tmux(1) Ubuntu Man Page - System Grab Bag

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

When is started, it creates a new with a single 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 under the management of Each session has one or more windows linked to it. A window occupies the entire screen and may be split into rectangular panes, each of which is a separate pseudo terminal (the manual page documents the technical details of pseudo terminals). Any number of instances may connect to the same session, and any number of windows may be present in the same session. Once all sessions are killed, exits.

Each session is persistent and will survive accidental disconnection (such as connection timeout) or intentional detaching (with the key strokes). may be reattached using:

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

The options are as follows: Force to assume the terminal supports 256 colours. This is equivalent to Start in control mode (see the section). Given twice disables echo. Execute using the default shell. If necessary, the server will be started to retrieve the option. This option is for compatibility with when is used as a login shell. Do not start the server as a daemon. This also turns the option off. With may not be specified. Specify an alternative configuration file. By default, loads the system configuration file from

if present, then looks for a user configuration file at

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

shows any error messages from commands in configuration files in the first session created, and continues to process the rest of the configuration file. stores the server socket in a directory under or

if it is unset. The default socket is named This option allows a different socket name to be specified, allowing several independent servers to be run. Unlike a full path is not necessary: the sockets are all created in a directory

under the directory given by or in

The

directory is created by and must not be world readable, writable or executable.

If the socket is accidentally removed, the signal may be sent to the server process to recreate it (note that this will fail if any parent directories are missing). Behave as a login shell. This flag currently has no effect and is for compatibility with other shells when using tmux as a login shell. Do not start the server even if the command would normally do so (for example or Specify a full alternative path to the server socket. If is specified, the default socket directory is not used and any flag is ignored. Write UTF-8 output to the terminal even if the first environment variable of or that is set does not contain or This is equivalent to Set terminal features for the client. This is a comma-separated list of features. See the option. Request verbose logging. Log messages will be saved into

and

files in the current directory, where is the PID of the server or client process. If is specified twice, an additional

file is generated with a copy of everything writes to the terminal.

The signal may be sent to the server process to toggle logging between on (as if was given) and off. Report the version. This specifies one of a set of commands used to control as described in the following sections. If no commands are specified, the command is assumed. may be controlled from an attached client by using a key combination of a prefix key, (Ctrl-b) by default, followed by a command key.

The default command key bindings are:

Send the prefix key (C-b) through to the application. Rotate the panes in the current window forwards. Suspend the 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. Select windows 0 to 9. Enter the command prompt. Move to the previously active pane. Choose which buffer to paste interactively from a list. List all key bindings. Choose a client to detach. 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. Create a new window. Detach the current client. Prompt to search for text in open windows. Display some information about the current window. Move to the previously selected window. Mark the current pane (see Clear the marked pane. Change to the next window. Select the next pane in the current window. Change to the previous window. Briefly display pane indexes. Force redraw of the attached client. Select a new session for the attached client interactively. Show the time. Choose the current window interactively. Kill the current pane. 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 if any. Enter copy mode and scroll one page up. Change to the pane above, below, to the left, or to the right of the current pane. Arrange panes in one of the five preset layouts: even-horizontal, even-vertical, main-horizontal, main-vertical, or tiled. Arrange the current window in the next preset layout. Move to the next window with a bell or activity marker. Rotate the panes in the current window backwards. Move to the previous window with a bell or activity marker. Resize the current pane in steps of one cell. Resize the current pane in steps of five cells.

Key bindings may be changed with the and commands. supports a large number of commands which can be used to control its behaviour. Each command is named and can accept zero or more flags and arguments. They may be bound to a key with the command or run from the shell prompt, a shell script, a configuration file or the command prompt. For example, the same command run from the shell prompt, from

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 is a flag and and are arguments.

distinguishes between command parsing and execution. In order to execute a command, 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 or from a configuration file, does. Examples of when parses commands are: in a configuration file; typed at the command prompt (see given to passed as arguments to or

To execute commands, each client has a A global command queue not attached to any client is used on startup for configuration files like

Parsed commands added to the queue are executed in order. Some commands, like and 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 is parsed and again when it parses and executes its command. Commands like and stop execution of subsequent commands on the queue until something happens - and until a shell command finishes and until a key is pressed. For example, the following commands: new-session; new-window if-shell "true" "split-window" kill-session

Will execute the shell command and in that order.

The section lists the commands and their arguments. This section describes the syntax of commands parsed by 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 or

Each command is terminated by a newline or a semicolon (;). Commands separated by semicolons together form a - if a command in the sequence encounters an error, no subsequent commands are executed.

It is recommended that a semicolon used as a command separator should be written as an individual token, for example from $ 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 commands: $ tmux neww\e\e; splitw

Or: $ tmux 'neww;' splitw

As in these examples, when running tmux from the shell extra care must be taken to properly quote semicolons: Semicolons that should be interpreted as a command separator should be escaped according to the shell conventions. For this typically means quoted (such as or escaped (such as 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 for example: $ tmux neww 'foo\e\e;' bar $ tmux neww foo\e\e\e\e; bar 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-\e\e;-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 \e, the line is joined with the following line (the \e 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 environment (see the section). A leading ~ or ~user is expanded to the home directory of the current or specified user. \euXXXX or \euXXXXXXXX is replaced by the Unicode codepoint corresponding to the given four or eight digit hexadecimal number. When preceded (escaped) by a \e, the following characters are replaced: \ee by the escape character; \er by a carriage return; \en by a newline; and \et by a tab. \eooo is replaced by a character of the octal value ooo. Three octal digits are required, for example \e001. The largest valid character is \e377. Any other characters preceded by \e are replaced by themselves (that is, the \e is removed) and are not treated as having any special meaning - so for example \e; will not mark a command sequence and \e$ will not expand an environment variable.

Braces are parsed as a configuration file (so conditions such as are processed) and then converted into a string. They are designed to avoid the need for additional escaping when passing a group of commands as an argument (for example to These two examples produce an identical command - note that no escaping is needed when using {}: if-shell true { display -p 'brace-dollar-foo: }$foo' } if-shell true "display -p 'brace-dollar-foo: }\e$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 for example Variables set during parsing are added to the global environment. A hidden variable may be set with for example: %hidden MYVAR=42

Hidden variables are not passed to the environment of processes created by tmux. See the section.

Commands may be parsed conditionally by surrounding them with and The argument to and is expanded as a format (see and if it evaluates to false (zero or empty), subsequent text is ignored until the closing or 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 green if running on 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 This section describes the commands supported by Most commands accept the optional (and sometimes argument with one of or These specify the client, session, window or pane which a command should affect.

should be the name of the client, typically the file to which the client is connected, for example either of

for the client attached to

If no client is specified, attempts to work out the client currently in use; if that fails, an error is reported. Clients may be listed with the command.

is tried as, in order: A session ID prefixed with a $. An exact name of a session (as listed by the command). The start of a session name, for example would match a session named An pattern which is matched against the session name.

