CHANGES

CHANGES FROM 3.4 TO 3.5

* Revamp extended keys support to more closely match xterm and support mode 2
  as well as mode 1. This is a substantial change to key handling which changes
  tmux to always request mode 2 from parent terminal, changes to an unambiguous
  internal representation of keys, and adds an option (extended-keys-format) to
  control the format similar to the xterm(1) formatOtherKeys resource.

* Clear an overlay (popup or menu) when command prompt is entered.

* Add copy-mode -d flag to scroll a page down if in copy mode already (matching
  -e).

* Display hyperlinks in copy mode and add copy_cursor_hyperlink format to get
  the hyperlink under the cursor.

* Add a prefix timeout option.

* Mouse move keys are not useful as key bindings because we do not turn them on
  unless the application requests them. Ignore them so they do not cause the
  prefix to be canceled

* Add search_count and search_count_partial formats in copy mode.

* Do not reset mouse pane if clicked on status line,

* Add mirrored versions of the main-horizontal and main-vertical layouts where
  the main pane is bottom or right instead of top or left.

* Allow REP to work with Unicode characters.

* Fix size calculation of terminators for clipboard escape sequences.

* Treat CRLF as LF in config files where it is easy to do so.

* The Linux console has some bugs with bright colours, so add some workarounds
  for it.

* If built with systemd, remove some environment variables it uses.

* Adjust the logic when deleting last buffer to better preserve the selection:
  if selecting the element below the deleted one fails (because as the last
  one), select the one above it instead.

* Add --enable-jemalloc to build with jemalloc memory allocator (since glibc
  malloc is so poor).

* Add a way (refresh-client -r) for control mode clients to provide OSC 10 and
  11 responses to tmux so they can set the default foreground and background
  colours.

* Add N to search backwards in tree modes.

* Use default-shell for command prompt, #() and popups.

* Revert part of a change intended to improve search performance by skipping
  parts of lines already searched, but which in fact skipped the ends of lines
  altogether.

* Add a command-error hook when a command fails.

* Add an option allow-set-title to forbid applications from changing the pane
  title.

* Correct handling of mouse up events (don't ignore all but the last released
  button), and always process down event for double click.

* Fix a crash if focusing a pane that is exiting.

* Pick newest session (as documented) when looking for next session for
  detach-on-destroy.

* Reduce default escape-time to 10 milliseconds.

* Add display-menu -M to always turn mouse on in a menu.

* Look for feature code 21 for DECSLRM and 28 for DECFRA in the device
  attributes and also accept level 1.

* Fix crash if built with SIXEL and the SIXEL colour register is invalid; also
  remove SIXEL images before reflow.

* Do not notify window-layout-changed if the window is about to be destroyed.

* Do not consider a selection present if it is empty for the selection_active
  and selection_present format variables.

* Fix split-window -p.

CHANGES FROM 3.3a TO 3.4

* Add options keep-last and keep-group to destroy-unattached to keep the last
  session whether in a group.

* Don't allow paste-buffer into dead panes.

* Add -t to source-file.

* Rewrite combined character handling to be more consistent and to support
  newer Unicode combined characters.

* Add basic support for SIXEL if built with --enable-sixel.

* Add a session, pane and user mouse range types for the status line and add
  format variables for mouse_status_line and mouse_status_range so they can be
  associated with different commands in the key bindings.

* Add flag (-o) to next-prompt/previous-prompt to go to OSC 133 command output.

* Add options and flags for menu styles (menu-style, menu-border-style) similar
  to those existing for popups.

* Add support for marking lines with a shell prompt based on the OSC 133 extension.

* Check for libterminfo for NetBSD.

* Add "us" to styles for underscore colour.

* Add flags (-c and -y) to change the confirm key and default behaviour of
  confirm-before.

* Use ncurses' new tparm_s function (added in 6.4-20230424) instead of tparm so
  it does not object to string arguments in c apabilities it doesn't already
  know. Also ignore errors from tparm if using previous ncurses versions.

* Set default lock command to vlock on Linux if present at build time.

* Discard mouse sequences that have the right form but actually are invalid.

* Add support for spawning panes in separate cgroups with systemd and a
  configure flag (--disable-cgroups) to turn off.

* Add a format (pane_unseen_changes) to show if there are unseen changes while
  in a mode.

* Remove old buffer when renaming rather than complaining.

* Add an L modifier like P, W, S to loop over clients.

* Add -f to list-clients like the other list commands.

* Extend display-message to work for control clients.

* Add a flag to display-menu to select the manu item selected when the menu is
  open.

* Have tmux recognise pasted text wrapped in bracket paste sequences, rather
  than only forwarding them to the program inside.

* Have client return 1 if process is interrupted to an input pane.

* Query the client terminal for foreground and background colours and if OSC 10
  or 11 is received but no colour has been set inside tmux, return the colour
  from the first attached client.

* Add send-keys -K to handle keys directly as if typed (so look up in key
  table).

* Process escape sequences in show-buffer.

* Add a -l flag to display-message to disable format expansion.

* Add paste-buffer-deleted notification and fix name of paste-buffer-changed.

* Do not attempt to connect to the socket as a client if systemd is active.

* Add scroll-top and scroll-bottom commands to scroll so cursor is at top or
  bottom.

