tmux.1

.\" $Id: tmux.1,v 1.219 2010-01-08 16:31:35 tcunha Exp $
.\"
.\" Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
.\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
.\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: January 7 2010 $
.Dt TMUX 1
.Os
.Sh NAME
.Nm tmux
.Nd terminal multiplexer
.Sh SYNOPSIS
.Nm tmux
.Bk -words
.Op Fl 28lquv
.Op Fl c Ar shell-command
.Op Fl f Ar file
.Op Fl L Ar socket-name
.Op Fl S Ar socket-path
.Op Ar command Op Ar flags
.Ek
.Sh DESCRIPTION
.Nm
is a terminal multiplexer:
it enables a number of terminals to be created, accessed, and
controlled from a single screen.
.Nm
may be detached from a screen
and continue running in the background,
then later reattached.
.Pp
When
.Nm
is started it creates a new
.Em session
with a single
.Em window
and displays it on screen.
A status line at the bottom of the screen
shows information on the current session
and is used to enter interactive commands.
.Pp
A session is a single collection of
.Em pseudo terminals
under the management of
.Nm .
Each session has one or more
windows linked to it.
A window occupies the entire screen
and may be split into rectangular panes,
each of which is a separate pseudo terminal
(the
.Xr pty 4
manual page documents the technical details of pseudo terminals).
Any number of
.Nm
instances may connect to the same session,
and any number of windows may be present in the same session.
Once all sessions are killed,
.Nm
exits.
.Pp
Each session is persistent and will survive accidental disconnection
(such as
.Xr ssh 1
connection timeout) or intentional detaching (with the
.Ql C-b d
key strokes).
.Nm
may be reattached using:
.Pp
.Dl $ tmux attach
.Pp
In
.Nm ,
a session is displayed on screen by a
.Em client
and all sessions are managed by a single
.Em server .
The server and each client are separate processes which communicate through a
socket in
.Pa /tmp .
.Pp
The options are as follows:
.Bl -tag -width "XXXXXXXXXXXX"
.It Fl 2
Force
.Nm
to assume the terminal supports 256 colours.
.It Fl 8
Like
.Fl 2 ,
but indicates that the terminal supports 88 colours.
.It Fl c Ar shell-command
Execute
.Ar shell-command
using the default shell.
If necessary, the
.Nm
server will be started to retrieve the
.Ic default-shell
option.
.It Fl f Ar file
Specify an alternative configuration file.
By default,
.Nm
loads the system configuration file from
.Pa /etc/tmux.conf ,
if present, then looks for a user configuration file at
.Pa ~/.tmux.conf .
The configuration file is a set of
.Nm
commands which are executed in sequence when the server is first started.
.Pp
If a command in the configuration file fails,
.Nm
will report an error and exit without executing further commands.
.It Fl l
Behave as a login shell.
This flag currently has no effect and is for compatibility with other shells
when using tmux as a login shell.
.It Fl L Ar socket-name
.Nm
stores the server socket in a directory under
.Pa /tmp ;
the default socket is named
.Em default .
This option allows a different socket name to be specified, allowing several
independent
.Nm
servers to be run.
Unlike
.Fl S
a full path is not necessary: the sockets are all created in the same
directory.
.Pp
If the socket is accidentally removed, the
.Dv SIGUSR1
signal may be sent to the
.Nm
server process to recreate it.
.It Fl q
Set the
.Ic quiet
server option to prevent the server sending various informational messages.
.It Fl S Ar socket-path
Specify a full alternative path to the server socket.
If
.Fl S
is specified, the default socket directory is not used and any
.Fl L
flag is ignored.
.It Fl u
.Nm
attempts to guess if the terminal is likely to support UTF-8 by checking the
first of the
.Ev LC_ALL ,
.Ev LC_CTYPE
and
.Ev LANG
environment variables to be set for the string "UTF-8".
This is not always correct: the
.Fl u
flag explicitly informs
.Nm
that UTF-8 is supported.
.Pp
If the server is started from a client passed
.Fl u
or where UTF-8 is detected, the
.Ic utf8
and
.Ic status-utf8
options are enabled in the global window and session options respectively.
.It Fl v
Request verbose logging.
This option may be specified multiple times for increasing verbosity.
Log messages will be saved into
.Pa tmux-client-PID.log
and
.Pa tmux-server-PID.log
files in the current directory, where
.Em PID
is the PID of the server or client process.
.It Ar command Op Ar flags
This specifies one of a set of commands used to control
.Nm ,
as described in the following sections.
If no commands are specified, the
.Ic new-session
command is assumed.
.El
.Sh KEY BINDINGS
.Nm
may be controlled from an attached client by using a key combination of a
prefix key,
.Ql C-b
(Ctrl-b) by default, followed by a command key.
.Pp
Some of the default key bindings are:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It c
Create a new window.
.It d
Detach the current client.
.It l
Move to the previously selected window.
.It n
Change to the next window.
.It p
Change to the previous window.
.It &
Kill the current window.
.It ,
Rename the current window.
.It \&?
List all key bindings.
.El
.Pp
A complete list may be obtained with the
.Ic list-keys
command (bound to
.Ql \&?
by default).
Key bindings may be changed with the
.Ic bind-key
and
.Ic unbind-key
commands.
.Sh COMMANDS
This section contains a list of the commands supported by
.Nm .
Most commands accept the optional
.Fl t
argument with one of
.Ar target-client ,
.Ar target-session
.Ar target-window ,
or
.Ar target-pane .
These specify the client, session, window or pane which a command should affect.
.Ar target-client
is the name of the
.Xr pty 4
file to which the client is connected, for example either of
.Pa /dev/ttyp1
or
.Pa ttyp1
for the client attached to
.Pa /dev/ttyp1 .
If no client is specified, the current client is chosen, if possible, or an
error is reported.
Clients may be listed with the
.Ic list-clients
command.
.Pp
.Ar target-session
is either the name of a session (as listed by the
.Ic list-sessions
command) or the name of a client with the same syntax as
.Ar target-client ,
in which case the session attached to the client is used.
When looking for the session name,
.Nm
initially searches for an exact match; if none is found, the session names
are checked for any for which
.Ar target-session
is a prefix or for which it matches as an
.Xr fnmatch 3
pattern.
If a single match is found, it is used as the target session; multiple matches
produce an error.
If a session is omitted, the current session is used if available; if no
current session is available, the most recently used is chosen.
.Pp
.Ar target-window
specifies a window in the form
.Em session Ns \&: Ns Em window .
.Em session
follows the same rules as for
.Ar target-session ,
and
.Em window
is looked for in order: as a window index, for example mysession:1; as an exact
window name, such as mysession:mywindow; then as an
.Xr fnmatch 3
pattern or the start of a window name, such as mysession:mywin* or
mysession:mywin.
An empty window name specifies the next unused index if appropriate (for
example the
.Ic new-window
and
.Ic link-window
commands)
otherwise the current window in
.Em session
is chosen.
When the argument does not contain a colon,
.Nm
first attempts to parse it as window; if that fails, an attempt is made to
match a session.
.Pp
.Ar target-pane
takes a similar form to
.Ar target-window
but with the optional addition of a period followed by a pane index, for
example: mysession:mywindow.1.
If the pane index is omitted, the currently active pane in the specified
window is used.
If neither a colon nor period appears,
.Nm
first attempts to use the argument as a pane index; if that fails, it is looked
up as for
.Ar target-window .