If the session name is prefixed with an only an exact match is accepted (so will only match exactly not

If a single session is found, it is used as the target session; multiple matches produce an error. If a session is omitted, the current session is used if available; if no current session is available, the most recently used is chosen.

(or or specifies a window in the form follows the same rules as for and is looked for in order as: A special token, listed below. A window index, for example is window 1 in session A window ID, such as @1. An exact window name, such as The start of a window name, such as As an 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 and commands) otherwise the current window in is chosen.

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

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

The tokens and may be followed by an offset, for example: select-window -t:+2

In addition, or may consist entirely of the token (alternative form to specify the session, window or pane where the most recent mouse event occurred (see the section) or (alternative form to specify the marked pane (see

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 server. The pane ID is passed to the child process of the pane in the environment variable. IDs may be displayed using the or formats (see the section) and the or commands.

arguments are 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 and commands allow to be given as multiple arguments and executed directly (without This can avoid issues with shell quoting. For example: $ tmux new-window vi ~/.tmux.conf

Will run directly without invoking the shell.

refers to a command, either passed with the command and arguments separately, for example: bind-key F1 set-option status off

Or passed as a single string argument in

for example: bind-key F1 { set-option status off }

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

Or from $ tmux kill-window -t :1 $ tmux new-window \e; split-window -d $ tmux new-session -d 'vi ~/.tmux.conf' \e; split-window -d \e; attach The server manages clients, sessions, windows and panes. Clients are attached to sessions to interact with them, either when they are created with the command, or later with the command. Each session has one or more windows 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 section.

The following commands are available to manage clients and sessions: If run from outside create a new client in the current terminal and attach it to If used from inside, switch the current client. If is specified, any other clients attached to the session are detached. If is given, send to the parent process of the client as well as detaching the client, typically causing it to exit. sets a comma-separated list of client flags. The flags are: the client has an independent active pane the client does not affect the size of other clients the client does not receive pane output in control mode output is paused once the pane is behind in control mode the client is read-only wait for an empty line input before exiting in control mode

A leading turns a flag off if the client is already attached. is an alias for When a client is read-only, only keys bound to the or commands have any effect. A client with the 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, will attempt to start it; this will fail unless sessions are created in the configuration file.

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

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

If is used, the option will not be applied. Detach the current client if bound to a key, the client specified with or all clients currently attached to the session specified by The option kills all but the client given with If is given, send to the parent process of the client, typically causing it to exit. With run to replace the client. Report an error and exit with 1 if the specified session does not exist. If it does exist, exit with 0. Kill the server and clients and destroy all sessions. Destroy the given session, closing any windows linked to it and no other sessions, and detaching all clients attached to it. If is given, all sessions but the specified one is killed. The flag clears alerts (bell, activity, or silence) in all windows linked to the session. List all clients attached to the server. For the meaning of the flag, see the section. If is specified, list only clients connected to that session. List the syntax of or - if omitted - of all commands supported by List all sessions managed by the server. specifies the format of each line and a filter. Only sessions for which the filter is true are shown. See the section. Lock see the command. Lock all clients attached to Create a new session with name

The new session is attached to the current terminal unless is given. and are the name of and shell command to execute in the initial window. With the initial size comes from the global option; and can be used to specify a different size. uses the size of the current client if any. If or is given, the option is set for the session. sets a comma-separated list of client flags (see

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

The flag makes behave like if already exists; in this case, behaves like to and behaves like to

If is given, it specifies a Sessions in the same group share the same set of windows - new windows are linked to all sessions in the group and any windows closed removed from all sessions. The current and previous window and any session options remain independent and any session in a group may be killed without affecting the others. The argument may be: the name of an existing group, in which case the new session is added to that group; the name of an existing session - the new session is added to the same group as that session, creating a new group if necessary; the name for a new group containing only the new session.

and are invalid if is used.

The option prints information about the new session after it has been created. By default, it uses the format but a different format may be specified with

If is used, the option will not be applied. takes the form and sets an environment variable for the newly created session; it may be specified multiple times. Refresh the current client if bound to a key, or a single client if one is given with If is specified, only update the client's status line.

The and flags allow the visible portion of a window which is larger than the client to be changed. moves the visible part up by rows and down, left by columns and right. returns to tracking the cursor automatically. If 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.

sets the width and height of a control mode client or of a window for a control mode client, must be one of or for example or allows a control mode client to trigger actions on a pane. The argument is a pane ID (with leading a colon, then one of or If 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 will return to sending output to the pane if it was paused (manually or with the flag). If will pause the pane. may be given multiple times for different panes.

sets a subscription to a format for a control mode client. The argument is split into three items by colons: is a name for the subscription; is a type of item to subscribe to; is the format. After a subscription is added, changes to the format are reported with the notification, at most once a second. If only the name is given, the subscription is removed. may be empty to check the format only for the attached session, or one of: a pane ID such as for all panes in the attached session; a window ID such as or for all windows in the attached session.

sets a comma-separated list of client flags, see

requests the clipboard from the client using the escape sequence. If Ar target-pane is given, the clipboard is sent (in encoded form), otherwise it is stored in a new paste buffer.

and move the visible portion of the window left, right, up or down by if the window is larger than the client. resets so that the position follows the cursor. See the option. Rename the session to Change the access or read/write permission of The user running the server (its owner) and the root user cannot be changed and are always permitted access.

and are used to give or revoke access for the specified user. If the user is already attached, the flag causes their clients to be detached.

and change the permissions for makes their clients read-only and writable. lists current access permissions.

By default, the access list is empty and creates sockets with file system permissions preventing access by any user other than the owner (and root). These permissions must be changed manually. Great care should be taken not to allow access to untrusted users even read-only. Show server messages or information. Messages are stored, up to a maximum of the limit set by the server option. and show debugging information about jobs and terminals. Execute commands from one or more files specified by (which may be patterns). If is present, then is expanded as a format. If is given, no error will be returned if does not exist. With the file is parsed but no commands are executed. shows the parsed commands and line numbers if possible. Start the server, if not already running, without creating any sessions.

Note that as by default the server will exit with no sessions, this is only useful if a session is created in

is turned off, or another command is run as part of the same command sequence. For example: $ tmux start \\; show -g Suspend a client by sending (tty stop). Switch the current session for client to As a special case, may refer to a pane (a target that contains or to change session, window and pane. In that case, keeps the window zoomed if it was zoomed. If or is used, the client is moved to the last, next or previous session respectively. toggles the client and flags (see the command).

