How to test which files will be copied with the cp command

cpfile-copy

I'm creating a simple script that copies all files from DIRECTORYA that do not exist in DIRECTORYB. I'm doing this through the use of the cp command:

cp -u DIRECTORYA/* DIRECTORYB

What I'd like to do is also send an email to an administrator that will list the files that have been copied.

So ideally, before I run the above command, I'd like to get the files that will be copied and store them in a variable for later use when building my email message.

Can anybody point me in the right direction? I've looked into using grep but I don't think this can be done with the cp command?

Best Answer

I don't think GNU cp has anything to help you if you want to see what it would do without acting. If you want to log the files that were modified, you can use the -v option:

cp -puv DIRECTORYA/* DIRECTORYB >copy.log

Instead of cp, you can use rsync, which is a lot more powerful and installed almost everywhere except for low-end embedded systems (and easy to install where it isn't present by default).

rsync -aun DIRECTORYA/* DIRECTORYB >what-would-be-done.txt

rsync -auv DIRECTORYA/* DIRECTORYB >copy.log

Related Solutions

Rsync – How to Compare Two Folders and Copy Differences

I am not sure whether you can do it with any existing linux commands such as rsync or diff. But in my case I had to write my own script using Python, as python has the "filecmp" module for file comparison. I have posted the whole script and usage in my personal site - http://linuxfreelancer.com/

It usage is simple - give it the absolute path of new directory, old directory and difference directory in that order.

#!/usr/bin/env python

import os, sys
import filecmp
import re
from distutils import dir_util
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()

Confusion on the cp command when creating a new directory

The command cp Foo Bar says "Copy the Foo directory to Bar". If it already exists, it will put Foo inside of Bar. If you want explicitly to copy the contents of Foo, use cp -r Foo/ Bar/ or, better, use rsync -a. To elaborate: if Bar does not exist, it will be created wtih cp; if it does not, it will act as the destination into which you want to copy files.

Best Answer

Related Solutions

Rsync – How to Compare Two Folders and Copy Differences

Confusion on the cp command when creating a new directory

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