#!/bin/bash

function extract() {

  # Expect the uncompressed log files of one site in the
  # current directory.
  for i in *; do
    # Get the suffix from the filename.
    export suffix=`echo $i | awk -F . '{print $NF}'`

    # Output space separated key value pairs (day/hits)
    awk -v "day=$suffix" 'BEGIN {hits=0} /GET \/ HTTP.*Googlebot/ {hits++} END {print day" "hits}' $i
  done
}

# gnuplot does not like its input data unordered. 
# Printing results may take a while.
extract | sort -n