ethereum gas telegram alert

gas_alert.sh

#!/bin/bash

# get channel id
# https://api.telegram.org/bot<YourBOTToken>/getUpdates

# crontab
#  */5 * * * bash /path/gas_alert.sh 2>&1 | logger -t gas_alert

cheapPrice="80"
url="https://api.etherscan.io/api?module=gastracker&action=gasoracle"
tempFile="/tmp/gas_alert_last_notification_time.txt"

price=$(curl $url | jq '.result.SafeGasPrice | tonumber' )

function isOneHourPassed {
  local lastNotificationTime=$(cat "$tempFile" 2> /dev/null)
  local currentTime=$(date +%s)

  if [ -z "$lastNotificationTime" ]; then
      echo "true"
      return
  fi

  local diff=$(($currentTime - $lastNotificationTime))
  local oneHour=3600
  if [ "$diff" -gt "$oneHour" ]; then
      echo "true"
  else
      echo "false"
  fi
}

if [ "$price" -lt "$cheapPrice" ] && [[ $(isOneHourPassed) == "true" ]] ; then
  curl -v "https://api.telegram.org/bot$TELEGRAM_TOKEN/sendMessage?chat_id=$TELEGRAM_CHANNEL_ID&text=ETH%20gas%20price%20${price}"

  date +%s > "$tempFile"
fi