From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jean Louis Newsgroups: gmane.emacs.help Subject: Better way to make sure external command exists in the system? Date: Thu, 18 Mar 2021 15:13:02 +0300 Message-ID: Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39338"; mail-complaints-to="usenet@ciao.gmane.io" To: Help GNU Emacs Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Mar 18 13:15:11 2021 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lMrYV-000A8y-Hk for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 18 Mar 2021 13:15:11 +0100 Original-Received: from localhost ([::1]:41014 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMrYU-0008Fl-JN for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 18 Mar 2021 08:15:10 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:54052) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMrXD-0007uV-N0 for help-gnu-emacs@gnu.org; Thu, 18 Mar 2021 08:13:55 -0400 Original-Received: from stw1.rcdrun.com ([217.170.207.13]:41721) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMrXA-0001Hr-GH for help-gnu-emacs@gnu.org; Thu, 18 Mar 2021 08:13:51 -0400 Original-Received: from localhost ([::ffff:41.202.241.30]) (AUTH: PLAIN securesender, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 0000000000027F30.00000000605343D8.0000202D; Thu, 18 Mar 2021 05:13:11 -0700 Received-SPF: pass client-ip=217.170.207.13; envelope-from=support1@rcdrun.com; helo=stw1.rcdrun.com X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:128440 Archived-At: I have changed the OS on one computer and noticed that my Emacs Lisp programs use external commands like: mailutils, mail, pandoc, markdown, and others. Sometimes I was hard coding the path names like /usr/local/bin and now some commands changed to /usr/bin And some functions should not even run if external command does not exist. I would even like to stop loading the .el program if necessary external programs do not exist in the system. For that reason I would do some changes: - instead of hard coding the program name within quotes, I will use variable. Instead of (shell-command "mogrify ...") I will rather use something like (shell-command (format "%s ..." mogrify-command)) - variables for commands I would place at beginning of programs - before variables get defined, I would use `executable-find' but I would like for the program loading to fail if those external programs cannot be found. Is it then recommended to use something like: (defun check-my-executables () ...) (check-my-executables) during the loading time? Jean