tmux

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:

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.

-8

Like -2, but indicates that the terminal supports 88 colours.

-C

Start in control mode. 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 /tmp (or TMPDIR if set); 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.

-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.

-q

Set the quiet server option to prevent the server sending various informational messages.

-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

tmux attempts to guess if the terminal is likely to support UTF-8 by checking the first of the LC_ALL, LC_CTYPE and LANG environment variables to be set for the string "UTF-8". This is not always correct: the -u flag explicitly informs tmux that UTF-8 is supported.

If the server is started from a client passed -u or where UTF-8 is detected, the utf8 and status-utf8 options are enabled in the global window and session options respectively.

-v

Request verbose logging. This option may be specified multiple times for increasing verbosity. 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.

-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.

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.

This section contains a list of the commands supported by tmux. Most commands accept the optional -t 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 is the name of 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, the current client is chosen, if possible, or an error is reported. Clients may be listed with the list-clients command.

target-session is the session id prefixed with a $, the name of a session (as listed by the list-sessions command), or the name of a client with the same syntax as target-client, in which case the session attached to the client is used. When looking for the session name, tmux initially searches for an exact match; if none is found, the session names are checked for any for which target-session is a prefix or for which it matches as an 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.

target-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 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 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 new-window and link-window commands) otherwise the current window in session is chosen. The special character ‘!’ uses the last (previously current) window, ‘^’ selects the highest numbered window, ‘$’ selects the lowest numbered window, and ‘+’ and ‘-’ select the next window or the previous window by number. When the argument does not contain a colon, tmux first attempts to parse it as window; if that fails, an attempt is made to match a session.

target-pane takes a similar form to 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, tmux first attempts to use the argument as a pane index; if that fails, it is looked up as for target-window. A ‘+’ or ‘-’ indicate the next or previous pane index, respectively. One of the strings top, bottom, left, right, top-left, top-right, bottom-left or bottom-right may be used instead of a pane index.

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

select-window -t:+2

When dealing with a session that doesn't contain sequential window indexes, they will be correctly skipped.

tmux also gives each pane created in a server an identifier consisting of a ‘%’ and a number, starting from zero. A pane's identifier is unique for the life of the tmux server and is passed to the child process of the pane in the TMUX_PANE environment variable. It may be used alone to target a pane or the window containing it.

shell-command arguments are sh(1) commands. These must be passed as a single item, which typically means quoting them, for example:

new-window 'vi /etc/passwd'

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

bind-key F1 set-window-option force-width 81

Or if using sh(1):

$ tmux bind-key F1 set-window-option force-width 81

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

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 [-dr] [-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.

detach-client [-P] [-a] [-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.

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

[-a] [-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.

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

(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 [-AdDP] [-F format] [-n window-name] [-s session-name] [-t target-session] [-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. If -d is used, -x and -y specify the size of the initial window (80 by 24 if not given).

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 the case, -D behaves like -d to attach-session.

If -t is given, the new session is grouped with target-session. This means they share the same set of windows - all windows from 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 -n or 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.

refresh-client [-S] [-t target-client]

(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 bar.

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

(alias: rename

) Rename the session to new-name.

show-messages [-t target-client]

(alias: showmsgs

) Any messages displayed on the status line are saved in a per-client message log, up to a maximum of the limit set by the message-limit session option for the session attached to that client. This command displays the log for target-client.

source-file path

(alias: source

) Execute commands from path.

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 [-lnpr] [-c target-client] [-t target-session]

(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).

A tmux 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 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.

The keys available depend on whether emacs or vi mode is selected (see the mode-keys option). The following keys are supported as appropriate for the mode:

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. For example, to move the cursor forward by ten words, use ‘M-1 0 M-f’ in emacs mode, and ‘10w’ in vi.

When copying the selection, the repeat count indicates the buffer index to replace, if used.

Mode key bindings are defined in a set of named tables: vi-edit and emacs-edit for keys used when line editing at the command prompt; vi-choice and emacs-choice for keys used when choosing from lists (such as produced by the choose-window command); and vi-copy and emacs-copy used in copy mode. The tables may be viewed with the list-keys command and keys modified or removed with bind-key and unbind-key. One command accepts an argument, copy-pipe, which copies the selection and pipes it to a command. For example the following will bind ‘C-q’ to copy the selection into /tmp as well as the paste buffer:

bind-key -temacs-copy C-q copy-pipe "cat >/tmp/out"

The paste buffer key pastes the first line from the top paste buffer on the stack.