If is used, option will not be applied.

sets the client's key table; the next key from the client will be interpreted from This may be used to configure multiple prefix keys, or to bind commands to sequences of keys. For example, to make typing run the command: bind-key -Ttable2 c list-keys bind-key -Ttable1 b switch-client -Ttable2 bind-key -Troot a switch-client -Ttable1 Each window displayed by may be split into one or more each pane takes up a certain area of the display and is a separate terminal. A window may be split into panes using the command. Windows may be split horizontally (with the flag) or vertically. Panes may be resized with the command (bound to and by default), the current pane may be changed with the command and the and 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 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 for later insertion into another window. This mode is entered with the command, bound to by default. Copied text can be pasted with the command, bound to View mode, which is like copy mode but is entered when a command that produces output, such as 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 and commands.

In copy mode an indicator is displayed in the top-right corner of the pane with the current position and the number of lines in the history.

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

The following commands are supported in copy mode:

The search commands come in several varieties: and search for a regular expression; the variants search for a plain text string rather than a regular expression; perform an incremental search and expect to be used with the flag to the command. repeats the last search and does the same but reverses the direction (forward becomes backward and backward becomes forward).

Copy commands may take an optional buffer prefix argument which is used to generate the buffer name (the default is so buffers are named and so on). Pipe commands take a command argument which is the command to which the selected text is piped. variants also copy the selection. The variants of some commands exit copy mode after they have completed (for copy commands) or when the cursor reaches the bottom (for scrolling commands). variants do not clear the selection.

The next and previous word keys skip over whitespace and treat consecutive runs of either word separators or other letters as words. Word separators can be customized with the session option. Next word moves to the start of the next word, next word end to the end of the next word and previous word to the start of the previous word. The three next and previous space keys work similarly but use a space alone as the word separator. Setting to the empty string makes next/previous word equivalent to next/previous space.

The jump commands enable quick movement within a line. For instance, typing 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 command is: Enter copy mode. The option scrolls one page up. begins a mouse drag (only valid if bound to a mouse key binding, see hides the position indicator in the top right. cancels copy mode and any other modes. copies from instead of

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 command or cycled with (bound to by default); once a layout is chosen, panes within it may be moved and resized as normal.

The following layouts are supported: Panes are spread out evenly from left to right across the window. Panes are spread evenly from top to bottom. 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 window option to specify the height of the top pane. Similar to but the large pane is placed on the left and the others spread from top to bottom along the right. See the window option. Panes are spread out as evenly as possible over the window in both rows and columns.

In addition, may be used to apply a previously used layout - the command displays the layout of each window in a form suitable for use with 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}

automatically adjusts the size of the layout for the current window size. Note that a layout cannot be applied to a window with more panes than that from which the layout was originally defined.

Commands related to windows and panes are as follows: Break off from its containing window to make it the only pane in With or the window is moved to the next index after or before (existing windows are moved if necessary). If is given, the new window does not become the current window. The option prints information about the new window after it has been created. By default, it uses the format but a different format may be specified with Capture the contents of a pane. If is given, the output goes to stdout, otherwise to the buffer specified with or a new buffer if omitted. If is given, the alternate screen is used, and the history is not accessible. If no alternate screen exists, an error will be returned unless is given. If is given, the output includes escape sequences for text and background attributes. also escapes non-printable characters as octal \exxx. preserves trailing spaces at each line's end and preserves trailing spaces and joins any wrapped lines. captures only any output that the pane has received that is the beginning of an as-yet incomplete escape sequence.

and 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 is the start of the history and to the end of the visible pane. The default is to capture only the visible contents of the pane. 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 brackets allowing for immediate choice, or the list may be navigated and an item chosen or otherwise manipulated using the keys below. zooms the pane. The following keys may be used in client mode:

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

After a session, window or pane is chosen, the first instance of and all instances of are replaced by the target in and the result executed as a command. If is not given, "switch-client -t '%%'" is used.

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. specifies the format for each item in the tree. starts without the option information. This command works only if at least one client is attached. Display a visible indicator of each pane shown by See the and session options. The indicator is closed when a key is pressed (unless is given) or milliseconds have passed. If is not given, 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 to keys, which will cause to be executed as a command with substituted by the pane ID. The default is "select-pane -t '%%'". With other commands are not blocked from running until the indicator is closed. Search for a pattern or, with regular expression in window names, titles, and visible content (but not history). The flags control matching behavior: matches only visible window contents, matches only the window name and matches only the window title. makes the search ignore case. The default is zooms the pane.

This command works only if at least one client is attached. Like but instead of splitting and creating a new pane, split it and move into the space. This can be used to reverse The option causes to be joined to left of or above

If is omitted and a marked pane is present (see the marked pane is used rather than the current pane. Destroy the given pane. If no panes remain in the containing window, it is also destroyed. The option kills all but the pane given with Kill the current window or the window at removing it from any sessions to which it is linked. The option kills all but the window given with Select the last (previously selected) pane. keeps the window zoomed if it was zoomed. enables or disables input to the pane. Select the last (previously selected) window. If no is specified, select the last window of the current session. Link the window at to the specified If is specified and no such window exists, the is linked there. With or the window is moved to the next index after or before (existing windows are moved if necessary). If is given and exists, it is killed, otherwise an error is generated. If is given, the newly linked window is not selected. If is given, is ignored and all panes on the server are listed. If is given, is a session (or the current session). If neither is given, is a window (or the current window). specifies the format of each line and a filter. Only panes for which the filter is true are shown. See the section. If is given, list all windows on the server. Otherwise, list windows in the current session or in specifies the format of each line and a filter. Only windows for which the filter is true are shown. See the section. Does the same as This is similar to except the window at is moved to With all windows in the session are renumbered in sequential order, respecting the option. Create a new window. With or the new window is inserted at the next index after or before the specified moving windows up if necessary; otherwise is the new window location.

If is given, the session does not make the new window the current window. represents the window to be created; if the target already exists an error is shown, unless the flag is used, in which case it is destroyed. If is given and a window named already exists, it is selected (unless is also given in which case the command does nothing).

is the command to execute. If is not specified, the value of the option is used. specifies the working directory in which the new window is created.

When the shell command completes, the window closes. See the option to change this behaviour.

takes the form and sets an environment variable for the newly created window; it may be specified multiple times.

The environment variable must be set to or for all programs running New windows will automatically have added to their environment, but care must be taken not to reset this in shell start-up files or by the option.

