*remote.txt*	For Vim version 9.2.  Last change: 2026 Jun 05


		  VIM REFERENCE MANUAL	  by Bram Moolenaar


Vim client-server communication				*client-server*

1. Common functionality		|clientserver|
2. X11 specific items		|x11-clientserver|
3. MS-Windows specific items	|w32-clientserver|
4. Socket server specific items	|socketserver-clientserver|

==============================================================================
1. Common functionality					*clientserver*

When compiled with the |+clientserver| option, Vim can act as a command
server.  It accepts messages from a client and executes them.  At the same
time, Vim can function as a client and send commands to a Vim server.

The following command line arguments are available:

    argument			meaning	~

   --remote [+{cmd}] {file} ...					*--remote*
				Open the file list in a remote Vim.  When
				there is no Vim server, execute locally.
				There is one optional init command: +{cmd}.
				This must be an Ex command that can be
				followed by "|".
				The rest of the command line is taken as the
				file list.  Thus any non-file arguments must
				come before this.
				You cannot edit stdin this way |--|.
				The remote Vim is raised.  If you don't want
				this use >
				 vim --remote-send "<C-\><C-N>:n filename<CR>"
<
   --remote-silent [+{cmd}] {file} ...			*--remote-silent*
				As above, but don't complain if there is no
				server and the file is edited locally.
   --remote-wait [+{cmd}] {file} ...				*--remote-wait*
				As --remote, but wait for files to complete
				(unload) in remote Vim.
   --remote-wait-silent [+{cmd}] {file} ...		*--remote-wait-silent*
				As --remote-wait, but don't complain if there
				is no server.
							*--remote-tab*
   --remote-tab			Like --remote but open each file in a new
				tabpage.
							*--remote-tab-silent*
   --remote-tab-silent		Like --remote-silent but open each file in a
				new tabpage.
							*--remote-tab-wait*
   --remote-tab-wait		Like --remote-wait but open each file in a new
				tabpage.

						*--remote-tab-wait-silent*
   --remote-tab-wait-silent	Like --remote-wait-silent but open each file
				in a new tabpage.
								*--servername*
   --servername {name}		Become the server {name}.  When used together
				with one of the --remote commands: connect to
				server {name} instead of the default (see
				below).  The name used will be uppercase.  If
				using the socketserver, you can specify a
				path, see |socketserver-name| for more
				details.
								*--remote-send*
   --remote-send {keys}		Send {keys} to server and exit.  The {keys}
				are not mapped.  Special key names are
				recognized, e.g., "<CR>" results in a CR
				character.
								*--remote-expr*
   --remote-expr {expr}		Evaluate {expr} in server and print the result
				on stdout.
								*--serverlist*
   --serverlist			Output a list of server names.
								*--clientserver*
   --clientserver {method}	Use the specified method {method} as the
				backend for clientserver functionality.  Can
				either be "socket", "x11", or "mswin".
							    *$VIM_CLIENTSERVER*
				If the "$VIM_CLIENTSERVER" environment
				variable is set, then Vim will interpret the
				value just like the --clientserver argument.
				If it is set and --clientserver is provided in
				the command line, then --clientserver takes
				priority.
				{only available when compiled with both |+X11|
				and |+socketserver| features, or
				|+socketserver| on MS-Windows}

Examples ~

Edit "file.txt" in an already running GVIM server: >
    gvim --remote file.txt

Edit "file.txt" in an already running server called FOOBAR: >
    gvim --servername FOOBAR --remote file.txt

Edit "file.txt" in server "FILES" if it exists, become server "FILES"
otherwise: >
    gvim --servername FILES --remote-silent file.txt

This doesn't work, all arguments after --remote will be used as file names: >
    gvim --remote --servername FOOBAR file.txt

Edit file "+foo" in a remote server (note the use of "./" to avoid the special
meaning of the leading plus): >
    vim --remote ./+foo

