How to prevent backup for files larger than 3MB?

Question

One of the emacs's nice features is Backup.
But is there any way to prevent backup for files larger than 3MB? Thanks!

Have you tried advising backup-enable-predicate, or setting it to a custom function which checks the size of its argument? — Basil, Mar 27 '21 at 15:40

score 1 · Answer 1 · answered Mar 27 '21 at 15:54

I haven't tested this, but here's an example of how you could advise backup-enable-predicate so that your size check happens only after the default backup-enable-predicate has determined that your file should be backed up:

(add-function :after-while backup-enable-predicate
              (lambda (file)
                ;; Back up FILE only if it is smaller than 3 MiB.
                (< (file-attribute-size (file-attributes file)) 3145728)))

How to prevent backup for files larger than 3MB?

1 Answers1