The synopsis for the copy-mode command is:

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

Enter copy mode. The -u option scrolls one page up.

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] [-t target-pane]

(alias: breakp

) Break target-pane off from its containing window to make it the only pane in a new 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 [-aepPq] [-b buffer-index] [-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. The default is to capture only the visible contents of the pane.

choose-client [-F format] [-t target-window] [template]

Put a window into client choice mode, allowing a client to be selected interactively from a list. After a client is chosen, ‘%%’ is replaced by the client pty(4) path in template and the result executed as a command. If template is not given, "detach-client -t '%%'" is used. For the meaning of the -F flag, see the FORMATS section. This command works only if at least one client is attached.

choose-list [-l items] [-t target-window] [template]

Put a window into list choice mode, allowing items to be selected. items can be a comma-separated list to display more than one item. If an item has spaces, that entry must be quoted. After an item is chosen, ‘%%’ is replaced by the chosen item in the template and the result is executed as a command. If template is not given, "run-shell '%%'" is used. items also accepts format specifiers. For the meaning of this see the FORMATS section. This command works only if at least one client is attached.

choose-session [-F format] [-t target-window] [template]

Put a window into session choice mode, where a session may be selected interactively from a list. When one is chosen, ‘%%’ is replaced by the session name in template and the result executed as a command. If template is not given, "switch-client -t '%%'" is used. For the meaning of the -F flag, see the FORMATS section. This command works only if at least one client is attached.

choose-tree [-suw] [-b session-template] [-c window-template] [-S format] [-W format] [-t target-window]

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.

Note that the choose-window and choose-session commands are wrappers around choose-tree.

If -s is given, will show sessions. If -w is given, will show windows.

By default, the tree is collapsed and sessions must be expanded to windows with the right arrow key. The -u option will start with all sessions expanded instead.

If -b is given, will override the default session command. Note that ‘%%’ can be used and will be replaced with the session name. The default option if not specified is "switch-client -t '%%'". If -c is given, will override the default window command. Like -b, ‘%%’ 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.

If -S is given will display the specified format instead of the default session format. If -W is given will display the specified format instead of the default window format. For the meaning of the -s and -w options, see the FORMATS section.

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

choose-window [-F format] [-t target-window] [template]

Put a window into window choice mode, where a window may be chosen interactively from a list. After a window is selected, ‘%%’ is replaced by the session name and window index in template and the result executed as a command. If template is not given, "select-window -t '%%'" is used. For the meaning of the -F flag, see the FORMATS section. This command works only if at least one client is attached.

display-panes [-t target-client]

(alias: displayp)

Display a visible indicator of each pane shown by target-client. See the display-panes-time, display-panes-colour, and display-panes-active-colour session options. While the indicator is on screen, a pane may be selected with the ‘0’ to ‘9’ keys.

find-window [-CNT] [-F format] [-t target-window] 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. If only one window is matched, it'll be automatically selected, otherwise a choice list is shown. For the meaning of the -F flag, see the FORMATS section. 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.

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 [-t target-window]

(alias: lastp

) Select the last (previously selected) 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 [-dk] [-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. 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 [-rdk] [-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. It may have an absolute path or one of the following values (or a subdirectory):

Empty string	Current pane's directory
~	User's home directory
-	Where session was started
.	Where server was started

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” 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 [-o] [-t target-pane] [shell-command]

(alias: pipep

) Pipe any output sent by the program in target-pane to a shell command. A pane may only be piped 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.

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 [-DLRUZ] [-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).

respawn-pane [-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.

respawn-window [-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.

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 [-np] [-t target-window] [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.

select-pane [-lDLRU] [-t target-pane]

(alias: selectp

) Make pane target-pane the active pane in window target-window. 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.

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 [-dhvP] [-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. 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.

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.

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.

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 F20, 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 [-cnr] [-t key-table] key command [arguments]

(alias: bind

) Bind key key to command. By default (without -t) the primary key bindings are modified (those normally activated with the prefix key); in this case, if -n is specified, it is not necessary to use the prefix key, command is bound to key alone. The -r flag indicates this key may repeat, see the repeat-time option.

If -t is present, key is bound in key-table: the binding for command mode with -c or for normal mode without. 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 the primary key bindings - those executed when preceded by the prefix key - are printed.

