pdf comparison

gistfile1.txt

If you have 2-3 huge pdf (or epub or other formats, read below) files to compare , then it is possible to combine the power of:

    calibre (to convert your source to text)

    meld (to visually search for the differences between the text files)

    parallel (to use all your system cores to speed up)

Below script accept as input any of the following file formats: MOBI, LIT, PRC, EPUB, ODT, HTML, CBR, CBZ, RTF, TXT, PDF and LRS.

If not installed, then install meld, calibre and parallel:

#install packages
#sudo apt-get -y install meld calibre parallel

usage="
*** usage:

diffepub - compare text in two files. Valid format for input files are:
MOBI, LIT, PRC, EPUB, ODT, HTML, CBR, CBZ, RTF, TXT, PDF and LRS.

diffepub -h | FILE1 FILE2

-h print this message

Example:
diffepub my_file1.pdf my_file2.pdf
diffepub my_file1.epub my_file2.epub

v0.2 (added parallel and 3 files processing)
"

#parse command line options
while getopts "h" OPTIONS ; do
  case ${OPTIONS} in
    h|-help) echo "${usage}"; exit;;
  esac
done
shift $(($OPTIND - 1))

#check if first 2 command line arguments are files
if [ -z "$1" ] || [ -z "$2" ] || [ ! -f "$1" ] || [ ! -f "$2" ]
then
  echo "ERROR: input files do not exist."
  echo
  echo "$usage"
  exit
fi



#create temporary files (first & last 10 characters of
# input files w/o extension)
file1=`basename "$1" | sed -r -e '
s/\..*$//                     #strip file extension
s/(^.{1,10}).*(.{10})/\1__\2/ #take first-last 10 chars
s/$/_XXX.txt/                 #add tmp file extension
'`
TMPFILE1=$(mktemp --tmpdir "$file1")

file2=`basename "$2" | sed -r -e '
s/\..*$//                     #strip file extension
s/(^.{1,10}).*(.{10})/\1__\2/ #take first-last 10 chars
s/$/_XXX.txt/                 #add tmp file extension
'`
TMPFILE2=$(mktemp --tmpdir "$file2")

if [ "$#" -gt 2 ] 
then
  file3=`basename "$3" | sed -r -e '
  s/\..*$//                     #strip file extension
  s/(^.{1,10}).*(.{10})/\1__\2/ #take first-last 10 chars
  s/$/_XXX.txt/                 #add tmp file extension
  '`
  TMPFILE3=$(mktemp --tmpdir "$file3")
fi

#convert to txt and compare using meld
doit(){ #to solve __space__ between filenames and parallel
  ebook-convert $1
}
export -f doit
if [ "$#" -gt 2 ] 
then
  (parallel doit ::: "$1 $TMPFILE1" \
                     "$2 $TMPFILE2" \
                     "$3 $TMPFILE3" ) &&
  (meld "$TMPFILE1" "$TMPFILE2" "$TMPFILE3")
else
  (parallel doit ::: "$1 $TMPFILE1" \
                     "$2 $TMPFILE2" ) &&
  (meld "$TMPFILE1" "$TMPFILE2")
fi