tmux/tmux.1

.\" $OpenBSD$
.\"
.\" 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 $Mdocdate$
.Dt TMUX 1
.Os
.Sh NAME
.Nm tmux
.Nd terminal multiplexer
.Sh SYNOPSIS
.Nm tmux
.Bk -words
.Op Fl 2lCuv
.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 C
Start in control mode (see the
.Sx CONTROL MODE
section).
Given twice
.Xo ( Fl CC ) Xc
disables echo.
.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.
This option is for compatibility with
.Xr sh 1
when
.Nm
is used as a login shell.
.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 .
.Pp
The configuration file is a set of
.Nm
commands which are executed in sequence when the server is first started.
.Nm
loads configuration files once when the server process has started.
The
.Ic source-file
command may be used to load a file later.
.Pp
.Nm
shows any error messages from commands in configuration files in the first
session created, and continues to process the rest of the configuration file.
.It Fl L Ar socket-name
.Nm
stores the server socket in a directory under
.Ev TMUX_TMPDIR ,
.Ev TMPDIR
if it is unset, or
.Pa /tmp
if both are unset.
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 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 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
The default command key bindings are:
.Pp
.Bl -tag -width "XXXXXXXXXX" -offset indent -compact
.It C-b
Send the prefix key (C-b) through to the application.
.It C-o
Rotate the panes in the current window forwards.
.It C-z
Suspend the
.Nm
client.
.It !
Break the current pane out of the window.
.It \&"
Split the current pane into two, top and bottom.
.It #
List all paste buffers.
.It $
Rename the current session.
.It %
Split the current pane into two, left and right.
.It &
Kill the current window.
.It '
Prompt for a window index to select.
.It ,
Rename the current window.
.It -
Delete the most recently copied buffer of text.
.It .
Prompt for an index to move the current window.
.It 0 to 9
Select windows 0 to 9.
.It :
Enter the
.Nm
command prompt.
.It ;
Move to the previously active pane.
.It =
Choose which buffer to paste interactively from a list.
.It \&?
List all key bindings.
.It D
Choose a client to detach.
.It \&[
Enter copy mode to copy text or view the history.
.It \&]
Paste the most recently copied buffer of text.
.It c
Create a new window.
.It d
Detach the current client.
.It f
Prompt to search for text in open windows.
.It i
Display some information about the current window.
.It l
Move to the previously selected window.
.It n
Change to the next window.
.It o
Select the next pane in the current window.
.It p
Change to the previous window.
.It q
Briefly display pane indexes.
.It r
Force redraw of the attached client.
.It s
Select a new session for the attached client interactively.
.It L
Switch the attached client back to the last session.
.It t
Show the time.
.It w
Choose the current window interactively.
.It x
Kill the current pane.
.It {
Swap the current pane with the previous pane.
.It }
Swap the current pane with the next pane.
.It ~
Show previous messages from
.Nm ,
if any.
.It Page Up
Enter copy mode and scroll one page up.
.It Up, Down
.It Left, Right
Change to the pane above, below, to the left, or to the right of the current
pane.
.It M-1 to M-5
Arrange panes in one of the five preset layouts: even-horizontal,
even-vertical, main-horizontal, main-vertical, or tiled.
.It M-n
Move to the next window with a bell or activity marker.
.It M-o
Rotate the panes in the current window backwards.
.It M-p
Move to the previous window with a bell or activity marker.
.It C-Up, C-Down
.It C-Left, C-Right
Resize the current pane in steps of one cell.
.It M-Up, M-Down
.It M-Left, M-Right
Resize the current pane in steps of five cells.
.El
.Pp
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 the session id prefixed with a $, 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 a window ID, such as @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.
The special character
.Ql \&!
uses the last (previously current) window,
.Ql ^
selects the highest numbered window,
.Ql $
selects the lowest numbered window, and
.Ql +
and
.Ql -
select the next window or the previous window by number.
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 .
A
.Ql + ,
.Ql -
or
.Ql \&!
indicate the next, previous or last pane.
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
The special characters
.Ql +
and
.Ql -
may be followed by an offset, for example:
.Bd -literal -offset indent
select-window -t:+2
.Ed
.Pp
When dealing with a session that doesn't contain sequential window indexes,
they will be correctly skipped.
.Pp
.Nm
also gives each pane created in a server an identifier consisting of a
.Ql %
and a number, starting from zero.
A pane's identifier is unique for the life of the
.Nm
server and is passed to the child process of the pane in the
.Ev TMUX_PANE
environment variable.
It may be used alone to target a pane or the window containing it.
.Pp
.Ar shell-command
arguments are
.Xr sh 1
commands.
This may be a single argument passed to the shell, for example:
.Bd -literal -offset indent
new-window 'vi /etc/passwd'
.Ed
.Pp
Will run:
.Bd -literal -offset indent
/bin/sh -c 'vi /etc/passwd'
.Ed
.Pp
Additionally, the
.Ic new-window ,
.Ic new-session ,
.Ic split-window ,
.Ic respawn-window
and
.Ic respawn-pane
commands allow
.Ar shell-command
to be given as multiple arguments and executed directly (without
.Ql sh -c ) .
This can avoid issues with shell quoting.
For example:
.Bd -literal -offset indent
$ tmux new-window vi /etc/passwd
.Ed
.Pp
Will run
.Xr vi 1
directly without invoking the shell.
.Pp
.Ar command
.Op Ar arguments
refers to a
.Nm
command, passed with the command and arguments separately, for example:
.Bd -literal -offset indent
bind-key F1 set-window-option force-width 81
.Ed
.Pp
Or if using
.Xr sh 1 :
.Bd -literal -offset indent
$ tmux bind-key F1 set-window-option force-width 81
.Ed
.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 and
lines ending with a backslash continue on to the next line,
except when escaped by another backslash.
A literal semicolon may be included by escaping it with a backslash (for
example, when specifying a command sequence to
.Ic bind-key ) .
.Pp
Example
.Nm
commands 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

bind-key R source-file ~/.tmux.conf \e; \e
	display-message "source-file done"
.Ed
.Pp
Or from
.Xr sh 1 :
.Bd -literal -offset indent
$ tmux kill-window -t :1

$ tmux new-window \e; split-window -d

$ tmux new-session -d 'vi /etc/passwd' \e; split-window -d \e; attach
.Ed
.Sh CLIENTS AND SESSIONS
The
.Nm
server manages clients, sessions, windows and panes.
Clients are attached to sessions to interact with them, either
when they are created with the
.Ic new-session
command, or later with the
.Ic attach-session
command.
Each session has one or more windows
.Em linked
into it.
Windows may be linked to multiple sessions and are made up of one or
more panes,
each of which contains a pseudo terminal.
Commands for creating, linking and otherwise manipulating windows
are covered
in the
.Sx WINDOWS AND PANES
section.
.Pp
The following commands are available to manage clients and sessions:
.Bl -tag -width Ds
.It Xo Ic attach-session
.Op Fl dr
.Op Fl c Ar working-directory
.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.
.Fl r
signifies the client is read-only (only keys bound to the
.Ic detach-client
or
.Ic switch-client
commands have any effect)
.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.
.Pp
The
.Ar target-session
rules for
.Ic attach-session
are slightly adjusted: if
.Nm
needs to select the most recently used session, it will prefer the most
recently used
.Em unattached
session.
.Pp
.Fl c
will set the session working directory (used for new windows) to
.Ar working-directory .