With -t, the key bindings in key-table are listed; this may be one of: vi-edit, emacs-edit, vi-choice, emacs-choice, vi-copy or emacs-copy.

send-keys [-lR] [-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.

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 [-acn] [-t key-table] key

(alias: unbind

) Unbind the command bound to key. Without -t the primary key bindings are modified; in this case, if -n is specified, the command bound to key without a prefix (if any) is removed. If -a is present, all key bindings are removed.

If -t is present, key in key-table is unbound: the binding for command mode with -c or for normal mode without.

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 [-agoqsuw] [-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 specified, the global session or window option is set. With -a, and if the option expects a string, value is appended to the existing setting. The -u flag unsets an option, so a session inherits the option from the global options. It is not possible to unset a global option.

The -o flag prevents setting an option that is already set.

The -q flag suppresses the informational message (as if the quiet server option was set).

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.

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-unattached [on | off]

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

quiet [on | off]

Enable or disable the display of various informational messages (see also the -q command line flag).

set-clipboard [on | off]

Attempt to set the terminal clipboard content using the \e]52;...\007 xterm(1) escape sequences. This option is on by default if there is an Ms entry in the terminfo(5) description for the client terminal. 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.

Available session options are:

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]

Set action on window bell. any means a bell in any window linked to a session causes a bell in the current window of that session, none means all bells are ignored and current means only bells in windows other than the current window are ignored.

bell-on-alert [on | off]

If on, ring the terminal bell when an alert occurs.

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-path path

Set the default working directory for new panes. If empty (the default), the working directory is determined from the process running in the active pane, from the command line environment or from the working directory where the session was created. Otherwise the same options are available as for the -c flag to new-window.

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-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’ or a derivative of it.

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. 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.

lock-after-time number

Lock the session (like the lock-session command) after number seconds of inactivity, or the entire server (all sessions) if the lock-server option is set. 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.

lock-server [on | off]

If this option is on (the default), instead of each session locking individually as each has been idle for lock-after-time, the entire server will lock after all sessions would have locked. This has no effect as a session option; it must be set as a global option.

message-attr attributes

Set status line message attributes, where attributes is either none or a comma-delimited list of one or more of: bright (or bold), dim, underscore, blink, reverse, hidden, or italics.

message-bg colour

Set status line message background colour, where colour is one of: black, red, green, yellow, blue, magenta, cyan, white, aixterm bright variants (if supported: brightred, brightgreen, and so on), colour0 to colour255 from the 256-colour set, default, or a hexadecimal RGB string such as ‘#ffffff’, which chooses the closest match from the default 256-colour set.

message-command-attr attributes

Set status line message attributes when in command mode.

message-command-bg colour

Set status line message background colour when in command mode.

message-command-fg colour

Set status line message foreground colour when in command mode.

message-fg colour

Set status line message foreground colour.

message-limit number

Set the number of error or information messages to save in the message log for each client. The default is 20.

mouse-resize-pane [on | off]

If on, tmux captures the mouse and allows panes to be resized by dragging on their borders.

mouse-select-pane [on | off]

If on, tmux 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.

mouse-select-window [on | off]

If on, clicking the mouse on a window name in the status line will select that window.

mouse-utf8 [on | off]

If enabled, request mouse input as UTF-8 on UTF-8 terminals.

pane-active-border-bg colour

 

pane-active-border-fg colour

Set the pane border colour for the currently active pane.

pane-border-bg colour

 

pane-border-fg colour

Set the pane border colour for panes aside from the active pane.

prefix key

Set the key accepted as a prefix key.

prefix2 key

Set a secondary key accepted as a prefix key.

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-remain-on-exit [on | off]

Set the 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 respawn-window command to reactivate such a window, or the kill-window command to destroy it.

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]2;...\007 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.

set-titles-string string

String used to set the window title if set-titles is on. Character sequences are replaced as for the status-left option.

status [on | off]

Show or hide the status line.

status-attr attributes

Set status line attributes.

status-bg colour

Set status line background colour.

status-fg colour

Set status line foreground colour.

status-interval interval

Update the status bar 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 to the left of the status bar. string will be passed through strftime(3) before being used. By default, the session name is shown. string may contain any of the following special character sequences:

Character pair	Replaced with
#(shell-command)	First line of the command's output
#[attributes]	Colour or attribute change
#H	Hostname of local host
#h	Hostname of local host without the domain name
#F	Current window flag
#I	Current window index
#D	Current pane unique identifier
#P	Current pane index
#S	Session name
#T	Current pane title
#W	Current window name
##	A literal ‘#’

The #(shell-command) form executes ‘shell-command’ and inserts the first line of its output. Note that shell commands are only executed once at the interval specified by the status-interval option: if the status line is redrawn in the meantime, the previous result is used. Shell commands are executed with the tmux global environment set (see the ENVIRONMENT section).

