Dumb question? Copying file when target dir contains file with same name

I’m looking for a way to make a copy a file named “filename.ext” and name it “filename_n.ext”, where n is the smallest integer such that there’s no file in the directory named “filename_n.ext”. The following seems to sort of work, but I’d love to know if there’s a function out there with the right kind of reputation that could do the work without introducing any potential issues: ```elisp (defun my/make-copy (file) (progn (setq new_file file) (setq index 1) (while (file-exists-p new_file) (setq new_file (concat (file-name-sans-extension file) “_” (number-to-string index) "." (file-name-extension file))) (setq index (1+ index))) (copy-file file new_file)) ``` If not, I’d appreciate it if you could let me know whether you know of a better way of doing this. I’m still very much a beginner here… Thanks!

I don't know a function that does that, sorry, but I would use a `let` in your function: (defun my/make-copy (file) (let ((new_file file) (index 1)) (while (file-exists-p new_file) (setq new_file (concat (file-name-sans-extension file) "_" (number-to-string index) "." (file-name-extension file))) (setq index (1+ index))) (copy-file file new_file))

Oh, right. Makes sense. Thanks!

> if you could let me know whether you know of a better way of doing this Learn to use version control (e.g. git) and stop backing things up via file name.

`format` would be better suited than `concat` here.

I do use git, even if I'm by no means a power user, but I'm not sure this is the best approach for what I'm ultimately trying to do with this little function.

What is it you're trying to do?

I’m looking to define a function that will act on a citation key and update the metadata of any associated PDF files using information from the bibtex entry for that key. And it seemed wise to first create a copy of the file in a backup folder before running the command which will call `exiftool` to update the metadata info. Using regular `copy-file` didn’t seem like a good idea since I’d either have to override any older backups of the file or not create any backups if there were older backups with the same file.

If you're going to copy the file anyhow, you could do it the other way around. Copy the file(s) you're interested in altering to a temp location, run the command on the temp files, if the command is successful, then you replace the originals. If not, then you discard them.

Thanks for the suggestion! I’ll think about that option.