* Add a -T flag to capture-pane to stop at the last used cell instead of the
  full width. Restore the previous behaviour by making it default to off unless
  -J is used.

* Add message-line option to control where message and prompt go.

* Notification when a paste buffer is deleted.

* Add a Nobr terminfo(5) capability to tell tmux the terminal does not use bright
  colours for bold.

* Change g and G to go to top and bottom in menus.

* Add a third state "all" to allow-passthrough to work even in invisible panes.

* Add support for OSC 8 hyperlinks.

* Store the time lines are scrolled into history and display in copy mode.

* Add a %config-error reply to control mode for configuration file errors since
  reporting them in view mode is useless.

* A new feature flag (ignorefkeys) to ignore terminfo(5) function key
  definitions for rxvt.

* Pass through first argument to OSC 52 (which clipboards to set) if the
  application provides it.

* Expand arguments to send-keys, capture-pane, split-window, join-pane where it
  makes sense to do so.

* Ignore named buffers when choosing a buffer if one is not specified by the user.

CHANGES FROM 3.3 TO 3.3a

* Do not crash when run-shell produces output from a config file.

* Do not unintentionally turn off all mouse mode when button mode is also
  present.

CHANGES FROM 3.2a TO 3.3

* Add an ACL list for users connecting to the tmux socket. Users may be
  forbidden from attaching, forced to attach read-only, or allowed to attach
  read-write. A new command, server-access, configures the list. File system
  permissions must still be configured manually.

* Emit window-layout-changed on swap-pane.

* Better error reporting when applying custom layouts.

* Handle ANSI escape sequences in run-shell output.

* Add pane_start_path to match start_command.

* Set PWD so shells have a hint about the real path.

* Do not allow pipe-pane on dead panes.

* Do not report mouse positions (incorrectly) above the maximum of 223 in
  normal mouse mode.

* Add an option (default off) to control the passthrough escape sequence.

* Support more mouse buttons when the terminal sends them.

* Add a window-resized hook which is fired when the window is actually resized
  which may be later than the client resize.

* Add next_session_id format with the next session ID.

* Add formats for client and server UID and user.

* Add argument to refresh-client -l to forward clipboard to a pane.

* Add remain-on-exit-format to set text shown when pane is dead.

* With split-window -f use percentages of window size not pane size.

* Add an option (fill-character) to set the character used for unused areas of
  a client.

* Add an option (scroll-on-clear) to control if tmux scrolls into history on
  clear.

* Add a capability for OSC 7 and use it similarly to how the title is set (and
  controlled by the same set-titles option).

* Add support for systemd socket activation (where systemd creates the Unix
  domain socket for tmux rather than tmux creating it). Build with
  --enable-systemd.

* Add an option (pane-border-indicators) to select how the active pane is shown
  on the pane border (colour, arrows or both).

* Support underscore styles with capture-pane -e.

* Make pane-border-format a pane option rather than window.

* Respond to OSC 4 queries

* Fix g/G keys in modes to do the same thing as copy mode (and vi).

* Bump the time terminals have to respond to device attributes queries to three
  seconds.

* If automatic-rename is off, allow the rename escape sequence to set an empty
  name.

* Trim menu item text more intelligently.

* Add cursor-style and cursor-colour options to set the default cursor style
  and colour.

* Accept some useful and non-conflicting emacs keys in vi normal mode at the
  command prompt.

* Add a format modifier (c) to force a colour to RGB.

* Add -s and -S to display-popup to set styles, -b to set lines and -T to set
  popup title. New popup-border-lines, popup-border-style and popup-style
  options set the defaults.

* Add -e flag to set an environment variable for a popup.

* Make send-keys without arguments send the key it is bound to (if bound to a
  key).

* Try to leave terminal cursor at the right position even when tmux is drawing
  its own cursor or selection (such as at the command prompt and in choose
  mode) for people using screen readers and similar which can make use of it.

* Change so that {} is converted to tmux commands immediately when parsed. This
  means it must contain valid tmux commands. For commands which expand %% and
  %%%, this now only happens within string arguments. Use of nested aliases
  inside {} is now forbidden. Processing of commands given in quotes remains
  the same.

* Disable evports on SunOS since they are broken.

* Do not expand the file given with tmux -f so it can contain :s.

* Bump FORMAT_LOOP_LIMIT and add a log message when hit.

* Add a terminal feature for the mouse (since FreeBSD termcap does not have kmous).

* Forbid empty session names.

* Improve error reporting when the tmux /tmp directory cannot be created or
  used.

* Give #() commands a one second grace period where the output is empty before
  telling the user they aren't doing anything ("not ready").

* When building, pick default-terminal from the first of tmux-256color, tmux,
  screen-256color, screen that is available on the build system (--with-TERM
  can override).

* Do not close popups on resize, instead adjust them to fit.

* Add a client-active hook.

* Make window-linked and window-unlinked window options.

* Do not configure on macOS without the user making a choice about utf8proc
  (either --enable-utf8proc or --disable-utf8proc).

* Do not freeze output in panes when a popup is open, let them continue to
  redraw.

* Add pipe variants of the line copy commands.

* Change copy-line and copy-end-of-line not to cancel and add -and-cancel
  variants, like the other copy commands.

* Support the OSC palette-setting sequences in popups.

* Add a pane-colours array option to specify the defaults palette.

