Re: emacs-home variable for Windows

[zugzwang <buyoninternt@bluebottle.com>]

On Oct 14, 4:49 pm, "B. T. Raven" <ni...@nihilo.net> wrote:
> Lennart Borgman wrote:
> > On Wed, Oct 14, 2009 at 6:50 AM, B. T. Raven <ni...@nihilo.net> wrote:
> >> Lennart Borgman wrote:
> >>> On Wed, Oct 14, 2009 at 2:00 AM, ken <geb...@mousecar.com> wrote:
> >>>> I carry a USB stick to the job.  It's got emacs installed on it and
> >>>> there's a link on my desktop that I click (after inserting the stick)
> >>>> and emacs fires up.  It's nice.  I use it every day.  With the paucity
> >>>> of decent editors from Windows, I *need* it.
>
> >>>> There's a couple minor hassles though that I'd like to dispense with.
> >>>> One is that I don't know a way to tell emacs what the HOME directory is.
> >>>>  In the past I've just gone into the registry and change some variable
> >>>> there.  I don't remember where that is or how to do it though.  Besides,
> >>>> I prefer to have the variable defined in my .emacs (which is at the
> >>>> top-level directory on the USB stick).  (After emacs loads, I do "M-x
> >>>> loadfile RETURN e:/.emacs" and that little task loads up the rest of the
> >>>> stuff emacs needs to know.  But I don't know how tell emacs to make e:/
> >>>> the home directory.
>
> >>> There is a library usb-setup.el in Emacs+EmacsW32 for this.
>
> >> Can this .el file be downloaded separately from EmacsW32 to use with the
> >> standard Emacs w32 build? Is it somewhere in nXhtml 1.97 or has it been
> >> removed?
>
> > No, at the moment it is only in Emacs+EmacsW32 and I have not had time
> > to setup a repository for that.
>
> > However all that file does is to use the ideas from
>
> >  http://at-aka.blogspot.com/2006/06/portable-emacs-22050-on-usb.html
>
> > and reorganises them a bit. So just look there instead.
>
> Thanks, Lennart. I almost understand the stuff at that link but I can't
> see how the variable 'data-directory refers to the right drive letter
> until after Emacs is launched from the flash drive. The drive letter
> could be G:\ when plugged in today and H:\ tomorrow.
>
> With GnuW32 utils I got as far as producing:
>
> df -a | tail -1 > usbemacs.bat
>
> with the result:
>
> STORE N GO             4021232   1850100   2171132  47% G:\
>
> I am at a loss as to where I should go from here.
>
> Thanks again,
>
> Ed

I've never used emacs, and my Dos batch-writing skills are rusty, so
all I can offer is a conceptual solution.  Presumably, your emacs
distribution contains a directory not found on any other drive (e.g.
<drive_letter>:\MyEmacsDir\).  Any unique path will do.  Simply have
the desk icon start a batch file that begins as follows:

dir C:\MyEmacsDir\
If error: directory not exist, continue : else set variable_1 to 'C'
and then goto Label_1:

dir D:\MyEmacsDir\
If error: directory not exist, continue : else set variable_1 to 'D'
and then goto Label_1:

dir E:\MyEmacsDir\
If error: directory not exist, continue : else set variable_1 to 'E'
and then goto Label_1:

...

Label_1:
set <Emacs_Home> to %variable_1%<desired_path>
execute %variable_1%:\<desired path_name + executable file_name>