Re: Why won't this command kill a buffer?

["B. T. Raven" <nihil@nihilo.net>]

Joe Fineman wrote:
> "B. T. Raven" <nihil@nihilo.net> writes:
> 
>> If you really mean "append" (put at the end) then this works
>> (on msw2000 with Emacs 22.3):
>>
>> "
>> append-to-file is an interactive compiled Lisp function in `files.el'.
>> It is bound to <f4>.
>> (append-to-file START END FILENAME)
>>
>> Append the contents of the region to the end of file FILENAME.
>> When called from a function, expects three arguments,
>> START, END and FILENAME.  START and END are buffer positions
>> saying what text to write.
>> "
>>
>> Interactively I had bound this function to f4 in .emacs
>> (define-key global-map [f4] 'append-to-file)
>> I made a test file with a few chars in it and saved it.
>> Inserted backspace into buffer with C-q *backspacekey* and then made
>> that single character (shows as ^?) the region and pressed f4.
>> Inspection of the last character of the file appended to shows:
>>
>> Char: DEL (127, #o177, #x7f) point=5 of 5 (80%) column=0
>>
>> I assume that what can be done interactively can also be done
>> programmatically.
> 
> Thank you.  I will give that a try.  It may turn out to be a nuisance,
> tho, that it requires inserting the character in the current buffer &
> then deleting it.  The function I defined is usually run in the
> background, and it might cause confusion in that it would cause the
> current buffer to be marked as modified, and might interact oddly with
> my keying.  What I would really like is an append-to-file command that
> takes as its argument an arbitrary character or string, rather than a
> substring of the current buffer.


It looks like Emacs sees such a procedure as too low-level. Since it
operates on files in buffers you would have to do
find-file-other-window, select-window, (goto-char (point-max)) and then
insert the char. I haven't been able to insert \ via elisp though. All
the functions produce 92, \nil, or "\\" or worse. I thought of creating
a file with only backslash in it and then running (shell-command "cat
file bacsla >> file") but if you need the character parameterized then
you need to shell-command on a program that does fputc on the file
opened for append.