Question

How do I make diff ignore temporary files like foo.c~? Is there a configuration file that will make ignoring temporaries the default?

More generally: what’s the best way to generate a ‘clean’ patch off a tarball? I do this rarely enough (submitting a bug fix to an OSS project by email) that I always struggle with it…

EDIT: OK, the short answer is

diff -ruN -x *~ ... 

Is there a better answer? E.g., can this go in a configuration file?

Answer 1

This doesn’t strictly answer your question, but you can avoid the problem by configuring Emacs to use a specific directory to keep the backup files in. There are different implementations for Emacs or XEmacs.

In GNU Emacs

     (defvar user-temporary-file-directory       (concat temporary-file-directory user-login-name '/'))     (make-directory user-temporary-file-directory t)     (setq backup-by-copying t)     (setq backup-directory-alist       `(('.' . ,user-temporary-file-directory)         (,tramp-file-name-regexp nil)))     (setq auto-save-list-file-prefix       (concat user-temporary-file-directory '.auto-saves-'))     (setq auto-save-file-name-transforms       `(('.*' ,user-temporary-file-directory t))) 

In XEmacs

     (require 'auto-save)      (require 'backup-dir)       (defvar user-temporary-file-directory       (concat (temp-directory) '/' (user-login-name)))     (make-directory user-temporary-file-directory t)     (setq backup-by-copying t)     (setq auto-save-directory user-temporary-file-directory)     (setq auto-save-list-file-prefix           (concat user-temporary-file-directory '.auto-saves-'))     (setq bkup-backup-directory-info       `((t ,user-temporary-file-directory full-path))) 

You can also remove them all with a simple find command

     find . -name “*~” -delete 

Note that the asterisk and tilde are in double quotes to stop the shell expanding them.

By the way, these aren’t strictly temporary files. They are a backup of the previous version of the file, so you can manually ‘undo’ your last edit at any time in the future.