* Add support for Unicode zero-width joiner.

* Make newline a style delimiter as well so they can cross multiple lines for
  readability in configuration files.

* Change focus to be driven by events rather than scanning panes so the
  ordering of in and out is consistent.

* Add display-popup -B to open a popup without a border.

* Add a menu for popups that can be opened with button three outside the popup
  or on the left or top border. Resizing now only works on the right and bottom
  borders or when using Meta. The menu allows a popup to be closed, expanded to
  the full size of the client, centered in the client or changed into a pane.

* Make command-prompt and confirm-before block by default (like run-shell). A
  new -b flags runs them in the background as before. Also set return code for
  confirm-before.

* Change cursor style handling so tmux understands which sequences contain
  blinking and sets the flag appropriately, means that it works whether cnorm
  disables blinking or not. This now matches xterm's behaviour.

* More accurate vi(1) word navigation in copy mode and on the status line. This
  changes the meaning of the word-separators option: setting it to the empty
  string is equivalent to the previous behavior.

* Add -F for command-prompt and use it to fix "Rename" on the window menu.

* Add different command histories for different types of prompts ("command",
  "search" etc).

CHANGES FROM 3.2 TO 3.2a

* Add an "always" value for the "extended-keys" option; if set then tmux will
  forward extended keys to applications even if they do not request them.

* Add a "mouse" terminal feature so tmux can enable the mouse on terminals
  where it is known to be supported even if terminfo(5) says otherwise.

* Do not expand the filename given to -f so it can contain colons.

* Fixes for problems with extended keys and modifiers, scroll region,
  source-file, crosscompiling, format modifiers and other minor issues.

CHANGES FROM 3.1c TO 3.2

* Add a flag to disable keys to close a message.

* Permit shortcut keys in buffer, client, tree modes to be configured with a
  format (-K flag to choose-buffer, choose-client, choose-tree).

* Add a current_file format for the config file being parsed.

* When display-message used in config file, show the message after the config
  file finishes.

* Add client-detached notification in control mode.

* Improve performance of format evaluation.

* Make jump command support UTF-8 in copy mode.

* Support X11 colour names and other colour formats for OSC 10 and 11.

* Add "pipe" variants of "copy-pipe" commands which do not copy.

* Include "focused" in client flags.

* Send Unicode directional isolate characters around horizontal pane borders if
  the terminal supports UTF-8 and an extension terminfo(5) capability "Bidi" is
  present.

* Add a -S flag to new-window to make it select the existing window if one
  with the given name already exists rather than failing with an error.

* Add a format modifier to check if a window or session name exists (N/w or
  N/s).

* Add compat clock_gettime for older macOS.

* Add a no-detached choice to detach-on-destroy which detaches only if there
  are no other detached sessions to switch to.

* Add rectangle-on and rectangle-off copy mode commands.

* Change so that window_flags escapes # automatically. A new format
  window_raw_flags contains the old unescaped version.

* Add -N flag to never start server even if command would normally do so.

* With incremental search, start empty and only repeat the previous search if
  the user tries to search again with an empty prompt.

* Add a value for remain-on-exit that only keeps the pane if the program
  failed.

* Add a -C flag to run-shell to use a tmux command rather than a shell command.

* Do not list user options with show-hooks.

* Remove current match indicator in copy mode which can't work anymore since we
  only search the visible region.

* Make synchronize-panes a pane option and add -U flag to set-option to unset
  an option on all panes.

* Make replacement of ##s consistent when drawing formats, whether followed by
  [ or not. Add a flag (e) to the q: format modifier to double up #s.

* Add -N flag to display-panes to ignore keys.

* Change how escaping is processed for formats so that ## and # can be used in
  styles.

* Add a 'w' format modifier for string width.

* Add support for Haiku.

* Expand menu and popup -x and -y as formats.

* Add numeric comparisons for formats.

* Fire focus events even when the pane is in a mode.

* Add -O flag to display-menu to not automatically close when all mouse buttons
  are released.

* Allow fnmatch(3) wildcards in update-environment.

* Disable nested job expansion so that the result of #() is not expanded again.

* Use the setal capability as well as (tmux's) Setulc.

* Add -q flag to unbind-key to hide errors.

* Allow -N without a command to change or add a note to an existing key.

* Add a -w flag to set- and load-buffer to send to clipboard using OSC 52.

* Add -F to set-environment and source-file.

* Allow colour to be spelt as color in various places.

* Add n: modifier to get length of a format.

* Respond to OSC colour requests if a colour is available.

* Add a -d option to display-message to set delay.

* Add a way for control mode clients to subscribe to a format and be notified
  of changes rather than having to poll.

* Add some formats for search in copy mode (search_present, search_match).

* Do not wait on shutdown for commands started with run -b.

* Add -b flags to insert a window before (like the existing -a for after) to
  break-pane, move-window, new-window.

* Make paste -p the default for ].

* Add support for pausing a pane when the output buffered for a control mode
  client gets too far behind. The pause-after flag with a time is set on the
  pane with refresh-client -f and a paused pane may be resumed with
  refresh-client -A.

* Allow strings in configuration files to span multiple lines - newlines and
  any leading whitespace are removed, as well as any following comments that
  couldn't be part of a format. This allows long formats or other strings to be
  annotated and indented.

