tail -f for a web page (I use it for following Bamboo build logs)

follow

#!/bin/bash
command="curl -s $1 2>/dev/null"
prev_output=$(eval "$command")
echo "$prev_output"

while :; do
    curr_output=$(eval "$command")
    curr_wc=$(echo "$curr_output" | wc -l)
    prev_wc=$(echo "$prev_output" | wc -l)
    wc_diff=$((curr_wc - prev_wc))
    if [[ $wc_diff -gt 0 ]]; then
        echo "$curr_output" | tail -n $wc_diff
    fi
    prev_output="$curr_output"
    sleep 2

done