key"
        then
          { begins_with_short_option "$_next" && shift && set -- "-c" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
        fi
        ;;
      -h|--help)
        print_help
        exit 0
        ;;
      -h*)
        print_help
        exit 0
        ;;
      *)
        _PRINT_HELP=yes die "FATAL ERROR: Got an unexpected argument '$1'" 1
        ;;
    esac
    shift
  done
}

#Functions
try_ping() {
  trap - SIGALRM
  [[ $verbose -eq 1 ]] &&  eval "$ping" || eval "$ping" >/dev/null 2>&1
}

logtofile() {
  [[ $_logtofile -ne 1 ]] && return 0
  D="$(get_date)"
  echo "$D: $1" >> $log
}

in_dnd() {
  currenttime=$(date +%H:%M)
  if [[ "$dndstart" < "$dndend" ]]; then
    [[ "$currenttime" > "$dndstart" ]] && [[ "$currenttime" < "$dndend" ]] &&  return 0 || return 1
  else
    [[ "$currenttime" > "$dndstart" ]] || [[ "$currenttime" < "$dndend" ]] &&  return 0 || return 1
  fi
}

retry_connection() {
  for I in $(seq 1 $retries)
  do
    pingfailures=$((pingfailures+1))
    if [[ $I -gt 1 ]]
    then
      #make sure it's not a one time ping loss
      ansi_msg notice "||Notice|| - Multiple ping failures detected after $(get_duration). (Total failures: $pingfailures). Retry: $I/$retries"
    fi
    sleep 2
    try_ping
    RET=$?
    if [[ $RET -eq 0 ]]
    then
      #Notify only on more than one ping failure
      [[ $I -gt 1 ]] && ansi_msg ok "||Notice|| - Internet is connected, temporary ping failure. resuming..."
      return 0
    fi
  done
  return 2
}

get_duration() {
  duration=$SECONDS
  minutes=$((duration /60))
  seconds=$((duration % 60))
  if [[ $minutes -gt 60 ]]
  then
    hours=$((minutes/60))
    minutes=$((minutes % 60))
    if [[ $hours -gt 24 ]]
    then
      days=$((hours/24))
      hours=$((hours % 24))
      hourstext="$days days and "
    fi
    hourstext="$hourstext $hours hours and"
  fi
  echo "$hourstext $minutes minutes and $seconds seconds"
}

status_update() {
  if [[ $((SECONDS-statustimer)) -ge $statusinterval ]]
  then
    statustimer=$SECONDS
    ansi_msg notice "||Status update|| - Internet is connected. $(get_duration) elapsed."
  fi
}

notify() {
  msg="$1"
  if [[ $usednd -eq 1 ]] && in_dnd
  then
    osascript -e 'display notification "'$msg'" with title "'$scrname:t' says"'
  else
    msg="${msg//./[[slnc 300]]}"
    say "$msg"
  fi
}

internet_down_message() {
  local flags="LN"
  [[ $1 =~ ^- ]] && flags="${1/-/}" && shift
  internetdownmessage="Internet connection is down. $(get_duration) elapsed."
  ansi_msg -${flags} err "||Error|| - $internetdownmessage"
  return 0
}

reset_wifi() {
  [[ -f $resetwifi ]] &&
    { ansi_msg -L notice "||Notice|| - Rsetting wifi" ;
    sudo $resetwifi ; }
  sleep 3
}

ansi_msg() {
  [[ $1 =~ ^- ]] && local flags="$1" && shift
  msgtype="$1"
  msg="$2"
  case "$msgtype" in
    ok)
      prefix=${green}
      ;;
    err)
      prefix=${red}
      ;;
    notice)
      prefix=${blue}
      ;;
  esac
  msg="$(echo $msg | sed 's/||/${prefix}/;s/||/${white}/;s/(/\\(/;s/)/\\)/')"
  eval echo -e "$(get_date) - ${msg}"

  if [[ -n "$flags" ]]
  then
    msg=$(echo "$2" | sed -E 's/\|\|.*\|\|//;s/\-//;s/^ +//')
    [[ $flags =~ L ]] && logtofile "$msg"
    [[ $flags =~ N ]] && notify "$msg"
  fi
}

ctrl_c() {
  ansi_msg -L notice "||Summary|| - Total internet losses: $internetlosses. Total ping failures: $pingfailures"
  ansi_msg -L notice "||Warning|| - Terminating..."
  exit 0
}

get_date() {
  date +'%b %d %H:%M:%S'
}

main() {
  [[ $_logtofile -eq 1 ]]   && log="$_arg_log" &&  echo "Notice: Logging to file: $log" && logtofile "Start logging"
  [[ $keeprunning -eq 1 ]] && echo "Notice: Continuous mode"
  [[ $verbose -eq 1 ]] && echo "Notice: Verbose output"
  [[ $usednd -eq 1 ]] && echo "Notice: Do not disturb period: $dndstart - $dndend"

  [[ $((statusinterval % 60)) -eq 0 ]] &&
    echo "Notice: Status update every $((statusinterval/60)) minutes" ||
    echo "Notice: Status update every $((statusinterval/60)) minutes and $((statusinterval % 60)) seconds"

  echo "$(get_date) - Check Internet connection - $scrname:t"

  trap ctrl_c INT

  #Main loop
  while [[ $RET -eq 0 ]]
  do
    status_update
    sleep 0.5
    try_ping
    RET=$?
    if [[ $RET -ne 0 ]]
    then
      retry_connection
      RET=$?
    fi
    if [[ $RET -eq 0 && ${internetwasdown:-0} -eq 1 ]]
    then
      internetwasdown=0
      ansi_msg -LN ok "||Update|| - Internet is connected again"
      wifialreadyreset=0
    fi

    if [[ $RET -ne 0 ]]
    then
      [[ $wifialreadyreset -ge 1 ]] &&
        internet_down_message -L ||
        internet_down_message
      internetwasdown=1
      SECONDS=0
      statustimer=0
      [[ $wifialreadyreset -lt $maxwifiresets ]] && reset_wifi && wifialreadyreset=$((wifialreadyreset+1))
      if [[ $keeprunning -eq 1 ]]
      then
        RET=0
        internetlosses=$((internetlosses+1))
        ansi_msg err "||Notice|| - Internet losses until now: $internetlosses"
      else
        break
      fi
    fi
  done
}

parse_commandline "$@"
# ansi_msg ok "asd ||this is at test|| asdasd"
main