Commit 98f01a13 authored by Reuben Thomas's avatar Reuben Thomas

Add support for arguments in emacsclient's ALTERNATE_EDITOR (Bug #25082)

* lib-src/emacsclient.c (fail): Parse ALTERNATE_EDITOR, or
corresponding command-line argument, into quote- or space-separated
tokens.  If a token starts with a quote, then it naturally is expected
to end with a quote; escaping is not supported. This is enough to cope
with the typical case of requiring the initial path to be quoted,
common on Windows where it may contain spaces.
* etc/NEWS: Document.
* doc/emacs/misc.texi: Likewise.
* doc/man/emacsclient.1: Tweak to remove the implication that only an
editor can be specified (the manual already mentions a “command”).
Fix a small error where “EDITOR” is referred to rather than
“ALTERNATE_EDITOR”.
* test/lib-src/emacsclient-tests.el: Add tests.
parent dc313922
......@@ -1821,8 +1821,10 @@ listed below:
@table @samp
@item -a @var{command}
@itemx --alternate-editor=@var{command}
Specify a command to run if @code{emacsclient} fails to contact Emacs.
Specify a shell command to run if @code{emacsclient} fails to contact Emacs.
This is useful when running @code{emacsclient} in a script.
The command may include arguments, which may be quoted "like this".
Currently, escaping of quotes is not supported.
As a special exception, if @var{command} is the empty string, then
@code{emacsclient} starts Emacs in daemon mode (as @command{emacs
......
......@@ -62,10 +62,10 @@ A missing
is treated as column 1.
This option applies only to the next file specified.
.TP
.B \-a, \-\-alternate-editor=EDITOR
if the Emacs server is not running, run the specified editor instead.
.B \-a, \-\-alternate-editor=COMMAND
if the Emacs server is not running, run the specified shell command instead.
This can also be specified via the ALTERNATE_EDITOR environment variable.
If the value of EDITOR is the empty string, run "emacs \-\-daemon" to
If the value of ALTERNATE_EDITOR is the empty string, run "emacs \-\-daemon" to
start Emacs in daemon mode, and try to connect to it.
.TP
.B -c, \-\-create-frame
......
......@@ -485,6 +485,13 @@ Linum mode and all similar packages are henceforth becoming obsolete.
Users and developers are encouraged to switch to this new feature
instead.
+++
** emacsclient now accepts command-line options in ALTERNATE_EDITOR
and --alternate-editor. For example, ALTERNATE_EDITOR="emacs -Q -nw".
Arguments may be quoted "like this", so that for example an absolute
path containing a space may be specified; quote escaping is not
supported.
* Editing Changes in Emacs 26.1
......
......@@ -110,6 +110,9 @@ char *w32_getenv (const char *);
/* Name used to invoke this program. */
const char *progname;
/* The first argument to main. */
int main_argc;
/* The second argument to main. */
char **main_argv;
......@@ -201,6 +204,35 @@ xmalloc (size_t size)
return result;
}
/* Like realloc but get fatal error if memory is exhausted. */
static void *
xrealloc (void *ptr, size_t size)
{
void *result = realloc (ptr, size);
if (result == NULL)
{
perror ("realloc");
exit (EXIT_FAILURE);
}
return result;
}
/* Like strdup but get a fatal error if memory is exhausted. */
char *xstrdup (const char *);
char *
xstrdup (const char *s)
{
char *result = strdup (s);
if (result == NULL)
{
perror ("strdup");
exit (EXIT_FAILURE);
}
return result;
}
/* From sysdep.c */
#if !defined (HAVE_GET_CURRENT_DIR_NAME) || defined (BROKEN_GET_CURRENT_DIR_NAME)
......@@ -264,21 +296,6 @@ get_current_dir_name (void)
#ifdef WINDOWSNT
/* Like strdup but get a fatal error if memory is exhausted. */
char *xstrdup (const char *);
char *
xstrdup (const char *s)
{
char *result = strdup (s);
if (result == NULL)
{
perror ("strdup");
exit (EXIT_FAILURE);
}
return result;
}
#define REG_ROOT "SOFTWARE\\GNU\\Emacs"
char *w32_get_resource (HKEY, const char *, LPDWORD);
......@@ -673,7 +690,7 @@ Report bugs with M-x report-emacs-bug.\n");
}
/* Try to run a different command, or --if no alternate editor is
defined-- exit with an errorcode.
defined-- exit with an error code.
Uses argv, but gets it from the global variable main_argv. */
static _Noreturn void
......@@ -681,9 +698,38 @@ fail (void)
{
if (alternate_editor)
{
int i = optind - 1;
size_t extra_args_size = (main_argc - optind + 1) * sizeof (char *);
size_t new_argv_size = extra_args_size;
char **new_argv = NULL;
char *s = xstrdup (alternate_editor);
unsigned toks = 0;
/* Unpack alternate_editor's space-separated tokens into new_argv. */
for (char *tok = s; tok != NULL && *tok != '\0';)
{
/* Allocate new token. */
++toks;
new_argv = xrealloc (new_argv, new_argv_size + toks * sizeof (char *));
/* Skip leading delimiters, and set separator, skipping any
opening quote. */
size_t skip = strspn (tok, " \"");
tok += skip;
char sep = (skip > 0 && tok[-1] == '"') ? '"' : ' ';
/* Record start of token. */
new_argv[toks - 1] = tok;
/* Find end of token and overwrite it with NUL. */
tok = strchr (tok, sep);
if (tok != NULL)
*tok++ = '\0';
}
/* Append main_argv arguments to new_argv. */
memcpy (&new_argv[toks], main_argv + optind, extra_args_size);
execvp (alternate_editor, main_argv + i);
execvp (*new_argv, new_argv);
message (true, "%s: error executing alternate editor \"%s\"\n",
progname, alternate_editor);
}
......@@ -696,6 +742,7 @@ fail (void)
int
main (int argc, char **argv)
{
main_argc = argc;
main_argv = argv;
progname = argv[0];
message (true, "%s: Sorry, the Emacs server is supported only\n"
......@@ -1629,6 +1676,7 @@ main (int argc, char **argv)
int start_daemon_if_needed;
int exit_status = EXIT_SUCCESS;
main_argc = argc;
main_argv = argv;
progname = argv[0];
......
;;; emacsclient-tests.el --- Test emacsclient
;; Copyright (C) 2016 Free Software Foundation, Inc.
;; 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 3 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. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;
;;; Code:
(require 'ert)
(defconst emacsclient-test-emacs
(expand-file-name "emacsclient" (concat
(file-name-directory
(directory-file-name
(file-name-directory invocation-directory)))
"lib-src"))
"Path to emacsclient binary in build tree.")
(ert-deftest emacsclient-test-alternate-editor-allows-arguments ()
(let (process-environment process-environment)
(setenv "ALTERNATE_EDITOR" (concat
(expand-file-name invocation-name invocation-directory)
" --batch"))
(should (= 0 (call-process emacsclient-test-emacs nil nil nil "foo")))))
(ert-deftest emacsclient-test-alternate-editor-allows-quotes ()
(let (process-environment process-environment)
(setenv "ALTERNATE_EDITOR" (concat
"\""
(expand-file-name invocation-name invocation-directory)
"\"" " --batch"))
(should (= 0 (call-process emacsclient-test-emacs nil nil nil "foo")))))
(provide 'emacsclient-tests)
;;; emacsclient-tests.el ends here
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