#!/bin/sh

usage()
{
    echo "usage: $0 [-o pngfile] file ..." 1>&2
    exit 1
}


if [ "X$1" = X-o ]; then
    out=$2
    shift 2
fi
[ "$1" ] || usage
[ "${1#-}" = "$1" ] || usage

gnuplot -persist <<EOF
`[ "$out" ] && ( echo set term png\;; echo set output \'$out\'; )`
set xlabel "MHz"
set ylabel "dB"
set xrange [2402:2483]
#set yrange [-30:-5]
set title "Received signal strength"
set data style errorlines
plot \
  `for n in $@; do
     if [ "$n" = "${n#*=}" ]; then
	file=$n
	title=${n%.*}
     else
	file=${n#*=}
	title=${n%%=*}
     fi
     echo -n $comma \'$file\' title \'$title\'
     comma=,
   done`
EOF