The option prints information about the new window after it has been created. By default, it uses the format but a different format may be specified with Move a window to the next layout and rearrange the panes to fit. Move to the next window in the session. If is used, move to the next window with an alert. Pipe output sent by the program in 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 is executed. The string may contain the special character sequences supported by the option. If no is given, the current pipe (if any) is closed.

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

The 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' Move to the previous layout in the session. Move to the previous window in the session. With move to the previous window with an alert. Rename the current window, or the window at if specified, to Resize a pane, up, down, left or right by with or or to an absolute size with or The is given in lines or columns (the default is 1); and may be a given as a number of lines or columns or followed by for a percentage of the window size (for example With the active pane is toggled between zoomed (occupying the whole of the window) and unzoomed (its normal position in the layout).

begins mouse resizing (only valid if bound to a mouse key binding, see

trims all lines below the current cursor position and moves lines out of the history to replace them. Resize a window, up, down, left or right by with or or to an absolute size with or The is given in lines or cells (the default is 1). sets the size of the largest session containing the window; the size of the smallest. This command will automatically set to manual in the window options. Reactivate a pane in which the command has exited (see the window option). If is not given, the command used when the pane was created or last respawned is executed. The pane must be already inactive, unless is given, in which case any existing command is killed. specifies a new working directory for the pane. The option has the same meaning as for the command. Reactivate a window in which the command has exited (see the window option). If is not given, the command used when the window was created or last respawned is executed. The window must be already inactive, unless is given, in which case any existing command is killed. specifies a new working directory for the window. The option has the same meaning as for the command. Rotate the positions of the panes within a window, either upward (numerically lower) with or downward (numerically higher). keeps the window zoomed if it was zoomed. Choose a specific layout for a window. If is not given, the last preset layout used (if any) is reapplied. and are equivalent to the and commands. applies the last set layout if possible (undoes the most recent layout change). spreads the current pane and any panes next to it out evenly. Make pane the active pane in its window. If one of or is used, respectively the pane below, to the left, to the right, or above the target pane is used. keeps the window zoomed if it was zoomed. is the same as using the command. enables or disables input to the pane. sets the pane title.

and are used to set and clear the There is one marked pane at a time, setting a new marked pane clears the last. The marked pane is the default target for to and Select the window at and are equivalent to the and commands. If is given and the selected window is already the current window, the command behaves like Create a new pane by splitting does a horizontal split and a vertical split; if neither is specified, is assumed. The option specifies the size of the new pane in lines (for vertical split) or in columns (for horizontal split); may be followed by to specify a percentage of the available space. The option causes the new pane to be created to the left of or above The option creates a new pane spanning the full window height (with or full window width (with instead of splitting the active pane. zooms if the window is not zoomed, or keeps it zoomed if already zoomed.

An empty ('') will create a pane with no command running in it. Output can be sent to such a pane with the command. The flag (if is not specified or empty) will create an empty pane and forward any output from stdin to it. For example: $ make 2>&1|tmux splitw -dI &

All other options have the same meaning as for the command. Swap two panes. If is used and no source pane is specified with is swapped with the previous pane (before it numerically); swaps with the next pane (after it numerically). instructs not to change the active pane and keeps the window zoomed if it was zoomed.

If is omitted and a marked pane is present (see the marked pane is used rather than the current pane. This is similar to except the source and destination windows are swapped. It is an error if no window exists at If is given, the new window does not become the current window.

If is omitted and a marked pane is present (see the window containing the marked pane is used rather than the current window. Unlink Unless is given, a window may be unlinked only if it is linked to multiple sessions - windows may not be linked to no sessions; if is specified and the window is linked to only one session, it is unlinked and destroyed. allows a command to be bound to most keys, with or without a prefix key. When specifying keys, most represent themselves (for example to Ctrl keys may be prefixed with or Shift keys with and Alt (meta) with In addition, the following special key names are accepted: (Delete), to (Insert), and 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 key will execute for all keys which do not have a more specific binding.

Commands related to key bindings are as follows: Bind key to Keys are bound in a key table. By default (without -T), the key is bound in the key table. This table is used for keys pressed after the prefix key (for example, by default is bound to in the table, so creates a new window). The table is used for keys pressed without the prefix key: binding to in the table (not recommended) means a plain will create a new window. is an alias for Keys may also be bound in custom key tables and the command used to switch to them from a key binding. The flag indicates this key may repeat, see the option. attaches a note to the key (shown with

To view the default bindings and possible commands, see the command. List key bindings. There are two forms: the default lists keys as commands; 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. lists only keys in

With the form, only keys in the and key tables are listed by default; also lists only keys in specifies a prefix to print before each key and lists only the first matching key. lists the command for keys that do not have a note rather than skipping them. Send a key or keys to a window. Each argument is the name of the key (such as or 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. If no keys are given and the command is bound to a key, then that key is used.

The flag disables key name lookup and processes the keys as literal UTF-8 characters. The flag expects each key to be a hexadecimal number for an ASCII character.

The flag causes the terminal state to be reset.

passes through a mouse event (only valid if bound to a mouse key binding, see

is used to send a command into copy mode - see the section. specifies a repeat count and expands formats in arguments where appropriate. Send the prefix key, or with the secondary prefix key, to a window as if it was pressed. Unbind the command bound to and are the same as for If is present, all key bindings are removed. The option prevents errors being returned. The appearance and behaviour of may be modified by changing the value of various options. There are four types of option: and

The 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 command, or displayed with the command.

In addition, each individual session may have a set of session options, and there is a separate set of global session options. Sessions which do not have a particular option configured inherit the value from the global session options. Session options are set or unset with the command and may be listed with the command. The available server and session options are listed under the 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 example 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 and commands and displayed with and

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 a pane option with a window option with a server option with otherwise a session option. If the option is not a user option, or may be unnecessary - will infer the type from the option name, assuming for pane options. If is given, the global session or window option is set.

expands formats in the option value. The flag unsets an option, so a session inherits the option from the global options (or with restores a global option to the default). unsets an option (like but if the option is a pane option also unsets the option on any panes in the window. depends on the option and may be a number, a string, or a flag (on, off, or omitted to toggle).

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

With and if the option expects a string or a style, is appended to the existing setting. For example: set -g status-left "foo" set -ag status-left "bar"

Will result in And: set -g status-style "bg=red" set -ag status-style "fg=blue"

Will result in a red background blue foreground. Without the result would be the default background and a blue foreground. Show the pane options (or a single option if is provided) with the window options with the server options with otherwise the session options. If the option is not a user option, or may be unnecessary - will infer the type from the option name, assuming for pane options. Global session or window options are listed if is used. shows only the option value, not the name. If is set, no error will be returned if is unset. includes hooks (omitted by default). includes options inherited from a parent set of options, such options are marked with an asterisk.

