Re: newbie tries to hack comint.el (help!)

[bill <please_post@nomail.edu>]

In <877jujt2bx.fsf@tc-1-100.kawasaki.gol.ne.jp> Miles Bader <miles@gnu.org> writes:

>bill <please_post@nomail.edu> writes:
>> One thing that this function must do, but I have not been able to
>> figure out is how to to move the point to the beginning of the line
>> of the immediately preceding shell input.  I've been able to handle
>> simple cases, but not tricky ones like:
>>
>> myhost:~/some/dir$ foo \
>>> bar \
>>> baz_
>>
>> where '_' immediately after 'baz' indicates the location of the
>> point at the time I want to move it to the beginning of the line
>> beginning with "myhost".

>Probably you're best bet is to write your own regexp that matches your
>own prompt, but not shell `subprompts' like ">" -- or perhaps a regexp
>that only matches prompts you want to avoid -- and then scan back
>through what comint things are prompts, until you find something that
>matches (or doesn't match).

>For instance:

>   ;; Regexp matching prompts that `foo-beginning-of-previous-important-prompt'
>   ;; should avoid.
>   (defvar foo-avoid-prompt-regexp "^> *$")

>   ;; Move to the beginning of the previous comint prompt that doesn't match
>   ;; `foo-avoid-prompt-regexp'.
>   (defun foo-beginning-of-previous-important-prompt ()
>     (interactive)
>     (while (and (comint-previous-prompt)
>                 (let ((prompt-end-pos (point)))
>                   (forward-line 0) ; move to true beginning-of-line
>                   (string-match foo-avoid-prompt-regexp
>                                 (buffer-substring (point) prompt-end-pos))))))

>seems to work for your current example.

Good idea; it works like a charm.  Well, almost: I had to give an
argument of 1 to comint-previous-prompt (actually, I'm surprised
your code worked at all, unless the code you posted was not a
faithful cut-and-paste of the code you tested).

Many thanks.

	-bill