Compare 2 directories and copy differences to directory 3

Question

Hello -

I have three directories. I would like to compare directory1 with directory2, then take those changes/new files and copy them over to directory3. Is there an easy way to do this, maybe by using linux diff and cp commands? I'm open to ideas.

Thanks!

Andrew

Answer 1

I believe this is what you want from your description.

for file in dir2/*; do
    file_in_dir1=dir1/$(basename ${file})
    if [ ! -e  ${file_in_dir1} ]; then
        # If the file in dir2 does not exist in dir1, copy
        cp ${file} dir3
    elif ! diff ${file} ${file_in_dir1}; then
        # if the file in dir2 is different then the one in dir1, copy
        cp ${file} dir3
    fi
done

One thing I wasn't sure about is what you wanted if a file exists in dir1 but not dir2.

Answer 2

The thread yonder solves your problem quite nicely, I should think!

Copied from there:

#!/bin/bash

# setup folders for our different stages
DIST=/var/www/localhost/htdocs/dist/
DIST_OLD=/var/www/localhost/htdocs/dist_old/
DIST_UPGRADE=/var/www/localhost/htdocs/dist_upgrade/

cd $DIST

list=`find . -type f`

for a in $list; do
   if [ ! -f "$DIST_OLD$a" ]; then
        cp --parents $a $DIST_UPGRADE
      continue
   fi
   diff $a $DIST_OLD$a > /dev/null
   if [[ "$?" == "1" ]]; then
        # File exists but is different so copy changed file
        cp --parents $a $DIST_UPGRADE
   fi
done