.It Xo Ic detach-client
.Op Fl P
.Op Fl a
.Op Fl s Ar target-session
.Op Fl t Ar target-client
.Xc
.D1 (alias: Ic detach )
Detach the current client if bound to a key, the client specified with
.Fl t ,
or all clients currently attached to the session specified by
.Fl s .
The
.Fl a
option kills all but the client given with
.Fl t .
If
.Fl P
is given, send SIGHUP to the parent process of the client, typically causing it
to exit.
.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 Xo Ic kill-session
.Op Fl a
.Op Fl t Ar target-session
.Xc
Destroy the given session, closing any windows linked to it and no other
sessions, and detaching all clients attached to it.
If
.Fl a
is given, all sessions but the specified one is killed.
.It Xo Ic list-clients
.Op Fl F Ar format
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic lsc )
List all clients attached to the server.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
If
.Ar target-session
is specified, list only clients connected to that session.
.It Ic list-commands
.D1 (alias: Ic lscm )
List the syntax of all commands supported by
.Nm .
.It Ic list-sessions Op Fl F Ar format
.D1 (alias: Ic ls )
List all sessions managed by the server.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
.It Ic lock-client Op Fl t Ar target-client
.D1 (alias: Ic lockc )
Lock
.Ar target-client ,
see the
.Ic lock-server
command.
.It Ic lock-session Op Fl t Ar target-session
.D1 (alias: Ic locks )
Lock all clients attached to
.Ar target-session .
.It Xo Ic new-session
.Op Fl AdDP
.Op Fl c Ar start-directory
.Op Fl F Ar format
.Op Fl n Ar window-name
.Op Fl s Ar session-name
.Op Fl t Ar target-session
.Op Fl x Ar width
.Op Fl y Ar height
.Op Ar shell-command
.Xc
.D1 (alias: Ic new )
Create a new session with name
.Ar session-name .
.Pp
The new session is attached to the current terminal unless
.Fl d
is given.
.Ar window-name
and
.Ar shell-command
are the name of and shell command to execute in the initial window.
If
.Fl d
is used,
.Fl x
and
.Fl y
specify the size of the initial window (80 by 24 if not given).
.Pp
If run from a terminal, any
.Xr termios 4
special characters are saved and used for new windows in the new session.
.Pp
The
.Fl A
flag makes
.Ic new-session
behave like
.Ic attach-session
if
.Ar session-name
already exists; in the case,
.Fl D
behaves like
.Fl d
to
.Ic attach-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 shell-command
are invalid if
.Fl t
is used.
.Pp
The
.Fl P
option prints information about the new session after it has been created.
By default, it uses the format
.Ql #{session_name}:
but a different format may be specified with
.Fl F .
.It Xo Ic refresh-client
.Op Fl S
.Op Fl t Ar target-client
.Xc
.D1 (alias: Ic refresh )
Refresh the current client if bound to a key, or a single client if one is given
with
.Fl t .
If
.Fl S
is specified, only update the client's status bar.
.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 IJT
.Op Fl t Ar target-client
.Xc
.D1 (alias: Ic showmsgs )
Show client messages or server information.
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
server option.
With
.Fl t ,
display the log for
.Ar target-client .
.Fl I ,
.Fl J
and
.Fl T
show debugging information about the running server, jobs and terminals.
.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 t Ar target-client
.Xc
.D1 (alias: Ic suspendc )
Suspend a client by sending
.Dv SIGTSTP
(tty stop).
.It Xo Ic switch-client
.Op Fl lnpr
.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 .
If
.Fl l ,
.Fl n
or
.Fl p
is used, the client is moved to the last, next or previous session
respectively.
.Fl r
toggles whether a client is read-only (see the
.Ic attach-session
command).
.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 other is copy mode, which 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.
It is also entered when a command that produces output, such as
.Ic list-keys ,
is executed from a key binding.
.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 "FunctionXXXXXXXXXXXXXXXXX" "viXXXXXXXXXX" "emacs" -offset indent
.It Sy "Function" Ta Sy "vi" Ta Sy "emacs"
.It Li "Append selection" Ta "A" Ta ""
.It Li "Back to indentation" Ta "^" Ta "M-m"
.It Li "Bottom of history" Ta "G" Ta "M-<"
.It Li "Clear selection" Ta "Escape" Ta "C-g"
.It Li "Copy selection" Ta "Enter" Ta "M-w"
.It Li "Copy to named buffer" Ta \&" Ta ""
.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/Copy to end of line" Ta "D" Ta "C-k"
.It Li "End of line" Ta "$" Ta "C-e"
.It Li "Go to 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 "Jump again" Ta ";" Ta ";"
.It Li "Jump again in reverse" Ta "," Ta ","
.It Li "Jump backward" Ta "F" Ta "F"
.It Li "Jump forward" Ta "f" Ta "f"
.It Li "Jump to backward" Ta "T" Ta ""
.It Li "Jump to forward" Ta "t" Ta ""
.It Li "Next page" Ta "C-f" Ta "Page down"
.It Li "Next space" Ta "W" Ta ""
.It Li "Next space, end of word" Ta "E" Ta ""
.It Li "Next word" Ta "w" Ta ""
.It Li "Next word end" Ta "e" Ta "M-f"
.It Li "Other end of selection" Ta "o" Ta ""
.It Li "Paste buffer" Ta "p" Ta "C-y"
.It Li "Previous page" Ta "C-b" Ta "Page up"
.It Li "Previous space" Ta "B" Ta ""
.It Li "Previous word" Ta "b" Ta "M-b"
.It Li "Quit mode" Ta "q" Ta "Escape"
.It Li "Rectangle toggle" Ta "v" Ta "R"
.It Li "Scroll down" Ta "C-Down or C-e" Ta "C-Down"
.It Li "Scroll up" Ta "C-Up or C-y" Ta "C-Up"
.It Li "Search again" Ta "n" Ta "n"
.It Li "Search again in reverse" Ta "N" Ta "N"
.It Li "Search backward" Ta "?" Ta "C-r"
.It Li "Search forward" Ta "/" Ta "C-s"
.It Li "Select line" Ta "V" Ta ""
.It Li "Start of line" Ta "0" Ta "C-a"
.It Li "Start selection" Ta "Space" Ta "C-Space"
.It Li "Top of history" Ta "g" Ta "M->"
.It Li "Transpose characters" Ta "" Ta "C-t"
.El
.Pp
The next and previous word keys use space and the
.Ql - ,
.Ql _
and
.Ql @
characters as word delimiters by default, but this can be adjusted by
setting the
.Em word-separators
session option.
Next word moves to the start of the next word, next word end to the end of the
next word and previous word to the start of the previous word.
The three next and previous space keys work similarly but use a space alone as
the word separator.
.Pp
The jump commands enable quick movement within a line.
For instance, typing
.Ql f
followed by
.Ql /
will move the cursor to the next
.Ql /
character on the current line.
A
.Ql \&;
will then jump to the next occurrence.
.Pp
Commands in copy mode may be prefaced by an optional repeat count.
With vi key bindings, a prefix is entered using the number keys; with
emacs, the Alt (meta) key and a number begins prefix entry.
For example, to move the cursor forward by ten words, use
.Ql M-1 0 M-f
in emacs mode, and
.Ql 10w
in vi.
.Pp
Mode 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 choose-window
command); 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 .
One command accepts an argument,
.Ic copy-pipe ,
which copies the selection and pipes it to a command.