One of the strings
.Em top ,
.Em bottom ,
.Em left ,
.Em right ,
.Em top-left ,
.Em top-right ,
.Em bottom-left or
.Em bottom-right
may be used instead of a pane index.
.Pp
Multiple commands may be specified together as part of a
.Em command sequence .
Each command should be separated by spaces and a semicolon;
commands are executed sequentially from left to right.
A literal semicolon may be included by escaping it with a backslash (for
example, when specifying a command sequence to
.Ic bind-key ) .
.Pp
Examples include:
.Bd -literal -offset indent
refresh-client -t/dev/ttyp2

rename-session -tfirst newname

set-window-option -t:0 monitor-activity on

new-window ; split-window -d
.Ed
.Sh CLIENTS AND SESSIONS
The following commands are available:
.Bl -tag -width Ds
.It Xo Ic attach-session
.Op Fl d
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic attach )
If run from outside
.Nm ,
create a new client in the current terminal and attach it to
.Ar target-session .
If used from inside, switch the current client.
If
.Fl d
is specified, any other clients attached to the session are detached.
.Pp
If no server is started,
.Ic attach-session
will attempt to start it; this will fail unless sessions are created in the
configuration file.
.It Ic detach-client Op Fl t Ar target-client
.D1 (alias: Ic detach )
Detach the current client if bound to a key, or the specified client with
.Fl t .
.It Ic has-session Op Fl t Ar target-session
.D1 (alias: Ic has )
Report an error and exit with 1 if the specified session does not exist.
If it does exist, exit with 0.
.It Ic kill-server
Kill the
.Nm
server and clients and destroy all sessions.
.It Ic kill-session Op Fl t Ar target-session
Destroy the given session, closing any windows linked to it and no other
sessions, and detaching all clients attached to it.
.It Ic list-clients
.D1 (alias: Ic lsc )
List all clients attached to the server.
.It Ic list-commands
.D1 (alias: Ic lscm )
List the syntax of all commands supported by
.Nm .
.It Ic list-sessions
.D1 (alias: Ic ls )
List all sessions managed by the server.
.It Xo Ic lock-client
.Op Fl t Ar target-client
.Xc
Lock
.Ar target-client ,
see the
.Ic lock-server
command.
.It Xo Ic lock-session
.Op Fl t Ar target-session
.Xc
Lock all clients attached to
.Ar target-session .
.It Xo Ic new-session
.Op Fl d
.Op Fl n Ar window-name
.Op Fl s Ar session-name
.Op Fl t Ar target-session
.Op Ar command
.Xc
.D1 (alias: Ic new )
Create a new session with name
.Ar session-name .
The new session is attached to the current terminal unless
.Fl d
is given.
.Ar window-name
and
.Ar command
are the name of and command to execute in the initial window.
.Pp
If run from a terminal, any
.Xr termios 4
special characters are saved and used for new windows in the new session.
.Pp
If
.Fl t
is given, the new session is
.Em grouped
with
.Ar target-session .
This means they share the same set of windows - all windows from
.Ar target-session
are linked to the new session and any subsequent new windows or windows being
closed are applied to both sessions.
The current and previous window and any session options remain independent and
either session may be killed without affecting the other.
Giving
.Fl n
or
.Ar command
are invalid if
.Fl t
is used.
.It Ic refresh-client Op Fl t Ar target-client
.D1 (alias: Ic refresh )
Refresh the current client if bound to a key, or a single client if one is given
with
.Fl t .
.It Xo Ic rename-session
.Op Fl t Ar target-session
.Ar new-name
.Xc
.D1 (alias: Ic rename )
Rename the session to
.Ar new-name .
.It Xo Ic show-messages
.Op Fl t Ar target-client
.Xc
.D1 (alias: Ic showmsgs )
Any messages displayed on the status line are saved in a per-client message
log, up to a maximum of the limit set by the
.Ar message-limit
session option for the session attached to that client.
This command displays the log for
.Ar target-client .
.It Ic source-file Ar path
.D1 (alias: Ic source )
Execute commands from
.Ar path .
.It Ic start-server
.D1 (alias: Ic start )
Start the
.Nm
server, if not already running, without creating any sessions.
.It Xo Ic suspend-client
.Op Fl c Ar target-client
.Xc
.D1 (alias: Ic suspendc )
Suspend a client by sending
.Dv SIGTSTP
(tty stop).
.It Xo Ic switch-client
.Op Fl c Ar target-client
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic switchc )
Switch the current session for client
.Ar target-client
to
.Ar target-session .
.El
.Sh WINDOWS AND PANES
A
.Nm
window may be in one of several modes.
The default permits direct access to the terminal attached to the window.
The others are:
.Bl -tag -width Ds
.It Em output mode
This is entered when a command which produces output, such as
.Ic list-keys ,
is executed from a key binding.
.It Em copy mode
This permits a section of a window or its history to be copied to a
.Em paste buffer
for later insertion into another window.
This mode is entered with the
.Ic copy-mode
command, bound to
.Ql \&[
by default.
.El
.Pp
The keys available depend on whether emacs or vi mode is selected
(see the
.Ic mode-keys
option).
The following keys are supported as appropriate for the mode:
.Bl -column "FunctionXXXXXXXXXXXX" "viXXXXXXXXX" "emacs" -offset indent
.It Sy "Function" Ta Sy "vi" Ta Sy "emacs"
.It Li "Back to indentation" Ta "^" Ta "M-m"
.It Li "Clear selection" Ta "Escape" Ta "C-g"
.It Li "Copy selection" Ta "Enter" Ta "M-w"
.It Li "Cursor down" Ta "j" Ta "Down"
.It Li "Cursor left" Ta "h" Ta "Left"
.It Li "Cursor right" Ta "l" Ta "Right"
.It Li "Cursor to bottom line" Ta "L" Ta ""
.It Li "Cursor to middle line" Ta "M" Ta "M-r"
.It Li "Cursor to top line" Ta "H" Ta "M-R"
.It Li "Cursor up" Ta "k" Ta "Up"
.It Li "Delete entire line" Ta "d" Ta "C-u"
.It Li "Delete to end of line" Ta "D" Ta "C-k"
.It Li "End of line" Ta "$" Ta "C-e"
.It Li "Goto line" Ta ":" Ta "g"
.It Li "Half page down" Ta "C-d" Ta "M-Down"
.It Li "Half page up" Ta "C-u" Ta "M-Up"
.It Li "Next page" Ta "C-f" Ta "Page down"
.It Li "Next word" Ta "w" Ta "M-f"
.It Li "Paste buffer" Ta "p" Ta "C-y"
.It Li "Previous page" Ta "C-b" Ta "Page up"
.It Li "Previous word" Ta "b" Ta "M-b"
.It Li "Quit mode" Ta "q" Ta "Escape"
.It Li "Scroll down" Ta "C-Down or J" Ta "C-Down"
.It Li "Scroll up" Ta "C-Up or K" Ta "C-Up"
.It Li "Search again" Ta "n" Ta "n"
.It Li "Search backward" Ta "?" Ta "C-r"
.It Li "Search forward" Ta "/" Ta "C-s"
.It Li "Start of line" Ta "0" Ta "C-a"
.It Li "Start selection" Ta "Space" Ta "C-Space"
.It Li "Transpose chars" Ta "" Ta "C-t"
.El
.Pp
These key bindings are defined in a set of named tables:
.Em vi-edit
and
.Em emacs-edit
for keys used when line editing at the command prompt;
.Em vi-choice
and
.Em emacs-choice
for keys used when choosing from lists (such as produced by the
.Ic window-choose
command) or in output mode; and
.Em vi-copy
and
.Em emacs-copy
used in copy mode.
