Re: Adding `#' at each new line with text until the end of the file

[Merciadri Luca <Luca.Merciadri@student.ulg.ac.be>]

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pjb@informatimago.com (Pascal J. Bourguignon) writes:

> Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> writes:
>
>> pjb@informatimago.com (Pascal J. Bourguignon) writes:
>>
>>> Merciadri Luca <Luca.Merciadri@student.ulg.ac.be> writes:
>>>
>>>> pjb@informatimago.com (Pascal J. Bourguignon) writes:
>>>>
>>>>>> Sure, but, as I explained in my previous message, it does not even
>>>>>> modify the Sayings file. Why?
>>>>>
>>>>> Because you didn't instruct the program to modify the file.
>>>>> Read the documentation of insert, for example.  Does it mention files?
>>>>> What does insert modify?
>>>> Insert modifies the current buffer, according to the manual. Or
>>>> find-file loads its arg into a buffer. So, if find-file loads its arg
>>>> into the *current* buffer, insert should modify the current buffer,
>>>> that is, `Sayings'.
>>>
>>> (list
>>>     (progn (find-file "/tmp/Sayings")
>>>            (buffer-name (current-buffer)))
>>>     (progn (find-file "/mnt/Sayings")
>>>            (buffer-name (current-buffer))))
>>> --> ("Sayings" "Sayings<2>")
>>>
>>> Here you have two files, named "/tmp/Sayings" and "/mnt/Sayings", and
>>> when opening them at the same time,  we get "Sayings" and "Sayings<2>"
>>> as buffer names.
>>>
>>> Clearly, the buffer names are not entirely independant from the file
>>> names, but it should be obvious from the example, that there's two
>>> name spaces and two different kind of entities.  A buffer named "X" is
>>> not a file name "X".
>>>
>>> So to repeat what you wrote above:
>>>
>>> - find-file (or find-file-noselect) loads the contents of a  _file_
>>>   into a _buffer_.
>>>
>>> - insert modifies the contents of a _buffer_.
>>>
>>> When  you do only these to action what happens to the _file_?
>> Nothing, actually. That's the problem.
>
> Yes.  That's because you haven't said something.  What should you say
> to have the file modified in any way?
>
> \f
> Something like: 
>
>   - save the buffer to the file, keeping a backup of the old file.
>
> or, in emacs lisp: 
>
>    (save-buffer 1)
>
> Remember: Computers only do what you tell them to do!  ;-)
Yes.

Thanks for your implication in this.

I am now trying with

==
(defun fildi ()
  (find-file "~/Sayings")
  ;(goto-char (point-min))
  (while (< (point) (point-max))
    (when (looking-at ".")
      (insert "#"))
    (forward-line)) 
  (save-buffer 1) 
  )
==
which `should' do the trick, as the file is found, opened in the
buffer, the buffer is modified as I want it to be, and the buffer is
then saved. Why is it still erroneous?

Thanks.
- -- 
Merciadri Luca
See http://www.student.montefiore.ulg.ac.be/~merciadri/
- -- 

A real friend is someone who walks in when the rest of the world walks out.
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