For example the following will bind
.Ql C-q
to copy the selection into
.Pa /tmp
as well as the paste buffer:
.Bd -literal -offset indent
bind-key -temacs-copy C-q copy-pipe "cat >/tmp/out"
.Ed
.Pp
The paste buffer key pastes the first line from the top paste buffer on the
stack.
.Pp
The synopsis for the
.Ic copy-mode
command is:
.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 select-pane
command 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 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.
.It Ic tiled
Panes are spread out as evenly as possible over the window in both rows and
columns.
.El
.Pp
In addition,
.Ic select-layout
may be used to apply a previously used layout - the
.Ic list-windows
command displays the layout of each window in a form suitable for use with
.Ic select-layout .
For example:
.Bd -literal -offset indent
$ tmux list-windows
0: ksh [159x48]
    layout: bb62,159x48,0,0{79x48,0,0,79x48,80,0}
$ tmux select-layout bb62,159x48,0,0{79x48,0,0,79x48,80,0}
.Ed
.Pp
.Nm
automatically adjusts the size of the layout for the current window size.
Note that a layout cannot be applied to a window with more panes than that
from which the layout was originally defined.
.Pp
Commands related to windows and panes are as follows:
.Bl -tag -width Ds
.It Xo Ic break-pane
.Op Fl dP
.Op Fl F Ar format
.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.
The
.Fl P
option prints information about the new window after it has been created.
By default, it uses the format
.Ql #{session_name}:#{window_index}
but a different format may be specified with
.Fl F .
.It Xo Ic capture-pane
.Op Fl aepPq
.Op Fl b Ar buffer-name
.Op Fl E Ar end-line
.Op Fl S Ar start-line
.Op Fl t Ar target-pane
.Xc
.D1 (alias: Ic capturep )
Capture the contents of a pane.
If
.Fl p
is given, the output goes to stdout, otherwise to the buffer specified with
.Fl b
or a new buffer if omitted.
If
.Fl a
is given, the alternate screen is used, and the history is not accessible.
If no alternate screen exists, an error will be returned unless
.Fl q
is given.
If
.Fl e
is given, the output includes escape sequences for text and background
attributes.
.Fl C
also escapes non-printable characters as octal \exxx.
.Fl J
joins wrapped lines and preserves trailing spaces at each line's end.
.Fl P
captures only any output that the pane has received that is the beginning of an
as-yet incomplete escape sequence.
.Pp
.Fl S
and
.Fl E
specify the starting and ending line numbers, zero is the first line of the
visible pane and negative numbers are lines in the history.
.Ql -
to
.Fl S
is the start of the history and to
.Fl E
the end of the visible pane.
The default is to capture only the visible contents of the pane.
.It Xo
.Ic choose-client
.Op Fl F Ar format
.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.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
This command works only if at least one client is attached.
.It Xo
.Ic choose-session
.Op Fl F Ar format
.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.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
This command works only if at least one client is attached.
.It Xo
.Ic choose-tree
.Op Fl suw
.Op Fl b Ar session-template
.Op Fl c Ar window-template
.Op Fl S Ar format
.Op Fl W Ar format
.Op Fl t Ar target-window
.Xc
Put a window into tree choice mode, where either sessions or windows may be
selected interactively from a list.
By default, windows belonging to a session are indented to show their
relationship to a session.
.Pp
Note that the
.Ic choose-window
and
.Ic choose-session
commands are wrappers around
.Ic choose-tree .
.Pp
If
.Fl s
is given, will show sessions.
If
.Fl w
is given, will show windows.
.Pp
By default, the tree is collapsed and sessions must be expanded to windows
with the right arrow key.
The
.Fl u
option will start with all sessions expanded instead.
.Pp
If
.Fl b
is given, will override the default session command.
Note that
.Ql %%
can be used and will be replaced with the session name.
The default option if not specified is "switch-client -t '%%'".
If
.Fl c
is given, will override the default window command.
Like
.Fl b ,
.Ql %%
can be used and will be replaced with the session name and window index.
When a window is chosen from the list, the session command is run before the
window command.
.Pp
If
.Fl S
is given will display the specified format instead of the default session
format.
If
.Fl W
is given will display the specified format instead of the default window
format.
For the meaning of the
.Fl s
and
.Fl w
options, see the
.Sx FORMATS
section.
.Pp
This command works only if at least one client is attached.
.It Xo
.Ic choose-window
.Op Fl F Ar format
.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.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
This command works only if at least one client is attached.
.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 ,
.Ic display-panes-colour ,
and
.Ic display-panes-active-colour
session options.
While the indicator is on screen, a pane may be selected with the
.Ql 0
to
.Ql 9
keys.
.It Xo Ic find-window
.Op Fl CNT
.Op Fl F Ar format
.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).
The flags control matching behavior:
.Fl C
matches only visible window contents,
.Fl N
matches only the window name and
.Fl T
matches only the window title.
The default is
.Fl CNT .
If only one window is matched, it'll be automatically selected,
otherwise a choice list is shown.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
This command works only if at least one client is attached.
.It Xo Ic join-pane
.Op Fl bdhv
.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 .
The
.Fl b
option causes
.Ar src-pane
to be joined to left of or above
.Ar dst-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 Xo Ic kill-window
.Op Fl a
.Op Fl t Ar target-window
.Xc
.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.
The
.Fl a
option kills all but the window given with
.Fl t .
.It Xo Ic last-pane
.Op Fl de
.Op Fl t Ar target-window
.Xc
.D1 (alias: Ic lastp )
Select the last (previously selected) pane.
.Fl e
enables or
.Fl d
disables input to the pane.
.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 Xo Ic list-panes
.Op Fl as
.Op Fl F Ar format
.Op Fl t Ar target
.Xc
.D1 (alias: Ic lsp )
If
.Fl a
is given,
.Ar target
is ignored and all panes on the server are listed.
If
.Fl s
is given,
.Ar target
is a session (or the current session).
If neither is given,
.Ar target
is a window (or the current window).
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
.It Xo Ic list-windows
.Op Fl a
.Op Fl F Ar format
.Op Fl t Ar target-session
.Xc
.D1 (alias: Ic lsw )
If
.Fl a
is given, list all windows on the server.
Otherwise, list windows in the current session or in
.Ar target-session .
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
.It Xo Ic move-pane
.Op Fl bdhv
.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 movep )
Like
.Ic join-pane ,
but
.Ar src-pane
and
.Ar dst-pane
may belong to the same window.
.It Xo Ic move-window
.Op Fl rdk
.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 .
With
.Fl r ,
all windows in the session are renumbered in sequential order, respecting
the
.Ic base-index
option.
.It Xo Ic new-window
.Op Fl adkP
.Op Fl c Ar start-directory
.Op Fl F Ar format
.Op Fl n Ar window-name
.Op Fl t Ar target-window
.Op Ar shell-command
.Xc
.D1 (alias: Ic neww )
Create a new window.
With
.Fl a ,
the new window is inserted at the next index up from the specified
.Ar target-window ,
moving windows up if necessary,
otherwise
.Ar target-window
is the new window location.
.Pp
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 shell-command
is the command to execute.
If
.Ar shell-command
is not specified, the value of the
.Ic default-command
option is used.
.Fl c
specifies the working directory in which the new window is created.
.Pp
When the shell command completes, the window closes.
See the
.Ic remain-on-exit
option to change this behaviour.
.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.
