This is my first attempt in response to a question posed in one of StackExchange sites for Unix/Linux – How do you compare two folders and copy the difference to a third folder?. The scripts compares the latest directory, given as argument one, to an old directory, argument two, and creates a difference directory if it doesn’t exist, third argument, and copies the files and directories which exist only in latest directory into the difference directory. It also copies files which are different in latest directory as compared to the old one, to the difference directory. Make sure to put the arguments in the right order – latest directory first, old directory next, and the difference directory last.

Sample usage:

daniel@linubuvma:~/scripts/python$ python copy_difference.py /tmp/test/current /tmp/test/old /tmp/test/difference

(Silent output is good).

daniel@linubuvma:~/practice/python$ ls -1R /tmp/test/current/
/tmp/test/current/:
dirc
extra
newone
one
three
two

/tmp/test/current/dirc:

/tmp/test/current/extra:
extra2
fourth

/tmp/test/current/extra/extra2:

/tmp/test/current/newone:
file2
fileone
daniel@linubuvma:~/practice/python$ ls -1R /tmp/test/old
/tmp/test/old:
extra
newone
one
two

/tmp/test/old/extra:

/tmp/test/old/newone:
file2
daniel@linubuvma:~/practice/python$ ls -1R /tmp/test/difference
ls: cannot access /tmp/test/difference: No such file or directory
daniel@linubuvma:~/practice/python$ python copy_difference.py /tmp/test/current /tmp/test/old /tmp/test/difference
daniel@linubuvma:~/practice/python$ ls -1R /tmp/test/difference
/tmp/test/difference:
extra
newone
three
two

/tmp/test/difference/extra:
fourth

/tmp/test/difference/newone:
fileone

Here is the Python script.

#!/usr/bin/env python

import os, sys
import filecmp
import re
import shutil
holderlist=[]

def compareme(dir1, dir2):
    dircomp=filecmp.dircmp(dir1,dir2)
    only_in_one=dircomp.left_only
    diff_in_one=dircomp.diff_files
    dirpath=os.path.abspath(dir1)
    [holderlist.append(os.path.abspath( os.path.join(dir1,x) )) for x in only_in_one]
    [holderlist.append(os.path.abspath( os.path.join(dir1,x) )) for x in diff_in_one]
    if len(dircomp.common_dirs) > 0:
        for item in dircomp.common_dirs:
            compareme(os.path.abspath(os.path.join(dir1,item)), os.path.abspath(os.path.join(dir2,item)))
        return holderlist

def main():
 if len(sys.argv) > 3:
   dir1=sys.argv[1]
   dir2=sys.argv[2]
   dir3=sys.argv[3]
 else:
   print "Usage: ", sys.argv[0], "currentdir olddir difference"
   sys.exit(1)

 if not dir3.endswith('/'): dir3=dir3+'/'

 source_files=compareme(dir1,dir2)
 dir1=os.path.abspath(dir1)
 dir3=os.path.abspath(dir3)
 destination_files=[]
 new_dirs_create=[]
 for item in source_files:
   destination_files.append(re.sub(dir1, dir3, item) )
 for item in destination_files:
  new_dirs_create.append(os.path.split(item)[0])
 for mydir in set(new_dirs_create):
   if not os.path.exists(mydir): os.makedirs(mydir)
#copy pair
 copy_pair=zip(source_files,destination_files)
 for item in copy_pair:
   if os.path.isfile(item[0]):
    shutil.copyfile(item[0], item[1])

if __name__ == '__main__':
 main()