For details on how the names and titles can be set see the NAMES AND TITLES section.

#[attributes] allows a comma-separated list of attributes to be specified, these may be ‘fg=colour’ to set the foreground colour, ‘bg=colour’ to set the background colour, the name of one of the attributes (listed under the message-attr option) to turn an attribute on, or an attribute prefixed with ‘no’ to turn one off, for example nobright. Examples are:

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

Where appropriate, special character sequences may be prefixed with a number to specify the maximum length, for example ‘#24T’.

By default, UTF-8 in string is not interpreted, to enable UTF-8, use the status-utf8 option.

status-left-attr attributes

Set the attribute of the left part of the status line.

status-left-bg colour

Set the background colour of the left part of the status line.

status-left-fg colour

Set the foreground colour of the left part of the status line.

status-left-length length

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

status-position [top | bottom]

Set the position of the status line.

status-right string

Display 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 status-left, string will be passed to strftime(3), character pairs are replaced, and UTF-8 is dependent on the status-utf8 option.

status-right-attr attributes

Set the attribute of the right part of the status line.

status-right-bg colour

Set the background colour of the right part of the status line.

status-right-fg colour

Set the foreground colour of the right part of the status line.

status-right-length length

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

status-utf8 [on | off]

Instruct tmux to treat top-bit-set characters in the status-left and status-right strings as UTF-8; notably, this is important for wide characters. This option defaults to off.

terminal-overrides string

Contains a list of entries which override terminal descriptions read using terminfo(5). string is a comma-separated list of items each 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 and the ‘dch1’ entry to ‘\e[P’ for the ‘rxvt’ terminal type, the option could be set to the string:

"*:clear=\e[H\e[2J,rxvt:dch1=\e[P"

The terminal entry value is passed through strunvis(3) before interpretation. The default value forcibly corrects the ‘colors’ entry for terminals which support 88 or 256 colours:

"*88col*:colors=88,*256col*:colors=256,xterm*:XT"

update-environment 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 -r was given to the set-environment command). The default is "DISPLAY SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION WINDOWID XAUTHORITY".

visual-activity [on | off]

If on, display a status line message when activity occurs in a window for which the monitor-activity window option is enabled.

visual-bell [on | off]

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 bell-action option.

visual-content [on | off]

Like visual-activity, display a message when content is present in a window for which the monitor-content window option is enabled.

visual-silence [on | off]

If monitor-silence is enabled, prints a message after the interval has expired on a given window.

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 [-agqu] [-t target-window] option value

(alias: setw

) Set a window option. The -a, -g, -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 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 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 (\033k...\033\\). The default is on.

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 attempt - on supported platforms - to rename the window to reflect the command currently running in it. This flag is automatically disabled for an individual window when a name is specified at creation with 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

c0-change-interval interval

 

c0-change-trigger trigger

These two options configure a simple form of rate limiting for a pane. If tmux sees more than 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 interval milliseconds. This helps to prevent fast output (such as 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.

clock-mode-colour colour

Set clock colour.

clock-mode-style [12 | 24]

Set clock hour format.

force-height height

 

force-width width

Prevent tmux from resizing a window to greater than width or height. A value of zero restores the default unlimited setting.

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-attr attributes

Set window modes attributes.

mode-bg colour

Set window modes background colour.

mode-fg colour

Set window modes foreground colour.

mode-keys [vi | emacs]

Use vi or emacs-style key bindings in copy and choice modes. As with the status-keys option, the default is emacs, unless VISUAL or EDITOR contains ‘vi’.

mode-mouse [on | off | copy-mode]

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 copy-mode, the mouse behaves as set to on, but cannot be used to enter copy mode.

monitor-activity [on | off]

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

monitor-content match-string

Monitor content in the window. When fnmatch(3) pattern match-string appears in the window, it is 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-base-index index

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

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).

utf8 [on | off]

Instructs tmux to expect UTF-8 sequences to appear in this window.

window-status-bell-attr attributes

Set status line attributes for windows which have a bell alert.

window-status-bell-bg colour

Set status line background colour for windows with a bell alert.

