tmux

Examples (TL;DR)

• Start a new tmux session: tmux

• Start a new named tmux session: tmux new -s name

• List sessions: tmux ls

• Attach to a session: tmux a

• Attach to a named session: tmux a -t name

• Detach from session: Ctrl + B, D

• Kill session: tmux kill-session -t name

• Kill session when attached: Ctrl + B, x (then hit 'y' for yes)

tldr.sh

Synopsis

Description

tmux is a terminal multiplexer: it enables a number of terminals to be created, accessed, and controlled from a single screen. tmux may be detached from a screen and continue running in the background, then later reattached.

When tmux is started it creates a new session with a single 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.

A session is a single collection of pseudo terminals under the management of tmux. 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 pty(4) manual page documents the technical details of pseudo terminals). Any number of tmux instances may connect to the same session, and any number of windows may be present in the same session. Once all sessions are killed, tmux exits.

Each session is persistent and will survive accidental disconnection (such as ssh(1) connection timeout) or intentional detaching (with the ‘C-b d’ key strokes). tmux may be reattached using:

$ tmux attach

In tmux, a session is displayed on screen by a client and all sessions are managed by a single server. The server and each client are separate processes which communicate through a socket in /tmp.

The options are as follows:

-2

Force tmux to assume the terminal supports 256 colours.

-C

Start in control mode (see the Control Mode section). Given twice (-CC) disables echo.

-c shell-command

Execute shell-command using the default shell. If necessary, the tmux server will be started to retrieve the default-shell option. This option is for compatibility with sh(1) when tmux is used as a login shell.

-f file

Specify an alternative configuration file. By default, tmux loads the system configuration file from /etc/tmux.conf, if present, then looks for a user configuration file at ~/.tmux.conf.

The configuration file is a set of tmux commands which are executed in sequence when the server is first started. tmux loads configuration files once when the server process has started. The source-file command may be used to load a file later.

tmux shows any error messages from commands in configuration files in the first session created, and continues to process the rest of the configuration file.

-L socket-name

tmux stores the server socket in a directory under TMUX_TMPDIR or /tmp if it is unset. The default socket is named default. This option allows a different socket name to be specified, allowing several independent tmux servers to be run. Unlike -S a full path is not necessary: the sockets are all created in the same directory.

If the socket is accidentally removed, the SIGUSR1 signal may be sent to the tmux server process to recreate it (note that this will fail if any parent directories are missing).

-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.

-S socket-path

Specify a full alternative path to the server socket. If -S is specified, the default socket directory is not used and any -L flag is ignored.

-u

When starting, tmux looks for the LC_ALL, LC_CTYPE and LANG environment variables: if the first found contains ‘UTF-8’, then the terminal is assumed to support UTF-8. This is not always correct: the -u flag explicitly informs tmux that UTF-8 is supported.

Note that tmux itself always accepts UTF-8; this controls whether it will send UTF-8 characters to the terminal it is running (if not, they are replaced by ‘_’).

-v

Request verbose logging. Log messages will be saved into tmux-client-PID.log and tmux-server-PID.log files in the current directory, where PID is the PID of the server or client process. If -v is specified twice, an additional tmux-out-PID.log file is generated with a copy of everything tmux writes to the terminal.

The SIGUSR2 signal may be sent to the tmux server process to toggle logging between on (as if -v was given) and off.

-V

Report the tmux version.

command [flags]

This specifies one of a set of commands used to control tmux, as described in the following sections. If no commands are specified, the new-session command is assumed.

Default Key Bindings

tmux may be controlled from an attached client by using a key combination of a prefix key, ‘C-b’ (Ctrl-b) by default, followed by a command key.

The default command key bindings are:

Key bindings may be changed with the bind-key and unbind-key commands.

Commands

This section contains a list of the commands supported by tmux. Most commands accept the optional -t (and sometimes -s) argument with one of target-client, target-session target-window, or target-pane. These specify the client, session, window or pane which a command should affect.

target-client should be the name of the client, typically the pty(4) file to which the client is connected, for example either of /dev/ttyp1 or ttyp1 for the client attached to /dev/ttyp1. If no client is specified, tmux attempts to work out the client currently in use; if that fails, an error is reported. Clients may be listed with the list-clients command.

target-session is tried as, in order:

1. A session ID prefixed with a $.

2. An exact name of a session (as listed by the list-sessions command).

3. The start of a session name, for example ‘mysess’ would match a session named ‘mysession’.

4. An fnmatch(3) pattern which is matched against the session name.

If the session name is prefixed with an ‘=’, only an exact match is accepted (so ‘=mysess’ will only match exactly ‘mysess’, not ‘mysession’).

If a single session 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.

target-window (or src-window or dst-window) specifies a window in the form session:window. session follows the same rules as for target-session, and window is looked for in order as:

1. A special token, listed below.

2. A window index, for example ‘mysession:1’ is window 1 in session ‘mysession’.

3. A window ID, such as @1.

4. An exact window name, such as ‘mysession:mywindow’.

5. The start of a window name, such as ‘mysession:mywin’.

6. As an fnmatch(3) pattern matched against the window name.

Like sessions, a ‘=’ prefix will do an exact match only. An empty window name specifies the next unused index if appropriate (for example the new-window and link-window commands) otherwise the current window in session is chosen.

The following special tokens are available to indicate particular windows. Each has a single-character alternative form.

target-pane (or src-pane or dst-pane) may be a pane ID or takes a similar form to target-window but with the optional addition of a period followed by a pane index or pane ID, for example: ‘mysession:mywindow.1’. If the pane index is omitted, the currently active pane in the specified window is used. The following special tokens are available for the pane index:

The tokens ‘+’ and ‘-’ may be followed by an offset, for example:

select-window -t:+2

In addition, target-session, target-window or target-pane may consist entirely of the token ‘{mouse}’ (alternative form ‘=’) to specify the most recent mouse event (see the Mouse Support section) or ‘{marked}’ (alternative form ‘~’) to specify the marked pane (see select-pane -m).

Sessions, window and panes are each numbered with a unique ID; session IDs are prefixed with a ‘$’, windows with a ‘@’, and panes with a ‘%’. These are unique and are unchanged for the life of the session, window or pane in the tmux server. The pane ID is passed to the child process of the pane in the TMUX_PANE environment variable. IDs may be displayed using the ‘session_id’, ‘window_id’, or ‘pane_id’ formats (see the Formats section) and the display-message, list-sessions, list-windows or list-panes commands.

shell-command arguments are sh(1) commands. This may be a single argument passed to the shell, for example:

new-window 'vi /etc/passwd'

Will run:

/bin/sh -c 'vi /etc/passwd'

Additionally, the new-window, new-session, split-window, respawn-window and respawn-pane commands allow shell-command to be given as multiple arguments and executed directly (without ‘sh -c’). This can avoid issues with shell quoting. For example:

$ tmux new-window vi /etc/passwd

Will run vi(1) directly without invoking the shell.

command [arguments] refers to a tmux command, passed with the command and arguments separately, for example:

bind-key F1 set-option status off

Or if using sh(1):

$ tmux bind-key F1 set-option status off

Multiple commands may be specified together as part of a 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 bind-key).

Example tmux commands include:

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 \; \ 
	display-message "source-file done"

Or from sh(1):

$ tmux kill-window -t :1 
 
$ tmux new-window \; split-window -d 
 
$ tmux new-session -d 'vi /etc/passwd' \; split-window -d \; attach

Clients and Sessions

The tmux server manages clients, sessions, windows and panes. Clients are attached to sessions to interact with them, either when they are created with the new-session command, or later with the attach-session command. Each session has one or more windows 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 Windows and Panes section.

The following commands are available to manage clients and sessions:

attach-session [-dEr] [-c working-directory] [-t target-session]

(alias: attach)

If run from outside tmux, create a new client in the current terminal and attach it to target-session. If used from inside, switch the current client. If -d is specified, any other clients attached to the session are detached. -r signifies the client is read-only (only keys bound to the detach-client or switch-client commands have any effect)

If no server is started, attach-session will attempt to start it; this will fail unless sessions are created in the configuration file.

The target-session rules for attach-session are slightly adjusted: if tmux needs to select the most recently used session, it will prefer the most recently used unattached session.

-c will set the session working directory (used for new windows) to working-directory.