The tables may be viewed with the
.Ic list-keys
command and keys modified or removed with
.Ic bind-key
and
.Ic unbind-key .
.Pp
The paste buffer key pastes the first line from the top paste buffer on the
stack.
.Pp
The mode commands are as follows:
.Bl -tag -width Ds
.It Xo Ic copy-mode
.Op Fl u
.Op Fl t Ar target-pane
.Xc
Enter copy mode.
The
.Fl u
option scrolls one page up.
.El
.Pp
Each window displayed by
.Nm
may be split into one or more
.Em panes ;
each pane takes up a certain area of the display and is a separate terminal.
A window may be split into panes using the
.Ic split-window
command.
Windows may be split horizontally (with the
.Fl h
flag) or vertically.
Panes may be resized with the
.Ic resize-pane
command (bound to
.Ql C-up ,
.Ql C-down
.Ql C-left
and
.Ql C-right
by default), the current pane may be changed with the
.Ic up-pane
and
.Ic down-pane
commands and the
.Ic rotate-window
and
.Ic swap-pane
commands may be used to swap panes without changing their position.
Panes are numbered beginning from zero in the order they are created.
.Pp
A number of preset
.Em layouts
are available.
These may be selected with the
.Ic select-layout
command or cycled with
.Ic next-layout
(bound to
.Ql C-space
by default); once a layout is chosen, panes within it may be moved and resized
as normal.
.Pp
The following layouts are supported:
.Bl -tag -width Ds
.It Ic even-horizontal
Panes are spread out evenly from left to right across the window.
.It Ic even-vertical
Panes are spread evenly from top to bottom.
.It Ic main-horizontal
A large (main) pane is shown at the top of the window and the remaining panes
are spread from left to right in the leftover space at the bottom.
Use the
.Em main-pane-height
window option to specify the height of the top pane.
.It Ic main-vertical
Similar to
.Ic main-horizontal
but the large pane is placed on the left and the others spread from top to
bottom along the right.
See the
.Em main-pane-width
window option.
.El
.Pp
Commands related to windows and panes are as follows:
.Bl -tag -width Ds
.It Xo Ic break-pane
.Op Fl d
.Op Fl t Ar target-pane
.Xc
.D1 (alias: Ic breakp )
Break
.Ar target-pane
off from its containing window to make it the only pane in a new window.
If
.Fl d
is given, the new window does not become the current window.
.It Xo Ic capture-pane
.Op Fl b Ar buffer-index
.Op Fl t Ar target-pane
.Xc
.D1 (alias: Ic capturep )
Capture the contents of a pane to the specified buffer, or a new buffer if none
is specified.
.It Xo
.Ic choose-client
.Op Fl t Ar target-window
.Op Ar template
.Xc
Put a window into client choice mode, allowing a client to be selected
interactively from a list.
After a client is chosen,
.Ql %%
is replaced by the client
.Xr pty 4
path in
.Ar template
and the result executed as a command.
If
.Ar template
is not given, "detach-client -t '%%'" is used.
This command works only from inside
.Nm .
.It Xo
.Ic choose-session
.Op Fl t Ar target-window
.Op Ar template
.Xc
Put a window into session choice mode, where a session may be selected
interactively from a list.
When one is chosen,
.Ql %%
is replaced by the session name in
.Ar template
and the result executed as a command.
If
.Ar template
is not given, "switch-client -t '%%'" is used.
This command works only from inside
.Nm .
.It Xo
.Ic choose-window
.Op Fl t Ar target-window
.Op Ar template
.Xc
Put a window into window choice mode, where a window may be chosen
interactively from a list.
After a window is selected,
.Ql %%
is replaced by the session name and window index in
.Ar template
and the result executed as a command.
If
.Ar template
is not given, "select-window -t '%%'" is used.
This command works only from inside
.Nm .
.It Ic display-panes Op Fl t Ar target-client
.D1 (alias: Ic displayp)
Display a visible indicator of each pane shown by
.Ar target-client .
See the
.Ic display-panes-time
and
.Ic display-panes-colour
session options.
While the indicator is on screen, a pane may be selected with the
.Ql 0
to
.Ql 9
keys.
.It Ic down-pane Op Fl t Ar target-pane
.D1 (alias: Ic downp )
Change the active pane to the next pane (higher index).
.It Xo Ic find-window
.Op Fl t Ar target-window
.Ar match-string
.Xc
.D1 (alias: Ic findw )
Search for the
.Xr fnmatch 3
pattern
.Ar match-string
in window names, titles, and visible content (but not history).
If only one window is matched, it'll be automatically selected, otherwise a
choice list is shown.
This command only works from inside
.Nm .
.It Xo Ic join-pane
.Op Fl dhv
.Oo Fl l
.Ar size |
.Fl p Ar percentage Oc
.Op Fl s Ar src-pane
.Op Fl t Ar dst-pane
.Xc
.D1 (alias: Ic joinp )
Like
.Ic split-window ,
but instead of splitting
.Ar dst-pane
and creating a new pane, split it and move
.Ar src-pane
into the space.
This can be used to reverse
.Ic break-pane .
.It Xo Ic kill-pane
.Op Fl a
.Op Fl t Ar target-pane
.Xc
.D1 (alias: Ic killp )
Destroy the given pane.
If no panes remain in the containing window, it is also destroyed.
The
.Fl a
option kills all but the pane given with
.Fl t .
.It Ic kill-window Op Fl t Ar target-window
.D1 (alias: Ic killw )
Kill the current window or the window at
.Ar target-window ,
removing it from any sessions to which it is linked.
.It Ic last-window Op Fl t Ar target-session
.D1 (alias: Ic last )
Select the last (previously selected) window.
If no
.Ar target-session
is specified, select the last window of the current session.
.It Xo Ic link-window
.Op Fl dk
.Op Fl s Ar src-window
.Op Fl t Ar dst-window
.Xc
.D1 (alias: Ic linkw )
Link the window at
.Ar src-window
to the specified
.Ar dst-window .
If
.Ar dst-window
is specified and no such window exists, the
.Ar src-window
is linked there.
If
.Fl k
is given and
.Ar dst-window
exists, it is killed, otherwise an error is generated.
If
.Fl d
is given, the newly linked window is not selected.
.It Ic list-panes Op Fl t Ar target-window
.D1 (alias: Ic lsp )
List the panes in the current window or in
.Ar target-window .
.It Ic list-windows Op Fl t Ar target-session
.D1 (alias: Ic lsw )
List windows in the current session or in
.Ar target-session .
.It Xo Ic move-window
.Op Fl d
.Op Fl s Ar src-window
.Op Fl t Ar dst-window
.Xc
.D1 (alias: Ic movew )
This is similar to
.Ic link-window ,
except the window at
.Ar src-window
is moved to
.Ar dst-window .
.It Xo Ic new-window
.Op Fl dk
.Op Fl n Ar window-name
.Op Fl t Ar target-window
.Op Ar command
.Xc
.D1 (alias: Ic neww )
Create a new window.
If
.Fl d
is given, the session does not make the new window the current window.
.Ar target-window
represents the window to be created; if the target already exists an error is
shown, unless the
.Fl k
flag is used, in which case it is destroyed.
.Ar command
is the command to execute.
If
.Ar command
is not specified, the default command is used.
.Pp
The
.Ev TERM
environment variable must be set to
.Dq screen
for all programs running
.Em inside
.Nm .
