In praise of gnuplot's dumb terminal support

I have to say, again, I find gnuplot's dumb terminal support is so useful when you are at the command line and need to see a plot of some data. The plot is very rough but this is usually enough to give you enough insight into the data as to whether or not to continue to exploring it. The script I am using now is
#!/bin/bash

function show_usage {
echo \
usage: $(basename $0) \
[-x label] \
[-y label] \
[-t title] \
[-s width:height] \
[-f time-format-strftime] \
timeseries-input ...
}

function swap {
echo $2 $1
}

function parse_size {
W=$(expr $1 : "\\([0-9]*\\):[0-9]*")
H=$(expr $1 : "[0-9]*:\\([0-9]*\\)")
echo "$W $H"
}

TIMEFMT="%Y-%m-%dT%H:%M:%S"
XLABEL="Time"
YLABEL="Units"
TITLE="Timeseries"
SIZE=$(swap $(stty size))

while getopts "x:y:t:f:s:h" opt
do
case $opt in
x) XLABEL=$OPTARG ;;
y) YLABEL=$OPTARG ;;
t) TITLE=$OPTARG ;;
f) TIMEFMT=$OPTARG ;;
s) SIZE=$(parse_size $OPTARG) ;;
h) show_usage ; exit 0 ;;
*) show_usage ; exit 1 ;;
esac
done
shift $(expr $OPTIND - 1)

for INPUT in $*
do
if [ "$INPUT" = "-" ]
then
INPUT=$(mktemp /tmp/timeplot.XXXXXXXXXX)
cat > $INPUT
fi

gnuplot <<EOH
set terminal dumb $SIZE
set autoscale
set xdata time
set timefmt "$TIMEFMT"
set xlabel "$XLABEL"
set ylabel "$YLABEL"
set title "$TITLE"
plot "$INPUT" using 1:2 with lines
EOH
done

# END
For example, if the data in /tmp/data is
2011 34
2012 34
2013 56
2014 24
then this can be quickly plotted using
timeplot -f %Y /tmp/data
and get