From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.emacs.help Subject: Re: Number of open buffers? Date: 20 Nov 2003 22:15:14 +0100 Organization: Organization?!? Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Message-ID: References: NNTP-Posting-Host: deer.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1069363932 27893 80.91.224.253 (20 Nov 2003 21:32:12 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 20 Nov 2003 21:32:12 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Nov 20 22:32:09 2003 Return-path: Original-Received: from monty-python.gnu.org ([199.232.76.173]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1AMwPI-0000jU-00 for ; Thu, 20 Nov 2003 22:32:08 +0100 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.24) id 1AMxKp-0006mn-DM for geh-help-gnu-emacs@m.gmane.org; Thu, 20 Nov 2003 17:31:35 -0500 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!news.tele.dk!news.tele.dk!small.news.tele.dk!fu-berlin.de!uni-berlin.de!p3ee20bb4.dip.t-dialin.NET!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 59 Original-NNTP-Posting-Host: p3ee20bb4.dip.t-dialin.net (62.226.11.180) Original-X-Trace: news.uni-berlin.de 1069362915 59824963 62.226.11.180 (16 [198409]) X-Face: 2FEFf>]>q>2iw=B6, xrUubRI>pR&Ml9=ao@P@i)L:\urd*t9M~y1^:+Y]'C0~{mAl`oQuAl \!3KEIp?*w`|bL5qr,H)LFO6Q=qx~iH4DN; i"; /yuIsqbLLCh/!U#X[S~(5eZ41to5f%E@'ELIi$t^ Vc\LWP@J5p^rst0+('>Er0=^1{]M9!p?&:\z]|;&=NP3AhB!B_bi^]Pfkw User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3.50 Original-Xref: shelby.stanford.edu gnu.emacs.help:118505 Original-To: help-gnu-emacs@gnu.org X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.2 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: main.gmane.org gmane.emacs.help:14446 X-Report-Spam: http://spam.gmane.org/gmane.emacs.help:14446 Ignoramus1904 writes: > In article , Micah Cowan wrote: > > Ignoramus1904 writes: > > > >> Eli Zaretskii wrote: > >> >> From: Ignoramus1904 > >> >> > >> >> I want to modify it so that if the # of open file buffers is more than > >> >> one, emacs would ask YES/NO, if less, I exit. I am a very bad lisp > >> >> programmer, any suggestions? > >> > > >> > > >> > For a more bullet-proof code, walk the buffer list returned by the > >> > function buffer-list, and filter out any buffer which doesn't have a > >> > file associated with it (its buffer-file-name will be nil). What is > >> > left are the buffers which visit files. > >> > > >> > >> Thanks Eli, sounds a little bit above my head to be honest. I do C++ > >> and Perl and do not know Lisp well. I just thought that there was a > >> function like get-number-of-file-buffers, or something like that. > > > > The following is what he's talking about, I think: > > > > (defun get-number-of-file-buffers () > > (interactive) > > (let (num) > > (setq num 0) > > (dolist (buf (buffer-list)) > > (when (buffer-file-name buf) > > (setq num (+ num 1)) > > )) > > num > > ) > > ) Somewhat shorter: (defun get-number-of-file-buffers () (interactive) (let ((num 0)) (dolist (buf (buffer-list) num) (when (buffer-file-name buf) (setq num (1+ num)))))) > Thanks. When I try to run it via eval-expr, saying > > (insert get-number-of-file-buffers) > > It says: Error: void-variable. Data: get-number-of-file-buffers Yes. One calls a function by putting it after an opening parenthesis. The way you tried to "call" it, just a variable of that name got referenced, and there is no such variable. In addition, the function returns a numeric expression, and `insert' expects a string. -- David Kastrup, Kriemhildstr. 15, 44793 Bochum