* Instead of using a custom parse function to process {} in configuration
  files, treat as a set of statements the same as outside {} and convert back
  to a string as the last step. This means the rules are consistent inside and
  outside {}, %if and friends work at the right time, and the final result
  isn't littered with unnecessary newlines.

* Add support for extended keys - both xterm(1)'s CSI 27 ~ sequence and the
  libtickit CSI u sequence are accepted; only the latter is output. tmux will
  only attempt to use these if the extended-keys option is on and it can detect
  that the terminal outside supports them (or is told it does with the
  "extkeys" terminal feature).

* Add an option to set the pane border lines style from a choice of single
  lines (ACS or UTF-8), double or heavy (UTF-8), simple (plain ASCII) or number
  (the pane numbers). Lines that won't work on a non-UTF-8 terminal are
  translated back into ACS when they are output.

* Make focus events update the latest client (like a key press).

* Store UTF-8 characters differently to reduce memory use.

* Fix break-pane -n when only one pane in the window.

* Instead of sending all data to control mode clients as fast as possible, add
  a limit of how much data will be sent to the client and try to use it for
  panes with some degree of fairness.

* Add an active-pane client flag (set with attach-session -f, new-session -f
  or refresh-client -f). This allows a client to have an independent active
  pane for interactive use (the window client pane is still used for many
  things however).

* Add a mark to copy mode, this is set with the set-mark command (bound to X)
  and appears with the entire line shown using copy-mode-mark-style and the
  marked character in reverse. The jump-to-mark command (bound to M-x) swaps
  the mark and the cursor positions.

* Add a -D flag to make the tmux server run in the foreground and not as a
  daemon.

* Do not loop forever in copy mode when search finds an empty match.

* Fix the next-matching-bracket logic when using vi(1) keys.

* Add a customize mode where options may be browsed and changed, includes
  adding a brief description of each option. Bound to C-b C by default.

* Change message log (C-b ~) so there is one for the server rather than one per
  client and it remains after detach, and make it useful by logging every
  command.

* Add M-+ and M-- to tree mode to expand and collapse all.

* Change the existing client flags for control mode to apply for any client,
  use the same mechanism for the read-only flag and add an ignore-size flag.

  refresh-client -F has become -f (-F stays for backwards compatibility) and
  attach-session and switch-client now have -f flags also. A new format
  client_flags lists the flags and is shown by list-clients by default.

  This separates the read-only flag from "ignore size" behaviour (new
  ignore-size) flag - both behaviours are useful in different circumstances.

  attach -r and switchc -r remain and set or toggle both flags together.

* Store and restore cursor position when copy mode is resized.

* Export TERM_PROGRAM and TERM_PROGRAM_VERSION like various other terminals.

* Add formats for after hook command arguments: hook_arguments with all the
  arguments together; hook_argument_0, hook_argument_1 and so on with
  individual arguments; hook_flag_X if flag -X is present; hook_flag_X_0,
  hook_flag_X_1 and so on if -X appears multiple times.

* Try to search the entire history first for up to 200 ms so a search count can
  be shown. If it takes too long, search the visible text only.

* Use VIS_CSTYLE for paste buffers also (show \012 as \n).

* Change default formats for tree mode, client mode and buffer mode to be more
  compact and remove some clutter.

* Add a key (e) in buffer mode to open the buffer in an editor. The buffer
  contents is updated when the editor exits.

* Add -e flag for new-session to set environment variables, like the same flag
  for new-window.

* Improve search match marking in copy mode. Two new options
  copy-mode-match-style and copy-mode-current-match-style to set the style for
  matches and for the current match respectively. Also a change so that if a
  copy key is pressed with no selection, the current match (if any) is copied.

* Sanitize session names like window names instead of forbidding invalid ones.

* Check if the clear terminfo(5) capability starts with CSI and if so then
  assume the terminal is VT100-like, rather than relying on the XT capability.

* Improve command prompt tab completion and add menus both for strings and -t
  and -s (when used without a trailing space). command-prompt has additional
  flags for only completing a window (-W) and a target (-T), allowing C-b ' to
  only show windows and C-b . only targets.

* Change all the style options to string options so they can support formats.
  Change pane-active-border-style to use this to change the border colour when
  in a mode or with synchronize-panes on. This also implies a few minor changes
  to existing behaviour:

  - set-option -a with a style option automatically inserts a comma between the
    old value and appended text.

  - OSC 10 and 11 no longer set the window-style option, instead they store the
    colour internally in the pane data and it is used as the default when the
    option is evaluated.

  - status-fg and -bg now override status-style instead of the option values
    being changed.

* Add extension terminfo(5) capabilities for margins and focus reporting.

* Try $XDG_CONFIG_HOME/tmux/tmux.conf as well as ~/.config/tmux/tmux.conf for
  configuration file (the search paths are in TMUX_CONF in Makefile.am).

* Remove the DSR 1337 iTerm2 extension and replace by the extended device
  attributes sequence (CSI > q) supported by more terminals.

* Add a -s flag to copy-mode to specify a different pane for the source
  content. This means it is possible to view two places in a pane's history at
  the same time in different panes, or view the history while still using the
  pane. Pressing r refreshes the content from the source pane.

* Add an argument to list-commands to show only a single command.

* Change copy mode to make copy of the pane history so it does not need to
  freeze the pane.

