Re: Making diff(1) of linux kernels faster

Nick Craig-Wood
2001-10-18T08:02:12Z

Horst von Brand wrote:
> =?iso-8859-1?q?willy=20tarreau?= <wtarreau@yahoo.fr> said:
> > Be very careful not to modify a multi-linked file, or
> > it will be damaged in all trees and won't be seen by
> > diff. your editor must unlink before saving.
>
> Most don't. ed(1), vi(1) and emacs(1) are careful tro write to the very
> same file. jed(1) is the only outlier I'm aware of...

emacs does mv file file~ before saving file so the edited file will
not be linked byt the backup file will be. You can stop it doing this
by setting backup-by-copying-when-linked.

$ echo "Test1" >> test1
$ ln test1 test2
$ emacs test2 # modify and save the file
$ ls -i test*
2491498 test1 2491500 test2 2491498 test2~

However as Horst von Brand noted if you try this with (standard) vi
you will edit the linked file which is the same behaviour as if you
set backup-by-copying-when-linked in emacs.

--
Nick Craig-Wood
ncw@axis.demon.co.uk