SFINX documents - Emacs

In case you prefer to start an editor every time there is some editing to do, we recommend you use MicroEmacs (mem), vi or vim. These editors are small and load quickly, and yet they provide all the features you need for simple editing (there are a couple of other editors which are not available on all systems, such as EDT, PICO and JOVE).

However, GNU emacs can be a very useful tool if you know how to use its features. One emacs process can edit many files, allowing you to switch between them. And one copy of GNU emacs takes less memory than three copies of MicroEmacs.

Now, this is all fine, but what if an editor is started automaticlly, e.g. from a mailer like elm ? Well, you can make such programs use the existing emacs, using a client-server protocol, implemented through the emacsclient command and the -f server-start command in Emacs.

To make the use of this system easier, Sfinx provides a command Emacs (note the capital E !!) which will show the appropriate behaviour in (almost) every case:

• If not on an X display, start emacs. (It is assumed that you need this editor here, on this screen, even if another copy is running anywhere else)
• If no emacs server is found running, start one (as a separate X window) and put it in server mode for future calls.
• If an emacs server is running, and a file name is supplied, contact the server through the emacsclient program, passing the name of the file to be edited. If the server is running on another host (but on the same display), it is contacted through a remote shell. This works, as long as:
  1. the user has a proper .rhosts file;
  2. the home directory is shared between the machines (which it is for almost all users, with the exception of a few who have moved their home directory to a data disk).
• In case a file is about to be edited which is not accessible to the remote system (such as files in /tmp), a local copy of emacs is started.
• In case no file name is supplied, and a server is already running, a message will be displayed to notify the user of this fact.
  It might be that the lock file is left behind, e.g. when the emacs process crashed. If you get this message, you should check if there still is an emacs process running. This is known to happen when X crashes.

  setenv EDITOR Emacs
  alias emacs Emacs

NOTE: to tell emacs that you are finished with the client buffer, use C-x # (server-edit). Of course you can re-bind this function to a more convenient function key, e.g.

  (global-set-key [f7] 'server-edit)

NOTE: If you intend to use Emacs from elm, make sure to tell elm to store its temporary files in a directory that is shared by all machines. To do this, include in ~/.elm/elmrc something like:

tmpdir = $HOME/Mail/tmp/

See also then Emacs (l), emacs (1) and emacsclient (1) man-pages.