.Pp
The
.Fl P
option prints information about the new window after it has been created.
By default, it uses the format
.Ql #{session_name}:#{window_index}
but a different format may be specified with
.Fl F .
.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 an alert.
.It Xo Ic pipe-pane
.Op Fl o
.Op Fl t Ar target-pane
.Op Ar shell-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 shell-command
is executed.
The
.Ar shell-command
string may contain the special character sequences supported by the
.Ic status-left
option.
If no
.Ar shell-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.#I-#P'
.Ed
.It Xo Ic previous-layout
.Op Fl t Ar target-window
.Xc
.D1 (alias: Ic prevl )
Move to the previous layout in the session.
.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 an 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 DLRUZ
.Op Fl t Ar target-pane
.Op Fl x Ar width
.Op Fl y Ar height
.Op Ar adjustment
.Xc
.D1 (alias: Ic resizep )
Resize a pane, up, down, left or right by
.Ar adjustment
with
.Fl U ,
.Fl D ,
.Fl L
or
.Fl R ,
or
to an absolute size
with
.Fl x
or
.Fl y .
The
.Ar adjustment
is given in lines or cells (the default is 1).
.Pp
With
.Fl Z ,
the active pane is toggled between zoomed (occupying the whole of the window)
and unzoomed (its normal position in the layout).
.It Xo Ic respawn-pane
.Op Fl k
.Op Fl t Ar target-pane
.Op Ar shell-command
.Xc
.D1 (alias: Ic respawnp )
Reactivate a pane in which the command has exited (see the
.Ic remain-on-exit
window option).
If
.Ar shell-command
is not given, the command used when the pane was created is executed.
The pane must be already inactive, unless
.Fl k
is given, in which case any existing command is killed.
.It Xo Ic respawn-window
.Op Fl k
.Op Fl t Ar target-window
.Op Ar shell-command
.Xc
.D1 (alias: Ic respawnw )
Reactivate a window in which the command has exited (see the
.Ic remain-on-exit
window option).
If
.Ar shell-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 np
.Op Fl t Ar target-window
.Op Ar layout-name
.Xc
.D1 (alias: Ic selectl )
Choose a specific layout for a window.
If
.Ar layout-name
is not given, the last preset layout used (if any) is reapplied.
.Fl n
and
.Fl p
are equivalent to the
.Ic next-layout
and
.Ic previous-layout
commands.
.It Xo Ic select-pane
.Op Fl DdeLlRU
.Op Fl t Ar target-pane
.Xc
.D1 (alias: Ic selectp )
Make pane
.Ar target-pane
the active pane in window
.Ar target-window .
If one of
.Fl D ,
.Fl L ,
.Fl R ,
or
.Fl U
is used, respectively the pane below, to the left, to the right, or above the
target pane is used.
.Fl l
is the same as using the
.Ic last-pane
command.
.Fl e
enables or
.Fl d
disables input to the pane.
.It Xo Ic select-window
.Op Fl lnpT
.Op Fl t Ar target-window
.Xc
.D1 (alias: Ic selectw )
Select the window at
.Ar target-window .
.Fl l ,
.Fl n
and
.Fl p
are equivalent to the
.Ic last-window ,
.Ic next-window
and
.Ic previous-window
commands.
If
.Fl T
is given and the selected window is already the current window,
the command behaves like
.Ic last-window .
.It Xo Ic split-window
.Op Fl bdhvP
.Op Fl c Ar start-directory
.Oo Fl l
.Ar size |
.Fl p Ar percentage Oc
.Op Fl t Ar target-pane
.Op Ar shell-command
.Op Fl F Ar format
.Xc
.D1 (alias: Ic 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.
The
.Fl b
option causes the new pane to be created to the left of or above
.Ar target-pane .
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).
.Fl d
instructs
.Nm
not to change the active pane.
.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.
.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 F12 ,
.Em Home ,
.Em IC
(Insert),
.Em NPage/PageDown/PgDn ,
.Em PPage/PageUp/PgUp ,
.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 "'" new-window
.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 mode-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 mode-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.
.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 lR
.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.
The
.Fl l
flag disables key name lookup and sends the keys literally.
All arguments are sent sequentially from first to last.
The
.Fl R
flag causes the terminal state to be reset.
.It Xo Ic send-prefix
.Op Fl 2
.Op Fl t Ar target-pane
.Xc
Send the prefix key, or with
.Fl 2
the secondary prefix key, to a window as if it was pressed.
.It Xo Ic unbind-key
.Op Fl acn
.Op Fl t Ar mode-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.
If
.Fl a
is present, all key bindings are removed.
.Pp
If
.Fl t
is present,
.Ar key
in
.Ar mode-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
.Nm
also supports user options which are prefixed with a
.Ql \&@ .
User options may have any name, so long as they are prefixed with
.Ql \&@ ,
and be set to any string.
For example
.Bd -literal -offset indent
$ tmux setw -q @foo "abc123"
$ tmux showw -v @foo
abc123
.Ed
.Pp
Commands which set options are as follows:
.Bl -tag -width Ds
.It Xo Ic set-option
.Op Fl agoqsuw
.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.
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
The
.Fl o
flag prevents setting an option that is already set.
.Pp
The
.Fl q
flag suppresses errors about unknown options.
.Pp
With
.Fl a ,
and if the option expects a string or a style,
.Ar value
is appended to the existing setting.
For example:
.Bd -literal -offset indent
set -g status-left "foo"
set -ag status-left "bar"
.Ed
.Pp
Will result in
.Ql foobar .
And:
.Bd -literal -offset indent
set -g status-style "bg=red"
set -ag status-style "fg=blue"
.Ed
.Pp
Will result in a red background
.Em and
blue foreground.
Without
.Fl a ,
the result would be the default background and a blue foreground.
.Pp
Available window options are listed under
.Ic set-window-option .
.Pp
.Ar value
depends on the option and may be a number, a string, or a flag (on, off, or
omitted to toggle).
.Pp
Available server options are:
.Bl -tag -width Ds
.It Ic buffer-limit Ar number
Set the number of buffers; 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 escape-time Ar 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 Xo Ic exit-unattached
.Op Ic on | off
.Xc
If enabled, the server will exit when there are no attached clients.
.It Xo Ic focus-events
.Op Ic on | off
.Xc
When enabled, focus events are requested from the terminal if supported and
passed through to applications running in
.Nm .
Attached clients should be detached and attached again after changing this
option.
.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 100.
.It Xo Ic set-clipboard
.Op Ic on | off
.Xc
Attempt to set the terminal clipboard content using the
\ee]52;...\e007
.Xr xterm 1
escape sequences.
This option is on by default if there is an
.Em \&Ms
entry in the
.Xr terminfo 5
description for the client terminal.
Note that this feature needs to be enabled in
.Xr xterm 1
by setting the resource:
.Bd -literal -offset indent
disallowedWindowOps: 20,21,SetXprop
.Ed
.Pp
Or changing this property from the
.Xr xterm 1
interactive menu when required.
.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 256 colours:
.Bd -literal -offset indent
"*256col*:colors=256,xterm*:XT"
.Ed
.El
.Pp
Available session options are:
.Bl -tag -width Ds
.It Ic assume-paste-time Ar milliseconds
If keys are entered faster than one in
.Ar milliseconds ,
they are assumed to have been pasted rather than typed and
.Nm
key bindings are not processed.
The default is one millisecond and zero disables.