If -E is used, the update-environment option will not be applied.

detach-client [-aP] [-E shell-command] [-s target-session] [-t target-client]

(alias: detach)

Detach the current client if bound to a key, the client specified with -t, or all clients currently attached to the session specified by -s. The -a option kills all but the client given with -t. If -P is given, send SIGHUP to the parent process of the client, typically causing it to exit. With -E, run shell-command to replace the client.

has-session [-t target-session]

(alias: has)

Report an error and exit with 1 if the specified session does not exist. If it does exist, exit with 0.

kill-server

Kill the tmux server and clients and destroy all sessions.

kill-session [-aC] [-t target-session]

Destroy the given session, closing any windows linked to it and no other sessions, and detaching all clients attached to it. If -a is given, all sessions but the specified one is killed. The -C flag clears alerts (bell, activity, or silence) in all windows linked to the session.

list-clients [-F format] [-t target-session]

(alias: lsc)

List all clients attached to the server. For the meaning of the -F flag, see the Formats section. If target-session is specified, list only clients connected to that session.

list-commands [-F format]

(alias: lscm)

List the syntax of all commands supported by tmux.

list-sessions [-F format]

(alias: ls)

List all sessions managed by the server. For the meaning of the -F flag, see the Formats section.

lock-client [-t target-client]

(alias: lockc)

Lock target-client, see the lock-server command.

lock-session [-t target-session]

(alias: locks)

Lock all clients attached to target-session.

new-session [-AdDEP] [-c start-directory] [-F format] [-n window-name] [-s session-name] [-t group-name] [-x width] [-y height] [shell-command]

(alias: new)

Create a new session with name session-name.

The new session is attached to the current terminal unless -d is given. window-name and shell-command are the name of and shell command to execute in the initial window. With -d, the initial size comes from the global default-size option; -x and -y can be used to specify a different size. ‘-’ uses the size of the current client if any. If -x or -y is given, the default-size option is set for the session.

If run from a terminal, any termios(4) special characters are saved and used for new windows in the new session.

The -A flag makes new-session behave like attach-session if session-name already exists; in this case, -D behaves like -d to attach-session.

If -t is given, it specifies a session group. Sessions in the same group share the same set of windows - new windows are linked to all sessions in the group and any windows closed removed from all sessions. The current and previous window and any session options remain independent and any session in a group may be killed without affecting the others. The group-name argument may be:

1. the name of an existing group, in which case the new session is added to that group;

2. the name of an existing session - the new session is added to the same group as that session, creating a new group if necessary;

3. the name for a new group containing only the new session.

-n and shell-command are invalid if -t is used.

The -P option prints information about the new session after it has been created. By default, it uses the format ‘#{session_name}:’ but a different format may be specified with -F.

If -E is used, the update-environment option will not be applied.

refresh-client [-cDlLRSU] [-C width,height] [-t target-client] [adjustment]

(alias: refresh)

Refresh the current client if bound to a key, or a single client if one is given with -t. If -S is specified, only update the client's status line.

The -U, -D, -L -R, and -c flags allow the visible portion of a window which is larger than the client to be changed. -U moves the visible part up by adjustment rows and -D down, -L left by adjustment columns and -R right. -c returns to tracking the cursor automatically. If adjustment is omitted, 1 is used. Note that the visible position is a property of the client not of the window, changing the current window in the attached session will reset it.

-C sets the width and height of a control client. -l requests the clipboard from the client using the xterm(1) escape sequence and stores it in a new paste buffer.

-L, -R, -U and -D move the visible portion of the window left, right, up or down by adjustment, if the window is larger than the client. -c resets so that the position follows the cursor. See the window-size option.

rename-session [-t target-session] new-name

(alias: rename)

Rename the session to new-name.

show-messages [-JT] [-t target-client]

(alias: 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 message-limit server option. With -t, display the log for target-client. -J and -T show debugging information about jobs and terminals.

source-file [-q] path

(alias: source)

Execute commands from path (which may be a glob(7) pattern). If -q is given, no error will be returned if path does not exist.

Within a configuration file, commands may be made conditional by surrounding them with %if and %endif lines. Additional %elif and %else lines may also be used. The argument to %if and %elif is expanded as a format and if it evaluates to false (zero or empty), subsequent lines are ignored until the next %elif, %else or %endif. For example:

%if #{==:#{host},myhost} 
set -g status-style bg=red 
%elif #{==:#{host},myotherhost} 
set -g status-style bg=green 
%else 
set -g status-style bg=blue 
%endif
    

Will change the status line to red if running on ‘myhost’, green if running on ‘myotherhost’, or blue if running on another host.

start-server

(alias: start)

Start the tmux server, if not already running, without creating any sessions.

suspend-client [-t target-client]

(alias: suspendc)

Suspend a client by sending SIGTSTP (tty stop).

switch-client [-Elnpr] [-c target-client] [-t target-session] [-T key-table]

(alias: switchc)

Switch the current session for client target-client to target-session. If -l, -n or -p is used, the client is moved to the last, next or previous session respectively. -r toggles whether a client is read-only (see the attach-session command).

If -E is used, update-environment option will not be applied.

-T sets the client's key table; the next key from the client will be interpreted from key-table. This may be used to configure multiple prefix keys, or to bind commands to sequences of keys. For example, to make typing ‘abc’ run the list-keys command:

bind-key -Ttable2 c list-keys 
bind-key -Ttable1 b switch-client -Ttable2 
bind-key -Troot   a switch-client -Ttable1
    

Windows and Panes

A tmux window may be in one of two 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 paste buffer for later insertion into another window. This mode is entered with the copy-mode command, bound to ‘[’ by default. It is also entered when a command that produces output, such as list-keys, is executed from a key binding.

Commands are sent to copy mode using the -X flag to the send-keys command. When a key is pressed, copy mode automatically uses one of two key tables, depending on the mode-keys option: copy-mode for emacs, or copy-mode-vi for vi. Key tables may be viewed with the list-keys command.

The following commands are supported in copy mode:

The ‘-and-cancel’ variants of some commands exit copy mode after they have completed (for copy commands) or when the cursor reaches the bottom (for scrolling commands).

The next and previous word keys use space and the ‘-’, ‘_’ and ‘@’ characters as word delimiters by default, but this can be adjusted by setting the 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.

The jump commands enable quick movement within a line. For instance, typing ‘f’ followed by ‘/’ will move the cursor to the next ‘/’ character on the current line. A ‘;’ will then jump to the next occurrence.

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.

The synopsis for the copy-mode command is:

copy-mode [-Meu] [-t target-pane]

Enter copy mode. The -u option scrolls one page up. -M begins a mouse drag (only valid if bound to a mouse key binding, see Mouse Support). -e specifies that scrolling to the bottom of the history (to the visible screen) should exit copy mode. While in copy mode, pressing a key other than those used for scrolling will disable this behaviour. This is intended to allow fast scrolling through a pane's history, for example with:

bind PageUp copy-mode -eu
    

Each window displayed by tmux may be split into one or more 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 split-window command. Windows may be split horizontally (with the -h flag) or vertically. Panes may be resized with the resize-pane command (bound to ‘C-Up’, ‘C-Down’ ‘C-Left’ and ‘C-Right’ by default), the current pane may be changed with the select-pane command and the rotate-window and 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.

A number of preset layouts are available. These may be selected with the select-layout command or cycled with next-layout (bound to ‘Space’ by default); once a layout is chosen, panes within it may be moved and resized as normal.

The following layouts are supported:

even-horizontal

Panes are spread out evenly from left to right across the window.

even-vertical

Panes are spread evenly from top to bottom.

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 main-pane-height window option to specify the height of the top pane.

main-vertical

Similar to main-horizontal but the large pane is placed on the left and the others spread from top to bottom along the right. See the main-pane-width window option.

tiled

Panes are spread out as evenly as possible over the window in both rows and columns.

In addition, select-layout may be used to apply a previously used layout - the list-windows command displays the layout of each window in a form suitable for use with select-layout. For example:

$ 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}

tmux 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.

Commands related to windows and panes are as follows:

break-pane [-dP] [-F format] [-n window-name] [-s src-pane] [-t dst-window]

(alias: breakp)

Break src-pane off from its containing window to make it the only pane in dst-window. If -d is given, the new window does not become the current window. The -P option prints information about the new window after it has been created. By default, it uses the format ‘#{session_name}:#{window_index}’ but a different format may be specified with -F.

capture-pane [-aepPqCJ] [-b buffer-name] [-E end-line] [-S start-line] [-t target-pane]

(alias: capturep)

Capture the contents of a pane. If -p is given, the output goes to stdout, otherwise to the buffer specified with -b or a new buffer if omitted. If -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 -q is given. If -e is given, the output includes escape sequences for text and background attributes. -C also escapes non-printable characters as octal \xxx. -J joins wrapped lines and preserves trailing spaces at each line's end. -P captures only any output that the pane has received that is the beginning of an as-yet incomplete escape sequence.

-S and -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. ‘-’ to -S is the start of the history and to -E the end of the visible pane. The default is to capture only the visible contents of the pane.

choose-client [-NZ] [-F format] [-f filter] [-O sort-order] [-t target-pane] [template]

Put a pane into client mode, allowing a client to be selected interactively from a list. -Z zooms the pane. The following keys may be used in client mode:

Key	Function
Enter	Choose selected client
Up	Select previous client
Down	Select next client
C-s	Search by name
n	Repeat last search
t	Toggle if client is tagged
T	Tag no clients
C-t	Tag all clients
d	Detach selected client
D	Detach tagged clients
x	Detach and HUP selected client
X	Detach and HUP tagged clients
z	Suspend selected client
Z	Suspend tagged clients
f	Enter a format to filter items
O	Change sort order
v	Toggle preview
q	Exit mode

After a client is chosen, ‘%%’ is replaced by the client name in template and the result executed as a command. If template is not given, "detach-client -t '%%'" is used.

-O specifies the initial sort order: one of ‘name’, ‘size’, ‘creation’, or ‘activity’. -f specifies an initial filter: the filter is a format - if it evaluates to zero, the item in the list is not shown, otherwise it is shown. If a filter would lead to an empty list, it is ignored. -F specifies the format for each item in the list. -N starts without the preview. This command works only if at least one client is attached.

choose-tree [-GNswZ] [-F format] [-f filter] [-O sort-order] [-t target-pane] [template]

Put a pane into tree mode, where a session, window or pane may be chosen interactively from a list. -s starts with sessions collapsed and -w with windows collapsed. -Z zooms the pane. The following keys may be used in tree mode:

Key	Function
Enter	Choose selected item
Up	Select previous item
Down	Select next item
x	Kill selected item
X	Kill tagged items
<	Scroll list of previews left
>	Scroll list of previews right
C-s	Search by name
n	Repeat last search
t	Toggle if item is tagged
T	Tag no items
C-t	Tag all items
:	Run a command for each tagged item
f	Enter a format to filter items
O	Change sort order
v	Toggle preview
q	Exit mode

After a session, window or pane is chosen, ‘%%’ is replaced by the target in template and the result executed as a command. If template is not given, "switch-client -t '%%'" is used.

-O specifies the initial sort order: one of ‘index’, ‘name’, or ‘time’. -f specifies an initial filter: the filter is a format - if it evaluates to zero, the item in the list is not shown, otherwise it is shown. If a filter would lead to an empty list, it is ignored. -F specifies the format for each item in the tree. -N starts without the preview. -G includes all sessions in any session groups in the tree rather than only the first. This command works only if at least one client is attached.

display-panes [-b] [-d duration] [-t target-client] [template]

(alias: displayp)

Display a visible indicator of each pane shown by target-client. See the display-panes-colour and display-panes-active-colour session options. The indicator is closed when a key is pressed or duration milliseconds have passed. If -d is not given, display-panes-time is used. A duration of zero means the indicator stays until a key is pressed. While the indicator is on screen, a pane may be chosen with the ‘0’ to ‘9’ keys, which will cause template to be executed as a command with ‘%%’ substituted by the pane ID. The default template is "select-pane -t '%%'". With -b, other commands are not blocked from running until the indicator is closed.

find-window [-CNTZ] [-t target-pane] match-string

(alias: findw)

Search for the fnmatch(3) pattern match-string in window names, titles, and visible content (but not history). The flags control matching behavior: -C matches only visible window contents, -N matches only the window name and -T matches only the window title. The default is -CNT. -Z zooms the pane.

This command works only if at least one client is attached.

join-pane [-bdhv] [-l size | -p percentage] [-s src-pane] [-t dst-pane]

(alias: joinp)

Like split-window, but instead of splitting dst-pane and creating a new pane, split it and move src-pane into the space. This can be used to reverse break-pane. The -b option causes src-pane to be joined to left of or above dst-pane.

If -s is omitted and a marked pane is present (see select-pane -m), the marked pane is used rather than the current pane.

kill-pane [-a] [-t target-pane]

(alias: killp)

Destroy the given pane. If no panes remain in the containing window, it is also destroyed. The -a option kills all but the pane given with -t.

kill-window [-a] [-t target-window]

(alias: killw)

Kill the current window or the window at target-window, removing it from any sessions to which it is linked. The -a option kills all but the window given with -t.

last-pane [-de] [-t target-window]

(alias: lastp)

Select the last (previously selected) pane. -e enables or -d disables input to the pane.

last-window [-t target-session]

(alias: last)

Select the last (previously selected) window. If no target-session is specified, select the last window of the current session.

link-window [-adk] [-s src-window] [-t dst-window]

(alias: linkw)

Link the window at src-window to the specified dst-window. If dst-window is specified and no such window exists, the src-window is linked there. With -a, the window is moved to the next index up (following windows are moved if necessary). If -k is given and dst-window exists, it is killed, otherwise an error is generated. If -d is given, the newly linked window is not selected.

list-panes [-as] [-F format] [-t target]

(alias: lsp)

If -a is given, target is ignored and all panes on the server are listed. If -s is given, target is a session (or the current session). If neither is given, target is a window (or the current window). For the meaning of the -F flag, see the Formats section.

list-windows [-a] [-F format] [-t target-session]

(alias: lsw)

If -a is given, list all windows on the server. Otherwise, list windows in the current session or in target-session. For the meaning of the -F flag, see the Formats section.

move-pane [-bdhv] [-l size | -p percentage] [-s src-pane] [-t dst-pane]

(alias: movep)

Like join-pane, but src-pane and dst-pane may belong to the same window.

move-window [-ardk] [-s src-window] [-t dst-window]

(alias: movew)

This is similar to link-window, except the window at src-window is moved to dst-window. With -r, all windows in the session are renumbered in sequential order, respecting the base-index option.

new-window [-adkP] [-c start-directory] [-F format] [-n window-name] [-t target-window] [shell-command]

(alias: neww)

Create a new window. With -a, the new window is inserted at the next index up from the specified target-window, moving windows up if necessary, otherwise target-window is the new window location.

If -d is given, the session does not make the new window the current window. target-window represents the window to be created; if the target already exists an error is shown, unless the -k flag is used, in which case it is destroyed. shell-command is the command to execute. If shell-command is not specified, the value of the default-command option is used. -c specifies the working directory in which the new window is created.

When the shell command completes, the window closes. See the remain-on-exit option to change this behaviour.

The TERM environment variable must be set to ‘screen’ or ‘tmux’ for all programs running inside tmux. New windows will automatically have ‘TERM=screen’ added to their environment, but care must be taken not to reset this in shell start-up files.

The -P option prints information about the new window after it has been created. By default, it uses the format ‘#{session_name}:#{window_index}’ but a different format may be specified with -F.

next-layout [-t target-window]

(alias: nextl)

Move a window to the next layout and rearrange the panes to fit.

next-window [-a] [-t target-session]

(alias: next)

Move to the next window in the session. If -a is used, move to the next window with an alert.

pipe-pane [-IOo] [-t target-pane] [shell-command]

(alias: pipep)

Pipe output sent by the program in target-pane to a shell command or vice versa. A pane may only be connected to one command at a time, any existing pipe is closed before shell-command is executed. The shell-command string may contain the special character sequences supported by the status-left option. If no shell-command is given, the current pipe (if any) is closed.

-I and -O specify which of the shell-command output streams are connected to the pane: with -I stdout is connected (so anything shell-command prints is written to the pane as if it were typed); with -O stdin is connected (so any output in the pane is piped to shell-command). Both may be used together and if neither are specified, -O is used.

The -o option only opens a new pipe if no previous pipe exists, allowing a pipe to be toggled with a single key, for example:

bind-key C-p pipe-pane -o 'cat >>~/output.#I-#P'
    

previous-layout [-t target-window]

(alias: prevl)

Move to the previous layout in the session.

previous-window [-a] [-t target-session]

(alias: prev)

Move to the previous window in the session. With -a, move to the previous window with an alert.

rename-window [-t target-window] new-name

(alias: renamew)

Rename the current window, or the window at target-window if specified, to new-name.

resize-pane [-DLMRUZ] [-t target-pane] [-x width] [-y height] [adjustment]

(alias: resizep)

Resize a pane, up, down, left or right by adjustment with -U, -D, -L or -R, or to an absolute size with -x or -y. The adjustment is given in lines or cells (the default is 1).

With -Z, the active pane is toggled between zoomed (occupying the whole of the window) and unzoomed (its normal position in the layout).