Available server options are: Set the key sent by for backspace. 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. This is an array of custom aliases for commands. If an unknown command matches it is replaced with For example, after:

Using:

Is equivalent to:

Note that aliases are expanded when a command is parsed rather than when it is executed, so binding an alias with will bind the expanded form. Set the default terminal for new windows created in this session - the default value of the environment variable. For to work correctly, this be set to or a derivative of them. Give the command to pipe to if the copy mode command is used without arguments. Set the time in milliseconds for which waits after an escape is input to determine if it is part of a function or meta key sequences. The default is 500 milliseconds. Set the command used when runs an editor. If enabled (the default), the server will exit when there are no active sessions. If enabled, the server will exit when there are no attached clients. When or the escape sequence to enable extended keys is sent to the terminal, if knows that it is supported. always recognises extended keys itself. If this option is will only forward extended keys to applications when they request them; if will always forward the keys. When enabled, focus events are requested from the terminal if supported and passed through to applications running in Attached clients should be detached and attached again after changing this option. If not empty, a file to which will write command prompt history on exit and load it from on start. Set the number of error or information messages to save in the message log for each client. Set the number of history items to save in the history file for each type of command prompt. Attempt to set the terminal clipboard content using the escape sequence, if there is an entry in the description (see the section).

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

Note that this feature needs to be enabled in by setting the resource: disallowedWindowOps: 20,21,SetXprop

Or changing this property from the interactive menu when required. Set terminal features for terminal types read from has a set of named terminal features. Each will apply appropriate changes to the entry in use.

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 option allows individual capabilities to be set instead, is intended for classes of functionality supported in a standard way but not reported by Care must be taken to configure this only with features the terminal actually supports.

This is an array option where each entry is a colon-separated string made up of a terminal type pattern (matched using followed by a list of terminal features. The available features are: Supports 256 colours with the SGR escape sequences. Allows setting the system clipboard. Allows setting the cursor colour. Allows setting the cursor style. Supports extended keys. Supports focus reporting. Supports DECSLRM margins. Supports mouse sequences. Supports the OSC 7 working directory extension. Supports the overline SGR attribute. Supports the DECFRA rectangle fill escape sequence. Supports RGB colour with the SGR escape sequences. Supports the strikethrough SGR escape sequence. Supports synchronized updates. Supports title setting. Allows underscore style and colour to be set. Allow terminal descriptions read using to be overridden. Each entry is a colon-separated string made up of a terminal type pattern (matched using and a set of entries.

For example, to set the entry to for all terminal types matching

The terminal entry value is passed through before interpretation. Set list of user-defined key escape sequences. Each item is associated with a key named and so on.

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

Available session options are: Set action on window activity when is on. means activity in any window linked to a session causes a bell or message (depending on in the current window of that session, means all activity is ignored (equivalent to being off), means only activity in windows other than the current window are ignored and means activity in the current window is ignored but not those in other windows. If keys are entered faster than one in they are assumed to have been pasted rather than typed and key bindings are not processed. The default is one millisecond and zero disables. Set the base index from which an unused index should be searched when a new window is created. The default is zero. Set action on a bell in a window when is on. The values are the same as those for Set the command used for new windows (if not specified when the window is created) to which may be any command. The default is an empty string, which instructs to create a login shell using the value of the option. Specify the default shell. This is used as the login shell for new windows when the option is set to empty, and must be the full path of the executable. When started tries to set a default value from the first suitable of the environment variable, the shell returned by or

This option should be configured when is used as a login shell. Set the default size of new windows when the option is set to manual or when a session is created with The value is the width and height separated by an character. The default is 80x24. If enabled and the session is no longer attached to any clients, it is destroyed. If on (the default), the client is detached when the session it is attached to is destroyed. If off, the client is switched to the most recently active of the remaining sessions. If the client is detached only if there are no detached sessions; if detached sessions exist, the client is switched to the most recently active. Set the colour used by the command to show the indicator for the active pane. Set the colour used by the command to show the indicators for inactive panes. Set the time in milliseconds for which the indicators shown by the command appear. 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. is in milliseconds. 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. Set the default key table to instead of Lock the session (like the command) after seconds of inactivity. The default is not to lock (set to 0). Command to run when locking each client. The default is to run with Set status line message command style. This is used for the command prompt with keys when in command mode. For how to specify see the section. Set status line message style. This is used for messages and for the command prompt. For how to specify see the section. If on, captures the mouse and allows mouse events to be bound as key bindings. See the section for details. Set the key accepted as a prefix key. In addition to the standard keys described under can be set to the special key to set no prefix. Set a secondary key accepted as a prefix key. Like can be set to If on, when a window is closed in a session, automatically renumber the other windows in numerical order. This respects the option if it has been set. If off, do not renumber the windows. Allow multiple commands to be entered without pressing the prefix-key again in the specified milliseconds (the default is 500). Whether a key repeats may be set when it is bound using the flag to Repeat is enabled for the default keys bound to the command. Attempt to set the client terminal title using the and entries if they exist. automatically sets these to the \ee]0;...\e007 sequence if the terminal appears to be This option is off by default. String used to set the client terminal title if is on. Formats are expanded, see the section. Set action on window silence when is on. The values are the same as those for Show or hide the status line or specify its size. Using gives a status line one row in height; or more rows. 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. Update the status line every seconds. By default, updates will occur every 15 seconds. A setting of zero disables redrawing at interval. 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-centre uses the centre of the entire horizontal space. Use vi or emacs-style key bindings in the status line, for example at the command prompt. The default is emacs, unless the or environment variables are set and contain the string Display (by default the session name) to the left of the status line. will be passed through Also see the and sections.

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

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

The default is Set the maximum of the left component of the status line. The default is 10. Set the style of the left part of the status line. For how to specify see the section. Set the position of the status line. Display 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 will be passed to and character pairs are replaced. Set the maximum of the right component of the status line. The default is 40. Set the style of the right part of the status line. For how to specify see the section. Set status line style. For how to specify see the section. 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 was given to the command). If on, display a message instead of sending a bell when activity occurs in a window for which the window option is enabled. If set to both, a bell and a message are produced. If on, a message is shown on a bell in a window for which the window option is enabled instead of it being passed through to the terminal (which normally makes a sound). If set to both, a bell and a message are produced. Also see the option. If is enabled, prints a message after the interval has expired on a given window instead of sending a bell. If set to both, a bell and a message are produced. 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.

