Re: extensions for emacsclient (CVS version)

["Andreas Büsching" <crunchy@tzi.de>]

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"Stefan Monnier" <monnier@IRO.UMontreal.CA> wrote:

>>>> Okay, I understand, we _would_ need to find good and emacs like method
>>>> to handle this potential problem, but what I would like to know first is,
>>>> if this patch has any chance to get into CVS.
>>> It seems perfectly reasonable to me.
>> This sounds great. So I will work on some security stuff and user
>> feedback, when this error occurs.
>
> I also like it (actually, in the past, I've suggested to obey $TMP
> so as to be able to use different sockets, but an explicit socket-name
> argument sounds much better).
>
>> Is there also a chance to get a patch into CVS which enables
>> emacsclient to read from stdin?
>
> Sounds good to me (especially for the -eval case).

Okay, I used the time to extend the first patch with a buffer overflow
check and I also added the feature to use stdin for input if:

1. -e or --eval is given on the command line
   (I think it does not make sense for filenames)
2. there is no argument after the options

RFC

crunchy



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--- emacsclient.c.orig	Tue Sep  9 09:21:31 2003
+++ emacsclient.c	Wed Sep 10 15:39:34 2003
@@ -67,6 +67,9 @@
    is not running.  --alternate-editor.   */
 const char * alternate_editor = NULL;
 
+/* If non-NULL, the filename of the UNIX socket */
+const char * socket_name = NULL;
+
 void print_help_and_exit ();
 
 struct option longopts[] =
@@ -76,6 +79,7 @@
   { "help",	no_argument,	   NULL, 'H' },
   { "version",	no_argument,	   NULL, 'V' },
   { "alternate-editor", required_argument, NULL, 'a' },
+  { "socket-name",	required_argument, NULL, 's' },
   { "display",	required_argument, NULL, 'd' },
   { 0, 0, 0, 0 }
 };
@@ -91,7 +95,7 @@
   while (1)
     {
       int opt = getopt_long (argc, argv,
-			     "VHnea:d:", longopts, 0);
+			     "VHnea:s:d:", longopts, 0);
 
       if (opt == EOF)
 	break;
@@ -109,6 +113,10 @@
 	  alternate_editor = optarg;
 	  break;
 
+	case 's':
+	  socket_name = optarg;
+	  break;
+
 	case 'd':
 	  display = optarg;
 	  break;
@@ -152,6 +160,8 @@
 -n, --no-wait           Don't wait for the server to return\n\
 -e, --eval              Evaluate the FILE arguments as ELisp expressions\n\
 -d, --display=DISPLAY   Visit the file in the given display\n\
+-s, --socket-name=FILENAME\n\
+                        Set the filename of the UNIX socket for communication\n\
 -a, --alternate-editor=EDITOR\n\
                         Editor to fallback to if the server is not running\n\
 \n\
@@ -300,7 +310,7 @@
   /* Process options.  */
   decode_options (argc, argv);
 
-  if (argc - optind < 1)
+  if ((argc - optind < 1) && !eval)
     {
       fprintf (stderr, "%s: file name or argument required\n", progname);
       fprintf (stderr, "Try `%s --help' for more information\n", progname);
@@ -347,7 +357,22 @@
   {
     int sock_status = 0;
 
-    sprintf (server.sun_path, "/tmp/emacs%d-%s/server", (int) geteuid (), system_name);
+    if (socket_name)
+      {
+	if (strlen (socket_name) > sizeof server.sun_path )
+	  {
+	    fprintf (stderr, "Invalid socket name (%s): the socket name is too long (max. %d)\n", socket_name, sizeof server.sun_path);
+	    exit (1);
+	  }
+        else
+	  {
+	    sprintf (server.sun_path, "%s", socket_name);
+	  }
+      }
+    else
+      {
+	sprintf (server.sun_path, "/tmp/emacs%d-%s/server", (int) geteuid (), system_name);
+      }
 
     /* See if the socket exists, and if it's owned by us. */
     sock_status = socket_status (server.sun_path);
@@ -457,22 +482,33 @@
   if (display)
     fprintf (out, "-display %s ", quote_file_name (display));
 
-  for (i = optind; i < argc; i++)
+  if ((argc - optind > 0))
     {
-      if (eval)
-	; /* Don't prepend any cwd or anything like that.  */
-      else if (*argv[i] == '+')
+      for (i = optind; i < argc; i++)
 	{
-	  char *p = argv[i] + 1;
-	  while (isdigit ((unsigned char) *p) || *p == ':') p++;
-	  if (*p != 0)
+	  if (eval)
+	    ; /* Don't prepend any cwd or anything like that.  */
+	  else if (*argv[i] == '+')
+	    {
+	      char *p = argv[i] + 1;
+	      while (isdigit ((unsigned char) *p) || *p == ':') p++;
+	      if (*p != 0)
+		fprintf (out, "%s/", quote_file_name (cwd));
+	    }
+	  else if (*argv[i] != '/')
 	    fprintf (out, "%s/", quote_file_name (cwd));
-	}
-      else if (*argv[i] != '/')
-	fprintf (out, "%s/", quote_file_name (cwd));
 
-      fprintf (out, "%s ", quote_file_name (argv[i]));
+	  fprintf (out, "%s ", quote_file_name (argv[i]));
+	}
+    }
+  else
+    {
+      while ((str = fgets (string, BUFSIZ, stdin)))
+	{
+	  fprintf (out, "%s ", quote_file_name (str));
+	}
     }
+  
   fprintf (out, "\n");
   fflush (out);
 

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-- 
What happens if a big asteroid hits the Earth? Judging from realistic
simulations involving a sledge hammer and a common laboratory frog, we
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