Re: How to automatically write *Messages" buffer to a file?

[Stefan Monnier]

>> (setq after-change-functions nil)

>    Never use `setq' on a hook.  Use `add-hook' or `remove-hook'.

> I didn't know it was a hook (though I did think to myself that it was
> very hook-like).  The variable name is not descriptive.  Maybe it
> should be aliased to or renamed `after-change-hook'.

Normal hooks have names that end in `-hook'.  Special hooks
(e.g. hooks whose functions take arguments, or whose return value is not
ignored) have names that end in `-functions'.  It's all explained in the
elisp manual, of course.

>    As for your question, don't use `append-to-file', use `write-region'
>    instead, and pass `quiet' as the VISIT argument to prevent the message.
> Shouldn't advice to `write-region' be sufficient?

You can't put "advice" and "sufficient" together like that without adding
a smiley somewhere.  `advice' is a sledghammer: it's the last resort before
modifying the source code.

`append-to-file' is only defined so as to make appending possible
interactively.  From elisp you should jsut call `write-region' directly.

> `append-to-file' just calls this function.  True, using `write-region' is
> more transparent (and I had an error in my advice to this function), but
> I don't see why advising `write-region' and then calling `append-to-file'
> wouldn't work.

Advising is a source of major headaches because of unexpected interactions
with other pieces of code which do not expect write-region to
behave differently.  Advice have to be written *extremely* carefully.
I.e. if you can do it without `advice', then don't use `advice'.


        Stefan