.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 bells in windows other than the current window are ignored.
.It Xo Ic bell-on-alert
.Op Ic on | off
.Xc
If on, ring the terminal bell when an alert
occurs.
.It Ic default-command Ar shell-command
Set the command used for new windows (if not specified when the window is
created) to
.Ar shell-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-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 Xo Ic destroy-unattached
.Op Ic on | off
.Xc
If enabled and the session is no longer attached to any clients, it is
destroyed.
.It Xo Ic detach-on-destroy
.Op Ic on | off
.Xc
If on (the default), the client is detached when the session it is attached to
is destroyed.
If off, the client is switched to the most recently active of the remaining
sessions.
.It Ic display-panes-active-colour Ar colour
Set the colour used by the
.Ic display-panes
command to show the indicator for the active pane.
.It Ic display-panes-colour Ar colour
Set the colour used by the
.Ic display-panes
command to show the indicators for inactive panes.
.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 shell-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-command-style Ar style
Set status line message command style, where
.Ar style
is a comma-separated list of characteristics to be specified.
.Pp
These may be
.Ql bg=colour
to set the background colour,
.Ql fg=colour
to set the foreground colour, and a list of attributes as specified below.
.Pp
The colour is one of:
.Ic black ,
.Ic red ,
.Ic green ,
.Ic yellow ,
.Ic blue ,
.Ic magenta ,
.Ic cyan ,
.Ic white ,
aixterm bright variants (if supported:
.Ic brightred ,
.Ic brightgreen ,
and so on),
.Ic colour0
to
.Ic colour255
from the 256-colour set,
.Ic default ,
or a hexadecimal RGB string such as
.Ql #ffffff ,
which chooses the closest match from the default 256-colour set.
.Pp
The attributes is either
.Ic none
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 ,
to turn an attribute on, or an attribute prefixed with
.Ql no
to turn one off.
.Pp
Examples are:
.Bd -literal -offset indent
fg=yellow,bold,underscore,blink
bg=black,fg=default,noreverse
.Ed
.Pp
With the
.Fl a
flag to the
.Ic set-option
command the new style is added otherwise the existing style is replaced.
.It Ic message-style Ar style
Set status line message style.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.It Xo Ic mouse-resize-pane
.Op Ic on | off
.Xc
If on,
.Nm
captures the mouse and allows panes to be resized by dragging on their borders.
.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 Xo Ic mouse-select-window
.Op Ic on | off
.Xc
If on, clicking the mouse on a window name in the status line will select that
window.
.It Xo Ic mouse-utf8
.Op Ic on | off
.Xc
If enabled, request mouse input as UTF-8 on UTF-8 terminals.
.It Ic pane-active-border-style Ar style
Set the pane border style for the currently active pane.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
Attributes are ignored.
.It Ic pane-border-style Ar style
Set the pane border style for panes aside from the active pane.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
Attributes are ignored.
.It Ic prefix Ar key
Set the key accepted as a prefix key.
.It Ic prefix2 Ar key
Set a secondary key accepted as a prefix key.
.It Xo Ic renumber-windows
.Op Ic on | off
.Xc
If on, when a window is closed in a session, automatically renumber the other
windows in numerical order.
This respects the
.Ic base-index
option if it has been set.
If off, do not renumber the windows.
.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.
When this option is true, windows in which the running program has
exited do not close, instead remaining open but inactivate.
Use the
.Ic respawn-window
command to reactivate such a window, or the
.Ic kill-window
command to destroy it.
.It Xo Ic set-titles
.Op Ic on | off
.Xc
Attempt to set the client terminal title using the
.Em tsl
and
.Em fsl
.Xr terminfo 5
entries if they exist.
.Nm
automatically sets these to the \ee]2;...\e007 sequence 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-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.
The default is emacs, unless the
.Ev VISUAL
or
.Ev EDITOR
environment variables are set and contain the string
.Ql vi .
.It Ic status-left Ar string
Display
.Ar string
(by default the session name) to the left of the status bar.
.Ar string
will be passed through
.Xr strftime 3
and formats (see
.Sx FORMATS )
will be expanded.
It may also 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 "#(shell-command)" Ta "First line of the command's output"
.It Li "#[attributes]" Ta "Colour or attribute change"
.It Li "##" Ta "A literal" Ql #
.El
.Pp
The #(shell-command) form executes
.Ql 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.
Shell commands are executed with the
.Nm
global environment set (see the
.Sx ENVIRONMENT
section).
.Pp
For details on how the names and titles can be set see the
.Sx "NAMES AND TITLES"
section.
For a list of allowed attributes see the
.Ic message-command-style
option.
.Pp
Examples are:
.Bd -literal -offset indent
#(sysctl vm.loadavg)
#[fg=yellow,bold]#(apm -l)%%#[default] [#S]
.Ed
.Pp
By default, UTF-8 in
.Ar string
is not interpreted, to enable UTF-8, use the
.Ic status-utf8
option.
.Pp
The default is
.Ql "[#S] " .
.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-left-style Ar style
Set the style of the left part of the status line.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.It Xo Ic status-position
.Op Ic top | bottom
.Xc
Set the position of the status line.
.It Ic status-right Ar string
Display
.Ar string
to the right of the status bar.
By default, the current window title in double quotes, the date and the time
are 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-length Ar length
Set the maximum
.Ar length
of the right component of the status bar.
The default is 40.
.It Ic status-right-style Ar style
Set the style of the right part of the status line.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.It Ic status-style Ar style
Set status line style.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.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 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 SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION WINDOWID
XAUTHORITY".
.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-silence
.Op Ic on | off
.Xc
If
.Ic monitor-silence
is enabled, prints a message after the interval has expired on a given window.
.It Ic word-separators Ar string
Sets the session's conception of what characters are considered word
separators, for the purposes of the next and previous word commands in
copy mode.
The default is
.Ql \ -_@ .
.El
.It Xo Ic set-window-option
.Op Fl agoqu
.Op Fl t Ar target-window
.Ar option Ar value
.Xc
.D1 (alias: Ic setw )
Set a window option.
The
.Fl a ,
.Fl g ,
.Fl o ,
.Fl q
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 allow-rename
.Op Ic on | off
.Xc
Allow programs to change the window name using a terminal escape
sequence (\\033k...\\033\\\\).
The default is on.
.Pp
.It Xo Ic alternate-screen
.Op Ic on | off
.Xc
This option configures whether programs running inside
.Nm
may use the terminal alternate screen feature, which allows the
.Em smcup
and
.Em rmcup
.Xr terminfo 5
capabilities.
The alternate screen feature preserves the contents of the window when an
interactive application starts and restores it on exit, so that any output
visible before the application starts reappears unchanged after it exits.
The default is on.
.Pp
.It Xo Ic automatic-rename
.Op Ic on | off
.Xc
Control automatic window renaming.
When this setting is enabled,
.Nm
will rename the window automatically using the format specified by
.Ic automatic-rename-format .
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 ,
or with a terminal escape sequence.
It may be switched off globally with:
.Bd -literal -offset indent
set-window-option -g automatic-rename off
.Ed
.Pp
.It Ic automatic-rename-format Ar format
The format (see
.Sx FORMATS )
used when the
.Ic automatic-rename
option is enabled.
.Pp
.It Ic c0-change-interval Ar interval
.It Ic c0-change-trigger Ar trigger
These two options configure a simple form of rate limiting for a pane.
