Multiple pdf 4 fb reader

#!/bin/bash
#place multiple PDF in working directory - all PDF after conversion will be deleted
rename 's/ /_/g' *.pdf
find -iname '*.pdf' -exec pdftotext {} {}.txt \;
find . -iname "*.txt" -exec sed -i "s/
                                      //g" '{}' \;
for i in `ls *.txt`;do tr "\n" " " < $i > $i.2.txt ;done
for i in `ls *.2.txt`;do sed -e "s/.\{1000\}/&\n\n/g" <$i>$i.3.txt ;done
rm *.pdf.txt *.2.txt *.pdf
rename "s/.pdf.txt.2.txt.3//g" *
rename 's/_/ /g' *.txt