Tell the remote server "BLA" to write all files and exit: >
    vim --servername BLA --remote-send '<C-\><C-N>:wqa<CR>'


SERVER NAME						*client-server-name*

By default Vim will try to register the name under which it was invoked (gvim,
egvim ...).  This can be overridden with the --servername argument.  If the
specified name is not available, a postfix is applied until a free name is
encountered, i.e. "gvim1" for the second invocation of gvim on a particular
X-server.  The resulting name is available in the servername builtin variable
|v:servername|.  The case of the server name is ignored, thus "gvim" and
"GVIM" are considered equal.  Note if a socket server is being used, there are
some differences, see |socketserver-differences|.

When Vim is invoked with --remote, --remote-wait or --remote-send it will try
to locate the server name determined by the invocation name and --servername
argument as described above.  If an exact match is not available, the first
server with the number postfix will be used.  If a name with the number
postfix is specified with the --servername argument, it must match exactly.

If no server can be located and --remote or --remote-wait was used, Vim will
start up according to the rest of the command line and do the editing by
itself.  This way it is not necessary to know whether gvim is already started
when sending command to it.

The --serverlist argument will cause Vim to print a list of registered command
servers on the standard output (stdout) and exit.  If a socket server is being
used, there are caveats, see |socketserver-differences|.
							*{server}*
The {server} argument is used by several functions.  When this is an empty
string then on Unix the default server name is used, which is "GVIM".  On
MS-Windows an empty string does not work.

Win32 Note: Making the Vim server go to the foreground doesn't always work,
because MS-Windows doesn't allow it.  The client will move the server to the
foreground when using the --remote or --remote-wait argument and the server
name starts with "g".


REMOTE EDITING

The --remote argument will cause a |:drop| command to be constructed from the
rest of the command line and sent as described above.
The --remote-wait argument does the same thing and additionally sets up to
wait for each of the files to have been edited.  This uses the BufUnload
event, thus as soon as a file has been unloaded, Vim assumes you are done
editing it.
Note that the --remote and --remote-wait arguments will consume the rest of
the command line.  I.e. all remaining arguments will be regarded as filenames.
You can not put options there!


FUNCTIONS
								*E240* *E573*
There are a number of Vim functions for scripting the command server.  See
the description in |builtin.txt| or use CTRL-] on the function name to jump to
the full explanation.

    synopsis				     explanation ~
    remote_startserver( name)		     run a server
    remote_expr( server, string, idvar)      send expression
    remote_send( server, string, idvar)      send key sequence
    serverlist()			     get a list of available servers
    remote_peek( serverid, retvar)	     check for reply string
    remote_read( serverid)		     read reply string
    server2client( serverid, string)	     send reply string
    remote_foreground( server)		     bring server to the front

See also the explanation of |CTRL-\_CTRL-N|.  Very useful as a leading key
sequence.
The {serverid} for server2client() can be obtained with expand("<client>")

==============================================================================
2. X11 specific items					*x11-clientserver*
				    *E247* *E248* *E251* *E258* *E277*

The communication between client and server goes through the X server.  The
display of the Vim server must be specified.  The usual protection of the X
server is used, you must be able to open a window on the X server for the
communication to work.  It is possible to communicate between different
systems.

By default, a GUI Vim will register a name on the X-server by which it can be
addressed for subsequent execution of injected strings.  Vim can also act as
a client and send strings to other instances of Vim on the same X11 display.

When an X11 GUI Vim (gvim) is started, it will try to register a send-server
name on the 'VimRegistry' property on the root window.

A non GUI Vim with access to the X11 display (|xterm-clipboard| enabled), can
also act as a command server if a server name is explicitly given with the
--servername argument, or when Vim was built with the |+autoservername|
feature.

An empty --servername argument will cause the command server to be disabled.

To send commands to a Vim server from another application, read the source
file src/if_xcmdsrv.c, it contains some hints about the protocol used.

