# TMUX(1) - man - phpman [TMUX(1)](https://www.chedong.com/phpMan.php/man/TMUX/1/markdown) BSD General Commands Manual [TMUX(1)](https://www.chedong.com/phpMan.php/man/TMUX/1/markdown) ## NAME **tmux** — terminal multiplexer ## SYNOPSIS **tmux** [**-2CDluvV**] [**-c** _shell-command_] [**-f** _file_] [**-L** _socket-name_] [**-S** _socket-path_] [**-T** _features_] [_command_ [_flags_]] ## 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 ses‐ sion 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)](https://www.chedong.com/phpMan.php/man/pty/4/markdown) 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)](https://www.chedong.com/phpMan.php/man/ssh/1/markdown) connection timeout) or intentional detaching (with the ‘C-b d’ key strokes). **tmux** may be reattached us‐ ing: $ 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 -T _256_. ### -C -CC echo. ### -c 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 compat‐ ibility with [sh(1)](https://www.chedong.com/phpMan.php/man/sh/1/markdown) when **tmux** is used as a login shell. ### -D off. With **-D**, _command_ may not be specified. ### -f configuration file from _/etc/tmux.conf_, if present, then looks for a user config‐ uration 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 **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 a direc‐ tory _tmux-UID_ under the directory given by TMUX_TMPDIR or in _/tmp_. The _tmux-UID_ directory is created by **tmux** and must not be world readable, writable or exe‐ cutable. 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 bility with other shells when using tmux as a login shell. ### -N **new-session** or **start-server**). ### -S 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 LC_ALL, LC_CTYPE, or LANG that is set does not contain "UTF-8" or "UTF8". This is equivalent to **-T** _UTF-8_. ### -T tures. See the **terminal-features** option. ### -v _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 be‐ tween on (as if **-v** was given) and off. ### -V _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 as‐ sumed. ## 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: C-b Send the prefix key (C-b) through to the application. C-o Rotate the panes in the current window forwards. C-z Suspend the **tmux** client. ! Break the current pane out of the window. " Split the current pane into two, top and bottom. # List all paste buffers. $ Rename the current session. % Split the current pane into two, left and right. & Kill the current window. ' Prompt for a window index to select. ( Switch the attached client to the previous session. ) Switch the attached client to the next session. , Rename the current window. - Delete the most recently copied buffer of text. . Prompt for an index to move the current window. 0 to 9 Select windows 0 to 9. : Enter the **tmux** command prompt. ; Move to the previously active pane. = Choose which buffer to paste interactively from a list. ? List all key bindings. D Choose a client to detach. L Switch the attached client back to the last session. [ Enter copy mode to copy text or view the history. ] Paste the most recently copied buffer of text. c Create a new window. d Detach the current client. f Prompt to search for text in open windows. i Display some information about the current window. l Move to the previously selected window. m Mark the current pane (see **select-pane** **-m**). M Clear the marked pane. n Change to the next window. o Select the next pane in the current window. p Change to the previous window. q Briefly display pane indexes. r Force redraw of the attached client. s Select a new session for the attached client interactively. t Show the time. w Choose the current window interactively. x Kill the current pane. z Toggle zoom state of the current pane. { Swap the current pane with the previous pane. } Swap the current pane with the next pane. ~ Show previous messages from **tmux**, if any. Page Up Enter copy mode and scroll one page up. Up, Down Left, Right Change to the pane above, below, to the left, or to the right of the current pane. M-1 to M-5 Arrange panes in one of the five preset layouts: even-horizontal, even-verti‐ cal, main-horizontal, main-vertical, or tiled. Space Arrange the current window in the next preset layout. M-n Move to the next window with a bell or activity marker. M-o Rotate the panes in the current window backwards. M-p Move to the previous window with a bell or activity marker. C-Up, C-Down C-Left, C-Right Resize the current pane in steps of one cell. M-Up, M-Down M-Left, M-Right Resize the current pane in steps of five cells. Key bindings may be changed with the **bind-key** and **unbind-key** commands. ## COMMAND PARSING AND EXECUTION **tmux** supports a large number of commands which can be used to control its behaviour. Each com‐ mand is named and can accept zero or more flags and arguments. They may be bound to a key with the **bind-key** command or run from the shell prompt, a shell script, a configuration file or the command prompt. For example, the same **set-option** command run from the shell prompt, from _~/.tmux.conf_ and bound to a key may look like: $ tmux set-option -g status-style bg=cyan set-option -g status-style bg=cyan bind-key C set-option -g status-style bg=cyan Here, the command name is ‘set-option’, ‘**-g**’ is a flag and ‘status-style’ and ‘bg=cyan’ are ar‐ guments. **tmux** distinguishes between command parsing and execution. In order to execute a command, **tmux** needs it to be split up into its name and arguments. This is command parsing. If a command is run from the shell, the shell parses it; from inside **tmux** or from a configuration file, **tmux** does. Examples of when **tmux** parses commands are: **-** in a configuration file; **-** typed at the command prompt (see **command-prompt**); **-** given to **bind-key**; **-** passed as arguments to **if-shell** or **confirm-before**. To execute commands, each client has a ‘command queue’. A global command queue not attached to any client is used on startup for configuration files like _~/.tmux.conf_. Parsed commands added to the queue are executed in order. Some commands, like **if-shell** and **confirm-before**, parse their argument to create a new command which is inserted immediately after themselves. This means that arguments can be parsed twice or more - once when the parent command (such as **if-shell**) is parsed and again when it parses and executes its command. Commands like **if-shell**, **run-shell** and **display-panes** stop execution of subsequent commands on the queue until something happens - **if-shell** and **run-shell** until a shell command finishes and **display-panes** until a key is pressed. For example, the following commands: new-session; new-window if-shell "true" "split-window" kill-session Will execute **new-session**, **new-window**, **if-shell**, the shell command [true(1)](https://www.chedong.com/phpMan.php/man/true/1/markdown), **split-window** and **kill-session** in that order. The _COMMANDS_ section lists the **tmux** commands and their arguments. ## PARSING SYNTAX This section describes the syntax of commands parsed by **tmux**, for example in a configuration file or at the command prompt. Note that when commands are entered into the shell, they are parsed by the shell - see for example [ksh(1)](https://www.chedong.com/phpMan.php/man/ksh/1/markdown) or [csh(1)](https://www.chedong.com/phpMan.php/man/csh/1/markdown). Each command is terminated by a newline or a semicolon (;). Commands separated by semicolons together form a ‘command sequence’ - if a command in the sequence encounters an error, no sub‐ sequent commands are executed. It is recommended that a semicolon used as a command separator should be written as an individ‐ ual token, for example from [sh(1)](https://www.chedong.com/phpMan.php/man/sh/1/markdown): $ tmux neww \; splitw Or: $ tmux neww ';' splitw Or from the tmux command prompt: neww ; splitw However, a trailing semicolon is also interpreted as a command separator, for example in these [sh(1)](https://www.chedong.com/phpMan.php/man/sh/1/markdown) commands: $ tmux neww\\; splitw Or: $ tmux 'neww;' splitw As in these examples, when running tmux from the shell extra care must be taken to properly quote semicolons: 1. Semicolons that should be interpreted as a command separator should be escaped ac‐ cording to the shell conventions. For [sh(1)](https://www.chedong.com/phpMan.php/man/sh/1/markdown) this typically means quoted (such as ‘neww ';' splitw’) or escaped (such as ‘neww \\\\; splitw’). 2. Individual semicolons or trailing semicolons that should be interpreted as arguments should be escaped twice: once according to the shell conventions and a second time for **tmux**; for example: $ tmux neww 'foo\\;' bar $ tmux neww foo\\\\; bar 3. Semicolons that are not individual tokens or trailing another token should only be escaped once according to shell conventions; for example: $ tmux neww 'foo-;-bar' $ tmux neww foo-\\;-bar Comments are marked by the unquoted # character - any remaining text after a comment is ignored until the end of the line. If the last character of a line is \, the line is joined with the following line (the \ and the newline are completely removed). This is called line continuation and applies both inside and outside quoted strings and in comments, but not inside braces. Command arguments may be specified as strings surrounded by single (') quotes, double quotes (") or braces ({}). This is required when the argument contains any special character. Single and double quoted strings cannot span multiple lines except with line continuation. Braces can span multiple lines. Outside of quotes and inside double quotes, these replacements are performed: **-** Environment variables preceded by $ are replaced with their value from the global en‐ vironment (see the _GLOBAL_ _AND_ _SESSION_ _ENVIRONMENT_ section). **-** A leading ~ or ~user is expanded to the home directory of the current or specified user. **-** \uXXXX or \uXXXXXXXX is replaced by the Unicode codepoint corresponding to the given four or eight digit hexadecimal number. **-** When preceded (escaped) by a \, the following characters are replaced: \e by the es‐ cape character; \r by a carriage return; \n by a newline; and \t by a tab. **-** \ooo is replaced by a character of the octal value ooo. Three octal digits are re‐ quired, for example \001. The largest valid character is \377. **-** Any other characters preceded by \ are replaced by themselves (that is, the \ is re‐ moved) and are not treated as having any special meaning - so for example \; will not mark a command sequence and \$ will not expand an environment variable. Braces are parsed as a configuration file (so conditions such