#!/bin/sh

test -n "$2" || {
  echo "Usage: $0 <pdf> <mincopies>" >&2
  exit 1
}

FILE="$1"
FNAME=$(basename $FILE .pdf)
MINCOPIES="$2"
COPIES=1

while test $COPIES -lt $MINCOPIES; do
  COPIES=$((COPIES*2))
  NFILE=${FNAME}-${COPIES}.pdf
  pdfunite $FILE $FILE $NFILE || exit 1
  FILE=$NFILE
done

echo "Done $COPIES copies"