If
.Nm
sees more than
.Ar trigger
C0 sequences that modify the screen (for example, carriage returns, linefeeds
or backspaces) in one millisecond, it will stop updating the pane immediately and
instead redraw it entirely every
.Ar interval
milliseconds.
This helps to prevent fast output (such as
.Xr yes 1 )
overwhelming the terminal.
The default is a trigger of 250 and an interval of 100.
A trigger of zero disables the rate limiting.
.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-height Ar height
.It Ic main-pane-width Ar width
Set the width or height of the main (left or top) pane in the
.Ic main-horizontal
or
.Ic main-vertical
layouts.
.Pp
.It Xo Ic mode-keys
.Op Ic vi | emacs
.Xc
Use vi or emacs-style key bindings in copy and choice modes.
As with the
.Ic status-keys
option, the default is emacs, unless
.Ev VISUAL
or
.Ev EDITOR
contains
.Ql vi .
.Pp
.It Xo Ic mode-mouse
.Op Ic on | off | copy-mode
.Xc
Mouse state in modes.
If on, the mouse may be used to enter copy mode and copy a selection by
dragging, to enter copy mode and scroll with the mouse wheel, or to select an
option in choice mode.
If set to
.Em copy-mode ,
the mouse behaves as set to on, but cannot be used to enter copy
mode.
.Pp
.It Ic mode-style Ar style
Set window modes style.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.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 Xo Ic monitor-silence
.Op Ic interval
.Xc
Monitor for silence (no activity) in the window within
.Ic interval
seconds.
Windows that have been silent for the interval are highlighted in the
status line.
An interval of zero disables the monitoring.
.Pp
.It Ic other-pane-height Ar height
Set the height of the other panes (not the main pane) in the
.Ic main-horizontal
layout.
If this option is set to 0 (the default), it will have no effect.
If both the
.Ic main-pane-height
and
.Ic other-pane-height
options are set, the main pane will grow taller to make the other panes the
specified height, but will never shrink to do so.
.Pp
.It Ic other-pane-width Ar width
Like
.Ic other-pane-height ,
but set the width of other panes in the
.Ic main-vertical
layout.
.Pp
.It Ic pane-base-index Ar index
Like
.Ic base-index ,
but set the starting index for pane numbers.
.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 (only
for panes that are not in any special mode).
.Pp
.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-activity-style Ar style
Set status line style for windows with an activity alert.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.Pp
.It Ic window-status-bell-style Ar style
Set status line style for windows with a bell alert.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.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 Ic window-status-current-style Ar style
Set status line style for the currently active window.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.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-last-style Ar style
Set status line style for the last active window.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.Pp
.It Ic window-status-separator Ar string
Sets the separator drawn between windows in the status line.
The default is a single space character.
.Pp
.It Ic window-status-style Ar style
Set status line style for a single window.
For how to specify
.Ar style ,
see the
.Ic message-command-style
option.
.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.
.Pp
.It Xo Ic wrap-search
.Op Ic on | off
.Xc
If this option is set, searches will wrap around the end of the pane contents.
The default is on.
.El
.It Xo Ic show-options
.Op Fl gqsvw
.Op Fl t Ar target-session | Ar target-window
.Op Ar option
.Xc
.D1 (alias: Ic show )
Show the window options (or a single window option if given) 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.
.Fl v
shows only the option value, not the name.
If
.Fl q
is set, no error will be returned if
.Ar option
is unset.
.It Xo Ic show-window-options
.Op Fl gv
.Op Fl t Ar target-window
.Op Ar option
.Xc
.D1 (alias: Ic showw )
List the window options or a single option for
.Ar target-window ,
or the global window options if
.Fl g
is used.
.Fl v
shows only the option value, not the name.
.El
.Sh FORMATS
Certain commands accept the
.Fl F
flag with a
.Ar format
argument.
This is a string which controls the output format of the command.
Replacement variables are enclosed in
.Ql #{
and
.Ql } ,
for example
.Ql #{session_name} .
Some variables also have an shorter alias such as
.Ql #S .
.Ql ##
is replaced by a single
.Ql # .
Conditionals are also accepted by prefixing with
.Ql \&?
and separating two alternatives with a comma;
if the specified variable exists and is not zero, the first alternative
is chosen, otherwise the second is used.
For example
.Ql #{?session_attached,attached,not attached}
will include the string
.Ql attached
if the session is attached and the string
.Ql not attached
if it is unattached.
A limit may be placed on the length of the resultant string by prefixing it
by an
.Ql = ,
a number and a colon, so
.Ql #{=10:pane_title}
will include at most the first 10 characters of the pane title.
.Pp
The following variables are available, where appropriate:
.Bl -column "XXXXXXXXXXXXXXXXXXX" "XXXXX"
.It Sy "Variable name" Ta Sy "Alias" Ta Sy "Replaced with"
.It Li "alternate_on" Ta "" Ta "If pane is in alternate screen"
.It Li "alternate_saved_x" Ta "" Ta "Saved cursor X in alternate screen"
.It Li "alternate_saved_y" Ta "" Ta "Saved cursor Y in alternate screen"
.It Li "buffer_sample" Ta "" Ta "Sample of start of buffer"
.It Li "buffer_size" Ta "" Ta "Size of the specified buffer in bytes"
.It Li "client_activity" Ta "" Ta "Integer time client last had activity"
.It Li "client_activity_string" Ta "" Ta "String time client last had activity"
.It Li "client_created" Ta "" Ta "Integer time client created"
.It Li "client_created_string" Ta "" Ta "String time client created"
.It Li "client_height" Ta "" Ta "Height of client"
.It Li "client_last_session" Ta "" Ta "Name of the client's last session"
.It Li "client_prefix" Ta "" Ta "1 if prefix key has been pressed"
.It Li "client_readonly" Ta "" Ta "1 if client is readonly"
.It Li "client_session" Ta "" Ta "Name of the client's session"
.It Li "client_termname" Ta "" Ta "Terminal name of client"
.It Li "client_tty" Ta "" Ta "Pseudo terminal of client"
.It Li "client_utf8" Ta "" Ta "1 if client supports utf8"
.It Li "client_width" Ta "" Ta "Width of client"
.It Li "cursor_flag" Ta "" Ta "Pane cursor flag"
.It Li "cursor_x" Ta "" Ta "Cursor X position in pane"
.It Li "cursor_y" Ta "" Ta "Cursor Y position in pane"
.It Li "history_bytes" Ta "" Ta "Number of bytes in window history"
.It Li "history_limit" Ta "" Ta "Maximum window history lines"
.It Li "history_size" Ta "" Ta "Size of history in bytes"
.It Li "host" Ta "#H" Ta "Hostname of local host"
.It Li "host_short" Ta "#h" Ta "Hostname of local host (no domain name)"
.It Li "insert_flag" Ta "" Ta "Pane insert flag"
.It Li "keypad_cursor_flag" Ta "" Ta "Pane keypad cursor flag"
.It Li "keypad_flag" Ta "" Ta "Pane keypad flag"
.It Li "line" Ta "" Ta "Line number in the list"
.It Li "mouse_any_flag" Ta "" Ta "Pane mouse any flag"
.It Li "mouse_button_flag" Ta "" Ta "Pane mouse button flag"