Available window options are:

Aggressively resize the chosen window. This means that will resize the window to the size of the smallest or largest session (see the 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 and poor for interactive programs such as shells.

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

The format (see used when the option is enabled.

Set clock colour.

Set clock hour format.

Set the character used to fill areas of the terminal unused by a window.

Set the width or height of the main (left or top) pane in the or layouts. If suffixed by this is a percentage of the window size.

Set the style of search matches in copy mode. For how to specify see the section.

Set the style of the line containing the mark in copy mode. For how to specify see the section.

Set the style of the current search match in copy mode. For how to specify see the section.

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

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

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

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

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

Set the height of the other panes (not the main pane) in the layout. If this option is set to 0 (the default), it will have no effect. If both the and 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 suffixed by this is a percentage of the window size.

Like but set the width of other panes in the layout.

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

Like but set the starting index for pane numbers.

Set the text shown in pane border status lines.

Indicate active pane by colouring only half of the border in windows with exactly two panes, by displaying arrow markers, by drawing both or neither.

Set the type of characters used for drawing pane borders. may be one of: single lines using ACS or UTF-8 characters double lines using UTF-8 characters heavy lines using UTF-8 characters simple ASCII characters the pane number

and will fall back to standard ACS line drawing when UTF-8 is not supported.

Turn pane border status lines off or set their position.

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

Set the popup style. For how to specify see the section. Attributes are ignored.

Set the popup border style. For how to specify see the section. Attributes are ignored.

Set the type of characters used for drawing popup borders. may be one of: single lines using ACS or UTF-8 characters (default) variation of single with rounded corners using UTF-8 characters double lines using UTF-8 characters heavy lines using UTF-8 characters simple ASCII characters simple ASCII space character no border

and will fall back to standard ACS line drawing when UTF-8 is not supported.

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

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

Like but is the format used when the window is the current window.

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

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

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

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

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

Configure how determines the window size. If set to the size of the largest attached session is used; if the size of the smallest. If the size of a new window is set from the option and windows are resized automatically. With uses the size of the client that had the most recent activity. See also the command and the option.

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

Available pane options are:

Allow programs in the pane to bypass using a terminal escape sequence (\eePtmux;...\ee\e\e).

Allow programs in the pane to change the window name using a terminal escape sequence (\eek...\ee\e\e).

This option configures whether programs running inside the pane may use the terminal alternate screen feature, which allows the and capabilities. The alternate screen feature preserves the contents of the window when an interactive application starts and restores it on exit, so that any output visible before the application starts reappears unchanged after it exits.

Set the colour of the cursor.

The default colour palette. Each entry in the array defines the colour uses when the colour with that index is requested. The index may be from zero to 255.

Set the style of the cursor. Available styles are:

A pane with this flag set is not destroyed when the program running in it exits. If set to then only when the program exit status is not zero. The pane may be reactivated with the command.

Set the text shown at the bottom of exited panes when is enabled.

When the entire screen is cleared and this option is on, scroll the contents of the screen into history before clearing it.

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).

Set the pane style when it is the active pane. For how to specify see the section.

Set the pane style. For how to specify see the section. allows commands to run on various triggers, called Most commands have an 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 or commands and displayed with or 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 prefix. For example, the following command adds a hook to select the even-vertical layout after every set-hook -g after-split-window "selectl even-vertical"

All the notifications listed in the section are hooks (without any arguments), except The following additional hooks are available: Run when a window has activity. See Run when a window has received a bell. See Run when a window has been silent. See Run when a client becomes the latest active client of its session. Run when a client is attached. Run when a client is detached Run when focus enters a client Run when focus exits a client Run when a client is resized. Run when a client's attached session is changed. Run when the program running in a pane exits, but is on so the pane has not closed. Run when the program running in a pane exits. Run when the focus enters a pane, if the option is on. Run when the focus exits a pane, if the option is on. Run when the terminal clipboard is set using the escape sequence. Run when a new session created. Run when a session closed. Run when a session is renamed. Run when a window is linked into a session. Run when a window is renamed. Run when a window is resized. This may be after the hook is run. Run when a window is unlinked from a session.

Hooks are managed with these commands: Without sets (or with unsets) hook to The flags are the same as for

With run immediately. Shows hooks. The flags are the same as for If the option is on (the default is off), allows mouse events to be bound as keys. The name of each key is made up of a mouse event (such as and a location suffix, one of the following:

The following mouse events are available:

The events are fired for the second click of a double click, even if there may be a third click which will fire instead of

Each should be suffixed with a location, for example

The special token or may be used as or 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 binding, or the pane over which the wheel was scrolled for a binding).

The 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 option is turned on. Certain commands accept the flag with a argument. This is a string which controls the output format of the command. Format variables are enclosed in and for example The possible variables are listed in the table below, or the name of a option may be used for an option's value. Some variables have a shorter alias such as 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 will include the string if the session is attached and the string if it is unattached, or will include if is enabled, or if not. Conditionals can be nested arbitrarily. Inside a conditional, and must be escaped as and unless they are part of a replacement. For example: #{?pane_in_mode,#[fg=white#,bg=red],#[fg=red#,bg=white]}#W .

String comparisons may be expressed by prefixing two comma-separated alternatives by or and a colon. For example will be replaced by if running on otherwise by and evaluate to true if either or both of two comma-separated alternatives are true, for example

An specifies an or regular expression comparison. The first argument is the pattern and the second the string to compare. An optional argument specifies flags: means the pattern is a regular expression instead of the default pattern, and means to ignore case. For example: or A performs a search for an pattern or regular expression in the pane content and evaluates to zero if not found, or a line number if found. Like an flag means search for a regular expression and ignores case. For example:

Numeric operators may be performed by prefixing two comma-separated alternatives with an and an operator. An optional 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 or (note that must be escaped as in formats which are also expanded by and numeric comparison operators and For example, multiplies 5.5 by 3 for a result with four decimal places and returns the modulus of 7 and 3. replaces a numeric argument by its ASCII equivalent, so results in replaces a colour by its six-digit hexadecimal RGB value.

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 will include at most the first five characters of the pane title, or the last five characters. A suffix or prefix may be given as a second argument - if provided then it is appended or prepended to the string if the length has been trimmed, for example will append if the pane title is more than five characters. Similarly, pads the string to a given width, for example will result in a width of at least 10 characters. A positive width pads on the left, a negative on the right. expands to the length of the variable and to its width when displayed, for example

Prefixing a time variable with will convert it to a string, so if gives gives Adding will use shorter but less accurate time format for times in the past. A custom format may be given using an suffix (note that must be escaped as if the format is separately being passed through for example in the option): see

The and prefixes are and of the variable respectively. will escape special characters or with a suffix, escape hash characters (so becomes will expand the format twice, for example is the result of expanding the content of the option rather than the option itself. is like but also expands specifiers. or 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} }

checks if a window (without any suffix or with the suffix) or a session (with the suffix) name exists, for example is replaced with 1 if a window named exists.

A prefix of the form will substitute with throughout. The first argument may be an extended regular expression and a final argument may be to ignore case, for example would change into

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

and with the global environment set (see the section).

An specifies that a string should be interpreted literally and not expanded. For example will be replaced by

The following variables are available, where appropriate: offers various options to specify the colour and attributes of aspects of the interface, for example for the status line. In addition, embedded styles may be specified in format options, such as by enclosing them in and

A style may be the single term to specify the default style (which may come from an option, for example in the status line) or a space or comma separated list of the following: Set the foreground colour. The colour is one of: if supported the bright variants to from the 256-colour set; for the default colour; for the terminal default colour; or a hexadecimal RGB string such as Set the background colour. Set no attributes (turn off any active attributes). (or Set an attribute. Any of the attributes may be prefixed with to unset. is the terminal alternate character set. (or Align text to the left, centre or right of the available space if appropriate. Fill the available space with a background colour if appropriate. Mark the position of the various window list components in the option: marks the start of the list; is the part of the list that should be kept in focus if the entire list won't fit in the available space (typically the current window); and 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. Store the current colours and attributes as the default or reset to the previous default. A affects any subsequent use of the term until a Only one default may be pushed (each replaces the previous saved default). Mark a range in the option. and are the text used for the and mouse keys. is the range for a window passed to the mouse key, where is a window index.

Examples are: fg=yellow bold underscore blink bg=black,fg=default,noreverse 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 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 window title in Windows themselves do not have titles - a window's title is the title of its active pane. itself may set the title of the terminal in which the client is running, see the option.

A session's name is set with the and commands. A window's name is set with one of: A command argument (such as for or An escape sequence (if the option is turned on): $ printf '\e033kWINDOW_NAME\e033\e\e' Automatic renaming, which sets the name to the active command in the window's active pane. See the option.

When a pane is first created, its title is the hostname. A pane's title can be set via the title setting escape sequence, for example: $ printf '\e033]2;My Title\e033\e\e'

It can also be modified with the command. When the server is started, copies the environment into the in addition, each session has a 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 session option may be used to update the session environment from the client when a new session is created or an old reattached. also initialises the variable with some internal information to allow commands to be executed from inside, and the variable with the correct terminal setting of

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 itself (for example in formats, see the section).

Commands to alter and view the environment are: Set or unset an environment variable. If is used, the change is made in the global environment; otherwise, it is applied to the session environment for If is present, then is expanded as a format. The flag unsets a variable. indicates the variable is to be removed from the environment before starting a new process. marks the variable as hidden. Display the environment for or the global environment with If is omitted, all variables are shown. Variables removed from the environment are prefixed with If is used, the output is formatted as a set of Bourne shell commands. shows hidden variables (omitted by default). includes an optional status line which is displayed in the bottom line of each terminal.

By default, the status line is enabled and one line in height (it may be disabled or made multiple lines with the 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 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 and options below), and a central window list. By default, the window list shows the index, name and (if any) flag of the windows present in the current session in ascending numerical order. It may be customised with the and options. The flag is one of the following symbols appended to the window name:

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

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

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

Commands related to the status line are as follows: Clear status prompt history for prompt type If is omitted, then clear history for all types. See for possible values for Open the command prompt in a client. This may be used from inside to execute commands interactively.

If is specified, it is used as the command. With is expanded as a format.

If present, is a comma-separated list of the initial text for each prompt. If is given, is a comma-separated list of prompts which are displayed in order; otherwise a single prompt is displayed, constructed from if it is present, or if not.

Before the command is executed, the first occurrence of the string and all occurrences of are replaced by the response to the first prompt, all are replaced with the response to the second prompt, and so on for further prompts. Up to nine prompt responses may be replaced

is like but any quotation marks are escaped.

makes the prompt only accept one key press, in this case the resulting input is a single character. is like but the key press is translated to a key name. makes the prompt only accept numeric key presses. executes the command every time the prompt input changes instead of when the user exits the command prompt.

tells the prompt type. This affects what completions are offered when is pressed. Available types are: and

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

With the prompt is shown in the background and the invoking client does not exit until it is dismissed. Ask for confirmation before executing If is given, is the prompt to display; otherwise a prompt is constructed from It may contain the special character sequences supported by the option. With the prompt is shown in the background and the invoking client does not exit until it is dismissed. Display a menu on 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 and sections. If the name begins 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.

is a format for the menu title (see

and give the position of the menu. Both may be a row or column number, or one of the following special values:

Or a format, which is expanded including the following additional variables:

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. changes this behaviour so that the menu does not close when the mouse button is released without 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: Display a message. If is given, the output is printed to stdout, otherwise it is displayed in the status line for up to milliseconds. If is not given, the option is used; a delay of zero waits for a key press. ignores key presses and closes only after the delay expires. The format of is described in the section; information is taken from if is given, otherwise the active pane.

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

forwards any input read from stdin to the empty pane given by Display a popup running on A popup is a rectangular box drawn over the top of any panes. Panes are not updated while a popup is present.

closes the popup automatically when exits. Two closes the popup only if exited with success.

and give the position of the popup, they have the same meaning as for the command. and give the width and height - both may be a percentage (followed by If omitted, half of the terminal size is used.

does not surround the popup by a border.

sets the type of border line for the popup. When is specified, the option is ignored. See for possible values for

sets the style for the popup and sets the style for the popup border. For how to specify see the section.

takes the form and sets an environment variable for the popup; it may be specified multiple times.

is a format for the popup title (see

The flag closes any popup on the client. Display status prompt history for prompt type If is omitted, then show history for all types. See for possible values for maintains a set of named Each buffer may be either explicitly or automatically named. Explicitly named buffers are named when created with the or commands, or by renaming an automatically named buffer with Automatically named buffers are given a name such as and so on. When the option is reached, the oldest automatically named buffer is deleted. Explicitly named buffers are not subject to and may be deleted with the command.

Buffers may be added using or the and commands, and pasted into a window using the 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 option (see the command above).