New windows will automatically have
.Dq TERM=screen
added to their environment, but care must be taken not to reset this in shell
start-up files.
.It Ic next-layout Op Fl t Ar target-window
.D1 (alias: Ic nextl )
Move a window to the next layout and rearrange the panes to fit.
.It Xo Ic next-window
.Op Fl a
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic next )
Move to the next window in the session.
If
.Fl a
is used, move to the next window with a bell, activity or content alert.
.It Xo Ic pipe-pane
.Op Fl o
.Op Fl t Ar target-pane
.Op Ar command
.Xc
.D1 (alias: Ic pipep )
Pipe any output sent by the program in
.Ar target-pane
to a shell command.
A pane may only be piped to one command at a time, any existing pipe is
closed before
.Ar command
is executed.
If no
.Ar command
is given, the current pipe (if any) is closed.
.Pp
The
.Fl o
option only opens a new pipe if no previous pipe exists, allowing a pipe to
be toggled with a single key, for example:
.Bd -literal -offset indent
bind-key C-p pipe-pane -o 'cat >>~/output'
.Ed
.It Xo Ic previous-window
.Op Fl a
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic prev )
Move to the previous window in the session.
With
.Fl a ,
move to the previous window with a bell, activity or content alert.
.It Xo Ic rename-window
.Op Fl t Ar target-window
.Ar new-name
.Xc
.D1 (alias: Ic renamew )
Rename the current window, or the window at
.Ar target-window
if specified, to
.Ar new-name .
.It Xo Ic resize-pane
.Op Fl DLRU
.Op Fl t Ar target-pane
.Op Ar adjustment
.Xc
.D1 (alias: Ic resizep )
Resize a pane, upward with
.Fl U
(the default), downward with
.Fl D ,
to the left with
.Fl L
and to the right with
.Fl R .
The
.Ar adjustment
is given in lines or cells (the default is 1).
.It Xo Ic respawn-window
.Op Fl k
.Op Fl t Ar target-window
.Op Ar command
.Xc
.D1 (alias: Ic respawnw )
Reactive a window in which the command has exited (see the
.Ic remain-on-exit
window option).
If
.Ar command
is not given, the command used when the window was created is executed.
The window must be already inactive, unless
.Fl k
is given, in which case any existing command is killed.
.It Xo Ic rotate-window
.Op Fl DU
.Op Fl t Ar target-window
.Xc
.D1 (alias: Ic rotatew )
Rotate the positions of the panes within a window, either upward (numerically
lower) with
.Fl U
or downward (numerically higher).
.It Xo Ic select-layout
.Op Fl t Ar target-window
.Op Ar layout-name
.Xc
.D1 (alias: selectl )
Choose a specific layout for a window.
If
.Ar layout-name
is not given, the last layout used (if any) is reapplied.
.It Ic select-pane Op Fl t Ar target-pane
.D1 (alias: Ic selectp )
Make pane
.Ar target-pane
the active pane in window
.Ar target-window .
.It Ic select-window Op Fl t Ar target-window
.D1 (alias: Ic selectw )
Select the window at
.Ar target-window .
.It Xo Ic split-window
.Op Fl dhv
.Oo Fl l
.Ar size |
.Fl p Ar percentage Oc
.Op Fl t Ar target-pane
.Op Ar command
.Xc
.D1 (alias: splitw )
Create a new pane by splitting
.Ar target-pane :
.Fl h
does a horizontal split and
.Fl v
a vertical split; if neither is specified,
.Fl v
is assumed.
The
.Fl l
and
.Fl p
options specify the size of the new pane in lines (for vertical split) or in
cells (for horizontal split), or as a percentage, respectively.
All other options have the same meaning as for the
.Ic new-window
command.
.It Xo Ic swap-pane
.Op Fl dDU
.Op Fl s Ar src-pane
.Op Fl t Ar dst-pane
.Xc
.D1 (alias: Ic swapp )
Swap two panes.
If
.Fl U
is used and no source pane is specified with
.Fl s ,
.Ar dst-pane
is swapped with the previous pane (before it numerically);
.Fl D
swaps with the next pane (after it numerically).
.It Xo Ic swap-window
.Op Fl d
.Op Fl s Ar src-window
.Op Fl t Ar dst-window
.Xc
.D1 (alias: Ic swapw )
This is similar to
.Ic link-window ,
except the source and destination windows are swapped.
It is an error if no window exists at
.Ar src-window .
.It Xo Ic unlink-window
.Op Fl k
.Op Fl t Ar target-window
.Xc
.D1 (alias: Ic unlinkw )
Unlink
.Ar target-window .
Unless
.Fl k
is given, a window may be unlinked only if it is linked to multiple sessions -
windows may not be linked to no sessions;
if
.Fl k
is specified and the window is linked to only one session, it is unlinked and
destroyed.
.It Ic up-pane Op Fl t Ar target-pane
.D1 (alias: Ic upp )
Change the active pane to the previous pane (lower index).
.El
.Sh KEY BINDINGS
.Nm
allows a command to be bound to most keys, with or without a prefix key.
When specifying keys, most represent themselves (for example
.Ql A
to
.Ql Z ) .
Ctrl keys may be prefixed with
.Ql C-
or
.Ql ^ ,
and Alt (meta) with
.Ql M- .
In addition, the following special key names are accepted:
.Em Up ,
.Em Down ,
.Em Left ,
.Em Right ,
.Em BSpace ,
.Em BTab ,
.Em DC
(Delete),
.Em End ,
.Em Enter ,
.Em Escape ,
.Em F1
to
.Em F20 ,
.Em Home ,
.Em IC
(Insert),
.Em NPage
(Page Up),
.Em PPage
(Page Down),
.Em Space ,
and
.Em Tab .
Note that to bind the
.Ql \&"
or
.Ql '
keys, quotation marks are necessary, for example:
.Bd -literal -offset indent
bind-key '"' split-window
bind-key "'" select-prompt
.Ed
.Pp
Commands related to key bindings are as follows:
.Bl -tag -width Ds
.It Xo Ic bind-key
.Op Fl cnr
.Op Fl t Ar key-table
.Ar key Ar command Op Ar arguments
.Xc
.D1 (alias: Ic bind )
Bind key
.Ar key
to
.Ar command .
By default (without
.Fl t )
the primary key bindings are modified (those normally activated with the prefix
key); in this case, if
.Fl n
is specified, it is not necessary to use the prefix key,
.Ar command
is bound to
.Ar key
alone.
The
.Fl r
flag indicates this key may repeat, see the
.Ic repeat-time
option.
.Pp
If
.Fl t
is present,
.Ar key
is bound in
.Ar key-table :
the binding for command mode with
.Fl c
or for normal mode without.
To view the default bindings and possible commands, see the
.Ic list-keys
command.
.It Ic list-keys Op Fl t Ar key-table
.D1 (alias: Ic lsk )
List all key bindings.
Without
.Fl t
the primary key bindings - those executed when preceded by the prefix key -
are printed.
Keys bound without the prefix key (see
.Ic bind-key
.Fl n )
are marked with
.Ql (no prefix) .
.Pp
With
.Fl t ,
the key bindings in
.Ar key-table
are listed; this may be one of:
.Em vi-edit ,
.Em emacs-edit ,
.Em vi-choice ,
.Em emacs-choice ,
.Em vi-copy
or
.Em emacs-copy .
.It Xo Ic send-keys
.Op Fl t Ar target-pane
.Ar key Ar ...
.Xc
.D1 (alias: Ic send )
Send a key or keys to a window.