as ‘%if’ are processed) and then converted into a string. They are designed to avoid the need for additional escaping when passing a group of **tmux** commands as an argument (for example to **if-shell**). These two examples produce an identical command - note that no escaping is needed when using {}: if-shell true { display -p 'brace-dollar-foo: }$foo' } if-shell true "display -p 'brace-dollar-foo: }\$foo'" Braces may be enclosed inside braces, for example: bind x if-shell "true" { if-shell "true" { display "true!" } } Environment variables may be set by using the syntax ‘name=value’, for example ‘HOME=/home/user’. Variables set during parsing are added to the global environment. A hidden variable may be set with ‘%hidden’, for example: %hidden MYVAR=42 Hidden variables are not passed to the environment of processes created by tmux. See the _GLOBAL_ _AND_ _SESSION_ _ENVIRONMENT_ section. Commands may be parsed conditionally by surrounding them with ‘%if’, ‘%elif’, ‘%else’ and ‘%endif’. The argument to ‘%if’ and ‘%elif’ is expanded as a format (see _FORMATS_) and if it evaluates to false (zero or empty), subsequent text is ignored until the closing ‘%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. Conditionals may be given on one line, for example: %if #{==:#{host},myhost} set -g status-style bg=red %endif ## COMMANDS This section describes 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)](https://www.chedong.com/phpMan.php/man/pty/4/markdown) 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)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown) 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 er‐ ror. 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)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown) 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) other‐ wise the current window in _session_ is chosen. The following special tokens are available to indicate particular windows. Each has a single- character alternative form. ### Token Meaning {start} ^ The lowest-numbered window {end} $ The highest-numbered window {last} ! The last (previously current) window {next} + The next window by number {previous} - The previous window by number _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 speci‐ fied window is used. The following special tokens are available for the pane index: ### Token Meaning {last} ! The last (previously active) pane {next} + The next pane by number {previous} - The previous pane by number {top} The top pane {bottom} The bottom pane {left} The leftmost pane {right} The rightmost pane {top-left} The top-left pane {top-right} The top-right pane {bottom-left} The bottom-left pane {bottom-right} The bottom-right pane {up-of} The pane above the active pane {down-of} The pane below the active pane {left-of} The pane to the left of the active pane {right-of} The pane to the right of the active pane 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 session, window or pane where the most recent mouse event occurred (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)](https://www.chedong.com/phpMan.php/man/sh/1/markdown) commands. This may be a single argument passed to the shell, for example: new-window 'vi ~/.tmux.conf' Will run: /bin/sh -c 'vi ~/.tmux.conf' Additionally, the **new-window**, **new-session**, **split-window**, **respawn-window** and **respawn-pane** com‐ mands 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 ~/.tmux.conf Will run [vi(1)](https://www.chedong.com/phpMan.php/man/vi/1/markdown) directly without invoking the shell. _command_ [_arguments_] refers to a **tmux** command, either passed with the command and arguments sep‐ arately, for example: bind-key F1 set-option status off Or passed as a single string argument in _.tmux.conf_, for example: bind-key F1 { set-option status off } Example **tmux** commands include: refresh-client -t/dev/ttyp2 rename-session -tfirst newname set-option -wt: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)](https://www.chedong.com/phpMan.php/man/sh/1/markdown): $ tmux kill-window -t :1 $ tmux new-window \; split-window -d $ tmux new-session -d 'vi ~/.tmux.conf' \; 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** [**-dErx**] [**-c** _working-directory_] [**-f** _flags_] [**-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. If **-x** is given, send SIGHUP to the parent process of the client as well as detaching the client, typically causing it to exit. **-f** sets a comma-separated list of client flags. The flags are: active-pane the client has an independent active pane ignore-size the client does not affect the size of other clients no-output the client does not receive pane output in control mode pause-after=seconds output is paused once the pane is _seconds_ behind in control mode read-only the client is read-only wait-exit wait for an empty line input before exiting in control mode A leading ‘!’ turns a flag off if the client is already attached. **-r** is an alias for **-f** _read-only,ignore-size_. When a client is read-only, only keys bound to the **detach-client** or **switch-client** commands have any effect. A client with the _active-pane_ flag allows the active pane to be selected independently of the window's active pane used by clients without the flag. This only affects the cursor position and commands issued from the client; other features such as hooks and styles continue to use the window's active pane. 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 se‐ lect 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_] [_command_] (alias: **lscm**) List the syntax of _command_ or - if omitted - of all commands supported by **tmux**. **list-sessions** [**-F** _format_] [**-f** _filter_] (alias: **ls**) List all sessions managed by the server. **-F** specifies the format of each line and **-f** a filter. Only sessions for which the filter is true are shown. See the _FORMATS_ sec‐ tion. **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** [**-AdDEPX**] [**-c** _start-directory_] [**-e** _environment_] [**-f** _flags_] [**-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. **-f** sets a comma- separated list of client flags (see **attach-session**). If run from a terminal, any [termios(4)](https://www.chedong.com/phpMan.php/man/termios/4/markdown) 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 ex‐ ists; in this case, **-D** behaves like **-d** to **attach-session**, and **-X** behaves like **-x** 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 win‐ dows 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. **-e** takes the form ‘VARIABLE=value’ and sets an environment variable for the newly created session; it may be specified multiple times. **refresh-client** [**-cDlLRSU**] [**-A** _pane:state_] [**-B** _name:what:format_] [**-C** _XxY_] [**-f** _flags_] [**-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 mode client. **-A** allows a control mode client to trigger actions on a pane. The argument is a pane ID (with leading ‘%’), a colon, then one of ‘on’, ‘off’, ‘continue’ or ‘pause’. If ‘off’, **tmux** will not send output from the pane to the client and if all clients have turned the pane off, will stop reading from the pane. If ‘continue’, **tmux** will return to sending output to the pane if it was paused (manually or with the _pause-after_ flag). If ‘pause’, **tmux** will pause the pane. **-A** may be given multiple times for different panes. **-B** sets a subscription to a format for a control mode client. The argument is split into three items by colons: _name_ is a name for the subscription; _what_ is a type of item to subscribe to; _format_ is the format. After a subscription is added, changes to the format are reported with the **%subscription-changed** notification, at most once a second. If only the name is given, the subscription is removed. _what_ may be empty to check the format only for the attached session, or one of: a pane ID such as ‘%0’; ‘%*’ for all panes in the attached session; a window ID such as ‘@0’; or ‘@*’ for all windows in the attached session. **-f** sets a comma-separated list of client flags, see **attach-session**. **-l** requests the clipboard from the client using the [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) 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 server messages or information. Messages are stored, up to a maximum of the limit set by the _message-limit_ server option. **-J** and **-T** show debugging information about jobs and terminals. **source-file** [**-Fnqv**] _path_ _..._ (alias: **source**) Execute commands from one or more files specified by _path_ (which may be [glob(7)](https://www.chedong.com/phpMan.php/man/glob/7/markdown) pat‐ terns). If **-F** is present, then _path_ is expanded as a format. If **-q** is given, no error will be returned if _path_ does not exist. With **-n**, the file is parsed but no commands are executed. **-v** shows the parsed commands and line numbers if possible. ### start-server (alias: **start**) Start the **tmux** server, if not already running, without creating any sessions. Note that as by default the **tmux** server will exit with no sessions, this is only useful if a session is created in _~/.tmux.conf_, **exit-empty** is turned off, or another command is run as part of the same command sequence. For example: $ tmux start \; show -g **suspend-client** [**-t** _target-client_] (alias: **suspendc**) Suspend a client by sending SIGTSTP (tty stop). **switch-client** [**-ElnprZ**] [**-c** _target-client_] [**-t** _target-session_] [**-T** _key-table_] (alias: **switchc**) Switch the current session for client _target-client_ to _target-session_. As a special case, **-t** may refer to a pane (a target that contains ‘:’, ‘.’ or ‘%’), to change ses‐ sion, window and pane. In that case, **-Z** keeps the window zoomed if it was zoomed. If **-l**, **-n** or **-p** is used, the client is moved to the last, next or previous session respec‐ tively. **-r** toggles the client **read-only** and **ignore-size** flags (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 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. By default, a **tmux** pane permits direct access to the terminal contained in the pane. A pane may also be put into one of several modes: **-** 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. Copied text can be pasted with the **paste-buffer** command, bound to ‘]’. **-** View mode, which is like copy mode but is entered when a command that produces out‐ put, such as **list-keys**, is executed from a key binding. **-** Choose mode, which allows an item to be chosen from a list. This may be a client, a session or window or pane, or a buffer. This mode is entered with the **choose-buffer**, **choose-client** and **choose-tree** commands. In copy mode an indicator is displayed in the top-right corner of the pane with the current po‐ sition and the number of lines in the history. 