* Restore pane_current_path format from portable tmux on OpenBSD.

* Wait until the initial command sequence is done before sending a device
  attributes request and other bits that prompt a reply from the terminal. This
  means that stray replies are not left on the terminal if the command has
  attached and then immediately detached and tmux will not be around to receive
  them.

* Add a -f filter argument to the list commands like choose-tree.

* Move specific hooks for panes to pane options and windows for window options
  rather than all hooks being session options. These hooks are now window options:

  window-layout-changed
  window-linked
  window-pane-changed
  window-renamed
  window-unlinked

  And these are now pane options:

  pane-died
  pane-exited
  pane-focus-in
  pane-focus-out
  pane-mode-changed
  pane-set-clipboard

  Any existing configurations using these hooks on a session rather than
  globally (that is, set-hook or set-option without -g) may need to be changed.

* Show signal names when a process exits with remain-on-exit on platforms which
  have a way to get them.

* Start menu with top item selected if no mouse and use mode-style for the
  selected item.

* Add a copy-command option and change copy-pipe and friends to pipe to it if
  used without arguments, allows all the default copy key bindings to be
  changed to pipe with one option rather than needing to change each key
  binding individually.

* Tidy up the terminal detection and feature code and add named sets of
  terminal features, each of which are defined in one place and map to a
  builtin set of terminfo(5) capabilities. Features can be specified based on
  TERM with a new terminal-features option or with the -T flag when running
  tmux. tmux will also detect a few common terminals from the DA and DSR
  responses.

  This is intended to make it easier to configure tmux's use of terminfo(5)
  even in the presence of outdated ncurses(3) or terminfo(5) databases or for
  features which do not yet have a terminfo(5) entry. Instead of having to grok
  terminfo(5) capability names and what they should be set to in the
  terminal-overrides option, the user can hopefully just give tmux a feature
  name and let it do the right thing.

  The terminal-overrides option remains both for backwards compatibility and to
  allow tweaks of individual capabilities.

* Support mintty's application escape sequence (means tmux doesn't have to
  delay to wait for Escape, so no need to reduce escape-time when using
  mintty).

* Change so main-pane-width and height can be given as a percentage.

* Support for the iTerm2 synchronized updates feature (allows the terminal to
  avoid unnecessary drawing while output is still in progress).

* Make the mouse_word and mouse_line formats work in copy mode and enable the
  default pane menu in copy mode.

* Add a -T flag to resize-pane to trim lines below the cursor, moving lines out
  of the history.

* Add a way to mark environment variables as "hidden" so they can be used by
  tmux (for example in formats) but are not set in the environment for new
  panes. set-environment and show-environment have a new -h flag and there is a
  new %hidden statement for the configuration file.

* Change default position for display-menu -x and -y to centre rather than top
  left.

* Add support for per-client transient popups, similar to menus but which are
  connected to an external command (like a pane). These are created with new
  command display-popup.

* Change double and triple click bindings so that only one is fired (previously
  double click was fired on the way to triple click). Also add default double
  and triple click bindings to copy the word or line under the cursor and
  change the existing bindings in copy mode to do the same.

* Add a default binding for button 2 to paste.

* Add -d flag to run-shell to delay before running the command and allow it to
  be used without a command so it just delays.

* Add C-g to cancel command prompt with vi keys as well as emacs, and q in
  command mode.

* When the server socket is given with -S, create it with umask 177 instead of
  117 (because it may not be in a safe directory like the default directory in
  /tmp).

* Add a copy-mode -H flag to hide the position marker in the top right.

* Add number operators for formats (+, -, *, / and m),

CHANGED FROM 3.1b TO 3.1c

* Do not write after the end of the array and overwrite the stack when
  colon-separated SGR sequences contain empty arguments.

CHANGES FROM 3.1a TO 3.1b

* Fix build on systems without sys/queue.h.

* Fix crash when allow-rename is on and an empty name is set.

CHANGES FROM 3.1 TO 3.1a

* Do not close stdout prematurely in control mode since it is needed to print
  exit messages. Prevents hanging when detaching with iTerm2.

CHANGES FROM 3.0a TO 3.1

* Only search the visible part of the history when marking (highlighting)
  search terms. This is much faster than searching the whole history and solves
  problems with large histories. The count of matches shown is now the visible
  matches rather than all matches.

* Search using regular expressions in copy mode. search-forward and
  search-backward use regular expressions by default; the incremental versions
  do not.

* Turn off mouse mode 1003 as well as the rest when exiting.

* Add selection_active format for when the selection is present but not moving
  with the cursor.

* Fix dragging with modifier keys, so binding keys such as C-MouseDrag1Pane and
  C-MouseDragEnd1Pane now work.

* Add -a to list-keys to also list keys without notes with -N.

* Do not jump to next word end if already on a word end when selecting a word;
  fixes select-word with single character words and vi(1) keys.

* Fix top and bottom pane calculation with pane border status enabled.

* Add support for adding a note to a key binding (with bind-key -N) and use
  this to add descriptions to the default key bindings. A new -N flag to
  list-keys shows key bindings with notes. Change the default ? binding to use
  this to show a readable summary of keys. Also extend command-prompt to return
  the name of the key pressed and add a default binding (/) to show the note
  for the next key pressed.