==============================================================================
3. Win32 specific items					*w32-clientserver*

Every Win32 Vim can work as a server, also in the console.  You do not need a
version compiled with OLE.  Windows messages are used, this works on any
version of MS-Windows.  But only communication within one system is possible.

Since MS-Windows messages are used, any other application should be able to
communicate with a Vim server.  An alternative is using the OLE functionality
|ole-interface|.

When using gvim, the --remote-wait only works properly this way: >

	start /w gvim --remote-wait file.txt
<
==============================================================================
4. Socket server specific items			    *socketserver-clientserver*
						    *E1564* *E1565* *E1566*

NOTE: Vim version before patch 9.2.511 use a different socketserver backend
which is incompatible with the new one, which is based on channels and JSON.

The communication between client and server is done using channels internally.
When using the traditional/generic clientserver naming (only available on
Unix), sockets are placed in these directories in the following order of
availability:
    1. "$XDG_RUNTIME_DIR/vim" if $XDG_RUNTIME_DIR is set in the environment.
    2. "$TMPDIR/vim-[uid]", where "[uid]" is the uid of the user.  This
       directory will have the access permissions set to 700 so only the user
       can read or write from/to it.  If $TMPDIR is not set, "/tmp" is used.

						    *socketserver-name*
When specifying the server id/name, it can be taken as a generic name or an
absolute or relative path.  If the server id starts with either a "/"
(absolute) or "./" | "../" (relative), then it is taken as path to the socket.
Otherwise the server id will be the filename of the socket which will be
placed in the above common directories.  Note that a server id/name can only
contain slashes "/" if it is taken as a path, so names such as "abc/dir" will
be invalid.  This feature is only available on Unix.

						    *socketserver-address*
In addition, the socketserver can also be created as a |channel-address|. To
do this, prefix the address with "channel:" (which will be ignored).  This is
available on both Unix and MS-Windows, and is the only available naming for the
socketserver backend on Windows.  However, note that |ch_listen()|
restrictions apply, meaning only port numbers can be used for TCP sockets.

If the name is prefixed with "name:", then the legacy servername behaviour is
used, so "name:VIM" is the same as "VIM".

Unless Vim is compiled with |+autoservername| feature, the socket server will
have to started explicitly, similar to X11. This is unless a X11 GUI Vim is
being used.

If Vim crashes or does not exit cleanly, the socket server will not remove the
socket file and it will be left around.  This is generally not a problem,
because if a socket name is taken, Vim checks if the socket in its place is
dead (not attached to any process), and can replace it instead of finding a
new name.  This is only relevant for Unix.

						    *socketserver-differences*
Most of the functionality is the same as the other clientserver backends.

However, the server id or client id will not be a number like X11 or
MS-Windows (shown in hex representation), instead it is the absolute path to
the socket.  This can be seen via the |v:servername| variable.  If the name is
a channel address, then it will be the address with the "a/" prefix as well.

Note when using |--remote-wait|, the client id will look like "t/<some
number>". This naming is specifically for this command, and attempting to use
it as an address will fail.

If on Unix, the |--serverlist| argument will act just like X11, however it
only checks the given common directories above.  If a custom path is used for
a socket, it will not be detected, such as a path either not in
$XDG_RUNTIME_DIR or <$TMPDIR or /tmp>/vim of the |--serverlist| Vim process.
If on MS-Windows, then the |--serverlist| argument will output nothing.

The |+socketserver| feature is automatically enabled when on Unix or
MS-Windows, and the |+channel| feature is enabled

						    *socketserver-x11*
If Vim is compiled with |+socketserver| and another clientserver backend, then
deciding which backend to use is done at startup time, via the
|--clientserver| argument.  By default if it is not specified, then the native
backend (X11 or MS-Window messages) will be used, if available.  A Vim
instance using a socket server cannot communicate with one using another
clientserver backend.

 vim:tw=78:sw=4:ts=8:noet:ft=help:norl:
