It is surprisingly hard to do this in Emacs, and I think it is a common
problem, as evidenced by e.g.:
https://stackoverflow.com/questions/384284/how-do-i-rename-an-open-file-in-emacs
http://emacsredux.com/blog/2013/05/04/rename-file-and-buffer/
http://rejeep.github.io/emacs/elisp/2010/03/26/rename-file-and-buffer-in-emacs.html
You can use dired, but I personally find it to be a distraction for this
use case.
There is set-visited-file-name, but:
a) it creates a copy of the file by default
b) the name is not intuitive and I doubt many people looking to rename a
file will find it
c) the best UI/UX is IMO different for different use cases, rename is
different from move
A very similar related pain point is that it is hard to get the path and
directory of the current buffers visited file. There exist ways to do
it, but this is a pair of related use cases and the handling is
completely different: for the path you have default-directory, an elisp
variable, and pwd, a command capable of displaying the path in
minibuffer or yanking it at point. For file name I am only aware of the
elisp function: buffer-file-name. Again, two closely related use cases,
handled very differently, I by now looked those up like 10 times and
every time I forget how to get this info because the names are so far
from what you would expect.
How can we fix or improve those issues?
For rename/delete/move I would create three distinct commands:
rename-visited-file-with-buffer
move-visited-file-with-buffer
delete-visited-file-with-buffer
Those names make the functions easy to discover if you are using
something like ivy or ido for M-x, while they are still precise from the
standpoint of Emacs concepts. It seems good to me to separate rename,
which should prefill the minibuffer prompt with the current name, and
ask only for a new filename, WITHOUT directory selection, from move,
which should prompt for a full new path, WITH directory selection.
For the current buffers file and directory name, I think aliasing
default-directory as visited-file-name-directory, and introducing
visited-file-name is one option. Another option: introduce
buffer-directory-name as a complement to the existing buffer-file-name
function. That would cleanup the elisp part, and then at least the names
are something you can remember, and with M-: you can kill, insert or
display those.
Question remains how to fix those things also on an user interface
level. I think it's a pity clicking on the filename in the modeline
changes the current buffer, I am happy to hear if I am mistaken, but
today this behavior is rather unexpected and I would be very surprised
to see somebody switching buffers this way. On the other hand it looks
like a nice place for a menu where all the operations mentioned could be
triggered (rename, move and delete file+buffer, display/kill/insert
directory name or file name). Providing default key bindings under a
common prefix for them could be nice too.
Maybe someone has some more, or better, ideas for this.
Finally, while we are discussing functions everyone re-implements in
their .emacs, please lets make transpose-windows happen as an Emacs
builtin :)
Cheers,
Jarosław Rzeszótko