* Add support for the iTerm2 DSR 1337 sequence to get the terminal version.

* Treat plausible but invalid keys (like C-BSpace) as literal like any other
  unrecognised string passed to send-keys.

* Detect iTerm2 and enable use of DECSLRM (much faster with horizontally split
  windows).

* Add -Z to default switch-client command in tree mode.

* Add ~ to quoted characters for %%%.

* Document client exit messages in the manual page.

* Do not let read-only clients limit the size, unless all clients are
  read-only.

* Add a number of new formats to inspect what sessions and clients a window is
  present or active in.

* Change file reading and writing to go through the client if necessary. This
  fixes commands like "tmux loadb /dev/fd/X". Also modify source-file to
  support "-" for standard input, like load-buffer and save-buffer.

* Add ~/.config/tmux/tmux.conf to the default search path for configuration
  files.

* Bump the escape sequence timeout to five seconds to allow for longer
  legitimate sequences.

* Make a best effort to set xpixel and ypixel for each pane and add formats for
  them.

* Add push-default to status-left and status-right in status-format[0].

* Do not clear search marks on cursor movement with vi(1) keys.

* Add p format modifier for padding to width and allow multiple substitutions
  in a single format.

* Add -f for full size to join-pane (like split-window).

* Do not use bright when emulating 256 colours on an 8 colour terminal because
  it is also bold on some terminals.

* Make select-pane -P set window-active-style also to match previous behaviour.

* Do not truncate list-keys output.

* Turn automatic-rename back on if the \033k rename escape sequence is used
  with an empty name.

* Add support for percentage sizes for resize-pane ("-x 10%"). Also change
  split-window and join-pane -l to accept similar percentages and deprecate the
  -p flag.

* Add -F flag to send-keys to expand formats in search-backward and forward
  copy mode commands and copy_cursor_word and copy_cursor_line formats for word
  and line at cursor in copy mode. Use for default # and * binding with vi(1)
  keys.

* Add formats for word and line at cursor position in copy mode.

* Add formats for cursor and selection position in copy mode.

* Support all the forms of RGB colour strings in OSC sequences rather than
  requiring two digits.

* Limit lazy resize to panes in attached sessions only.

* Add an option to set the key sent by backspace for those whose system uses ^H
  rather than ^?.

* Change new-session -A without a session name (that is, no -s option also) to
  attach to the best existing session like attach-session rather than a new
  one.

* Add a "latest" window-size option which tries to size windows based on the
  most recently used client. This is now the default.

* Add simple support for OSC 7 (result is available in the pane_path format).

* Add push-default and pop-default for styles which change the colours and
  attributes used for #[default]. These are used in status-format to restore
  the behaviour of window-status-style being the default for
  window-status-format.

* Add window_marked_flag.

* Add cursor-down-and-cancel in copy mode.

* Default to previous search string for search-forward and search-backward.

* Add -Z flag to rotate-window, select-pane, swap-pane, switch-client to
  preserve zoomed state.

* Add -N to capture-pane to preserve trailing spaces.

* Add reverse sorting in tree, client and buffer modes.

CHANGES FROM 3.0 TO 3.0a

* Do not require REG_STARTEND.

* Respawn panes or windows correctly if default-command is set.

* Add missing option for after-kill-pane hook.

* Fix for crash with a format variable that doesn't exist.

* Do not truncate list-keys output on some platforms.

* Do not crash when restoring a layout with only one pane.

CHANGES FROM 2.9 TO 3.0

* Workaround invalid layout strings generated by older tmux versions and add
  some additional sanity checks

* xterm 348 now disables margins when resized, so send DECLRMM again after
  resize.

* Add support for the SD (scroll down) escape sequence.

* Expand arguments to C and s format modifiers to match the m modifier.

* Add support for underscore colours (Setulc capability must be added with
  terminal-overrides as described in tmux(1)).

* Add a "fill" style attribute for the fill colour of the drawing area (where
  appropriate).

* New -H flag to send-keys to send literal keys.

* Format variables for pane mouse modes (mouse_utf8_flag and mouse_sgr_flag)
  and for origin mode (origin_flag).

* Add -F to refresh-client for flags for control mode clients, only one flag
  (no-output) supported at the moment.

* Add a few vi(1) keys for menus.

* Add pane options, set with set-option -p and displayed with show-options -p.
  Pane options inherit from window options (so every pane option is also
  a window option). The pane style is now configured by setting window-style
  and window-active-style in the pane options; select-pane -P and -g now change
  the option but are no longer documented.

* Do not document set-window-option and show-window-options. set-option -w and
  show-options -w should be used instead.

* Add a -A flag to show-options to show parent options as well (they are marked
  with a *).

* Resize panes lazily - do not resize unless they are in an attached, active
  window.

* Add regular expression support for the format search, match and substitute
  modifiers and make them able to ignore case. find-window now accepts -r to
  use regular expressions.

* Do not use $TMUX to find the session because for windows in multiple sessions
  it is wrong as often as it is right, and for windows in one session it is
  pointless. Instead use TMUX_PANE if it is present.

* Do not always resize the window back to its original size after applying a
  layout, keep it at the layout size until it must be resized (for example when
  attached and window-size is not manual).

* Add new-session -X and attach-session -x to send SIGHUP to parent when
  detaching (like detach-client -P).

