Emacs - Support for Perl embedded in GNU Emacs
perlmacs -w -MEmacs -e main -- --display :0.0 file.txt
#! /usr/bin/perlmacs
use Emacs;
use Emacs::Lisp;
setq { $mail_self_blind = t; };
exit main ($0, "-q", @ARGV);
This module replaces STDIN, STDOUT, STDERR, %ENV, and
%SIG with versions that work safely within an Emacs session. It
also defines a function named main, which launches an Emacs editing
session from within a script.
When you use Emacs in a perlmacs script, a Perl sub named
main may be used to invoke the Emacs editor. This makes it
possible to put customization code, which would normally appear as
Lisp in ~/.emacs, into a Perl script. For example, this startup
code
(setq
user-mail-address "gnaeus@perl.moc"
mail-self-blind t
mail-yank-prefix "> "
)
(put 'eval-expression 'disabled nil)
(global-font-lock-mode 1 t)
(set-face-background 'highlight "maroon")
(set-face-background 'region "Sienna")
could be placed in a file with the following contents:
#! /usr/local/bin/perlmacs
use Emacs;
use Emacs::Lisp;
setq {
$user_mail_address = 'gnaeus@perl.moc';
$mail_self_blind = t;
$mail_yank_prefix = '> ';
$eval_expression{\*disabled} = undef;
};
&global_font_lock_mode(1, t);
&set_face_background(\*highlight, "maroon");
&set_face_background(\*region, "Sienna");
exit main($0, "-q", @ARGV);
When you wanted to run Emacs, you would invoke this program.
The arguments to main correspond to the argv of the main
function in a C program. The first argument should be the program's
invocation name, as in this example. -q inhibits running
~/.emacs (which is the point, after all).
Reading a line from Perl's STDIN filehandle causes a string to be
read from the minibuffer with the prompt "Enter input: ". To show
a different prompt, use:
use Emacs::Lisp;
$string = &read_string ("Prompt: ");
Printing to Perl's STDOUT filehandle inserts text into the current
buffer as though typed, unless you have changed the Lisp variable
standard-output to do something different.
Perl's warn operator and STDERR filehandle are redirected to the
minibuffer.
Access to %ENV is redirected to the Lisp variable
process-environment.
Setting signal handlers is not currently permitted under Emacs.
main sub may open an X display and not close it. That is the
most obvious of many problems with main.
The thing is, Emacs was not written with the expectation of being embedded in another program, least of all a language interpreter such as Perl. Therefore, when Emacs is told to exit, it believes the process is really about to exit, and it neglects to tidy up after itself.
For best results, the value returned by main should be passed to
Perl's exit soon, as in this code:
exit (main($0, @args));
Copyright (C) 1998,1999,2000 by John Tobey, jtobey@john-edwin-tobey.org. All rights reserved.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
perl, Emacs::Lisp, emacs.