.It Li "mouse_standard_flag" Ta "" Ta "Pane mouse standard flag"
.It Li "mouse_utf8_flag" Ta "" Ta "Pane mouse UTF-8 flag"
.It Li "pane_active" Ta "" Ta "1 if active pane"
.It Li "pane_bottom" Ta "" Ta "Bottom of pane"
.It Li "pane_current_command" Ta "" Ta "Current command if available"
.It Li "pane_dead" Ta "" Ta "1 if pane is dead"
.It Li "pane_height" Ta "" Ta "Height of pane"
.It Li "pane_id" Ta "#D" Ta "Unique pane ID"
.It Li "pane_in_mode" Ta "" Ta "If pane is in a mode"
.It Li "pane_input_off" Ta "" Ta "If input to pane is disabled"
.It Li "pane_index" Ta "#P" Ta "Index of pane"
.It Li "pane_left" Ta "" Ta "Left of pane"
.It Li "pane_pid" Ta "" Ta "PID of first process in pane"
.It Li "pane_right" Ta "" Ta "Right of pane"
.It Li "pane_start_command" Ta "" Ta "Command pane started with"
.It Li "pane_synchronized" Ta "" Ta "If pane is synchronized"
.It Li "pane_tabs" Ta "" Ta "Pane tab positions"
.It Li "pane_title" Ta "#T" Ta "Title of pane"
.It Li "pane_top" Ta "" Ta "Top of pane"
.It Li "pane_tty" Ta "" Ta "Pseudo terminal of pane"
.It Li "pane_width" Ta "" Ta "Width of pane"
.It Li "saved_cursor_x" Ta "" Ta "Saved cursor X in pane"
.It Li "saved_cursor_y" Ta "" Ta "Saved cursor Y in pane"
.It Li "scroll_region_lower" Ta "" Ta "Bottom of scroll region in pane"
.It Li "scroll_region_upper" Ta "" Ta "Top of scroll region in pane"
.It Li "session_attached" Ta "" Ta "Number of clients session is attached to"
.It Li "session_created" Ta "" Ta "Integer time session created"
.It Li "session_created_string" Ta "" Ta "String time session created"
.It Li "session_group" Ta "" Ta "Number of session group"
.It Li "session_grouped" Ta "" Ta "1 if session in a group"
.It Li "session_height" Ta "" Ta "Height of session"
.It Li "session_id" Ta "" Ta "Unique session ID"
.It Li "session_many_attached" Ta "" Ta "1 if multiple clients attached"
.It Li "session_name" Ta "#S" Ta "Name of session"
.It Li "session_width" Ta "" Ta "Width of session"
.It Li "session_windows" Ta "" Ta "Number of windows in session"
.It Li "window_active" Ta "" Ta "1 if window active"
.It Li "window_activity_flag" Ta "" Ta "1 if window has activity alert"
.It Li "window_bell_flag" Ta "" Ta "1 if window has bell"
.It Li "window_find_matches" Ta "" Ta "Matched data from the find-window"
.It Li "window_flags" Ta "#F" Ta "Window flags"
.It Li "window_height" Ta "" Ta "Height of window"
.It Li "window_id" Ta "" Ta "Unique window ID"
.It Li "window_index" Ta "#I" Ta "Index of window"
.It Li "window_last_flag" Ta "" Ta "1 if window is the last used"
.It Li "window_layout" Ta "" Ta "Window layout description"
.It Li "window_name" Ta "#W" Ta "Name of window"
.It Li "window_panes" Ta "" Ta "Number of panes in window"
.It Li "window_silence_flag" Ta "" Ta "1 if window has silence alert"
.It Li "window_width" Ta "" Ta "Width of window"
.It Li "window_zoomed_flag" Ta "" Ta "1 if window is zoomed"
.It Li "wrap_flag" Ta "" Ta "Pane wrap flag"
.El
.Sh NAMES AND TITLES
.Nm
distinguishes between names and titles.
Windows and sessions have names, which may be used to specify them in targets
and are displayed in the status line and various lists: the name is the
.Nm
identifier for a window or session.
Only panes have titles.
A pane's title is typically set by the program running inside the pane and
is not modified by
.Nm .
It is the same mechanism used to set for example the
.Xr xterm 1
window title in an
.Xr X 7
window manager.
Windows themselves do not have titles - a window's title is the title of its
active pane.
.Nm
itself may set the title of the terminal in which the client is running, see
the
.Ic set-titles
option.
.Pp
A session's name is set with the
.Ic new-session
and
.Ic rename-session
commands.
A window's name is set with one of:
.Bl -enum -width Ds
.It
A command argument (such as
.Fl n
for
.Ic new-window
or
.Ic new-session ) .
.It
An escape sequence:
.Bd -literal -offset indent
$ printf '\e033kWINDOW_NAME\e033\e\e'
.Ed
.It
Automatic renaming, which sets the name to the active command in the window's
active pane.
See the
.Ic automatic-rename
option.
.El
.Pp
When a pane is first created, its title is the hostname.
A pane's title can be set via the OSC title setting sequence, for example:
.Bd -literal -offset indent
$ printf '\e033]2;My Title\e033\e\e'
.Ed
.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.
If a variable exists in both, the value from the session environment is used.
The result 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
.Op Ar variable
.Xc
.D1 (alias: Ic showenv )
Display the environment for
.Ar target-session
or the global environment with
.Fl g .
If
.Ar variable
is omitted, all variables are shown.
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 title of the active pane
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 "The window has been silent for the monitor-silence interval."
.It Li "Z" Ta "The window's active pane is zoomed."
.El
.Pp
The # symbol relates to the
.Ic monitor-activity
window option.
The window name is printed in inverted colours if an alert (bell, activity or
silence) is present.
.Pp
The colour and attributes of the status line may be configured, the entire
status line using the
.Ic status-style
session option and individual windows using the
.Ic window-status-style
window option.
.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 I Ar inputs
.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.
.Pp
If
.Ar template
is specified, it is used as the command.
If present,
.Fl I
is a comma-separated list of the initial text for each prompt.
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.
.Pp
Both
.Ar inputs
and
.Ar prompts
may contain the special character sequences supported by the
.Ic status-left
option.
.Pp
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 p Ar prompt
.Op Fl t Ar target-client
.Ar command
.Xc
.D1 (alias: Ic confirm )
Ask for confirmation before executing
.Ar command .
If
.Fl p
is given,
.Ar prompt
is the prompt to display; otherwise a prompt is constructed from
.Ar command .
It may contain the special character sequences supported by the
.Ic status-left
option.
.Pp
This command works only from inside
.Nm .
.It Xo Ic display-message
.Op Fl p
.Op Fl c Ar target-client
.Op Fl t Ar target-pane
.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 described in the
.Sx FORMATS
section; information is taken from
.Ar target-pane
if
.Fl t
is given, otherwise the active pane for the session attached to
.Ar target-client .
.El
.Sh BUFFERS
.Nm
maintains a set of named
.Em paste buffers .
Each buffer may be either explicitly or automatically named.
Explicitly named buffers are named when created with the
.Ic set-buffer
or
.Ic load-buffer
commands, or by renaming an automatically named buffer with
.Ic set-buffer
.Fl n .
Automatically named buffers are given a name such as
.Ql buffer0001 ,
.Ql buffer0002
and so on.
When the
.Ic buffer-limit
option is reached, the oldest automatically named buffer is deleted.
Explicitly named are not subject to
.Ic buffer-limit
and may be deleted with
.Ic delete-buffer
command.
.Pp
Buffers may be added using
.Ic copy-mode
or the
.Ic set-buffer
and
.Ic load-buffer
commands, and pasted into a window using the
.Ic paste-buffer
command.