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** com‐ mand. The following commands are supported in copy mode: **Command** **vi** **emacs** append-selection append-selection-and-cancel A back-to-indentation ^ M-m begin-selection Space C-Space bottom-line L cancel q Escape clear-selection Escape C-g copy-end-of-line [] D C-k copy-line [] copy-pipe [] [] copy-pipe-no-clear [] [] copy-pipe-and-cancel [] [] copy-selection [] copy-selection-no-clear [] copy-selection-and-cancel [] Enter M-w cursor-down j Down cursor-down-and-cancel cursor-left h Left cursor-right l Right cursor-up k Up end-of-line $ C-e goto-line : g halfpage-down C-d M-Down halfpage-down-and-cancel halfpage-up C-u M-Up history-bottom G M-> history-top g M-< jump-again ; ; jump-backward F F jump-forward f f jump-reverse , , jump-to-backward T jump-to-forward t jump-to-mark M-x M-x middle-line M M-r next-matching-bracket % M-C-f next-paragraph } M-} next-space W next-space-end E next-word w next-word-end e M-f other-end o page-down C-f PageDown page-down-and-cancel page-up C-b PageUp pipe [] [] pipe-no-clear [] [] pipe-and-cancel [] [] previous-matching-bracket M-C-b previous-paragraph { M-{ previous-space B previous-word b M-b rectangle-on rectangle-off rectangle-toggle v R refresh-from-pane r r scroll-down C-e C-Down scroll-down-and-cancel scroll-up C-y C-Up search-again n n search-backward ? search-backward-incremental C-r search-backward-text search-forward / search-forward-incremental C-s search-forward-text search-reverse N N select-line V select-word set-mark X X start-of-line 0 C-a stop-selection top-line H M-R The search commands come in several varieties: ‘search-forward’ and ‘search-backward’ search for a regular expression; the ‘-text’ variants search for a plain text string rather than a regular expression; ‘-incremental’ perform an incremental search and expect to be used with the ### -i ‘search-reverse’ does the same but reverses the direction (forward becomes backward and back‐ ward becomes forward). Copy commands may take an optional buffer prefix argument which is used to generate the buffer name (the default is ‘buffer’ so buffers are named ‘buffer0’, ‘buffer1’ and so on). Pipe com‐ mands take a command argument which is the command to which the selected text is piped. ‘copy-pipe’ variants also copy the selection. 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). ‘-no-clear’ variants do not clear the selection. The next and previous word keys use space and the ‘-’, ‘_’ and ‘@’ characters as word delim‐ iters 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 previ‐ ous word to the start of the previous word. The three next and previous space keys work simi‐ larly 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** [**-eHMqu**] [**-s** _src-pane_] [**-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_). **-H** hides the position indi‐ cator in the top right. **-q** cancels copy mode and any other modes. **-s** copies from _src-pane_ instead of _target-pane_. **-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 A number of preset arrangements of panes are available, these are called layouts. These may be selected with the **select-layout** command or cycled with **next-layout** (bound to ‘Space’ by de‐ fault); 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 origi‐ nally defined. Commands related to windows and panes are as follows: **break-pane** [**-abdP**] [**-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_. With **-a** or **-b**, the window is moved to the next index after or before (existing windows are moved if necessary). 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 cre‐ ated. By default, it uses the format ‘#{session_name}:#{window_index}.#{pane_index}’ but a different format may be specified with **-F**. **capture-pane** [**-aepPqCJN**] [**-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 alter‐ nate 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 es‐ cape sequences for text and background attributes. **-C** also escapes non-printable char‐ acters as octal \xxx. **-N** preserves trailing spaces at each line's end and **-J** preserves trailing spaces and joins any wrapped lines. **-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** [**-NrZ**] [**-F** _format_] [**-f** _filter_] [**-K** _key-format_] [**-O** _sort-order_] [**-t** _target-pane_] [_template_] Put a pane into client mode, allowing a client to be selected interactively from a list. Each client is shown on one line. A shortcut key is shown on the left in brack‐ ets allowing for immediate choice, or the list may be navigated and an item chosen or otherwise manipulated using the keys below. **-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 field r Reverse sort order v Toggle preview q Exit mode After a client is chosen, ‘%%’ is replaced by the client name in _template_ and the re‐ sult executed as a command. If _template_ is not given, "detach-client -t '%%'" is used. **-O** specifies the initial sort field: one of ‘name’, ‘size’, ‘creation’, or ‘activity’. **-r** reverses the sort order. **-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 and **-K** a format for each shortcut key; both are evaluated once for each line. **-N** starts without the preview. This command works only if at least one client is attached. **choose-tree** [**-GNrswZ**] [**-F** _format_] [**-f** _filter_] [**-K** _key-format_] [**-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 tree. Each session, window or pane is shown on one line. A shortcut key is shown on the left in brackets allowing for immediate choice, or the tree may be navi‐ gated and an item chosen or otherwise manipulated using the keys below. **-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 + Expand selected item - Collapse selected item M-+ Expand all items M-- Collapse all items x Kill selected item X Kill tagged items < Scroll list of previews left > Scroll list of previews right C-s Search by name m Set the marked pane M Clear the marked pane 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 H Jump to the starting pane O Change sort field r Reverse 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 field: one of ‘index’, ‘name’, or ‘time’. **-r** reverses the sort order. **-f** specifies an initial filter: the filter is a format - if it evalu‐ ates 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 and **-K** a format for each shortcut key; both are evaluated once for each line. **-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 at‐ tached. **customize-mode** [**-NZ**] [**-F** _format_] [**-f** _filter_] [**-t** _target-pane_] [_template_] Put a pane into customize mode, where options and key bindings may be browsed and modi‐ fied from a list. Option values in the list are shown for the active pane in the cur‐ rent window. **-Z** zooms the pane. The following keys may be used in customize mode: **Key** **Function** Enter Set pane, window, session or global option value Up Select previous item Down Select next item + Expand selected item - Collapse selected item M-+ Expand all items M-- Collapse all items s Set option value or key attribute S Set global option value w Set window option value, if option is for pane and window d Set an option or key to the default D Set tagged options and tagged keys to the default u Unset an option (set to default value if global) or unbind a key U Unset tagged options and unbind tagged keys C-s Search by name n Repeat last search t Toggle if item is tagged T Tag no items C-t Tag all items f Enter a format to filter items v Toggle option information q Exit mode **-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 option information. This command works only if at least one client is attached. **display-panes** [**-bN**] [**-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 (unless **-N** is given) 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** [**-iCNrTZ**] [**-t** _target-pane_] _match-string_ (alias: **findw**) Search for a [fnmatch(3)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown) pattern or, with **-r**, regular expression _match-string_ in window names, titles, and visible content (but not history). The flags control matching be‐ havior: **-C** matches only visible window contents, **-N** matches only the window name and **-T** matches only the window title. **-i** makes the search ignore case. The default is **-CNT**. **-Z** zooms the pane. This command works only if at least one client is attached. **join-pane** [**-bdfhv**] [**-l** _size_] [**-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** op‐ tion 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 de‐ stroyed. 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** [**-deZ**] [**-t** _target-window_] (alias: **lastp**) Select the last (previously selected) pane. **-Z** keeps the window zoomed if it was zoomed. **-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, se‐ lect the last window of the current session. **link-window** [**-abdk**] [**-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** or **-b** the window is moved to the next index after or before _dst-window_ (existing windows are moved if nec‐ essary). 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_] [**-f** _filter_] [**-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). **-F** specifies the format of each line and **-f** a filter. Only panes for which the filter is true are shown. See the _FORMATS_ section. **list-windows** [**-a**] [**-F** _format_] [**-f** _filter_] [**-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_. **-F** specifies the format of each line and **-f** a filter. Only windows for which the filter is true are shown. See the _FORMATS_ section. **move-pane** [**-bdfhv**] [**-l** _size_] [**-s** _src-pane_] [**-t** _dst-pane_] (alias: **movep**) Does the same as **join-pane**. **move-window** [**-abrdk**] [**-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** [**-abdkPS**] [**-c** _start-directory_] [**-e** _environment_] [**-F** _format_] [**-n** _window-name_] [**-t** _target-window_] [_shell-command_] (alias: **neww**) Create a new window. With **-a** or **-b**, the new window is inserted at the next index after or before 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 er‐ ror is shown, unless the **-k** flag is used, in which case it is destroyed. If **-S** is given and a window named _window-name_ already exists, it is selected (unless **-d** is also given in which case the command does nothing). _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. **-e** takes the form ‘VARIABLE=value’ and sets an environment variable for the newly cre‐ ated window; it may be specified multiple times. The TERM environment variable must be set to ‘screen’ or ‘tmux’ for all programs run‐ ning _inside_ **tmux**. New windows will automatically have ‘TERM=screen’ added to their en‐ vironment, but care must be taken not to reset this in shell start-up files or by the **-e** option. 