window-status-bell-fg colour

Set status line foreground colour for windows with a bell alert.

window-status-content-attr attributes

Set status line attributes for windows which have a content alert.

window-status-content-bg colour

Set status line background colour for windows with a content alert.

window-status-content-fg colour

Set status line foreground colour for windows with a content alert.

window-status-activity-attr attributes

Set status line attributes for windows which have an activity (or silence) alert.

window-status-activity-bg colour

Set status line background colour for windows with an activity alert.

window-status-activity-fg colour

Set status line foreground colour for windows with an activity alert.

window-status-attr attributes

Set status line attributes for a single window.

window-status-bg colour

Set status line background colour for a single window.

window-status-current-attr attributes

Set status line attributes for the currently active window.

window-status-current-bg colour

Set status line background colour for the currently active window.

window-status-current-fg colour

Set status line foreground colour for the currently active window.

window-status-current-format string

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

window-status-last-attr attributes

Set status line attributes for the last active window.

window-status-last-bg colour

Set status line background colour for the last active window.

window-status-last-fg colour

Set status line foreground colour for the last active window.

window-status-fg colour

Set status line foreground colour for a single window.

window-status-format string

Set the format in which the window is displayed in the status line window list. See the status-left option for details of special character sequences available. The default is ‘#I:#W#F’.

window-status-separator string

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

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. The default is off.

wrap-search [on | off]

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

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.

Certain commands accept the -F flag with a format argument. This is a string which controls the output format of the command. Special character sequences are replaced as documented under the status-left option and an additional long form is accepted. Replacement variables are enclosed in ‘#{’ and ‘}’, for example ‘#{session_name}’ is equivalent to ‘#S’. Conditionals are also accepted 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.

The following variables are available, where appropriate:

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 and is not modified by tmux. It is the same mechanism used to set for example the xterm(1) window title in an X(7) window manager. 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:

   $ 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 OSC title setting sequence, for example:

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

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 [-g] [-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 ‘-’.

tmux 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 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.

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 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 and + to the monitor-content window options. The window name is printed in inverted colours if an alert (bell, activity or content) is present.

The colour and attributes of the status line may be configured, the entire status line using the status-attr, status-fg and status-bg session options and individual windows using the window-status-attr, window-status-fg and window-status-bg window options.

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 [-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.

Both inputs and prompts may contain the special character sequences supported by the status-left option.

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, the second ‘%%’ and 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’).

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 [-p] [-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.

tmux maintains a stack of paste buffers. Up to the value of the buffer-limit option are kept; when a new buffer is added, the buffer at the bottom of the stack is removed. Buffers may be added using copy-mode or the set-buffer command, and pasted into a window using the paste-buffer command.

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 [-F format] [-t target-window] [template]

Put a window into buffer choice mode, where a buffer may be chosen interactively from a list. After a buffer is selected, ‘%%’ is replaced by the buffer index in template and the result executed as a command. If template is not given, "paste-buffer -b '%%'" is used. For the meaning of the -F flag, see the FORMATS section. 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-index]

(alias: deleteb

) Delete the buffer at buffer-index, or the top 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-index] path

(alias: loadb

) Load the contents of the specified paste buffer from path.

paste-buffer [-dpr] [-b buffer-index] [-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 from the stack. 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-index] 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 [-b buffer-index] data

(alias: setb

) Set the contents of the specified buffer to data.

show-buffer [-b buffer-index]

(alias: showb

) Display the contents of the specified buffer.

Miscellaneous commands are as follows:

clock-mode [-t target-pane]

Display a large clock.

if-shell [-b] [-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.

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.

server-info

(alias: info

) Show server information and terminal details.

wait-for -LSU 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. This command only works from outside tmux.

tmux understands some extensions to terminfo(5):

Cc, 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\\'

Cs, Csr

Change 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 Csr is set, it will be used to reset the cursor style instead of Cs.

Ms

This sequence can be used by tmux to store the current buffer in the host terminal's selection (clipboard). See the set-clipboard option above and the xterm(1) man page.

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

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

The following notifications are defined:

%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

The layout of a window with ID window-id changed. The new layout is window-layout.

%output pane-id value

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

%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.

%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-renamed window-id name

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

~/.tmux.conf

Default tmux configuration file.

/etc/tmux.conf

System-wide configuration file.

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

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

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:

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-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'"

pty(4)

Nicholas Marriott ⟨nicm@users.sourceforge.net⟩