The buffer commands are as follows: 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 allowing for immediate choice, or the list may be navigated and an item chosen or otherwise manipulated using the keys below. zooms the pane. The following keys may be used in buffer mode:

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

specifies the initial sort field: one of or reverses the sort order. 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. specifies the format for each item in the list and a format for each shortcut key; both are evaluated once for each line. starts without the preview. This command works only if at least one client is attached. Remove and free the history for the specified pane. Delete the buffer named or the most recently added automatically named buffer if not specified. List the global buffers. specifies the format of each line and a filter. Only buffers for which the filter is true are shown. See the section. Load the contents of the specified paste buffer from If is given, the buffer is also sent to the clipboard for using the escape sequence, if possible. Insert the contents of a paste buffer into the specified pane. If not specified, paste into the current one. With also delete the paste buffer. When output, any linefeed (LF) characters in the paste buffer are replaced with a separator, by default carriage return (CR). A custom separator may be specified using the flag. The flag means to do no replacement (equivalent to a separator of LF). If is specified, paste bracket control codes are inserted around the buffer if the application has requested bracketed paste mode. Save the contents of the specified paste buffer to The option appends to rather than overwriting the file. Set the contents of the specified buffer to If is given, the buffer is also sent to the clipboard for using the escape sequence, if possible. The option appends to rather than overwriting the buffer. The option renames the buffer to Display the contents of the specified buffer. Miscellaneous commands are as follows: Display a large clock. Execute the first if (run with

returns success or the second otherwise. Before being executed, is expanded using the rules specified in the section, including those relevant to With is run in the background.

If is given, is not executed but considered success if neither empty nor zero (after formats are expanded). Lock each client individually by running the command specified by the option. Execute using

or (with a command in the background without creating a window. Before being executed, is expanded using the rules specified in the section. With the command is run in the background. waits for seconds before starting the command. If is not given, any output to stdout is displayed in view mode (in the pane specified by or the current pane if omitted) after the command finishes. If the command fails, the exit status is also displayed. When used without options, prevents the client from exiting until woken using with the same channel. When 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 When a client detaches, it prints a message. This may be one of: The client was detached normally. The client was detached and its parent sent the signal (for example with The client's or was unexpectedly destroyed. The client was killed with The client is in control mode and became unable to keep up with the data from The server exited when it had no sessions. The server exited when it received The server crashed or otherwise exited without telling the client the reason. understands some unofficial extensions to It is not normally necessary to set these manually, instead the option should be used. An existing extension that tells the terminal supports default colours. Tell that the terminal supports the VTE bidirectional text extensions. 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 $ printf '\e033]12;red\e033\e\e'

The colour is an colour, see Set, clear, disable or enable DECSLRM margins. These are set automatically if the terminal reports it is compatible. Disable and enable bracketed paste. These are set automatically if the capability is present. Disable and enable extended keys. Disable and enable focus reporting. These are set automatically if the capability is present. Tell that the terminal supports rectangle operations. Enable the overline attribute. 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 underscore and 5 for dashed underscore. Set the underscore colour or reset to the default. The argument is (red * 65536) + (green * 256) + blue where each is between 0 and 255. Set or reset the cursor style. If set, a sequence such as this may be used to change the cursor to an underline: $ printf '\e033[4 q'

If is not set, \&Ss with argument 0 will be used to reset the cursor style instead. Set the opening sequence for the working directory notification. The sequence is terminated using the standard capability. Start (parameter is 1) or end (parameter is 2) a synchronized update. Indicate that the terminal supports the RGB escape sequence (for example, \ee[38;2;255;255;255m).

If supported, this is used for the initialize colour escape sequence (which may be enabled by adding the and capabilities to the entry).

This is equivalent to the capability. Store the current buffer in the host terminal's selection (clipboard). See the option above and the man page. This is an existing extension capability that tmux uses to mean that the terminal supports the title set sequences and to automatically set some of the capabilities above. offers a textual interface called This allows applications to communicate with using a simple text-only protocol.

In control mode, a client sends 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 line followed by the output (which may be empty). The output block ends with a or and matching or have three arguments: an integer 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 command may be used to set the size of a client in control mode.

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

The following notifications are defined: The client has detached. The client is now attached to the session with ID which is named The pane has been continued after being paused (if the flag is set, see The client is exiting immediately, either because it is not attached to any session or an error occurred. If present, describes why the client exited. New form of sent when the flag is set. is the time in milliseconds 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. The layout of a window with ID changed. The new layout is The window's visible layout is and the window flags are A window pane produced output. escapes non-printable characters and backslash as octal \\xxx. The pane with ID has changed mode. The pane has been paused (if the flag is set). The client is now attached to the session with ID which is named The current session was renamed to The session with ID changed its active window to the window with ID A session was created or destroyed. The value of the format associated with subscription has changed to See Any arguments after up until a single are for future use and should be ignored. The window with ID was created but is not linked to the current session. The window with ID which is not linked to the current session, was closed. The window with ID which is not linked to the current session, was renamed. The window with ID was linked to the current session. The window with ID closed. The active pane in the window with ID changed to the pane with ID The window with ID was renamed to When is started, it inspects the following environment variables: If the command specified in this variable contains the string and is unset, use vi-style key bindings. Overridden by the and options. The user's login directory. If unset, the database is consulted. The character encoding It is used for two separate purposes. For output to the terminal, UTF-8 is used if the option is given or if contains or Otherwise, only ASCII characters are written and non-ASCII characters are replaced with underscores

For input, always runs with a UTF-8 locale. If en_US.UTF-8 is provided by the operating system, it is used and is ignored for input. Otherwise, tells what the UTF-8 locale is called on the current system. If the locale specified by is not available or is not a UTF-8 locale, exits with an error message. The date and time format It is used for locale-dependent format specifiers. The current working directory to be set in the global environment. This may be useful 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 is used instead. The absolute path to the default shell for new windows. See the option for details. The parent directory of the directory containing the server sockets. See the option for details. If the command specified in this variable contains the string use vi-style key bindings. Overridden by the and options. Default configuration file. System-wide configuration file. To create a new session running

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

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 (Ctrl followed by the key followed by the key).

Windows may be navigated with: (to select window 0), (to select window 1), and so on; to select the next window; and to select the previous window.

A session may be detached using (or by an external event such as disconnection) and reattached with:

Typing lists the current key bindings in the current window; up and down may be used to navigate the list or to exit from it.

Commands to be run when the server is started may be placed in the

configuration file. Common examples include:

Changing the default prefix key: set-option -g prefix C-a unbind-key C-b bind-key C-a send-prefix

Turning the status line off, or changing its colour: set-option -g status off set-option -g status-style bg=blue

Setting other options, such as the default command, or locking after 30 minutes of inactivity: set-option -g default-command "exec /bin/ksh" set-option -g lock-after-time 1800

Creating new key bindings: bind-key b set-option status bind-key / command-prompt "split-window 'exec man %%'" bind-key S command-prompt "new-window -n %1 'ssh %1'"