-M begins mouse resizing (only valid if bound to a mouse key binding, see Mouse Support).

resize-window [-aADLRU] [-t target-window] [-x width] [-y height] [adjustment]

(alias: resizew)

Resize a window, up, down, left or right by adjustment with -U, -D, -L or -R, or to an absolute size with -x or -y. The adjustment is given in lines or cells (the default is 1). -A sets the size of the largest session containing the window; -a the size of the smallest. This command will automatically set window-size to manual in the window options.

respawn-pane [-c start-directory] [-k] [-t target-pane] [shell-command]

(alias: respawnp)

Reactivate a pane in which the command has exited (see the remain-on-exit window option). If shell-command is not given, the command used when the pane was created is executed. The pane must be already inactive, unless -k is given, in which case any existing command is killed. -c specifies a new working directory for the pane.

respawn-window [-c start-directory] [-k] [-t target-window] [shell-command]

(alias: respawnw)

Reactivate a window in which the command has exited (see the remain-on-exit window option). If shell-command is not given, the command used when the window was created is executed. The window must be already inactive, unless -k is given, in which case any existing command is killed. -c specifies a new working directory for the window.

rotate-window [-DU] [-t target-window]

(alias: rotatew)

Rotate the positions of the panes within a window, either upward (numerically lower) with -U or downward (numerically higher).

select-layout [-Enop] [-t target-pane] [layout-name]

(alias: selectl)

Choose a specific layout for a window. If layout-name is not given, the last preset layout used (if any) is reapplied. -n and -p are equivalent to the next-layout and previous-layout commands. -o applies the last set layout if possible (undoes the most recent layout change). -E spreads the current pane and any panes next to it out evenly.

select-pane [-DdegLlMmRU] [-P style] [-T title] [-t target-pane]

(alias: selectp)

Make pane target-pane the active pane in window target-window, or set its style (with -P). If one of -D, -L, -R, or -U is used, respectively the pane below, to the left, to the right, or above the target pane is used. -l is the same as using the last-pane command. -e enables or -d disables input to the pane.

-m and -M are used to set and clear the marked pane. There is one marked pane at a time, setting a new marked pane clears the last. The marked pane is the default target for -s to join-pane, swap-pane and swap-window.

Each pane has a style: by default the window-style and window-active-style options are used, select-pane -P sets the style for a single pane. For example, to set the pane 1 background to red:

select-pane -t:.1 -P 'bg=red'
    

-g shows the current pane style.

-T sets the pane title.

select-window [-lnpT] [-t target-window]

(alias: selectw)

Select the window at target-window. -l, -n and -p are equivalent to the last-window, next-window and previous-window commands. If -T is given and the selected window is already the current window, the command behaves like last-window.

split-window [-bdfhvP] [-c start-directory] [-l size | -p percentage] [-t target-pane] [shell-command] [-F format]

(alias: splitw)

Create a new pane by splitting target-pane: -h does a horizontal split and -v a vertical split; if neither is specified, -v is assumed. The -l and -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 -b option causes the new pane to be created to the left of or above target-pane. The -f option creates a new pane spanning the full window height (with -h) or full window width (with -v), instead of splitting the active pane. All other options have the same meaning as for the new-window command.

swap-pane [-dDU] [-s src-pane] [-t dst-pane]

(alias: swapp)

Swap two panes. If -U is used and no source pane is specified with -s, dst-pane is swapped with the previous pane (before it numerically); -D swaps with the next pane (after it numerically). -d instructs tmux not to change the active pane.

If -s is omitted and a marked pane is present (see select-pane -m), the marked pane is used rather than the current pane.

swap-window [-d] [-s src-window] [-t dst-window]

(alias: swapw)

This is similar to link-window, except the source and destination windows are swapped. It is an error if no window exists at src-window.

Like swap-pane, if -s is omitted and a marked pane is present (see select-pane -m), the window containing the marked pane is used rather than the current window.

unlink-window [-k] [-t target-window]

(alias: unlinkw)

Unlink target-window. Unless -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 -k is specified and the window is linked to only one session, it is unlinked and destroyed.

Key Bindings

tmux allows a command to be bound to most keys, with or without a prefix key. When specifying keys, most represent themselves (for example ‘A’ to ‘Z’). Ctrl keys may be prefixed with ‘C-’ or ‘^’, and Alt (meta) with ‘M-’. In addition, the following special key names are accepted: Up, Down, Left, Right, BSpace, BTab, DC (Delete), End, Enter, Escape, F1 to F12, Home, IC (Insert), NPage/PageDown/PgDn, PPage/PageUp/PgUp, Space, and Tab. Note that to bind the ‘"’ or ‘'’ keys, quotation marks are necessary, for example:

bind-key '"' split-window 
bind-key "'" new-window

Commands related to key bindings are as follows:

bind-key [-nr] [-T key-table] key command [arguments]

(alias: bind)

Bind key key to command. Keys are bound in a key table. By default (without -T), the key is bound in the prefix key table. This table is used for keys pressed after the prefix key (for example, by default ‘c’ is bound to new-window in the prefix table, so ‘C-b c’ creates a new window). The root table is used for keys pressed without the prefix key: binding ‘c’ to new-window in the root table (not recommended) means a plain ‘c’ will create a new window. -n is an alias for -T root. Keys may also be bound in custom key tables and the switch-client -T command used to switch to them from a key binding. The -r flag indicates this key may repeat, see the repeat-time option.

To view the default bindings and possible commands, see the list-keys command.

list-keys [-T key-table]

(alias: lsk)

List all key bindings. Without -T all key tables are printed. With -T only key-table.

send-keys [-lMRX] [-N repeat-count] [-t target-pane] key ...

(alias: send)

Send a key or keys to a window. Each argument key is the name of the key (such as ‘C-a’ or ‘NPage’) to send; if the string is not recognised as a key, it is sent as a series of characters. The -l flag disables key name lookup and sends the keys literally. All arguments are sent sequentially from first to last. The -R flag causes the terminal state to be reset.

-M passes through a mouse event (only valid if bound to a mouse key binding, see Mouse Support).

-X is used to send a command into copy mode - see the Windows and Panes section. -N specifies a repeat count.

send-prefix [-2] [-t target-pane]

Send the prefix key, or with -2 the secondary prefix key, to a window as if it was pressed.

unbind-key [-an] [-T key-table] key

(alias: unbind)

Unbind the command bound to key. -n and -T are the same as for bind-key. If -a is present, all key bindings are removed.

Options

The appearance and behaviour of tmux may be modified by changing the value of various options. There are three types of option: server options, session options and window options.

The tmux server has a set of global options which do not apply to any particular window or session. These are altered with the set-option -s command, or displayed with the show-options -s command.

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 set-option command and may be listed with the show-options command. The available server and session options are listed under the set-option command.

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 set-window-option command and can be listed with the show-window-options command. All window options are documented with the set-window-option command.

tmux also supports user options which are prefixed with a ‘@’. User options may have any name, so long as they are prefixed with ‘@’, and be set to any string. For example:

$ tmux setw -q @foo "abc123" 
$ tmux showw -v @foo 
abc123

Commands which set options are as follows:

set-option [-aFgoqsuw] [-t target-session | target-window] option value

(alias: set)

Set a window option with -w (equivalent to the set-window-option command), a server option with -s, otherwise a session option. If -g is given, the global session or window option is set. -F expands formats in the option value. The -u flag unsets an option, so a session inherits the option from the global options (or with -g, restores a global option to the default).

The -o flag prevents setting an option that is already set and the -q flag suppresses errors about unknown or ambiguous options.

With -a, and if the option expects a string or a style, value is appended to the existing setting. For example:

set -g status-left "foo" 
set -ag status-left "bar"
    

Will result in ‘foobar’. And:

set -g status-style "bg=red" 
set -ag status-style "fg=blue"
    

Will result in a red background and blue foreground. Without -a, the result would be the default background and a blue foreground.

Available window options are listed under set-window-option.

value depends on the option and may be a number, a string, or a flag (on, off, or omitted to toggle).

Available server options are:

buffer-limit 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.

command-alias[] name=value

This is an array of custom aliases for commands. If an unknown command matches name, it is replaced with value. For example, after:

set -s command-alias[100] zoom='resize-pane -Z'

Using:

zoom -t:.1

Is equivalent to:

resize-pane -Z -t:.1

Note that aliases are expanded when a command is parsed rather than when it is executed, so binding an alias with bind-key will bind the expanded form.

default-terminal terminal

Set the default terminal for new windows created in this session - the default value of the TERM environment variable. For tmux to work correctly, this must be set to ‘screen’, ‘tmux’ or a derivative of them.

escape-time time

Set the time in milliseconds for which tmux waits after an escape is input to determine if it is part of a function or meta key sequences. The default is 500 milliseconds.

exit-empty [on | off]

If enabled (the default), the server will exit when there are no active sessions.

exit-unattached [on | off]

If enabled, the server will exit when there are no attached clients.

focus-events [on | off]

When enabled, focus events are requested from the terminal if supported and passed through to applications running in tmux. Attached clients should be detached and attached again after changing this option.

history-file path

If not empty, a file to which tmux will write command prompt history on exit and load it from on start.

message-limit number

Set the number of error or information messages to save in the message log for each client. The default is 100.

set-clipboard [on | external | off]

Attempt to set the terminal clipboard content using the xterm(1) escape sequence, if there is an Ms entry in the terminfo(5) description (see the Terminfo Extensions section).