If a buffer command is used and no buffer is specified, the most
recently added automatically named buffer is assumed.
.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 Xo
.Ic choose-buffer
.Op Fl F Ar format
.Op Fl t Ar target-window
.Op Ar template
.Xc
Put a window into buffer choice mode, where a buffer may be chosen
interactively from a list.
After a buffer is selected,
.Ql %%
is replaced by the buffer name in
.Ar template
and the result executed as a command.
If
.Ar template
is not given, "paste-buffer -b '%%'" is used.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
This command works only if at least one client is attached.
.It Ic clear-history Op Fl t Ar target-pane
.D1 (alias: Ic clearhist )
Remove and free the history for the specified pane.
.It Ic delete-buffer Op Fl b Ar buffer-name
.D1 (alias: Ic deleteb )
Delete the buffer named
.Ar buffer-name ,
or the most recently added automatically named buffer if not specified.
.It Xo Ic list-buffers
.Op Fl F Ar format
.Xc
.D1 (alias: Ic lsb )
List the global buffers.
For the meaning of the
.Fl F
flag, see the
.Sx FORMATS
section.
.It Xo Ic load-buffer
.Op Fl b Ar buffer-name
.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 dpr
.Op Fl b Ar buffer-name
.Op Fl s Ar separator
.Op Fl t Ar target-pane
.Xc
.D1 (alias: Ic pasteb )
Insert the contents of a paste buffer into the specified pane.
If not specified, paste into the current one.
With
.Fl d ,
also delete the paste buffer.
When output, any linefeed (LF) characters in the paste buffer are replaced with
a separator, by default carriage return (CR).
A custom separator may be specified using the
.Fl s
flag.
The
.Fl r
flag means to do no replacement (equivalent to a separator of LF).
If
.Fl p
is specified, paste bracket control codes are inserted around the
buffer if the application has requested bracketed paste mode.
.It Xo Ic save-buffer
.Op Fl a
.Op Fl b Ar buffer-name
.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 a
.Op Fl b Ar buffer-name
.Op Fl n Ar new-buffer-name
.Ar data
.Xc
.D1 (alias: Ic setb )
Set the contents of the specified buffer to
.Ar data .
The
.Fl a
option appends to rather than overwriting the buffer.
The
.Fl n
option renames the buffer to
.Ar new-buffer-name .
.It Xo Ic show-buffer
.Op Fl b Ar buffer-name
.Xc
.D1 (alias: Ic showb )
Display the contents of the specified buffer.
.El
.Sh MISCELLANEOUS
Miscellaneous commands are as follows:
.Bl -tag -width Ds
.It Ic clock-mode Op Fl t Ar target-pane
Display a large clock.
.It Xo Ic if-shell
.Op Fl b
.Op Fl t Ar target-pane
.Ar shell-command command
.Op Ar command
.Xc
.D1 (alias: Ic if )
Execute the first
.Ar command
if
.Ar shell-command
returns success or the second
.Ar command
otherwise.
Before being executed, shell-command is expanded using the rules specified in the
.Sx FORMATS
section, including those relevant to
.Ar target-pane .
With
.Fl b ,
.Ar shell-command
is run in the background.
.It Ic lock-server
.D1 (alias: Ic lock )
Lock each client individually by running the command specified by the
.Ic lock-command
option.
.It Xo Ic run-shell
.Op Fl b
.Op Fl t Ar target-pane
.Ar shell-command
.Xc
.D1 (alias: Ic run )
Execute
.Ar shell-command
in the background without creating a window.
Before being executed, shell-command is expanded using the rules specified in
the
.Sx FORMATS
section.
With
.Fl b ,
the command is run in the background.
After it finishes, any output to stdout is displayed in copy mode (in the pane
specified by
.Fl t
or the current pane if omitted).
If the command doesn't return success, the exit status is also displayed.
.It Xo Ic wait-for
.Op Fl L | S | U
.Ar channel
.Xc
.D1 (alias: Ic wait )
When used without options, prevents the client from exiting until woken using
.Ic wait-for
.Fl S
with the same channel.
When
.Fl L
is used, the channel is locked and any clients that try to lock the same
channel are made to wait until the channel is unlocked with
.Ic wait-for
.Fl U .
This command only works from outside
.Nm .
.El
.Sh TERMINFO EXTENSIONS
.Nm
understands some extensions to
.Xr terminfo 5 :
.Bl -tag -width Ds
.It Em Cs , Cr
Set the cursor colour.
The first takes a single string argument and is used to set the colour;
the second takes no arguments and restores the default cursor colour.
If set, a sequence such as this may be used
to change the cursor colour from inside
.Nm :
.Bd -literal -offset indent
$ printf '\e033]12;red\e033\e\e'
.Ed
.It Em \&Ss , Se
Set or reset the cursor style.
If set, a sequence such as this may be used
to change the cursor to an underline:
.Bd -literal -offset indent
$ printf '\e033[4 q'
.Ed
.Pp
If
.Em Se
is not set, \&Ss with argument 0 will be used to reset the cursor style instead.
.It Em \&Ms
This sequence can be used by
.Nm
to store the current buffer in the host terminal's selection (clipboard).
See the
.Em set-clipboard
option above and the
.Xr xterm 1
man page.
.El
.Sh CONTROL MODE
.Nm
offers a textual interface called
.Em control mode .
This allows applications to communicate with
.Nm
using a simple text-only protocol.
.Pp
In control mode, a client sends
.Nm
commands or command sequences terminated by newlines on standard input.
Each command will produce one block of output on standard output.
An output block consists of a
.Em %begin
line followed by the output (which may be empty).
The output block ends with a
.Em %end
or
.Em %error .
.Em %begin
and matching
.Em %end
or
.Em %error
have two arguments: an integer time (as seconds from epoch) and command number.
For example:
.Bd -literal -offset indent
%begin 1363006971 2
0: ksh* (1 panes) [80x24] [layout b25f,80x24,0,0,2] @2 (active)
%end 1363006971 2
.Ed
.Pp
In control mode,
.Nm
outputs notifications.
A notification will never occur inside an output block.
.Pp
The following notifications are defined:
.Bl -tag -width Ds
.It Ic %exit Op Ar reason
The
.Nm
client is exiting immediately, either because it is not attached to any session
or an error occurred.
If present,
.Ar reason
describes why the client exited.
.It Ic %layout-change Ar window-id Ar window-layout
The layout of a window with ID
.Ar window-id
changed.
The new layout is
.Ar window-layout .
.It Ic %output Ar pane-id Ar value
A window pane produced output.
.Ar value
escapes non-printable characters and backslash as octal \\xxx.
.It Ic %session-changed Ar session-id Ar name
The client is now attached to the session with ID
.Ar session-id ,
which is named
.Ar name .
.It Ic %session-renamed Ar name
The current session was renamed to
.Ar name .
.It Ic %sessions-changed
A session was created or destroyed.
.It Ic %unlinked-window-add Ar window-id
The window with ID
.Ar window-id
was created but is not linked to the current session.
.It Ic %window-add Ar window-id
The window with ID
.Ar window-id
was linked to the current session.
.It Ic %window-close Ar window-id
The window with ID
.Ar window-id
closed.
.It Ic %window-renamed Ar window-id Ar name
The window with ID
.Ar window-id
was renamed to
.Ar name .
.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-style 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 Mt nicm@users.sourceforge.net