* Support for octal escapes in strings (such as \007) and improve list-keys
  output so it parses correctly if copied into a configuration file.

* INCOMPATIBLE: Add a new {} syntax to the configuration file. This is a string
  similar to single quotes but also includes newlines and allows commands that
  take other commands as string arguments to be expressed more clearly and
  without additional escaping.

  A literal { and } or a string containing { or } must now be escaped or
  quoted, for example '{' and '}' instead of { or }, or 'X#{foo}' instead of
  X#{foo}.

* New <, >, <= and >= comparison operators for formats.

* Improve escaping of special characters in list-keys output.

* INCOMPATIBLE: tmux's configuration parsing has changed to use yacc(1). There
  is one incompatible change: a \ on its own must be escaped or quoted as
  either \\ or '\' (the latter works on older tmux versions).

  Entirely the same parser is now used for parsing the configuration file
  and for string commands. This means that constructs previously only
  available in .tmux.conf, such as %if, can now be used in string commands
  (for example, those given to if-shell - not commands invoked from the
  shell, they are still parsed by the shell itself).

* Add support for the overline attribute (SGR 53). The Smol capability is
  needed in terminal-overrides.

* Add the ability to create simple menus. Introduces new command
  display-menu. Default menus are bound to MouseDown3 on the status line;
  MouseDown3 or M-MouseDown3 on panes; MouseDown3 in tree, client and
  buffer modes; and C-b < and >.

* Allow panes to be empty (no command). They can be created either by piping to
  split-window -I, or by passing an empty command ('') to split-window. Output
  can be sent to an existing empty window with display-message -I.

* Add keys to jump between matching brackets (emacs C-M-f and C-M-b, vi %).

* Add a -e flag to new-window, split-window, respawn-window, respawn-pane to
  pass environment variables into the newly created process.

* Hooks are now stored in the options tree as array options, allowing them to
  have multiple separate commands. set-hook and show-hooks remain but
  set-option and show-options can now also be used (show-options will only show
  hooks if given the -H flag). Hooks with multiple commands are run in index
  order.

* Automatically scroll if dragging to create a selection with the mouse and the
  cursor reaches the top or bottom line.

* Add -no-clear variants of copy-selection and copy-pipe which do not clear the
  selection after copying. Make copy-pipe clear the selection by default to be
  consistent with copy-selection.

* Add an argument to copy commands to set the prefix for the buffer name, this
  (for example) allows buffers for different sessions to be named separately.

* Update session activity on focus event.

* Pass target from source-file into the config file parser so formats in %if
  and %endif have access to more useful variables.

* Add the ability to infer an option type (server, session, window) from its
  name to show-options (it was already present in set-option).

CHANGES FROM 2.9 TO 2.9a

* Fix bugs in select-pane and the main-horizontal and main-vertical layouts.

CHANGES FROM 2.8 TO 2.9

* Attempt to preserve horizontal cursor position as well as vertical with
  reflow.

* Rewrite main-vertical and horizontal and change layouts to better handle the
  case where all panes won't fit into the window size, reduce problems with
  pane border status lines and fix other bugs mostly found by Thomas Sattler.

* Add format variables for the default formats in the various modes
  (tree_mode_format and so on) and add a -a flag to display-message to list
  variables with values.

* Add a -v flag to display-message to show verbose messages as the format is
  parsed, this allows formats to be debugged

* Add support for HPA (\033[`).

* Add support for origin mode (\033[?6h).

* No longer clear history on RIS.

* Extend the #[] style syntax and use that together with previous format
  changes to allow the status line to be entirely configured with a single
  option.

  Now that it is possible to configure their content, enable the existing code
  that lets the status line be multiple lines in height. The status option can
  now take a value of 2, 3, 4 or 5 (as well as the previous on or off) to
  configure more than one line. The new status-format array option configures
  the format of each line, the default just references the existing status-*
  options, although some of the more obscure status options may be eliminated
  in time.

  Additions to the #[] syntax are: "align" to specify alignment (left, centre,
  right), "list" for the window list and "range" to configure ranges of text
  for the mouse bindings.

  The "align" keyword can also be used to specify alignment of entries in tree
  mode and the pane status lines.

* Add E: and T: format modifiers to expand a format twice (useful to expand the
  value of an option).

* The individual -fg, -bg and -attr options have been removed; they
  were superseded by -style options in tmux 1.9.

* Allow more than one mode to be opened in a pane. Modes are kept on a stack
  and retrieved if the same mode is entered again. Exiting the active mode goes
  back to the previous one.

* When showing command output in copy mode, call it view mode instead (affects
  pane_mode format).

* Add -b to display-panes like run-shell.

* Handle UTF-8 in word-separators option.

* New "terminal" colour allowing options to use the terminal default colour
  rather than inheriting the default from a parent option.

* Do not move the cursor in copy mode when the mouse wheel is used.

* Use the same working directory rules for jobs as new windows rather than
  always starting in the user's home.

* Allow panes to be one line or column in size.

* Go to last line when goto-line number is out of range in copy mode.

* Yank previously cut text if any with C-y in the command prompt, only use the
  buffer if no text has been cut.

* Add q: format modifier to quote shell special characters.

* Add StatusLeft and StatusRight mouse locations (keys such as
  MouseDown1StatusLeft) for the status-left and status-right areas of the
  status line.