If set to on, tmux will both accept the escape sequence to create a buffer and attempt to set the terminal clipboard. If set to external, tmux will attempt to set the terminal clipboard but ignore attempts by applications to set tmux buffers. If off, tmux will neither accept the clipboard escape sequence nor attempt to set the clipboard.

Note that this feature needs to be enabled in xterm(1) by setting the resource:

disallowedWindowOps: 20,21,SetXprop
        

Or changing this property from the xterm(1) interactive menu when required.

terminal-overrides[] string

Allow terminal descriptions read using terminfo(5) to be overridden. Each entry is a colon-separated string made up of a terminal type pattern (matched using fnmatch(3)) and a set of name=value entries.

For example, to set the ‘clear’ terminfo(5) entry to ‘\e[H\e[2J’ for all terminal types matching ‘rxvt*’:

rxvt*:clear=\e[H\e[2J

The terminal entry value is passed through strunvis(3) before interpretation.

Available session options are:

activity-action [any | none | current | other]

Set action on window activity when monitor-activity is on. any means activity in any window linked to a session causes a bell or message (depending on visual-activity) in the current window of that session, none means all activity is ignored (equivalent to monitor-activity being off), current means only activity in windows other than the current window are ignored and other means activity in the current window is ignored but not those in other windows.

assume-paste-time milliseconds

If keys are entered faster than one in milliseconds, they are assumed to have been pasted rather than typed and tmux key bindings are not processed. The default is one millisecond and zero disables.

base-index index

Set the base index from which an unused index should be searched when a new window is created. The default is zero.

bell-action [any | none | current | other]

Set action on a bell in a window when monitor-bell is on. The values are the same as those for activity-action.

default-command shell-command

Set the command used for new windows (if not specified when the window is created) to shell-command, which may be any sh(1) command. The default is an empty string, which instructs tmux to create a login shell using the value of the default-shell option.

default-size XxY

Set the default size of new windows when the window-size option is set to manual or when a session is created with new-session -d. The value is the width and height separated by an ‘x’ character. The default is 80x24.

default-shell path

Specify the default shell. This is used as the login shell for new windows when the default-command option is set to empty, and must be the full path of the executable. When started tmux tries to set a default value from the first suitable of the SHELL environment variable, the shell returned by getpwuid(3), or /bin/sh. This option should be configured when tmux is used as a login shell.

default-size XxY

Set the default size of windows when the size is not set or the window-size option is manual.

destroy-unattached [on | off]

If enabled and the session is no longer attached to any clients, it is destroyed.

detach-on-destroy [on | off]

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.

display-panes-active-colour colour

Set the colour used by the display-panes command to show the indicator for the active pane.

display-panes-colour colour

Set the colour used by the display-panes command to show the indicators for inactive panes.

display-panes-time time

Set the time in milliseconds for which the indicators shown by the display-panes command appear.

display-time time

Set the amount of time for which status line messages and other on-screen indicators are displayed. If set to 0, messages and indicators are displayed until a key is pressed. time is in milliseconds.

history-limit 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.

key-table key-table

Set the default key table to key-table instead of root.

lock-after-time number

Lock the session (like the lock-session command) after number seconds of inactivity. The default is not to lock (set to 0).

lock-command shell-command

Command to run when locking each client. The default is to run lock(1) with -np.

message-command-style style

Set status line message command style. For how to specify style, see the Styles section.

message-style style

Set status line message style. For how to specify style, see the Styles section.

mouse [on | off]

If on, tmux captures the mouse and allows mouse events to be bound as key bindings. See the Mouse Support section for details.

prefix key

Set the key accepted as a prefix key. In addition to the standard keys described under Key Bindings, prefix can be set to the special key ‘None’ to set no prefix.

prefix2 key

Set a secondary key accepted as a prefix key. Like prefix, prefix2 can be set to ‘None’.

renumber-windows [on | off]

If on, when a window is closed in a session, automatically renumber the other windows in numerical order. This respects the base-index option if it has been set. If off, do not renumber the windows.

repeat-time time

Allow multiple commands to be entered without pressing the prefix-key again in the specified time milliseconds (the default is 500). Whether a key repeats may be set when it is bound using the -r flag to bind-key. Repeat is enabled for the default keys bound to the resize-pane command.

set-titles [on | off]

Attempt to set the client terminal title using the tsl and fsl terminfo(5) entries if they exist. tmux automatically sets these to the \e]0;...\007 sequence if the terminal appears to be xterm(1). This option is off by default.

set-titles-string string

String used to set the window title if set-titles is on. Formats are expanded, see the Formats section.

silence-action [any | none | current | other]

Set action on window silence when monitor-silence is on. The values are the same as those for activity-action.

status [off | on | 2 | 3 | 4 | 5]

Show or hide the status line or specify its size. Using on gives a status line one row in height; 2, 3, 4 or 5 more rows.

status-format[] format

Specify the format to be used for each line of the status line. The default builds the top status line from the various individual status options below.

status-interval interval

Update the status line every interval seconds. By default, updates will occur every 15 seconds. A setting of zero disables redrawing at interval.

status-justify [left | centre | right]

Set the position of the window list component of the status line: left, centre or right justified.

status-keys [vi | emacs]

Use vi or emacs-style key bindings in the status line, for example at the command prompt. The default is emacs, unless the VISUAL or EDITOR environment variables are set and contain the string ‘vi’.

status-left string

Display string (by default the session name) to the left of the status line. string will be passed through strftime(3). Also see the Formats and Styles sections.

For details on how the names and titles can be set see the Names and Titles section.

Examples are:

#(sysctl vm.loadavg) 
#[fg=yellow,bold]#(apm -l)%%#[default] [#S]
        

The default is ‘[#S] ’.

status-left-length length

Set the maximum length of the left component of the status line. The default is 10.

status-left-style style

Set the style of the left part of the status line. For how to specify style, see the Styles section.

status-position [top | bottom]

Set the position of the status line.

status-right string

Display string to the right of the status line. By default, the current pane title in double quotes, the date and the time are shown. As with status-left, string will be passed to strftime(3) and character pairs are replaced.

status-right-length length

Set the maximum length of the right component of the status line. The default is 40.

status-right-style style

Set the style of the right part of the status line. For how to specify style, see the Styles section.

status-style style

Set status line style. For how to specify style, see the Styles section.

update-environment[] variable

Set 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 -r was given to the set-environment command).

user-keys[] key

Set list of user-defined key escape sequences. Each item is associated with a key named ‘User0’, ‘User1’, and so on.

For example:

set -s user-keys[0] "\e[5;30012~" 
bind User0 resize-pane -L 3
        

visual-activity [on | off | both]

If on, display a message instead of sending a bell when activity occurs in a window for which the monitor-activity window option is enabled. If set to both, a bell and a message are produced.

visual-bell [on | off | both]

If on, a message is shown on a bell in a window for which the monitor-bell window option is enabled instead of it being passed through to the terminal (which normally makes a sound). If set to both, a bell and a message are produced. Also see the bell-action option.

visual-silence [on | off | both]

If monitor-silence is enabled, prints a message after the interval has expired on a given window instead of sending a bell. If set to both, a bell and a message are produced.

word-separators 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 ‘ -_@’.

set-window-option [-aFgoqu] [-t target-window] option value

(alias: setw)

Set a window option. The -a, -F, -g, -o, -q and -u flags work similarly to the set-option command.