Each argument
.Ar key
is the name of the key (such as
.Ql C-a
or
.Ql npage
) to send; if the string is not recognised as a key, it is sent as a series of
characters.
All arguments are sent sequentially from first to last.
.It Ic send-prefix Op Fl t Ar target-pane
Send the prefix key to a window as if it was pressed.
If multiple prefix keys are configured, only the first is sent.
.It Xo Ic unbind-key
.Op Fl cn
.Op Fl t Ar key-table
.Ar key
.Xc
.D1 (alias: Ic unbind )
Unbind the command bound to
.Ar key .
Without
.Fl t
the primary key bindings are modified; in this case, if
.Fl n
is specified, the command bound to
.Ar key
without a prefix (if any) is removed.
.Pp
If
.Fl t
is present,
.Ar key
in
.Ar key-table
is unbound: the binding for command mode with
.Fl c
or for normal mode without.
.El
.Sh OPTIONS
The appearance and behaviour of
.Nm
may be modified by changing the value of various options.
There are three types of option:
.Em server options ,
.Em session options
and
.Em window options .
.Pp
The
.Nm
server has a set of global options which do not apply to any particular
window or session.
These are altered with the
.Ic set-option
.Fl s
command, or displayed with the
.Ic show-options
.Fl s
command.
.Pp
In addition, each individual session may have a set of session options, and
there is a separate set of global session options.
Sessions which do not have a particular option configured inherit the value
from the global session options.
Session options are set or unset with the
.Ic set-option
command and may be listed with the
.Ic show-options
command.
The available server and session options are listed under the
.Ic set-option
command.
.Pp
Similarly, a set of window options is attached to each window, and there is
a set of global window options from which any unset options are inherited.
Window options are altered with the
.Ic set-window-option
command and can be listed with the
.Ic show-window-options
command.
All window options are documented with the
.Ic set-window-option
command.
.Pp
Commands which set options are as follows:
.Bl -tag -width Ds
.It Xo Ic set-option
.Op Fl agsuw
.Op Fl t Ar target-session | Ar target-window
.Ar option Ar value
.Xc
.D1 (alias: Ic set )
Set a window option with
.Fl w
(equivalent to the
.Ic set-window-option
command),
a server option with
.Fl s ,
otherwise a session option.
.Pp
If
.Fl g
is specified, the global session or window option is set.
With
.Fl a ,
and if the option expects a string,
.Ar value
is appended to the existing setting.
The
.Fl u
flag unsets an option, so a session inherits the option from the global
options.
It is not possible to unset a global option.
.Pp
Available window options are listed under
.Ic set-window-option .
.Pp
Available server options are:
.Bl -tag -width Ds
.It Ic escape-time
Set the time in milliseconds for which
.Nm
waits after an escape is input to determine if it is part of a function or meta
key sequences.
The default is 500 milliseconds.
.It Ic quiet
Enable or disable the display of various informational messages (see also the
.Fl q
command line flag).
.El
.Pp
Available session options are:
.Bl -tag -width Ds
.It Ic base-index Ar index
Set the base index from which an unused index should be searched when a new
window is created.
The default is zero.
.It Xo Ic bell-action
.Op Ic any | none | current
.Xc
Set action on window bell.
.Ic any
means a bell in any window linked to a session causes a bell in the current
window of that session,
.Ic none
means all bells are ignored and
.Ic current
means only bell in windows other than the current window are ignored.
.It Ic buffer-limit Ar number
Set the number of buffers kept for each session; as new buffers are added to
the top of the stack, old ones are removed from the bottom if necessary to
maintain this maximum length.
.It Ic default-command Ar command
Set the command used for new windows (if not specified when the window is
created) to
.Ar command ,
which may be any
.Xr sh 1
command.
The default is an empty string, which instructs
.Nm
to create a login shell using the value of the
.Ic default-shell
option.
.It Ic default-shell Ar path
Specify the default shell.
This is used as the login shell for new windows when the
.Ic default-command
option is set to empty, and must be the full path of the executable.
When started
.Nm
tries to set a default value from the first suitable of the
.Ev SHELL
environment variable, the shell returned by
.Xr getpwuid 3 ,
or
.Pa /bin/sh .
This option should be configured when
.Nm
is used as a login shell.
.It Ic default-path Ar path
Set the default working directory for processes created from keys, or
interactively from the prompt.
The default is the current working directory when the server is started.
.It Ic default-terminal Ar terminal
Set the default terminal for new windows created in this session - the
default value of the
.Ev TERM
environment variable.
For
.Nm
to work correctly, this
.Em must
be set to
.Ql screen
or a derivative of it.
.It Ic display-panes-colour Ar colour
Set the colour used for the
.Ic display-panes
command.
.It Ic display-panes-time Ar time
Set the time in milliseconds for which the indicators shown by the
.Ic display-panes
command appear.
.It Ic display-time Ar time
Set the amount of time for which status line messages and other on-screen
indicators are displayed.
.Ar time
is in milliseconds.
.It Ic history-limit Ar lines
Set the maximum number of lines held in window history.
This setting applies only to new windows - existing window histories are not
resized and retain the limit at the point they were created.
.It Ic lock-after-time Ar number
Lock the session (like the
.Ic lock-session
command) after
.Ar number
seconds of inactivity, or the entire server (all sessions) if the
.Ic lock-server
option is set.
The default is not to lock (set to 0).
.It Ic lock-command Ar command
Command to run when locking each client.
The default is to run
.Xr lock 1
with
.Fl np .
.It Xo Ic lock-server
.Op Ic on | off
.Xc
If this option is
.Ic on
(the default),
instead of each session locking individually as each has been
idle for
.Ic lock-after-time ,
the entire server will lock after
.Em all
sessions would have locked.
This has no effect as a session option; it must be set as a global option.
.It Ic message-attr Ar attributes
Set status line message attributes, where
.Ar attributes
is either
.Ic default
or a comma-delimited list of one or more of:
.Ic bright
(or
.Ic bold ) ,
.Ic dim ,
.Ic underscore ,
.Ic blink ,
.Ic reverse ,
.Ic hidden ,
or
.Ic italics .
.It Ic message-bg Ar colour
Set status line message background colour, where
.Ar colour
is one of:
.Ic black ,
.Ic red ,
.Ic green ,
.Ic yellow ,
.Ic blue ,
.Ic magenta ,
.Ic cyan ,
.Ic white ,
.Ic colour0
to
.Ic colour255
from the 256-colour palette, or
.Ic default .
.It Ic message-fg Ar colour
Set status line message foreground colour.
.It Ic message-limit Ar number
Set the number of error or information messages to save in the message log for
each client.
The default is 20.
.It Xo Ic mouse-select-pane
.Op Ic on | off
.Xc
If on,
.Nm
captures the mouse and when a window is split into multiple panes the mouse may
be used to select the current pane.
The mouse click is also passed through to the application as normal.
.It Ic pane-border-fg Ar colour
.It Ic pane-border-bg Ar colour
Set the pane border colour for panes aside from the active pane.
.It Ic pane-active-border-fg Ar colour
.It Ic pane-active-border-bg Ar colour
Set the pane border colour for the currently active pane.
.It Ic prefix Ar keys
Set the keys accepted as a prefix key.
.Ar keys
is a comma-separated list of key names, each of which individually behave as
the prefix key.
.It Ic repeat-time Ar time
Allow multiple commands to be entered without pressing the prefix-key again
in the specified
.Ar time
milliseconds (the default is 500).
