dired copy files without overwriting?

Question

Q: how do I use dired to copy/move files without overwriting?

I'd like to use dired to copy (or move) files from directory A to directory B. However, I only want to copy files in A that do not already exist in B.

Example:

• Directory A contains file1.txt, file2.txt, and file3.txt.
• Directory B contains file1.txt.

How do I tell dired to copy only file2.txt and file3.txt from directory A to directory B? I can tell which ones to mark with just a few files, but I'm thinking about situations in which there are potentially thousands of files in the two directories.

Answer 1

Dired should prompt the user before overwriting any files by default.

Try this:

1. Create directories A and B and populate them as per your example.
2. Mark all files in directory A using dired-mark-subdir-files (default binding * s).
3. Copy them to directory B using dired-do-copy (default binding C).
4. Dired should prompt you with something like Overwrite 'B/file1.txt'? [Type yn!q or C-h].
5. If you type C-h, Dired will explain that you can either overwrite/skip this and/or all following conflicts using the different options. In your case, ESC or q will only copy non-conflicting files.
6. Dired should report something like Copy failed for 1 of 3 files--type ? for details ((file1.txt)).