Supported window options are:

aggressive-resize [on | off]

Aggressively resize the chosen window. This means that tmux will resize the window to the size of the smallest or largest session (see the window-size option) for which it is the current window, rather than the session to which it is attached. The window may resize when the current window is changed on another session; this option is good for full-screen programs which support SIGWINCH and poor for interactive programs such as shells.

allow-rename [on | off]

Allow programs to change the window name using a terminal escape sequence (\ek...\e\\). The default is off.

alternate-screen [on | off]

This option configures whether programs running inside tmux may use the terminal alternate screen feature, which allows the smcup and rmcup 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.

automatic-rename [on | off]

Control automatic window renaming. When this setting is enabled, tmux will rename the window automatically using the format specified by automatic-rename-format. This flag is automatically disabled for an individual window when a name is specified at creation with new-window or new-session, or later with rename-window, or with a terminal escape sequence. It may be switched off globally with:

set-window-option -g automatic-rename off
        

automatic-rename-format format

The format (see Formats) used when the automatic-rename option is enabled.

clock-mode-colour colour

Set clock colour.

clock-mode-style [12 | 24]

Set clock hour format.

main-pane-height height

main-pane-width width

Set the width or height of the main (left or top) pane in the main-horizontal or main-vertical layouts.

mode-keys [vi | emacs]

Use vi or emacs-style key bindings in copy mode. The default is emacs, unless VISUAL or EDITOR contains ‘vi’.

mode-style style

Set window modes style. For how to specify style, see the Styles section.

monitor-activity [on | off]

Monitor for activity in the window. Windows with activity are highlighted in the status line.

monitor-bell [on | off]

Monitor for a bell in the window. Windows with a bell are highlighted in the status line.

monitor-silence [interval]

Monitor for silence (no activity) in the window within interval seconds. Windows that have been silent for the interval are highlighted in the status line. An interval of zero disables the monitoring.

other-pane-height height

Set the height of the other panes (not the main pane) in the main-horizontal layout. If this option is set to 0 (the default), it will have no effect. If both the main-pane-height and 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.

other-pane-width width

Like other-pane-height, but set the width of other panes in the main-vertical layout.

pane-active-border-style style

Set the pane border style for the currently active pane. For how to specify style, see the Styles section. Attributes are ignored.

pane-base-index index

Like base-index, but set the starting index for pane numbers.

pane-border-format format

Set the text shown in pane border status lines.

pane-border-status [off | top | bottom]

Turn pane border status lines off or set their position.

pane-border-style style

Set the pane border style for panes aside from the active pane. For how to specify style, see the Styles section. Attributes are ignored.

remain-on-exit [on | off]

A window with this flag set is not destroyed when the program running in it exits. The window may be reactivated with the respawn-window command.

synchronize-panes [on | off]

Duplicate input to any pane to all other panes in the same window (only for panes that are not in any special mode).

window-active-style style

Set the style for the window's active pane. For how to specify style, see the Styles section.

window-status-activity-style style

Set status line style for windows with an activity alert. For how to specify style, see the Styles section.

window-status-bell-style style

Set status line style for windows with a bell alert. For how to specify style, see the Styles section.

window-status-current-format string

Like window-status-format, but is the format used when the window is the current window.

window-status-current-style style

Set status line style for the currently active window. For how to specify style, see the Styles section.

window-status-format string

Set the format in which the window is displayed in the status line window list. See the Formats and Styles sections.

window-status-last-style style

Set status line style for the last active window. For how to specify style, see the Styles section.

window-status-separator string

Sets the separator drawn between windows in the status line. The default is a single space character.

window-status-style style

Set status line style for a single window. For how to specify style, see the Styles section.

window-size largest | smallest | manual

Configure how tmux determines the window size. If set to largest, the size of the largest attached session is used; if smallest, the size of the smallest. If manual, the size of a new window is set from the default-size option and windows are resized automatically. See also the resize-window command and the aggressive-resize option.

window-style style

Set the default window style. For how to specify style, see the Styles section.

window-size [smallest | largest | manual]

Tell tmux how to automatically size windows either the size of the smallest session containing the window, the size of the largest, or manual size. See also the resize-window command and the default-size and aggressive-resize options.

wrap-search [on | off]

If this option is set, searches will wrap around the end of the pane contents. The default is on.

xterm-keys [on | off]

If this option is set, tmux will generate xterm(1) -style function key sequences; these have a number included to indicate modifiers such as Shift, Alt or Ctrl.

show-options [-gqsvw] [-t target-session | target-window] [option]

(alias: show)

Show the window options (or a single window option if given) with -w (equivalent to show-window-options), the server options with -s, otherwise the session options for target session. Global session or window options are listed if -g is used. -v shows only the option value, not the name. If -q is set, no error will be returned if option is unset.

show-window-options [-gv] [-t target-window] [option]

(alias: showw)

List the window options or a single option for target-window, or the global window options if -g is used. -v shows only the option value, not the name.

Hooks

tmux allows commands to run on various triggers, called hooks. Most tmux commands have an after hook and there are a number of hooks not associated with commands.

A command's after hook is run after it completes, except when the command is run as part of a hook itself. They are named with an ‘after-’ prefix. For example, the following command adds a hook to select the even-vertical layout after every split-window:

set-hook after-split-window "selectl even-vertical"

All the notifications listed in the Control Mode section are hooks (without any arguments), except %exit. The following additional hooks are available:

alert-activity

Run when a window has activity. See monitor-activity.

alert-bell

Run when a window has received a bell. See monitor-bell.

alert-silence

Run when a window has been silent. See monitor-silence.

client-attached

Run when a client is attached.

client-detached

Run when a client is detached

client-resized

Run when a client is resized.

client-session-changed

Run when a client's attached session is changed.

pane-died

Run when the program running in a pane exits, but remain-on-exit is on so the pane has not closed.

pane-exited

Run when the program running in a pane exits.

pane-focus-in

Run when the focus enters a pane, if the focus-events option is on.

pane-focus-out

Run when the focus exits a pane, if the focus-events option is on.

pane-set-clipboard

Run when the terminal clipboard is set using the xterm(1) escape sequence.

session-created

Run when a new session created.

session-closed

Run when a session closed.

session-renamed

Run when a session is renamed.

window-linked

Run when a window is linked into a session.

window-renamed

Run when a window is renamed.

window-unlinked

Run when a window is unlinked from a session.

Hooks are managed with these commands:

set-hook [-gRu] [-t target-session] hook-name command

Without -R, sets (or with -u unsets) hook hook-name to command. If -g is given, hook-name is added to the global list of hooks, otherwise it is added to the session hooks (for target-session with -t). Like options, session hooks inherit from the global ones.

With -R, run hook-name immediately.

show-hooks [-g] [-t target-session]

Shows the global list of hooks with -g, otherwise the session hooks.

Mouse Support

If the mouse option is on (the default is off), tmux allows mouse events to be bound as keys. The name of each key is made up of a mouse event (such as ‘MouseUp1’) and a location suffix, one of the following:

The following mouse events are available:

Each should be suffixed with a location, for example ‘MouseDown1Status’.

The special token ‘{mouse}’ or ‘=’ may be used as target-window or target-pane in commands bound to mouse key bindings. It resolves to the window or pane over which the mouse event took place (for example, the window in the status line over which button 1 was released for a ‘MouseUp1Status’ binding, or the pane over which the wheel was scrolled for a ‘WheelDownPane’ binding).

The send-keys -M flag may be used to forward a mouse event to a pane.

The default key bindings allow the mouse to be used to select and resize panes, to copy text and to change window using the status line. These take effect if the mouse option is turned on.

Formats

Certain commands accept the -F flag with a format argument. This is a string which controls the output format of the command. Replacement variables are enclosed in ‘#{’ and ‘}’, for example ‘#{session_name}’. The possible variables are listed in the table below, or the name of a tmux option may be used for an option's value. Some variables have a shorter alias such as ‘#S’; ‘##’ is replaced by a single ‘#’, ‘#,’ by a ‘,’ and ‘#}’ by a ‘}’.

Conditionals are available by prefixing with ‘?’ 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 ‘#{?session_attached,attached,not attached}’ will include the string ‘attached’ if the session is attached and the string ‘not attached’ if it is unattached, or ‘#{?automatic-rename,yes,no}’ will include ‘yes’ if automatic-rename is enabled, or ‘no’ if not. Conditionals can be nested arbitrarily. Inside a conditional, ‘,’ and ‘}’ must be escaped as ‘#,’ and ‘#}’, unless they are part of a ‘#{...}’ replacement. For example:

#{?pane_in_mode,#[fg=white#,bg=red],#[fg=red#,bg=white]}#W .

Comparisons may be expressed by prefixing two comma-separated alternatives by ‘==’ or ‘!=’ and a colon. For example ‘#{==:#{host},myhost}’ will be replaced by ‘1’ if running on ‘myhost’, otherwise by ‘0’. An ‘m’ specifies an fnmatch(3) comparison where the first argument is the pattern and the second the string to compare, for example ‘#{m:*foo*,#{host}}’. ‘||’ and ‘&&’ evaluate to true if either or both of two comma-separated alternatives are true, for example ‘#{||:#{pane_in_mode},#{alternate_on}}’. A ‘C’ performs a search for an fnmatch(3) pattern in the pane content and evaluates to zero if not found, or a line number if found.