Whether a key repeats may be set when it is bound using the
.Fl r
flag to
.Ic bind-key .
Repeat is enabled for the default keys bound to the
.Ic resize-pane
command.
.It Xo Ic set-remain-on-exit
.Op Ic on | off
.Xc
Set the
.Ic remain-on-exit
window option for any windows first created in this session.
.It Xo Ic set-titles
.Op Ic on | off
.Xc
Attempt to set the window title using the \ee]2;...\e007 xterm code if
the terminal appears to be an xterm.
This option is off by default.
Note that elinks
will only attempt to set the window title if the STY environment
variable is set.
.It Ic set-titles-string Ar string
String used to set the window title if
.Ic set-titles
is on.
Character sequences are replaced as for the
.Ic status-left
option.
.It Xo Ic status
.Op Ic on | off
.Xc
Show or hide the status line.
.It Ic status-attr Ar attributes
Set status line attributes.
.It Ic status-bg Ar colour
Set status line background colour.
.It Ic status-fg Ar colour
Set status line foreground colour.
.It Ic status-interval Ar interval
Update the status bar every
.Ar interval
seconds.
By default, updates will occur every 15 seconds.
A setting of zero disables redrawing at interval.
.It Xo Ic status-justify
.Op Ic left | centre | right
.Xc
Set the position of the window list component of the status line: left, centre
or right justified.
.It Xo Ic status-keys
.Op Ic vi | emacs
.Xc
Use vi or emacs-style
key bindings in the status line, for example at the command prompt.
Defaults to emacs.
.It Ic status-left Ar string
Display
.Ar string
to the left of the status bar.
.Ar string
will be passed through
.Xr strftime 3
before being used.
By default, the session name is shown.
.Ar string
may contain any of the following special character sequences:
.Bl -column "Character pair" "Replaced with" -offset indent
.It Sy "Character pair" Ta Sy "Replaced with"
.It Li "#(command)" Ta "First line of command's output"
.It Li "#[attributes]" Ta "Colour or attribute change"
.It Li "#H" Ta "Hostname of local host"
.It Li "#F" Ta "Current window flag"
.It Li "#I" Ta "Current window index"
.It Li "#P" Ta "Current pane index"
.It Li "#S" Ta "Session name"
.It Li "#T" Ta "Current window title"
.It Li "#W" Ta "Current window name"
.It Li "##" Ta "A literal" Ql #
.El
.Pp
The #(command) form executes
.Ql command
as a shell command and inserts the first line of its output.
Note that shell commands are only executed once at the interval specified by
the
.Ic status-interval
option: if the status line is redrawn in the meantime, the previous result is
used.
.Pp
#[attributes] allows a comma-separated list of attributes to be specified,
these may be
.Ql fg=colour
to set the foreground colour,
.Ql bg=colour
to set the background colour, the name of one of the attributes (listed under
the
.Ic message-attr
option) to turn an attribute on, or an attribute prefixed with
.Ql no
to turn one off, for example
.Ic nobright .
Examples are:
.Bd -literal -offset indent
#(sysctl vm.loadavg)
#[fg=yellow,bold]#(apm -l)%%#[default] [#S]
.Ed
.Pp
Where appropriate, special character sequences may be prefixed with a number to
specify the maximum length, for example
.Ql #24T .
.Pp
By default, UTF-8 in
.Ar string
is not interpreted, to enable UTF-8, use the
.Ic status-utf8
option.
.It Ic status-left-attr Ar attributes
Set the attribute of the left part of the status line.
.It Ic status-left-fg Ar colour
Set the foreground colour of the left part of the status line.
.It Ic status-left-bg Ar colour
Set the background colour of the left part of the status line.
.It Ic status-left-length Ar length
Set the maximum
.Ar length
of the left component of the status bar.
The default is 10.
.It Ic status-right Ar string
Display
.Ar string
to the right of the status bar.
By default, the date and time will be shown.
As with
.Ic status-left ,
.Ar string
will be passed to
.Xr strftime 3 ,
character pairs are replaced, and UTF-8 is dependent on the
.Ic status-utf8
option.
.It Ic status-right-attr Ar attributes
Set the attribute of the right part of the status line.
.It Ic status-right-fg Ar colour
Set the foreground colour of the right part of the status line.
.It Ic status-right-bg Ar colour
Set the background colour of the right part of the status line.
.It Ic status-right-length Ar length
Set the maximum
.Ar length
of the right component of the status bar.
The default is 40.
.Pp
.It Xo Ic status-utf8
.Op Ic on | off
.Xc
Instruct
.Nm
to treat top-bit-set characters in the
.Ic status-left
and
.Ic status-right
strings as UTF-8; notably, this is important for wide characters.
This option defaults to off.
.It Ic terminal-overrides Ar string
Contains a list of entries which override terminal descriptions read using
.Xr terminfo 5 .
.Ar string
is a comma-separated list of items each a colon-separated string made up of a
terminal type pattern (matched using
.Xr fnmatch 3 )
and a set of
.Em name=value
entries.
.Pp
For example, to set the
.Ql clear
.Xr terminfo 5
entry to
.Ql \ee[H\ee[2J
for all terminal types and the
.Ql dch1
entry to
.Ql \ee[P
for the
.Ql rxvt
terminal type, the option could be set to the string:
.Bd -literal -offset indent
"*:clear=\ee[H\ee[2J,rxvt:dch1=\ee[P"
.Ed
.Pp
The terminal entry value is passed through
.Xr strunvis 3
before interpretation.
The default value forcibly corrects the
.Ql colors
entry for terminals which support 88 or 256 colours:
.Bd -literal -offset indent
"*88col*:colors=88,*256col*:colors=256"
.Ed
.It Ic update-environment Ar variables
Set a space-separated string containing a list of environment variables to be
copied into the session environment when a new session is created or an
existing session is attached.
Any variables that do not exist in the source environment are set to be
removed from the session environment (as if
.Fl r
was given to the
.Ic set-environment
command).
The default is
"DISPLAY WINDOWID SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION".
.It Xo Ic visual-activity
.Op Ic on | off
.Xc
If on, display a status line message when activity occurs in a window
for which the
.Ic monitor-activity
window option is enabled.
.It Xo Ic visual-bell
.Op Ic on | off
.Xc
If this option is on, a message is shown on a bell instead of it being passed
through to the terminal (which normally makes a sound).
Also see the
.Ic bell-action
option.
.It Xo Ic visual-content
.Op Ic on | off
.Xc
Like
.Ic visual-activity ,
display a message when content is present in a window
for which the
.Ic monitor-content
window option is enabled.
.El
.It Xo Ic set-window-option
.Op Fl agu
.Op Fl t Ar target-window
.Ar option Ar value
.Xc
.D1 (alias: Ic setw )
Set a window option.
The
.Fl a ,
.Fl g
and
.Fl u
flags work similarly to the
.Ic set-option
command.
.Pp
Supported window options are:
.Pp
.Bl -tag -width Ds -compact
.It Xo Ic aggressive-resize
.Op Ic on | off
.Xc
Aggressively resize the chosen window.
This means that
.Nm
will resize the window to the size of the smallest session for which it is the
current window, rather than the smallest session to which it is attached.
The window may resize when the current window is changed on another sessions;
this option is good for full-screen programs which support
.Dv SIGWINCH
and poor for interactive programs such as shells.
.Pp
.It Xo Ic automatic-rename
.Op Ic on | off
.Xc
Control automatic window renaming.
When this setting is enabled,
.Nm
will attempt - on supported platforms - to rename the window to reflect the
command currently running in it.