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 cur‐ rent 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** [**-DLMRTUZ**] [**-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 columns (the default is 1); **-x** and **-y** may be a given as a number of lines or columns or followed by ‘%’ for a percentage of the window size (for example ‘-x 10%’). With **-Z**, the active pane is toggled between zoomed (occupying the whole of the window) and unzoomed (its normal po‐ sition in the layout). **-M** begins mouse resizing (only valid if bound to a mouse key binding, see _MOUSE_ _SUPPORT_). **-T** trims all lines below the current cursor position and moves lines out of the history to replace them. **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 op‐ tions. **respawn-pane** [**-k**] [**-c** _start-directory_] [**-e** _environment_] [**-t** _target-pane_] [_shell-command_] (alias: **respawnp**) Reactivate a pane in which the command has exited (see the **remain-on-exit** window op‐ tion). If _shell-command_ is not given, the command used when the pane was created or last respawned 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. The **-e** option has the same meaning as for the **new-window** command. **respawn-window** [**-k**] [**-c** _start-directory_] [**-e** _environment_] [**-t** _target-window_] [_shell-command_] (alias: **respawnw**) Reactivate a window in which the command has exited (see the **remain-on-exit** window op‐ tion). If _shell-command_ is not given, the command used when the window was created or last respawned 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. The **-e** option has the same meaning as for the **new-window** command. **rotate-window** [**-DUZ**] [**-t** _target-window_] (alias: **rotatew**) Rotate the positions of the panes within a window, either upward (numerically lower) with **-U** or downward (numerically higher). **-Z** keeps the window zoomed if it was zoomed. **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** [**-DdeLlMmRUZ**] [**-T** _title_] [**-t** _target-pane_] (alias: **selectp**) Make pane _target-pane_ the active pane in its 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. **-Z** keeps the window zoomed if it was zoomed. **-l** is the same as using the **last-pane** command. **-e** enables or **-d** disables input to the pane. **-T** sets the pane ti‐ tle. **-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**, **move-pane**, **swap-pane** and **swap-window**. **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** [**-bdfhIvPZ**] [**-c** _start-directory_] [**-e** _environment_] [**-l** _size_] [**-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 verti‐ cal split; if neither is specified, **-v** is assumed. The **-l** option specifies the size of the new pane in lines (for vertical split) or in columns (for horizontal split); _size_ may be followed by ‘%’ to specify a percentage of the available space. 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. **-Z** zooms if the window is not zoomed, or keeps it zoomed if already zoomed. An empty _shell-command_ ('') will create a pane with no command running in it. Output can be sent to such a pane with the **display-message** command. The **-I** flag (if _shell-command_ is not specified or empty) will create an empty pane and forward any out‐ put from stdin to it. For example: $ make 2>&1|tmux splitw -dI & All other options have the same meaning as for the **new-window** command. **swap-pane** [**-dDUZ**] [**-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 and **-Z** keeps the window zoomed if it was zoomed. 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_. If **-d** is given, the new window does not become the current window. If **-s** is omitted and a marked pane is present (see **select-pane** **-m**), the window contain‐ ing 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 speci‐ fied 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 ‘^’, Shift keys with ‘S-’ 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 A command bound to the _Any_ key will execute for all keys which do not have a more specific binding. Commands related to key bindings are as follows: **bind-key** [**-nr**] [**-N** _note_] [**-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. **-N** attaches a note to the key (shown with **list-keys** **-N**). To view the default bindings and possible commands, see the **list-keys** command. **list-keys** [**-1aN**] [**-P** _prefix-string_ **-T** _key-table_] [_key_] (alias: **lsk**) List key bindings. There are two forms: the default lists keys as **bind-key** commands; **-N** lists only keys with attached notes and shows only the key and note for each key. With the default form, all key tables are listed by default. **-T** lists only keys in _key-table_. With the **-N** form, only keys in the _root_ and _prefix_ key tables are listed by default; **-T** also lists only keys in _key-table_. **-P** specifies a prefix to print before each key and **-1** lists only the first matching key. **-a** lists the command for keys that do not have a note rather than skipping them. **send-keys** [**-FHlMRX**] [**-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. All arguments are sent sequentially from first to last. The **-l** flag disables key name lookup and processes the keys as literal UTF-8 charac‐ ters. The **-H** flag expects each key to be a hexadecimal number for an ASCII character. 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 and **-F** expands formats in arguments where appropriate. **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** [**-anq**] [**-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. The **-q** option prevents errors being returned. ## OPTIONS The appearance and behaviour of **tmux** may be modified by changing the value of various options. There are four types of option: _server_ _options_, _session_ _options_, _window_ _options_, and _pane_ _options_. The **tmux** server has a set of global server options which do not apply to any particular window or session or pane. 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 in‐ herit 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 a set of pane options to each pane. Pane options inherit from window options. This means any pane option may be set as a window option to apply the option to all panes in the window without the option set, for exam‐ ple these commands will set the background colour to red for all panes except pane 0: set -w window-style bg=red set -pt:.0 window-style bg=blue There is also a set of global window options from which any unset window or pane options are inherited. Window and pane options are altered with **set-option** **-w** and **-p** commands and dis‐ played with **show-option** **-w** and **-p**. **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 set -wq @foo "abc123" $ tmux show -wv @foo abc123 Commands which set options are as follows: **set-option** [**-aFgopqsuUw**] [**-t** _target-pane_] _option_ _value_ (alias: **set**) Set a pane option with **-p**, a window option with **-w**, a server option with **-s**, otherwise a session option. If the option is not a user option, **-w** or **-s** may be unnecessary - **tmux** will infer the type from the option name, assuming **-w** for pane options. 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 in‐ herits the option from the global options (or with **-g**, restores a global option to the default). **-U** unsets an option (like **-u**) but if the option is a pane option also unsets the option on any panes in the window. _value_ depends on the option and may be a num‐ ber, a string, or a flag (on, off, or omitted to toggle). 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 exist‐ ing 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. **show-options** [**-AgHpqsvw**] [**-t** _target-pane_] [_option_] (alias: **show**) Show the pane options (or a single option if _option_ is provided) with **-p**, the window options with **-w**, the server options with **-s**, otherwise the session options. If the op‐ tion is not a user option, **-w** or **-s** may be unnecessary - **tmux** will infer the type from the option name, assuming **-w** for pane options. 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. **-H** includes hooks (omitted by default). **-A** includes options inherited from a parent set of options, such options are marked with an asterisk. Available server options are: **backspace** _key_ Set the key sent by **tmux** for backspace. **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 exe‐ cuted, 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. **copy-command** _shell-command_ Give the command to pipe to if the **copy-pipe** copy mode command is used without argu‐ ments. **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. **editor** _shell-command_ Set the command used when **tmux** runs an editor. **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. **extended-keys** [**on** | **off** | **always**] When **on** or **always**, the escape sequence to enable extended keys is sent to the terminal, if **tmux** knows that it is supported. **tmux** always recognises extended keys itself. If this option is **on**, **tmux** will only forward extended keys to applications when they re‐ quest them; if **always**, **tmux** will always forward the keys. **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 at‐ tached 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)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) escape sequence, if there is an _Ms_ entry in the [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) description (see the _TERMINFO_ _EXTENSIONS_ sec‐ tion). 