Is there a way to check whether `cp -r` would overwrite anything?

Question

Is there a way to check if cp -r would overwrite anything, without actually copying anything?

-n seems to copy files that don't collide, which is not what I want.

Possible duplicate of [Linux how to copy but not overwrite?](https://stackoverflow.com/questions/9392735/linux-how-to-copy-but-not-overwrite) — l'L'l, Jan 01 '19 at 18:13
Cross-site duplicate: https://unix.stackexchange.com/questions/187937/how-to-test-which-files-will-be-copied-with-the-cp-command — tripleee, Jan 02 '19 at 05:12

René Höhle · Answer 1 · 2019-01-01T18:15:55.287

2

The easiest way is to use the rsync command there you have a lot of parameters to override the target or delete files on the target if you want.

https://linux.die.net/man/1/rsync

or like mentioned in the comments you could use cp -n for --no-clobber. But in general i would suggest rsync there you have a lot more possibilities.

edited Jan 01 '19 at 18:15

answered Jan 01 '19 at 18:02

René Höhle

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Agree. If you need to know, cp is not the right tool. – Thorbjørn Ravn Andersen Jan 01 '19 at 18:03
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Note that cp has the -i --interactive option and the -n, --no-clobber option. – Jan 01 '19 at 18:11

score 0 · Answer 2 · answered Jan 01 '19 at 18:13

0

cp has the -i --interactive option and the -n, --no-clobber option. See `man 1 cp'.

answered Jan 01 '19 at 18:13

score 0 · Answer 3 · answered Jan 02 '19 at 11:09

To only check if the file exists in the target location, but not actually perform any copying you can use the diff command with the -r option.

From man diff:

-r, --recursive
recursively compare any subdirectories found

diff -r --brief --report-identical-files /source-folder/ /target-folder/ | grep -v '^Only in'

--brief is listing files that differ (same as -q)
--report-identical-files does the same for files that don't differ (same as -s)
The grep -v '^Only in' removes files that are only in one directory tree, because those will not be overwritten.

The output will look something like this:

Files /source-folder/file1.txt and /target-folder/file1.txt are identical
Files /source-folder/file2.jpg and /target-folder/file2.jpg differ

Is there a way to check whether `cp -r` would overwrite anything?

3 Answers3