This flag is automatically disabled for an individual window when a name
is specified at creation with
.Ic new-window or
.Ic new-session ,
or later with
.Ic rename-window .
It may be switched off globally with:
.Bd -literal -offset indent
set-window-option -g automatic-rename off
.Ed
.Pp
.It Ic clock-mode-colour Ar colour
Set clock colour.
.Pp
.It Xo Ic clock-mode-style
.Op Ic 12 | 24
.Xc
Set clock hour format.
.Pp
.It Ic force-height Ar height
.It Ic force-width Ar width
Prevent
.Nm
from resizing a window to greater than
.Ar width
or
.Ar height .
A value of zero restores the default unlimited setting.
.Pp
.It Ic main-pane-width Ar width
.It Ic main-pane-height Ar height
Set the width or height of the main (left or top) pane in the
.Ic main-horizontal
or
.Ic main-vertical
layouts.
.Pp
.It Ic mode-attr Ar attributes
Set window modes attributes.
.Pp
.It Ic mode-bg Ar colour
Set window modes background colour.
.Pp
.It Ic mode-fg Ar colour
Set window modes foreground colour.
.Pp
.It Xo Ic mode-keys
.Op Ic vi | emacs
.Xc
Use vi or emacs-style key bindings in copy and choice modes.
Key bindings default to emacs.
.Pp
.It Xo Ic mode-mouse
.Op Ic on | off
.Xc
Mouse state in modes.
If on,
.Nm
will respond to mouse clicks by moving the cursor in copy mode or selecting an
option in choice mode.
.Pp
.It Xo Ic monitor-activity
.Op Ic on | off
.Xc
Monitor for activity in the window.
Windows with activity are highlighted in the status line.
.Pp
.It Ic monitor-content Ar match-string
Monitor content in the window.
When
.Xr fnmatch 3
pattern
.Ar match-string
appears in the window, it is highlighted in the status line.
.Pp
.It Xo Ic remain-on-exit
.Op Ic on | off
.Xc
A window with this flag set is not destroyed when the program running in it
exits.
The window may be reactivated with the
.Ic respawn-window
command.
.Pp
.It Xo Ic synchronize-panes
.Op Ic on | off
.Xc
Duplicate input to any pane to all other panes in the same window, except
for panes that are not in output mode.
.It Xo Ic utf8
.Op Ic on | off
.Xc
Instructs
.Nm
to expect UTF-8 sequences to appear in this window.
.Pp
.It Ic window-status-attr Ar attributes
Set status line attributes for a single window.
.Pp
.It Ic window-status-bg Ar colour
Set status line background colour for a single window.
.Pp
.It Ic window-status-fg Ar colour
Set status line foreground colour for a single window.
.Pp
.It Ic window-status-format Ar string
Set the format in which the window is displayed in the status line window list.
See the
.Ar status-left
option for details of special character sequences available.
The default is
.Ql #I:#W#F .
.Pp
.It Ic window-status-current-attr Ar attributes
Set status line attributes for the currently active window.
.Pp
.It Ic window-status-current-bg Ar colour
Set status line background colour for the currently active window.
.Pp
.It Ic window-status-current-fg Ar colour
Set status line foreground colour for the currently active window.
.Pp
.It Ic window-status-current-format Ar string
Like
.Ar window-status-format ,
but is the format used when the window is the current window.
.Pp
.It Xo Ic xterm-keys
.Op Ic on | off
.Xc
If this option is set,
.Nm
will generate
.Xr xterm 1 -style
function key sequences; these have a number included to indicate modifiers such
as Shift, Alt or Ctrl.
The default is off.
.El
.It Xo Ic show-options
.Op Fl gsw
.Op Fl t Ar target-session | Ar target-window
.Xc
.D1 (alias: Ic show )
Show the window options with
.Fl w
(equivalent to
.Ic show-window-options ) ,
the server options with
.Fl s ,
otherwise the session options for
.Ar target session .
Global session or window options are listed if
.Fl g
is used.
.It Xo Ic show-window-options
.Op Fl g
.Op Fl t Ar target-window
.Xc
.D1 (alias: Ic showw )
List the window options for
.Ar target-window ,
or the global window options if
.Fl g
is used.
.El
.Sh ENVIRONMENT
When the server is started,
.Nm
copies the environment into the
.Em global environment ;
in addition, each session has a
.Em session environment .
When a window is created, the session and global environments are merged with
the session environment overriding any variable present in both.
This is the initial environment passed to the new process.
.Pp
The
.Ic update-environment
session option may be used to update the session environment from the client
when a new session is created or an old reattached.
.Nm
also initialises the
.Ev TMUX
variable with some internal information to allow commands to be executed
from inside, and the
.Ev TERM
variable with the correct terminal setting of
.Ql screen .
.Pp
Commands to alter and view the environment are:
.Bl -tag -width Ds
.It Xo Ic set-environment
.Op Fl gru
.Op Fl t Ar target-session
.Ar name Op Ar value
.Xc
.D1 (alias: Ic setenv )
Set or unset an environment variable.
If
.Fl g
is used, the change is made in the global environment; otherwise, it is applied
to the session environment for
.Ar target-session .
The
.Fl u
flag unsets a variable.
.Fl r
indicates the variable is to be removed from the environment before starting a
new process.
.It Xo Ic show-environment
.Op Fl g
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic showenv )
Display the environment for
.Ar target-session
or the global environment with
.Fl g .
Variables removed from the environment are prefixed with
.Ql - .
.El
.Sh STATUS LINE
.Nm
includes an optional status line which is displayed in the bottom line of each
terminal.
By default, the status line is enabled (it may be disabled with the
.Ic status
session option) and contains, from left-to-right: the name of the current
session in square brackets; the window list; the current window title in double
quotes; and the time and date.
.Pp
The status line is made of three parts: configurable left and right sections
(which may contain dynamic content such as the time or output from a shell
command, see the
.Ic status-left ,
.Ic status-left-length ,
.Ic status-right ,
and
.Ic status-right-length
options below), and a central window list.
By default, the window list shows the index, name and (if any) flag of the
windows present in the current session in ascending numerical order.
It may be customised with the
.Ar window-status-format
and
.Ar window-status-current-format
options.
The flag is one of the following symbols appended to the window name:
.Bl -column "Symbol" "Meaning" -offset indent
.It Sy "Symbol" Ta Sy "Meaning"
.It Li "*" Ta "Denotes the current window."
.It Li "-" Ta "Marks the last window (previously selected)."
.It Li "#" Ta "Window is monitored and activity has been detected."
.It Li "!" Ta "A bell has occurred in the window."
.It Li "+" Ta "Window is monitored for content and it has appeared."
.El
.Pp
The # symbol relates to the
.Ic monitor-activity
and + to the
.Ic monitor-content
window options.
The window name is printed in inverted colours if an alert (bell, activity or
content) is present.
.Pp
The colour and attributes of the status line may be configured, the entire
status line using the
.Ic status-attr ,
.Ic status-fg
and
.Ic status-bg
session options and individual windows using the
.Ic window-status-attr ,
.Ic window-status-fg
and
.Ic window-status-bg
window options.
.Pp
The status line is automatically refreshed at interval if it has changed, the
interval may be controlled with the
.Ic status-interval
session option.
.Pp
Commands related to the status line are as follows:
.Bl -tag -width Ds
.It Xo Ic command-prompt
.Op Fl p Ar prompts
.Op Fl t Ar target-client
.Op Ar template
.Xc
Open the command prompt in a client.
