Compare files and rename if contents differ

Question

I need to create a code that will:

1. Check for two arguments at the start minus the script name itself (i.e dar /mnt/sdb1 /root/testdir/testarc with $1 = /mnt/sdb1 and $2 = /root/testdir/testarc)
2. Copy all files with a .doc, .pdf and .PDF file extension from the source directory sdb1 (and its sub directories) to the destination directory
3. Use some type of cmp command (or perhaps diff?) to rename any files that may have the same name but different data during the copy process
4. If there is a .PDF/.pdf file with the same data as a .doc file then the .PDF/.pdf file should not be copied, only the .doc version

So far I have managed 1 and 2. 3 and 4 have me stumped.

Ignore the for loop, it's useless.

Here's my source code:

#!/bin/bash
sourcePath=$1
destPath=$2
Filedoc="*.doc"
Filepdf="*.pdf"
FilePDF="*.PDF"

if [[ $# -ne 2 ]]; then
    echo "Usage ; dar doc_path archive_path"
    exit 1
fi

if [ ! -d sourcePath ]
    then echo Directory does not exist
fi

if [ ! -d destPath ]
    then mkdir -p $destPath
fi

for file in $(find "${sourcePath}" -type f -exec basename {} \; | sort | uniq -d); do
  num=1 
  fileName=$(echo "${file}" | cut -d '.' -f1)
  fileExtension=$(echo "${file}" | cut -d '.' -f2)
  dirName=$(dirname "${duplicate}")
  for duplicate in $(find "${sourcePath}" -name "${file}" | tail -n +2 ); do
    mv "${duplicate}" "${duplicate}${fileName}_${num}.${fileExtension}"
    echo "Renamed duplicate file ${duplicate} ${duplicate}_${num}.${fileExtension}"
    (( num = num + 1 ))
  done
done

for file in $(find "${sourcePath}" -name "*.pdf"); do
  fileName=$(echo "${file}" | cut -d '.' -f1)
  if $(find $(sourcePath) -name "${fileName}.doc" &>/dev/nulll; then
    echo "Sorry, a .doc file with that extension already exists, skipping copy"
    continue
  fi
done

find "${sourcePath}" -name "$Filedoc" -exec cp -r {} "${destPath}" \;
find "${sourcePath}" -name "$Filepdf" -exec cp -r {} "${destPath}" \;
find "${sourcePath}" -name "$FilePDF" -exec cp -r {} "${destPath}" \;

Answer 1

You could use rsync with the --backup option to automatically make backups of files that exist in the destination directory. Note: this will only keep one backup copy - if the src file is changed twice, you will only have the most recent previous version as backup (renamed to filename~ by default)

e.g. something like:

#! /bin/bash

src="$1"
dst="$2"

# comment out the next line when you are sure it does what you want.
# And then try it with a trial destination dir a few times before
# running it with your real destination.
dryrun="--dry-run"

rsync $dryrun -avu --stats --progress --backup "$src" --include '**.doc' \
--include '**.pdf' --include '**.PDF' --exclude '**' "$dst/"  

If you wanted more backup copies, you could use the --backup-dir option. e.g.

#! /bin/bash

src="$1"
dst="$2"

dryrun="--dry-run"

BD=$(date '+%Y%m%d-%H%M%S')

rsync $dryrun -avu --stats --progress --backup --backup-dir="./$BD/" "$src" \
    --include '**.doc' --include '**.pdf' --include '**.PDF' \
    --exclude '**' "$dst/"  

Answer 2

cmp_or_rename()
    if    ! cmp -- "$1" "${2?NEED TWO ARGS}"
    then  ln -- "$1" "${1%.*}$((i+=1))${1#"${1%.*}"}"
    fi

...that only makes a hardlink, and I'm kinda iffy on which is source and which is dest and also a little on why... but if "$1" and "$2" are not names of two readable, identical files then "$1" is hardlinked to $1 - last ..* + (i++) + last ..*, or ln will let you know why not.