Re: M-! M-n should fetch filename (Re: FFAP)

[Juri Linkov]

>> What is missing is an ability of M-! M-n to fetch the filename as the
>> default in Dired mode using `dired-get-filename'.
>
> I don't have an opinion on whether that's good/bad/useful/...

It is useful when there is a need to prepare and run a command
from Dired with a file name in the middle of the command line,
i.e. instead of fiddling with `*' and `?' surrounded by whitespace
and hoping to get the right result with the `!' command,
it is easier just to type `M-! M-n' and build the explicit
command line based on the file name at point.

> If people find it to be a good feature, please rework the patch so
> there's only one call to file-relative-name, rather than one in each
> branch of the test.

Below is a version with only one call to file-relative-name:

Index: lisp/simple.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/simple.el,v
retrieving revision 1.1022
diff -c -r1.1022 simple.el
*** lisp/simple.el      30 Oct 2009 02:00:30 -0000      1.1022
--- lisp/simple.el      10 Nov 2009 00:57:27 -0000
***************
*** 2136,2143 ****
    (interactive
     (list
      (read-shell-command "Shell command: " nil nil
!                       (and buffer-file-name
!                            (file-relative-name buffer-file-name)))
      current-prefix-arg
      shell-command-default-error-buffer))
    ;; Look for a handler in case default-directory is a remote file name.
--- 2152,2163 ----
    (interactive
     (list
      (read-shell-command "Shell command: " nil nil
!                       (let ((filename
!                              (cond
!                               ((eq major-mode 'dired-mode)
!                                (dired-get-filename nil t))
!                               (buffer-file-name))))
!                         (and filename (file-relative-name filename))))
      current-prefix-arg
      shell-command-default-error-buffer))
    ;; Look for a handler in case default-directory is a remote file name.

-- 
Juri Linkov
http://www.jurta.org/emacs/