This may be used from inside
.Nm
to execute commands interactively.
If
.Ar template
is specified, it is used as the command.
If
.Fl p
is given,
.Ar prompts
is a comma-separated list of prompts which are displayed in order; otherwise
a single prompt is displayed, constructed from
.Ar template
if it is present, or
.Ql \&:
if not.
Before the command is executed, the first occurrence of the string
.Ql %%
and all occurrences of
.Ql %1
are replaced by the response to the first prompt, the second
.Ql %%
and all
.Ql %2
are replaced with the response to the second prompt, and so on for further
prompts.
Up to nine prompt responses may be replaced
.Po
.Ql %1
to
.Ql %9
.Pc .
.It Xo Ic confirm-before
.Op Fl t Ar target-client
.Ar command
.Xc
.D1 (alias: Ic confirm )
Ask for confirmation before executing
.Ar command .
This command works only from inside
.Nm .
.It Xo Ic display-message
.Op Fl p
.Op Fl t Ar target-client
.Op Ar message
.Xc
.D1 (alias: Ic display )
Display a message.
If
.Fl p
is given, the output is printed to stdout, otherwise it is displayed in the
.Ar target-client
status line.
The format of
.Ar message
is as for
.Ic status-left ,
with the exception that #() are not handled.
.It Ic select-prompt Op Fl t Ar target-client
Open a prompt inside
.Ar target-client
allowing a window index to be entered interactively.
.El
.Sh BUFFERS
.Nm
maintains a stack of
.Em paste buffers
for each session.
Up to the value of the
.Ic buffer-limit
option are kept; when a new buffer is added, the buffer at the bottom of the
stack is removed.
Buffers may be added using
.Ic copy-mode
or the
.Ic set-buffer
command, and pasted into a window using the
.Ic paste-buffer
command.
.Pp
A configurable history buffer is also maintained for each window.
By default, up to 2000 lines are kept; this can be altered with the
.Ic history-limit
option (see the
.Ic set-option
command above).
.Pp
The buffer commands are as follows:
.Bl -tag -width Ds
.It Ic clear-history Op Fl t Ar target-pane
.D1 (alias: Ic clearhist )
Remove and free the history for the specified pane.
.It Xo Ic copy-buffer
.Op Fl a Ar src-index
.Op Fl b Ar dst-index
.Op Fl s Ar src-session
.Op Fl t Ar dst-session
.Xc
.D1 (alias: Ic copyb )
Copy a session paste buffer to another session.
If no sessions are specified, the current one is used instead.
.It Xo Ic delete-buffer
.Op Fl b Ar buffer-index
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic deleteb )
Delete the buffer at
.Ar buffer-index ,
or the top buffer if not specified.
.It Ic list-buffers Op Fl t Ar target-session
.D1 (alias: Ic lsb )
List the buffers in the given session.
.It Xo Ic load-buffer
.Op Fl b Ar buffer-index
.Op Fl t Ar target-session
.Ar path
.Xc
.D1 (alias: Ic loadb )
Load the contents of the specified paste buffer from
.Ar path .
.It Xo Ic paste-buffer
.Op Fl dr
.Op Fl b Ar buffer-index
.Op Fl t Ar target-window
.Xc
.D1 (alias: Ic pasteb )
Insert the contents of a paste buffer into the current window.
With
.Fl d ,
also delete the paste buffer from the stack.
When output, any linefeed (LF) characters in the paste buffer are replaced with
carriage returns (CR).
This translation may be disabled with the
.Fl r
flag.
.It Xo Ic save-buffer
.Op Fl a
.Op Fl b Ar buffer-index
.Op Fl t Ar target-session
.Ar path
.Xc
.D1 (alias: Ic saveb )
Save the contents of the specified paste buffer to
.Ar path .
The
.Fl a
option appends to rather than overwriting the file.
.It Xo Ic set-buffer
.Op Fl b Ar buffer-index
.Op Fl t Ar target-session
.Ar data
.Xc
.D1 (alias: Ic setb )
Set the contents of the specified buffer to
.Ar data .
.It Xo Ic show-buffer
.Op Fl b Ar buffer-index
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic showb )
Display the contents of the specified buffer.
.El
.Sh MISCELLANEOUS
.Pp
Miscellaneous commands are as follows:
.Bl -tag -width Ds
.It Ic clock-mode Op Fl t Ar target-pane
Display a large clock.
.It Ic if-shell Ar shell-command command
.D1 (alias: Ic if )
Execute
.Ar command
if
.Ar shell-command
returns success.
.It Ic lock-server
.D1 (alias: Ic lock )
Lock each client individually by running the command specified by the
.Ic lock-command
option.
.It Ic run-shell Ar command
.D1 (alias: Ic run )
Execute
.Ar command
in the background without creating a window.
After the command finishes, any output to stdout is displayed in output mode.
If
.Ar command
doesn't return success, the exit status is also displayed.
.It Ic server-info
.D1 (alias: Ic info )
Show server information and terminal details.
.El
.Sh FILES
.Bl -tag -width "/etc/tmux.confXXX" -compact
.It Pa ~/.tmux.conf
Default
.Nm
configuration file.
.It Pa /etc/tmux.conf
System-wide configuration file.
.El
.Sh EXAMPLES
To create a new
.Nm
session running
.Xr vi 1 :
.Pp
.Dl $ tmux new-session vi
.Pp
Most commands have a shorter form, known as an alias.
For new-session, this is
.Ic new :
.Pp
.Dl $ tmux new vi
.Pp
Alternatively, the shortest unambiguous form of a command is accepted.
If there are several options, they are listed:
.Bd -literal -offset indent
$ tmux n
ambiguous command: n, could be: new-session, new-window, next-window
.Ed
.Pp
Within an active session, a new window may be created by typing
.Ql C-b c
(Ctrl
followed by the
.Ql b
key
followed by the
.Ql c
key).
.Pp
Windows may be navigated with:
.Ql C-b 0
(to select window 0),
.Ql C-b 1
(to select window 1), and so on;
.Ql C-b n
to select the next window; and
.Ql C-b p
to select the previous window.
.Pp
A session may be detached using
.Ql C-b d
(or by an external event such as
.Xr ssh 1
disconnection) and reattached with:
.Pp
.Dl $ tmux attach-session
.Pp
Typing
.Ql C-b \&?
lists the current key bindings in the current window; up and down may be used
to navigate the list or
.Ql q
to exit from it.
.Pp
Commands to be run when the
.Nm
server is started may be placed in the
.Pa ~/.tmux.conf
configuration file.
Common examples include:
.Pp
Changing the default prefix key:
.Bd -literal -offset indent
set-option -g prefix C-a
unbind-key C-b
bind-key C-a send-prefix
.Ed
.Pp
Turning the status line off, or changing its colour:
.Bd -literal -offset indent
set-option -g status off
set-option -g status-bg blue
.Ed
.Pp
Setting other options, such as the default command,
or locking after 30 minutes of inactivity:
.Bd -literal -offset indent
set-option -g default-command "exec /bin/ksh"
set-option -g lock-after-time 1800
.Ed
.Pp
Creating new key bindings:
.Bd -literal -offset indent
bind-key b set-option status
bind-key / command-prompt "split-window 'exec man %%'"
bind-key S command-prompt "new-window -n %1 'ssh %1'"
.Ed
.Sh SEE ALSO
.Xr pty 4
.Sh AUTHORS
.An Nicholas Marriott Aq nicm@users.sourceforge.net