A limit may be placed on the length of the resultant string by prefixing it by an ‘=’, a number and a colon. Positive numbers count from the start of the string and negative from the end, so ‘#{=5:pane_title}’ will include at most the first 5 characters of the pane title, or ‘#{=-5:pane_title}’ the last 5 characters. Prefixing a time variable with ‘t:’ will convert it to a string, so if ‘#{window_activity}’ gives ‘1445765102’, ‘#{t:window_activity}’ gives ‘Sun Oct 25 09:25:02 2015’. The ‘b:’ and ‘d:’ prefixes are basename(3) and dirname(3) of the variable respectively. ‘q:’ will escape sh(1) special characters. ‘E:’ will expand the format twice, for example ‘#{E:status-left}’ is the result of expanding the content of the status-left option rather than the content itself. ‘T:’ is like ‘E:’ but also expands strftime(3) specifiers. ‘S:’, ‘W:’ or ‘P:’ will loop over each session, window or pane and insert the format once for each. For windows and panes, two comma-separated formats may be given: the second is used for the current window or active pane. For example, to get a list of windows formatted like the status line:

#{W:#{E:window-status-format} ,#{E:window-status-current-format} }

A prefix of the form ‘s/foo/bar/:’ will substitute ‘foo’ with ‘bar’ throughout.

In addition, the first line of a shell command's output may be inserted using ‘#()’. For example, ‘#(uptime)’ will insert the system's uptime. When constructing formats, tmux does not wait for ‘#()’ commands to finish; instead, the previous result from running the same command is used, or a placeholder if the command has not been run before. If the command hasn't exited, the most recent line of output will be used, but the status line will not be updated more than once a second. Commands are executed with the tmux global environment set (see the Environment section).

The following variables are available, where appropriate:

Styles

tmux offers various options to specify the colour and attributes of aspects of the interface, for example status-style for the status line. In addition, embedded styles may be specified in format options, such as status-left-format, by enclosing them in ‘#[’ and ‘’].

A style may be the single term ‘default’ to specify the default style (which may inherit from another option) or a space or comma separated list of the following:

fg=colour

Set the foreground colour. The colour is one of: black, red, green, yellow, blue, magenta, cyan, white; if supported the bright variants brightred, brightgreen, brightyellow; colour0 to colour255 from the 256-colour set; default for the default colour; terminal for the terminal default colour; or a hexadecimal RGB string such as ‘#ffffff’.

bg=colour

Set the background colour.

none

Set no attributes (turn off any active attributes).

bright (or bold), dim, underscore, blink, reverse, hidden, italics, strikethrough, double-underscore, curly-underscore, dotted-underscore, dashed-underscore

Set an attribute. Any of the attributes may be prefixed with ‘no’ to unset.

align=left (or noalign), align=centre, align=right

Align text to the left, centre or right of the available space if appropriate.

list=on, list=focus, list=left-marker, list=right=marker, nolist

Mark the position of the various window list components in the status-format option: list=on marks the start of the list; list=focus is the part of the list that should be kept in focus if the entire list won't fit in the available space (typically the current window); list=left-marker and list=right-marker mark the text to be used to mark that text has been trimmed from the left or right of the list if there is not enough space.

range=left, range=right, range=window|X, norange

Mark a range in the status-format option. range=left and range=right are the text used for the ‘StatusLeft’ and ‘StatusRight’ mouse keys. range=window|X is the range for a window passed to the ‘Status’ mouse key, where ‘X’ is a window index.

Examples are:

fg=yellow bold underscore blink 
bg=black,fg=default,noreverse

Names and Titles

tmux 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 tmux identifier for a window or session. Only panes have titles. A pane's title is typically set by the program running inside the pane using an escape sequence (like it would set the xterm(1) window title in X(7)). Windows themselves do not have titles - a window's title is the title of its active pane. tmux itself may set the title of the terminal in which the client is running, see the set-titles option.

A session's name is set with the new-session and rename-session commands. A window's name is set with one of:

1. A command argument (such as -n for new-window or new-session).

2. An escape sequence (if the allow-rename option is turned on):

   $ printf '\033kWINDOW_NAME\033\\'
       

3. Automatic renaming, which sets the name to the active command in the window's active pane. See the automatic-rename option.

When a pane is first created, its title is the hostname. A pane's title can be set via the title setting escape sequence, for example:

$ printf '\033]2;My Title\033\\'

It can also be modified with the select-pane -T command.

Environment

When the server is started, tmux copies the environment into the global environment; in addition, each session has a 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.

The 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. tmux also initialises the TMUX variable with some internal information to allow commands to be executed from inside, and the TERM variable with the correct terminal setting of ‘screen’.

Commands to alter and view the environment are:

set-environment [-gru] [-t target-session] name [value]

(alias: setenv)

Set or unset an environment variable. If -g is used, the change is made in the global environment; otherwise, it is applied to the session environment for target-session. The -u flag unsets a variable. -r indicates the variable is to be removed from the environment before starting a new process.

show-environment [-gs] [-t target-session] [variable]

(alias: showenv)

Display the environment for target-session or the global environment with -g. If variable is omitted, all variables are shown. Variables removed from the environment are prefixed with ‘-’. If -s is used, the output is formatted as a set of Bourne shell commands.

Status Line

tmux includes an optional status line which is displayed in the bottom line of each terminal.

By default, the status line is enabled and one line in height (it may be disabled or made multiple lines with the 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.

Each line of the status line is configured with the status-format option. The default 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 status-left, status-left-length, status-right, and 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 window-status-format and window-status-current-format options. The flag is one of the following symbols appended to the window name:

The # symbol relates to the monitor-activity window option. The window name is printed in inverted colours if an alert (bell, activity or silence) is present.

The colour and attributes of the status line may be configured, the entire status line using the status-style session option and individual windows using the window-status-style window option.

The status line is automatically refreshed at interval if it has changed, the interval may be controlled with the status-interval session option.

Commands related to the status line are as follows:

command-prompt [-1i] [-I inputs] [-p prompts] [-t target-client] [template]

Open the command prompt in a client. This may be used from inside tmux to execute commands interactively.

If template is specified, it is used as the command. If present, -I is a comma-separated list of the initial text for each prompt. If -p is given, prompts is a comma-separated list of prompts which are displayed in order; otherwise a single prompt is displayed, constructed from template if it is present, or ‘:’ if not.

Before the command is executed, the first occurrence of the string ‘%%’ and all occurrences of ‘%1’ are replaced by the response to the first prompt, all ‘%2’ are replaced with the response to the second prompt, and so on for further prompts. Up to nine prompt responses may be replaced (‘%1’ to ‘%9’). ‘%%%’ is like ‘%%’ but any quotation marks are escaped.

-1 makes the prompt only accept one key press, in this case the resulting input is a single character. -i executes the command every time the prompt input changes instead of when the user exits the command prompt.

The following keys have a special meaning in the command prompt, depending on the value of the status-keys option:

Function	vi	emacs
Cancel command prompt	Escape	Escape
Delete current word		C-w
Delete entire command	d	C-u
Delete from cursor to end	D	C-k
Execute command	Enter	Enter
Get next command from history		Down
Get previous command from history		Up
Insert top paste buffer	p	C-y
Look for completions	Tab	Tab
Move cursor left	h	Left
Move cursor right	l	Right
Move cursor to end	$	C-e
Move cursor to next word	w	M-f
Move cursor to previous word	b	M-b
Move cursor to start	0	C-a
Transpose characters		C-t

confirm-before [-p prompt] [-t target-client] command

(alias: confirm)

Ask for confirmation before executing command. If -p is given, prompt is the prompt to display; otherwise a prompt is constructed from command. It may contain the special character sequences supported by the status-left option.

This command works only from inside tmux.

display-message [-apv] [-c target-client] [-t target-pane] [message]

(alias: display)

Display a message. If -p is given, the output is printed to stdout, otherwise it is displayed in the target-client status line. The format of message is described in the Formats section; information is taken from target-pane if -t is given, otherwise the active pane for the session attached to target-client.

-v prints verbose logging as the format is parsed and -a lists the format variables and their values.

Buffers

tmux maintains a set of named paste buffers. Each buffer may be either explicitly or automatically named. Explicitly named buffers are named when created with the set-buffer or load-buffer commands, or by renaming an automatically named buffer with set-buffer -n. Automatically named buffers are given a name such as ‘buffer0001’, ‘buffer0002’ and so on. When the buffer-limit option is reached, the oldest automatically named buffer is deleted. Explicitly named buffers are not subject to buffer-limit and may be deleted with delete-buffer command.