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 termi‐ nal 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)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) by setting the resource: disallowedWindowOps: 20,21,SetXprop Or changing this property from the [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) interactive menu when required. **terminal-features[]** _string_ Set terminal features for terminal types read from [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown). **tmux** has a set of named terminal features. Each will apply appropriate changes to the [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) entry in use. **tmux** can detect features for a few common terminals; this option can be used to easily tell tmux about features supported by terminals it cannot detect. The **terminal-overrides** option allows individual [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) capabilities to be set instead, **terminal-features** is intended for classes of functionality supported in a standard way but not reported by [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown). Care must be taken to configure this only with fea‐ tures the terminal actually supports. This is an array option where each entry is a colon-separated string made up of a ter‐ minal type pattern (matched using [fnmatch(3)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown)) followed by a list of terminal features. The available features are: 256 Supports 256 colours with the SGR escape sequences. clipboard Allows setting the system clipboard. ccolour Allows setting the cursor colour. cstyle Allows setting the cursor style. extkeys Supports extended keys. focus Supports focus reporting. margins Supports DECSLRM margins. mouse Supports [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) mouse sequences. overline Supports the overline SGR attribute. rectfill Supports the DECFRA rectangle fill escape sequence. RGB Supports RGB colour with the SGR escape sequences. strikethrough Supports the strikethrough SGR escape sequence. sync Supports synchronized updates. title Supports [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) title setting. usstyle Allows underscore style and colour to be set. **terminal-overrides[]** _string_ Allow terminal descriptions read using [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) to be overridden. Each entry is a colon-separated string made up of a terminal type pattern (matched using [fnmatch(3)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown)) and a set of _name=value_ entries. For example, to set the ‘clear’ [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) 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)](https://www.chedong.com/phpMan.php/man/strunvis/3/markdown) before interpretation. **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 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 cur‐ rent 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)](https://www.chedong.com/phpMan.php/man/sh/1/markdown) command. The default is an empty string, which instructs **tmux** to create a login shell using the value of the **default-shell** option. **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 en‐ vironment variable, the shell returned by [getpwuid(3)](https://www.chedong.com/phpMan.php/man/getpwuid/3/markdown), or _/bin/sh_. This option should be configured when **tmux** is used as a login shell. **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 sepa‐ rated by an ‘x’ character. The default is 80x24. **destroy-unattached** [**on** | **off**] If enabled and the session is no longer attached to any clients, it is destroyed. **detach-on-destroy** [**off** | **on** | **no-detached**] If on (the default), the client is detached when the session it is attached to is de‐ stroyed. If off, the client is switched to the most recently active of the remaining sessions. If **no-detached**, the client is detached only if there are no detached ses‐ sions; if detached sessions exist, the client is switched to the most recently active. **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** com‐ mand 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)](https://www.chedong.com/phpMan.php/man/lock/1/markdown) with **-np**. **message-command-style** _style_ Set status line message command style. This is used for the command prompt with [vi(1)](https://www.chedong.com/phpMan.php/man/vi/1/markdown) keys when in command mode. For how to specify _style_, see the _STYLES_ section. **message-style** _style_ Set status line message style. This is used for messages and for the command prompt. 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)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) entries if they exist. **tmux** automatically sets these to the \e]0;...\007 sequence if the terminal appears to be [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown). This option is off by default. **set-titles-string** _string_ String used to set the client terminal title if **set-titles** is on. Formats are ex‐ panded, 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** | **absolute-centre**] Set the position of the window list in the status line: left, centre or right. centre puts the window list in the relative centre of the available free space; absolute-cen‐ tre uses the centre of the entire horizontal space. **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)](https://www.chedong.com/phpMan.php/man/strftime/3/markdown). 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)](https://www.chedong.com/phpMan.php/man/strftime/3/markdown) 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). **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 mes‐ sage 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 op‐ tion 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 pro‐ duced. **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 ‘ -_@’. Available 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. **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-option -wg 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. If suffixed by ‘%’, this is a percentage of the window size. **copy-mode-match-style** _style_ Set the style of search matches in copy mode. For how to specify _style_, see the _STYLES_ section. **copy-mode-mark-style** _style_ Set the style of the line containing the mark in copy mode. For how to specify _style_, see the _STYLES_ section. **copy-mode-current-match-style** _style_ Set the style of the current search match in copy mode. For how to specify _style_, see the _STYLES_ section. **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 sta‐ tus 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. If suf‐ fixed by ‘%’, this is a percentage of the window size. **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-lines** _type_ Set the type of characters used for drawing pane borders. _type_ may be one of: single single lines using ACS or UTF-8 characters double double lines using UTF-8 characters heavy heavy lines using UTF-8 characters simple simple ASCII characters number the pane number ‘double’ and ‘heavy’ will fall back to standard ACS line drawing when UTF-8 is not sup‐ ported. **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. **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 win‐ dow. **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_ | _latest_ 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. With _latest_, **tmux** uses the size of the client that had the most recent activity. See also the **resize-window** command and the **aggressive-resize** option. **wrap-search** [**on** | **off**] If this option is set, searches will wrap around the end of the pane contents. The de‐ fault is on. Available pane options are: **allow-rename** [**on** | **off**] Allow programs in the pane to change the window name using a terminal escape sequence (\ek...\e\\). **alternate-screen** [**on** | **off**] This option configures whether programs running inside the pane may use the terminal alternate screen feature, which allows the _smcup_ and _rmcup_ [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) 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 ap‐ plication starts reappears unchanged after it exits. **remain-on-exit** [**on** | **off** | **failed**] A pane with this flag set is not destroyed when the program running in it exits. If set to **failed**, then only when the program exit status is not zero. The pane may be re‐ activated with the **respawn-pane** command. **synchronize-panes** [**on** | **off**] Duplicate input to all other panes in the same window where this option is also on (only for panes that are not in any mode). **window-active-style** _style_ Set the pane style when it is the active pane. For how to specify _style_, see the _STYLES_ section. **window-style** _style_ Set the pane style. For how to specify _style_, see the _STYLES_ section. ## 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. Hooks are stored as array options, members of the array are executed in order when the hook is triggered. Like options different hooks may be global or belong to a session, window or pane. Hooks may be configured with the **set-hook** or **set-option** commands and displayed with **show-hooks** or **show-options** **-H**. The following two commands are equivalent: set-hook -g pane-mode-changed[42] 'set -g status-left-style bg=red' set-option -g pane-mode-changed[42] 'set -g status-left-style bg=red' Setting a hook without specifying an array index clears the hook and sets the first member of the array. 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 -g after-split-window "selectl even-vertical" All the notifications listed in the _CONTROL_ _MODE_ section are hooks (without any arguments), ex‐ cept **%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)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) escape se‐ quence. 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** [**-agpRuw**] [**-t** _target-pane_] _hook-name_ _command_ Without **-R**, sets (or with **-u** unsets) hook _hook-name_ to _command_. The flags are the same as for **set-option**. With **-R**, run _hook-name_ immediately. **show-hooks** [**-gpw**] [**-t** _target-pane_] Shows hooks. The flags are the same as for **show-options**. ## 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: Pane the contents of a pane Border a pane border Status the status line window list StatusLeft the left part of the status line StatusRight the right part of the status line StatusDefault any other part of the status line The following mouse events are available: WheelUp WheelDown MouseDown1 MouseUp1 MouseDrag1 MouseDragEnd1 MouseDown2 MouseUp2 MouseDrag2 MouseDragEnd2 MouseDown3 MouseUp3 MouseDrag3 MouseDragEnd3 SecondClick1 SecondClick2 SecondClick3 DoubleClick1 DoubleClick2 DoubleClick3 TripleClick1 TripleClick2 TripleClick3 The ‘SecondClick’ events are fired for the second click of a double click, even if there may be a third click which will fire ‘TripleClick’ instead of ‘DoubleClick’. 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. Format 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 es‐ caped as ‘#,’ and ‘#}’, unless they are part of a ‘#{...