build png from nginx access log

buildgraph.sh

#!/bin/bash

FILE=$1

FDATE=$(head -1 $FILE |awk '{print $4}'|sed -e 's/\[//'|sed -e 's/\//-/g'|sed -e 's/:/ /')
FDATE_S=$(date -d "$FDATE" '+%s');
FDATE_T=$((FDATE_S + 3600));
COUNT=0

DATAFILE=$(mktemp)
RESULTFILE="result-"$(date -d "$FDATE" '+%Y-%m-%d')".png"

while read line
do
    LDATE=$(echo $line|awk '{print $4}'|sed -e 's/\[//'|sed -e 's/\//-/g'|sed -e 's/:/ /')
    LDATE_S=$(date -d "$LDATE" '+%s');
    if (( LDATE_S < FDATE_T )); then
        COUNT=$((COUNT + 1))
    else
        echo "$(date -d @"$((FDATE_T - 3600))" '+%Y-%m-%d %H:%M:%S') $COUNT" >>$DATAFILE
        FDATE_T=$((FDATE_T + 3600))
        COUNT=1;
    fi
done <$FILE

gnuplot << EOF
reset
set xdata time
set timefmt "%Y-%m-%d %H:%M:%S"
set format x "%m/%d\n%H:%M"
set autoscale
set ytics
#for sane graduation
set xtics 10000, 3600
set grid y
set auto y
set term png truecolor
set output "$RESULTFILE"
set xlabel "Time"
set ylabel "Request per hour"
set grid
set boxwidth 0.95 relative
set style fill transparent solid 0.5 noborder
#size
set term png size 2800,400
#x inscriptions rotation
#set xtics rotate by -30
plot "$DATAFILE" using 1:3 w boxes lc rgb "green" notitle
EOF

rm -f $DATAFILE