Buffers may be added using copy-mode or the set-buffer and load-buffer commands, and pasted into a window using the paste-buffer command. If a buffer command is used and no buffer is specified, the most recently added automatically named buffer is assumed.

A configurable history buffer is also maintained for each window. By default, up to 2000 lines are kept; this can be altered with the history-limit option (see the set-option command above).

The buffer commands are as follows:

choose-buffer [-NZ] [-F format] [-f filter] [-O sort-order] [-t target-pane] [template]

Put a pane into buffer mode, where a buffer may be chosen interactively from a list. -Z zooms the pane. The following keys may be used in buffer mode:

Key	Function
Enter	Paste selected buffer
Up	Select previous buffer
Down	Select next buffer
C-s	Search by name or content
n	Repeat last search
t	Toggle if buffer is tagged
T	Tag no buffers
C-t	Tag all buffers
p	Paste selected buffer
P	Paste tagged buffers
d	Delete selected buffer
D	Delete tagged buffers
f	Enter a format to filter items
O	Change sort order
v	Toggle preview
q	Exit mode

After a buffer is chosen, ‘%%’ is replaced by the buffer name in template and the result executed as a command. If template is not given, "paste-buffer -b '%%'" is used.

-O specifies the initial sort order: one of ‘time’, ‘name’ or ‘size’. -f specifies an initial filter: the filter is a format - if it evaluates to zero, the item in the list is not shown, otherwise it is shown. If a filter would lead to an empty list, it is ignored. -F specifies the format for each item in the list. -N starts without the preview. This command works only if at least one client is attached.

clear-history [-t target-pane]

(alias: clearhist)

Remove and free the history for the specified pane.

delete-buffer [-b buffer-name]

(alias: deleteb)

Delete the buffer named buffer-name, or the most recently added automatically named buffer if not specified.

list-buffers [-F format]

(alias: lsb)

List the global buffers. For the meaning of the -F flag, see the Formats section.

load-buffer [-b buffer-name] path

(alias: loadb)

Load the contents of the specified paste buffer from path.

paste-buffer [-dpr] [-b buffer-name] [-s separator] [-t target-pane]

(alias: pasteb)

Insert the contents of a paste buffer into the specified pane. If not specified, paste into the current one. With -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 -s flag. The -r flag means to do no replacement (equivalent to a separator of LF). If -p is specified, paste bracket control codes are inserted around the buffer if the application has requested bracketed paste mode.

save-buffer [-a] [-b buffer-name] path

(alias: saveb)

Save the contents of the specified paste buffer to path. The -a option appends to rather than overwriting the file.

set-buffer [-a] [-b buffer-name] [-n new-buffer-name] data

(alias: setb)

Set the contents of the specified buffer to data. The -a option appends to rather than overwriting the buffer. The -n option renames the buffer to new-buffer-name.

show-buffer [-b buffer-name]

(alias: showb)

Display the contents of the specified buffer.

Miscellaneous

Miscellaneous commands are as follows:

clock-mode [-t target-pane]

Display a large clock.

if-shell [-bF] [-t target-pane] shell-command command [command]

(alias: if)

Execute the first command if shell-command returns success or the second command otherwise. Before being executed, shell-command is expanded using the rules specified in the Formats section, including those relevant to target-pane. With -b, shell-command is run in the background.

If -F is given, shell-command is not executed but considered success if neither empty nor zero (after formats are expanded).

lock-server

(alias: lock)

Lock each client individually by running the command specified by the lock-command option.

run-shell [-b] [-t target-pane] shell-command

(alias: run)

Execute shell-command in the background without creating a window. Before being executed, shell-command is expanded using the rules specified in the Formats section. With -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 -t or the current pane if omitted). If the command doesn't return success, the exit status is also displayed.

wait-for [-L | -S | -U] channel

(alias: wait)

When used without options, prevents the client from exiting until woken using wait-for -S with the same channel. When -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 wait-for -U.

Terminfo Extensions

tmux understands some unofficial extensions to terminfo(5):

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 tmux:

$ printf '\033]12;red\033\\'
    

Smulx

Set a styled underline. The single parameter is one of: 0 for no underline, 1 for normal underline, 2 for double underline, 3 for curly underline, 4 for dotted underline and 5 for dashed underline.

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:

$ printf '\033[4 q'
    

If Se is not set, Ss with argument 0 will be used to reset the cursor style instead.

Tc

Indicate that the terminal supports the ‘direct colour’ RGB escape sequence (for example, \e[38;2;255;255;255m).

If supported, this is used for the initialize colour escape sequence (which may be enabled by adding the ‘initc’ and ‘ccc’ capabilities to the tmux terminfo(5) entry).

Ms

Store the current buffer in the host terminal's selection (clipboard). See the set-clipboard option above and the xterm(1) man page.

Control Mode

tmux offers a textual interface called control mode. This allows applications to communicate with tmux using a simple text-only protocol.

In control mode, a client sends tmux 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 %begin line followed by the output (which may be empty). The output block ends with a %end or %error. %begin and matching %end or %error have two arguments: an integer time (as seconds from epoch) and command number. For example:

%begin 1363006971 2 
0: ksh* (1 panes) [80x24] [layout b25f,80x24,0,0,2] @2 (active) 
%end 1363006971 2

The refresh-client -C command may be used to set the size of a client in control mode.

In control mode, tmux outputs notifications. A notification will never occur inside an output block.

The following notifications are defined:

%client-session-changed client session-id name

The client is now attached to the session with ID session-id, which is named name.

%exit [reason]

The tmux client is exiting immediately, either because it is not attached to any session or an error occurred. If present, reason describes why the client exited.

%layout-change window-id window-layout window-visible-layout window-flags

The layout of a window with ID window-id changed. The new layout is window-layout. The window's visible layout is window-visible-layout and the window flags are window-flags.

%output pane-id value

A window pane produced output. value escapes non-printable characters and backslash as octal \xxx.

%pane-mode-changed pane-id

The pane with ID pane-id has changed mode.

%session-changed session-id name

The client is now attached to the session with ID session-id, which is named name.

%session-renamed name

The current session was renamed to name.

%session-window-changed session-id window-id

The session with ID session-id changed its active window to the window with ID window-id.

%sessions-changed

A session was created or destroyed.

%unlinked-window-add window-id

The window with ID window-id was created but is not linked to the current session.

%window-add window-id

The window with ID window-id was linked to the current session.

%window-close window-id

The window with ID window-id closed.

%window-pane-changed window-id pane-id

The active pane in the window with ID window-id changed to the pane with ID pane-id.

%window-renamed window-id name

The window with ID window-id was renamed to name.

Files

~/.tmux.conf

Default tmux configuration file.

/etc/tmux.conf

System-wide configuration file.

Examples

To create a new tmux session running vi(1):

$ tmux new-session vi

Most commands have a shorter form, known as an alias. For new-session, this is new:

$ tmux new vi

Alternatively, the shortest unambiguous form of a command is accepted. If there are several options, they are listed:

$ tmux n 
ambiguous command: n, could be: new-session, new-window, next-window

Within an active session, a new window may be created by typing ‘C-b c’ (Ctrl followed by the ‘b’ key followed by the ‘c’ key).

Windows may be navigated with: ‘C-b 0’ (to select window 0), ‘C-b 1’ (to select window 1), and so on; ‘C-b n’ to select the next window; and ‘C-b p’ to select the previous window.

A session may be detached using ‘C-b d’ (or by an external event such as ssh(1) disconnection) and reattached with:

$ tmux attach-session

Typing ‘C-b ?’ lists the current key bindings in the current window; up and down may be used to navigate the list or ‘q’ to exit from it.

Commands to be run when the tmux server is started may be placed in the ~/.tmux.conf configuration file. Common examples include:

Changing the default prefix key:

set-option -g prefix C-a 
unbind-key C-b 
bind-key C-a send-prefix

Turning the status line off, or changing its colour:

set-option -g status off 
set-option -g status-style bg=blue

Setting other options, such as the default command, or locking after 30 minutes of inactivity:

set-option -g default-command "exec /bin/ksh" 
set-option -g lock-after-time 1800

Creating new key bindings:

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'"

See Also

pty(4)

Authors

Nicholas Marriott <nicholas.marriott@gmail.com>

Referenced By

abduco(1), byobu(1), byobu-keybindings(1), byobu-layout(1), byobu-select-backend(1), byobu-tmux(1), logind.conf(5), pty(7), qtermy(1), termy-server(1).

The man page tmate(1) is an alias of tmux(1).