}’ replacement. For example: #{?pane_in_mode,#[fg=white#,bg=red],#[fg=red#,bg=white]}#W . String 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’. ‘||’ and ‘&&’ evaluate to true if either or both of two comma-separated alternatives are true, for example ‘#{||:#{pane_in_mode},#{alternate_on}}’. An ‘m’ specifies an [fnmatch(3)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown) or regular expression comparison. The first argument is the pattern and the second the string to compare. An optional argument specifies flags: ‘r’ means the pattern is a regular expression instead of the default [fnmatch(3)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown) pattern, and ‘i’ means to ignore case. For example: ‘#{m:*foo*,#{host}}’ or ‘#{m/ri:^A,MYVAR}’. A ‘C’ performs a search for an [fnmatch(3)](https://www.chedong.com/phpMan.php/man/fnmatch/3/markdown) pattern or regular expression in the pane content and evaluates to zero if not found, or a line number if found. Like ‘m’, an ‘r’ flag means search for a regular expres‐ sion and ‘i’ ignores case. For example: ‘#{C/r:^Start}’ Numeric operators may be performed by prefixing two comma-separated alternatives with an ‘e’ and an operator. An optional ‘f’ flag may be given after the operator to use floating point numbers, otherwise integers are used. This may be followed by a number giving the number of decimal places to use for the result. The available operators are: addition ‘+’, subtraction ‘-’, multiplication ‘*’, division ‘/’, modulus ‘m’ or ‘%’ (note that ‘%’ must be escaped as ‘%%’ in formats which are also expanded by [strftime(3)](https://www.chedong.com/phpMan.php/man/strftime/3/markdown)) and numeric comparison operators ‘==’, ‘!=’, ‘<’, ‘<=’, ‘>’ and ‘>=’. For example, ‘#{e|*|f|4:5.5,3}’ multiplies 5.5 by 3 for a re‐ sult with four decimal places and ‘#{e|%%:7,3}’ returns the modulus of 7 and 3. ‘a’ replaces a numeric argument by its ASCII equivalent, so ‘#{a:98}’ results in ‘b’. 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 five characters of the pane title, or ‘#{=-5:pane_title}’ the last five characters. A suffix or prefix may be given as a second ar‐ gument - if provided then it is appended or prepended to the string if the length has been trimmed, for example ‘#{=/5/...:pane_title}’ will append ‘...’ if the pane title is more than five characters. Similarly, ‘p’ pads the string to a given width, for example ‘#{p10:pane_title}’ will result in a width of at least 10 characters. A positive width pads on the left, a negative on the right. ‘n’ expands to the length of the variable and ‘w’ to its width when displayed, for example ‘#{n:window_name}’. 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’. Adding ‘p (’ ‘`t/p`’) will use shorter but less accurate time format for times in the past. A custom format may be given using an ‘f’ suffix (note that ‘%’ must be escaped as ‘%%’ if the format is sepa‐ rately being passed through [strftime(3)](https://www.chedong.com/phpMan.php/man/strftime/3/markdown), for example in the **status-left** option): ‘#{t/f/%%H#:%%M:window_activity}’, see [strftime(3)](https://www.chedong.com/phpMan.php/man/strftime/3/markdown). The ‘b:’ and ‘d:’ prefixes are [basename(3)](https://www.chedong.com/phpMan.php/man/basename/3/markdown) and [dirname(3)](https://www.chedong.com/phpMan.php/man/dirname/3/markdown) of the variable respectively. ‘q:’ will escape [sh(1)](https://www.chedong.com/phpMan.php/man/sh/1/markdown) special characters or with a ‘h’ suffix, escape hash characters (so ‘#’ be‐ comes ‘##’). ‘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 option itself. ‘T:’ is like ‘E:’ but also expands [strftime(3)](https://www.chedong.com/phpMan.php/man/strftime/3/markdown) 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} } ‘N:’ checks if a window (without any suffix or with the ‘w’ suffix) or a session (with the ‘s’ suffix) name exists, for example ‘`N/w:foo`’ is replaced with 1 if a window named ‘foo’ exists. A prefix of the form ‘s/foo/bar/:’ will substitute ‘foo’ with ‘bar’ throughout. The first ar‐ gument may be an extended regular expression and a final argument may be ‘i’ to ignore case, for example ‘s/a(.)/\1x/i:’ would change ‘abABab’ into ‘bxBxbx’. In addition, the last line of a shell command's output may be inserted using ‘#()’. For exam‐ ple, ‘#(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 ex‐ ited, 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 _GLOBAL_ _AND_ _SESSION_ _ENVIRONMENT_ section). An ‘l’ specifies that a string should be interpreted literally and not expanded. For example ‘#{l:#{?pane_in_mode,yes,no}}’ will be replaced by ‘#{?pane_in_mode,yes,no}’. The following variables are available, where appropriate: ### Variable name Alias Replaced with active_window_index Index of active window in session alternate_on 1 if pane is in alternate screen alternate_saved_x Saved cursor X in alternate screen alternate_saved_y Saved cursor Y in alternate screen buffer_created Time buffer created buffer_name Name of buffer buffer_sample Sample of start of buffer buffer_size Size of the specified buffer in bytes client_activity Time client last had activity client_cell_height Height of each client cell in pixels client_cell_width Width of each client cell in pixels client_control_mode 1 if client is in control mode client_created Time client created client_discarded Bytes discarded when client behind client_flags List of client flags client_height Height of client client_key_table Current key table client_last_session Name of the client's last session client_name Name of client client_pid PID of client process client_prefix 1 if prefix key has been pressed client_readonly 1 if client is readonly client_session Name of the client's session client_termfeatures Terminal features of client, if any client_termname Terminal name of client client_termtype Terminal type of client, if available client_tty Pseudo terminal of client client_utf8 1 if client supports UTF-8 client_width Width of client client_written Bytes written to client command Name of command in use, if any command_list_alias Command alias if listing commands command_list_name Command name if listing commands command_list_usage Command usage if listing commands config_files List of configuration files loaded copy_cursor_line Line the cursor is on in copy mode copy_cursor_word Word under cursor in copy mode copy_cursor_x Cursor X position in copy mode copy_cursor_y Cursor Y position in copy mode current_file Current configuration file cursor_character Character at cursor in pane cursor_flag Pane cursor flag cursor_x Cursor X position in pane cursor_y Cursor Y position in pane history_bytes Number of bytes in window history history_limit Maximum window history lines history_size Size of history in lines hook Name of running hook, if any hook_pane ID of pane where hook was run, if any hook_session ID of session where hook was run, if any hook_session_name Name of session where hook was run, if any hook_window ID of window where hook was run, if any hook_window_name Name of window where hook was run, if any host #H Hostname of local host host_short #h Hostname of local host (no domain name) insert_flag Pane insert flag keypad_cursor_flag Pane keypad cursor flag keypad_flag Pane keypad flag last_window_index Index of last window in session line Line number in the list mouse_all_flag Pane mouse all flag mouse_any_flag Pane mouse any flag mouse_button_flag Pane mouse button flag mouse_line Line under mouse, if any mouse_sgr_flag Pane mouse SGR flag mouse_standard_flag Pane mouse standard flag mouse_utf8_flag Pane mouse UTF-8 flag mouse_word Word under mouse, if any mouse_x Mouse X position, if any mouse_y Mouse Y position, if any origin_flag Pane origin flag pane_active 1 if active pane pane_at_bottom 1 if pane is at the bottom of window pane_at_left 1 if pane is at the left of window pane_at_right 1 if pane is at the right of window pane_at_top 1 if pane is at the top of window pane_bg Pane background colour pane_bottom Bottom of pane pane_current_command Current command if available pane_current_path Current path if available pane_dead 1 if pane is dead pane_dead_status Exit status of process in dead pane pane_fg Pane foreground colour pane_format 1 if format is for a pane pane_height Height of pane pane_id #D Unique pane ID pane_in_mode 1 if pane is in a mode pane_index #P Index of pane pane_input_off 1 if input to pane is disabled pane_last 1 if last pane pane_left Left of pane pane_marked 1 if this is the marked pane pane_marked_set 1 if a marked pane is set pane_mode Name of pane mode, if any pane_path Path of pane (can be set by application) pane_pid PID of first process in pane pane_pipe 1 if pane is being piped pane_right Right of pane pane_search_string Last search string in copy mode pane_start_command Command pane started with pane_synchronized 1 if pane is synchronized pane_tabs Pane tab positions pane_title #T Title of pane (can be set by application) pane_top Top of pane pane_tty Pseudo terminal of pane pane_width Width of pane pid Server PID rectangle_toggle 1 if rectangle selection is activated scroll_position Scroll position in copy mode scroll_region_lower Bottom of scroll region in pane scroll_region_upper Top of scroll region in pane search_match Search match if any search_present 1 if search started in copy mode selection_active 1 if selection started and changes with the cursor in copy mode selection_end_x X position of the end of the selection selection_end_y Y position of the end of the selection selection_present 1 if selection started in copy mode selection_start_x X position of the start of the selection selection_start_y Y position of the start of the selection session_activity Time of session last activity session_alerts List of window indexes with alerts session_attached Number of clients session is attached to session_attached_list List of clients session is attached to session_created Time session created session_format 1 if format is for a session session_group Name of session group session_group_attached Number of clients sessions in group are attached to session_group_attached_list List of clients sessions in group are attached to session_group_list List of sessions in group session_group_many_attached 1 if multiple clients attached to sessions in group session_group_size Size of session group session_grouped 1 if session in a group session_id Unique session ID session_last_attached Time session last attached session_many_attached 1 if multiple clients attached session_marked 1 if this session contains the marked pane session_name #S Name of session session_path Working directory of session session_stack Window indexes in most recent order session_windows Number of windows in session socket_path Server socket path start_time Server start time version Server version window_active 