Does your wifi drop because of dodgy infrastructure or hardware?

.bash_extras

# Put the function below in your .profile or .bashrc or other suitable file
# Name the function whatever you fancy - I chose wifi 
# Change remote & delay accordingly
# Call it with no parameters, to watch and recover the existing wifi connection with feedback
# Call it with any parameter(s) to check and/or recover the existing wifi connection with feedback
# Capture some stats to a logfile as evidence of your crappy infrastructure. :-)


function wifi () {
  # TODO: Use GNU date to calculate seconds instead of SECONDS
  # TODO: Persist daily stats.

  # TODAY          = Today's date
  # DELAY          = number of seconds to wait befor retrying re-connect
  # REMOTE         = Remote IP address for pinger function
  # RECONNECTS     = Number of reconnections today.
  # DURATION_MAX   = Used to calculate MAX connection time.
  # DURATION_TOTAL = Used to calculate AVG connection time.
  # SECONDS        = Duration of last connection / re-connect.
  # SSID           = The SSID of the wireless network
  # LOGFILE        = Where to log output

  local oneShot=${1:-}
  local TODAY=$(date +%F)
  local DELAY=2
  local REMOTE=8.8.8.8
  local RECONNECTS=1
  local DURATION_MAX=0
  local DURATION_TOTAL=0
  local SSID=$(nmcli device | awk '$2 == "wifi" {print $NF; exit}')
  local WIFI=$(nmcli device | awk '$2 == "wifi" {print $1; exit}')
  local LOGFILE=/tmp/wifi_status_${SSID}
  SECONDS=0

  show_banner() {
    echo "${TODAY}: Watching ${SSID} connection on ${WIFI}..."
    echo " - [Reconnects] (Duration) {Average}"
  }

  show_duration() {
    printf "% 5i" ${SECONDS}
  }

  show_duration_avg() {
    printf "% 5i" $((${DURATION_TOTAL} / ${RECONNECTS}))
  }

  show_reconnects() {
    printf "% 4i" ${RECONNECTS}
  }

  show_stats() {
    case $1 in
      reconnect)  echo -n "No connection at $(date +%T) [$(show_reconnects)] ($(show_duration)) {$(show_duration_avg)} "
                  ;;
      daily|*)      echo "${TODAY}: Reconnects: [$(show_reconnects)] / Duration Max: (${DURATION_MAX}) / Duration Avg: {$(show_duration_avg)}"
                  ;;
    esac

  }

  set_duration_max() {
    if [ $SECONDS -gt $DURATION_MAX ]
    then
      DURATION_MAX=$SECONDS
    fi
  }

  set_duration_total() {
    DURATION_TOTAL=$((${DURATION_TOTAL} + ${SECONDS}))
  }

  pinger() {
    ping -c 1 -W 1 $REMOTE > /dev/null 2>&1
  }

  wifi_restart() {
    nmcli r wifi off
    nmcli r wifi on
  }

  trap show_stats 1 2 3 4

  if [ -z "$oneShot" ]
  then
    show_banner
  fi

  while true
  do
    # If today is a new day, output some stats and reset some counters.
    if [ "${TODAY}" != "$(date +%F)" ]
    then
      show_stats daily
      TODAY=$(date +%F)
      show_banner
      RECONNECTS=1
    fi

    local reconnected=0

    if ! pinger
      then
        set_duration_total
        set_duration_max
        show_stats reconnect
        wifi_restart
        SECONDS=0

        while ! pinger
        do
          if [ $((${SECONDS} % ${DELAY})) -eq 0 ]
          then
            echo -n ">"
            nmcli r wifi on
            nmcli device wifi rescan ssid ${SSID} > /dev/null 2>&1
          fi

          sleep ${DELAY}
        done

        echo " Re-Connected in $SECONDS seconds."

        reconnected=1
        RECONNECTS=$((${RECONNECTS} + 1))
        SECONDS=0
    fi

    if [[ -n "$oneShot" && $reconnected -eq 0 ]]
      then
        echo "Already cnnected."
        break
      else
      if [[ -n "$oneShot" ]]
      then
        break
      fi
    fi

    sleep ${DELAY}

  done | tee -a ${LOGFILE}
}