Grabbing environment variables in gnuplot
set environment variables from bash e.g:
export positionsfile="$outputfile".positions export rankprogressfile="$outputfile"
Then use them from gnuplot e.g.:
set size 1,1 set ylabel "Count" set xlabel "Positions" set terminal postscript eps color set output "`echo $positionsfile`.eps" plot "`echo $positionsfile`" using 1:2 with lines