1 if window active window_active_clients Number of clients viewing this window window_active_clients_list List of clients viewing this window window_active_sessions Number of sessions on which this window is active window_active_sessions_list List of sessions on which this window is active window_activity Time of window last activity window_activity_flag 1 if window has activity window_bell_flag 1 if window has bell window_bigger 1 if window is larger than client window_cell_height Height of each cell in pixels window_cell_width Width of each cell in pixels window_end_flag 1 if window has the highest index window_flags #F Window flags with # escaped as ## window_raw_flags Window flags with nothing escaped window_format 1 if format is for a window window_height Height of window window_id Unique window ID window_index #I Index of window window_last_flag 1 if window is the last used window_layout Window layout description, ignoring zoomed window panes window_linked 1 if window is linked across sessions window_linked_sessions Number of sessions this window is linked to window_linked_sessions_list List of sessions this window is linked to window_marked_flag 1 if window contains the marked pane window_name #W Name of window window_offset_x X offset into window if larger than client window_offset_y Y offset into window if larger than client window_panes Number of panes in window window_silence_flag 1 if window has silence alert window_stack_index Index in session most recent stack window_start_flag 1 if window has the lowest index window_visible_layout Window layout description, respecting zoomed window panes window_width Width of window window_zoomed_flag 1 if window is zoomed wrap_flag Pane wrap flag ## 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**, by enclosing them in ‘#[’ and ‘]’. A style may be the single term ‘default’ to specify the default style (which may come from an option, for example **status-style** in the status line) 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). **acs**, **bright** (or **bold**), **dim**, **underscore**, **blink**, **reverse**, **hidden**, **italics**, **overline**, **strikethrough**, **double-underscore**, **curly-underscore**, **dotted-underscore**, **dashed-underscore** Set an attribute. Any of the attributes may be prefixed with ‘no’ to unset. **acs** is the terminal alternate character set. **align=left** (or **noalign**), **align=centre**, **align=right** Align text to the left, centre or right of the available space if appropriate. ### fill=colour Fill the available space with a background colour 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 cur‐ rent 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. **push-default**, **pop-default** Store the current colours and attributes as the default or reset to the previous de‐ fault. A **push-default** affects any subsequent use of the **default** term until a **pop-default**. Only one default may be pushed (each **push-default** replaces the previous saved default). **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)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) window title in [X(7)](https://www.chedong.com/phpMan.php/man/X/7/markdown)). Windows themselves do not have titles - a window's ti‐ tle 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 ti‐ tle setting escape sequence, for example: $ printf '\033]2;My Title\033\\' It can also be modified with the **select-pane** **-T** command. ## GLOBAL AND SESSION ENVIRONMENT When the server is started, **tmux** copies the environment into the _global_ _environment_; in addi‐ tion, 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’. Variables in both session and global environments may be marked as hidden. Hidden variables are not passed into the environment of new processes and instead can only be used by tmux it‐ self (for example in formats, see the _FORMATS_ section). Commands to alter and view the environment are: **set-environment** [**-Fhgru**] [**-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_. If **-F** is present, then _value_ is expanded as a format. The **-u** flag unsets a variable. **-r** indicates the variable is to be removed from the environment before starting a new process. **-h** marks the variable as hidden. **show-environment** [**-hgs**] [**-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. **-h** shows hidden variables (omitted by default). ## 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 mul‐ tiple 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 as‐ cending 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: **Symbol** **Meaning** * Denotes the current window. - Marks the last window (previously selected). # Window activity is monitored and activity has been detected. ! Window bells are monitored and a bell has occurred in the window. ~ The window has been silent for the monitor-silence interval. M The window contains the marked pane. Z The window's active pane is zoomed. The # symbol relates to the **monitor-activity** window option. The window name is printed in in‐ verted 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 op‐ tion. 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** [**-1ikNTW**] [**-I** _inputs_] [**-p** _prompts_] [**-t** _target-client_] [_template_] Open the command prompt in a client. This may be used from inside **tmux** to execute com‐ mands interactively. If _template_ is specified, it is used as the command. If present, **-I** is a comma-sepa‐ rated 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 occur‐ rences 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. **-k** is like **-1** but the key press is translated to a key name. **-N** makes the prompt only accept numeric key presses. **-i** executes the command every time the prompt input changes instead of when the user exits the command prompt. **-T** tells **tmux** that the prompt is for a target which affects what completions are offered when _Tab_ is pressed; **-W** is similar but indicates the prompt is for a window. 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 q Escape Delete from cursor to start of 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-menu** [**-O**] [**-c** _target-client_] [**-t** _target-pane_] [**-T** _title_] [**-x** _position_] [**-y** _position_] _name_ _key_ _command_ _..._ (alias: **menu**) Display a menu on _target-client_. _target-pane_ gives the target for any commands run from the menu. A menu is passed as a series of arguments: first the menu item name, second the key shortcut (or empty for none) and third the command to run when the menu item is chosen. The name and command are formats, see the _FORMATS_ and _STYLES_ sections. If the name be‐ gins with a hyphen (-), then the item is disabled (shown dim) and may not be chosen. The name may be empty for a separator line, in which case both the key and command should be omitted. **-T** is a format for the menu title (see _FORMATS_). **-x** and **-y** give the position of the menu. Both may be a row or column number, or one of the following special values: **Value** **Flag** **Meaning** C Both The centre of the terminal R **-x** The right side of the terminal P Both The bottom left of the pane M Both The mouse position W Both The window position on the status line S **-y** The line above or below the status line Or a format, which is expanded including the following additional variables: **Variable** **name** **Replaced** **with** popup_centre_x Centered in the client popup_centre_y Centered in the client popup_height Height of menu or popup popup_mouse_bottom Bottom of at the mouse popup_mouse_centre_x Horizontal centre at the mouse popup_mouse_centre_y Vertical centre at the mouse popup_mouse_top Top at the mouse popup_mouse_x Mouse X position popup_mouse_y Mouse Y position popup_pane_bottom Bottom of the pane popup_pane_left Left of the pane popup_pane_right Right of the pane popup_pane_top Top of the pane popup_status_line_y Above or below the status line popup_width Width of menu or popup popup_window_status_line_x At the window position in status line popup_window_status_line_y At the status line showing the window Each menu consists of items followed by a key shortcut shown in brackets. If the menu is too large to fit on the terminal, it is not displayed. Pressing the key shortcut chooses the corresponding item. If the mouse is enabled and the menu is opened from a mouse key binding, releasing the mouse button with an item selected chooses that item and releasing the mouse button without an item selected closes the menu. **-O** changes this behaviour so that the menu does not close when the mouse button is released with‐ out an item selected the menu is not closed and a mouse button must be clicked to choose an item. The following keys are also available: **Key** **Function** Enter Choose selected item Up Select previous item Down Select next item q Exit menu **display-message** [**-aINpv**] [**-c** _target-client_] [**-d** _delay_] [**-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 for up to _delay_ milliseconds. If _delay_ is not given, the **message-time** option is used; a delay of zero waits for a key press. ‘N’ ignores key presses and closes only after the delay expires. The format of _message_ is described in the _FORMATS_ section; information is taken from _target-pane_ if **-t** is given, otherwise the active pane. **-v** prints verbose logging as the format is parsed and **-a** lists the format variables and their values. **-I** forwards any input read from stdin to the empty pane given by _target-pane_. **display-popup** [**-CE**] [**-c** _target-client_] [**-d** _start-directory_] [**-h** _height_] [**-t** _target-pane_] [**-w** _width_] [**-x** _position_] [**-y** _position_] [_shell-command_] (alias: **popup**) Display a popup running _shell-command_ on _target-client_. A popup is a rectangular box drawn over the top of any panes. Panes are not updated while a popup is present. **-E** closes the popup automatically when _shell-command_ exits. Two **-E** closes the popup only if _shell-command_ exited with success. **-x** and **-y** give the position of the popup, they have the same meaning as for the **display-menu** command. **-w** and **-h** give the width and height - both may be a percentage (followed by ‘%’). If omitted, half of the terminal size is used. The **-C** flag closes any popup on the client. ## BUFFERS **tmux** maintains a set of named _paste_ _buffers_. Each buffer may be either explicitly or automati‐ cally 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**. Auto‐ matically 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. Explic‐ itly named buffers are not subject to **buffer-limit** and may be deleted with the **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** [**-NZr**] [**-F** _format_] [**-f** _filter_] [**-K** _key-format_] [**-O** _sort-order_] [**-t** _target-pane_] [_template_] Put a pane into buffer mode, where a buffer may be chosen interactively from a list. Each buffer is shown on one line. A shortcut key is shown on the left in brackets al‐ lowing for immediate choice, or the list may be navigated and an item chosen or other‐ wise manipulated using the keys below. **-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 e Open the buffer in an editor f Enter a format to filter items O Change sort field r Reverse sort order v Toggle preview q Exit mode After a buffer is chosen, ‘%%’ is replaced by the buffer name in _template_ and the re‐ sult executed as a command. If _template_ is not given, "paste-buffer -b '%%'" is used. **-O** specifies the initial sort field: one of ‘time’, ‘name’ or ‘size’. **-r** reverses the sort order. **-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 and **-K** a format for each shortcut key; both are evaluated once for each line. **-N** starts without the preview. This command works only if at least one client is at‐ tached. **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_] [**-f** _filter_] (alias: **lsb**) List the global buffers. **-F** specifies the format of each line and **-f** a filter. Only buffers for which the filter is true are shown. See the _FORMATS_ section. **load-buffer** [**-w**] [**-b** _buffer-name_] [**-t** _target-client_] _path_ (alias: **loadb**) Load the contents of the specified paste buffer from _path_. If **-w** is given, the buffer is also sent to the clipboard for _target-client_ using the [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) escape sequence, if possible. **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 line‐ feed (LF) characters in the paste buffer are replaced with a separator, by default car‐ riage 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 re‐ quested 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** [**-aw**] [**-b** _buffer-name_] [**-t** _target-client_] [**-n** _new-buffer-name_] _data_ (alias: **setb**) Set the contents of the specified buffer to _data_. If **-w** is given, the buffer is also sent to the clipboard for _target-client_ using the [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) escape sequence, if possi‐ ble. The **-a** option appends to rather than overwriting the buffer. The **-n** option re‐ names 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_ other‐ wise. 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** op‐ tion. **run-shell** [**-bC**] [**-d** _delay_] [**-t** _target-pane_] [_shell-command_] (alias: **run**) Execute _shell-command_ or (with **-C**) a **tmux** 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. **-d** waits for _delay_ seconds before starting the command. If **-C** is not given, any output to stdout is displayed in view mode (in the pane specified by **-t** or the current pane if omitted) af‐ ter the command finishes. If the command fails, 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**. ## EXIT MESSAGES When a **tmux** client detaches, it prints a message. This may be one of: detached (from session ...) The client was detached normally. detached and SIGHUP The client was detached and its parent sent the SIGHUP signal (for example with **detach-client** **-P**). lost tty The client's [tty(4)](https://www.chedong.com/phpMan.php/man/tty/4/markdown) or [pty(4)](https://www.chedong.com/phpMan.php/man/pty/4/markdown) was unexpectedly destroyed. terminated The client was killed with SIGTERM. too far behind The client is in control mode and became unable to keep up with the data from **tmux**. exited The server exited when it had no sessions. server exited The server exited when it received SIGTERM. server exited unexpectedly The server crashed or otherwise exited without telling the client the reason. ## TERMINFO EXTENSIONS **tmux** understands some unofficial extensions to [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown). It is not normally necessary to set these manually, instead the **terminal-features** option should be used. _AX_ An existing extension that tells **tmux** the terminal supports default colours. _Bidi_ Tell **tmux** that the terminal supports the VTE bidirectional text extensions. _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\\' _Cmg,_ _Clmg,_ _Dsmg_, _Enmg_ Set, clear, disable or enable DECSLRM margins. These are set automatically if the ter‐ minal reports it is _VT420_ compatible. _Dsbp_, _Enbp_ Disable and enable bracketed paste. These are set automatically if the _XT_ capability is present. _Dseks_, _Eneks_ Disable and enable extended keys. _Dsfcs_, _Enfcs_ Disable and enable focus reporting. These are set automatically if the _XT_ capability is present. _Rect_ Tell **tmux** that the terminal supports rectangle operations. _Smol_ Enable the overline attribute. _Smulx_ Set a styled underscore. The single parameter is one of: 0 for no underscore, 1 for normal underscore, 2 for double underscore, 3 for curly underscore, 4 for dotted under‐ score and 5 for dashed underscore. _Setulc_, _ol_ Set the underscore colour or reset to the default. The argument is (red * 65536) + (green * 256) + blue where each is between 0 and 255. _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. _Sync_ Start (parameter is 1) or end (parameter is 2) a synchronized update. _Tc_ Indicate that the terminal supports the ‘direct colour’ RGB escape sequence (for exam‐ ple, \e[38;2;255;255;255m). If supported, this is used for the initialize colour escape sequence (which may be en‐ abled by adding the ‘initc’ and ‘ccc’ capabilities to the **tmux** [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) entry). This is equivalent to the _RGB_ [terminfo(5)](https://www.chedong.com/phpMan.php/man/terminfo/5/markdown) capability. _Ms_ Store the current buffer in the host terminal's selection (clipboard). See the _set-clipboard_ option above and the [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) man page. _XT_ This is an existing extension capability that tmux uses to mean that the terminal sup‐ ports the [xterm(1)](https://www.chedong.com/phpMan.php/man/xterm/1/markdown) title set sequences and to automatically set some of the capabili‐ ties above. ## 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 three arguments: an inte‐ ger time (as seconds from epoch), command number and flags (currently not used). For example: %begin 1363006971 2 1 0: ksh* (1 panes) [80x24] [layout b25f,80x24,0,0,2] @2 (active) %end 1363006971 2 1 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-detached** _client_ The client has detached. **%client-session-changed** _client_ _session-id_ _name_ The client is now attached to the session with ID _session-id_, which is named _name_. **%continue** _pane-id_ The pane has been continued after being paused (if the _pause-after_ flag is set, see **refresh-client** **-A**). **%exit** [_reason_] The **tmux** client is exiting immediately, either because it is not attached to any ses‐ sion or an error occurred. If present, _reason_ describes why the client exited. **%extended-output** _pane-id_ _age_ _..._ : _value_ New form of **%output** sent when the _pause-after_ flag is set. _age_ is the time in mil‐ liseconds for which tmux had buffered the output before it was sent. Any subsequent arguments up until a single ‘:’ are for future use and should be ignored. **%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. **%pause** _pane-id_ The pane has been paused (if the _pause-after_ flag is set). **%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. **%subscription-changed** _name_ _session-id_ _window-id_ _window-index_ _pane-id_ _..._ : _value_ The value of the format associated with subscription _name_ has changed to _value_. See **refresh-client** **-B**. Any arguments after _pane-id_ up until a single ‘:’ are for future use and should be ignored. **%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_. ## ENVIRONMENT When **tmux** is started, it inspects the following environment variables: EDITOR If the command specified in this variable contains the string ‘vi’ and VISUAL is un‐ set, use vi-style key bindings. Overridden by the **mode-keys** and **status-keys** options. HOME The user's login directory. If unset, the [passwd(5)](https://www.chedong.com/phpMan.php/man/passwd/5/markdown) database is consulted. LC_CTYPE The character encoding [locale(1)](https://www.chedong.com/phpMan.php/man/locale/1/markdown). It is used for two separate purposes. For output to the terminal, UTF-8 is used if the **-u** option is given or if LC_CTYPE contains "UTF-8" or "UTF8". Otherwise, only ASCII characters are written and non-ASCII char‐ acters are replaced with underscores (‘_’). For input, **tmux** always runs with a UTF-8 locale. If en_US.UTF-8 is provided by the operating system it is used and LC_CTYPE is ignored for input. Otherwise, LC_CTYPE tells **tmux** what the UTF-8 locale is called on the current system. If the locale specified by LC_CTYPE is not available or is not a UTF-8 locale, **tmux** exits with an error message. LC_TIME The date and time format [locale(1)](https://www.chedong.com/phpMan.php/man/locale/1/markdown). It is used for locale-dependent [strftime(3)](https://www.chedong.com/phpMan.php/man/strftime/3/markdown) for‐ mat specifiers. PWD The current working directory to be set in the global environment. This may be use‐ ful if it contains symbolic links. If the value of the variable does not match the current working directory, the variable is ignored and the result of [getcwd(3)](https://www.chedong.com/phpMan.php/man/getcwd/3/markdown) is used instead. SHELL The absolute path to the default shell for new windows. See the **default-shell** option for details. TMUX_TMPDIR The parent directory of the directory containing the server sockets. See the **-L** op‐ tion for details. VISUAL If the command specified in this variable contains the string ‘vi’, use vi-style key bindings. Overridden by the **mode-keys** and **status-keys** options. ## FILES ~/.tmux.conf Default **tmux** configuration file. /etc/tmux.conf System-wide configuration file. ## EXAMPLES To create a new **tmux** session running [vi(1)](https://www.chedong.com/phpMan.php/man/vi/1/markdown): $ 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)](https://www.chedong.com/phpMan.php/man/ssh/1/markdown) 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_ configura‐ tion 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)](https://www.chedong.com/phpMan.php/man/pty/4/markdown) ## AUTHORS Nicholas Marriott <<_nicholas.marriott@gmail.com_>> BSD June 3, 2026 BSD