* Add -Z to find-window.

* Support for windows larger than the client. This adds two new options,
  window-size and default-size, and a new command, resize-window. The
  force-width and force-height options and the session_width and session_height
  formats have been removed.

  The new window-size option tells tmux how to work out the size of windows:
  largest means it picks the size of the largest session, smallest the smallest
  session (similar to the old behaviour) and manual means that it does not
  automatically resize windows. aggressive-resize modifies the choice of
  session for largest and smallest as it did before.

  If a window is in a session attached to a client that is too small, only part
  of the window is shown. tmux attempts to keep the cursor visible, so the part
  of the window displayed is changed as the cursor moves (with a small delay,
  to try and avoid excess redrawing when applications redraw status lines or
  similar that are not currently visible).

  Drawing windows which are larger than the client is not as efficient as those
  which fit, particularly when the cursor moves, so it is recommended to avoid
  using this on slow machines or networks (set window-size to smallest or
  manual).

  The resize-window command can be used to resize a window manually. If it is
  used, the window-size option is automatically set to manual for the window
  (undo this with "setw -u window-size"). resize-window works in a similar way
  to resize-pane (-U -D -L -R -x -y flags) but also has -a and -A flags. -a
  sets the window to the size of the smallest client (what it would be if
  window-size was smallest) and -A the largest.

  For the same behaviour as force-width or force-height, use resize-window -x
  or -y.

  If the global window-size option is set to manual, the default-size option is
  used for new windows. If -x or -y is used with new-session, that sets the
  default-size option for the new session.

  The maximum size of a window is 10000x10000. But expect applications to
  complain and higher memory use if making a window that big. The minimum size
  is the size required for the current layout including borders.

  The refresh-client command can be used to pan around a window, -U -D -L -R
  moves up, down, left or right and -c returns to automatic cursor
  tracking. The position is reset when the current window is changed.

CHANGES FROM 2.7 TO 2.8

* Make display-panes block the client until a pane is chosen or it
  times out.

* Clear history on RIS like most other terminals do.

* Add an "Any" key to run a command if a key is pressed that is not
  bound in the current key table.

* Expand formats in load-buffer and save-buffer.

* Add a rectangle_toggle format.

* Add set-hook -R to run a hook immediately.

* Add README.ja.

* Add pane focus hooks.

* Allow any punctuation as separator for s/x/y not only /.

* Improve resizing with the mouse (fix resizing the wrong pane in some
  layouts, and allow resizing multiple panes at the same time).

* Allow , and } to be escaped in formats as #, and #}.

* Add KRB5CCNAME to update-environment.

* Change meaning of -c to display-message so the client is used if it
  matches the session given to -t.

* Fixes to : form of SGR.

* Add x and X to choose-tree to kill sessions, windows or panes.

CHANGES FROM 2.6 TO 2.7

* Remove EVENT_* variables from environment on platforms where tmux uses them
  so they do not pass on to panes.

* Fixes for hooks at server exit.

* Remove SGR 10 (was equivalent to SGR 0 but no other terminal seems to do
  this).

* Expand formats in window and session names.

* Add -Z flag to choose-tree, choose-client, choose-buffer to automatically
  zoom the pane when the mode is entered and unzoom when it exits, assuming the
  pane is not already zoomed. This is now part of the default key bindings.

* Add C-g to exit modes with emacs keys.

* Add exit-empty option to exit server if no sessions (defaults to on).

* Show if a filter is present in choose modes.

* Add pipe-pane -I to to connect stdin of the child process.

* Performance improvements for reflow.

* Use RGB terminfo(5) capability to detect RGB colour terminals (the existing
  Tc extension remains unchanged).

* Support for ISO colon-separated SGR sequences.

* Add select-layout -E to spread panes out evenly (bound to E key).

* Support wide characters properly when reflowing.

* Pass PWD to new panes as a hint to shells, as well as calling chdir().

* Performance improvements for the various choose modes.

* Only show first member of session groups in tree mode (-G flag to choose-tree
  to show all).

* Support %else in config files to match %if; from Brad Town in GitHub issue
  1071.

* Fix "kind" terminfo(5) capability to be S-Down not S-Up.

* Add a box around the preview label in tree mode.

* Show exit status and time in the remain-on-exit pane text; from Timo
  Boettcher in GitHub issue 1103.

* Correctly use pane-base-index in tree mode.

* Change the allow-rename option default to off.

* Support for xterm(1) title stack escape sequences (GitHub issue 1075 from
  Brad Town).

* Correctly remove padding cells to fix a UTF-8 display problem (GitHub issue
  1090).

CHANGES FROM 2.5 TO 2.6, 05 October 2017

* Add select-pane -T to set pane title.

* Fix memory leak when lines with BCE are removed from history.

* Fix (again) the "prefer unattached" behaviour of attach-session.

* Reorder how keys are checked to allow keys to be specified that have a
  leading escape. GitHub issue 1048.

* Support REP escape sequence (\033[b).

* Run alert hooks based on options rather than always, and allow further bells
  even if there is an existing bell.

* Add -d flag to display-panes to override display-panes-time.

* Add selection_present format when in copy mode (allows key bindings that do
  something different if there is a selection).

* Add pane_at_left, pane_at_right, pane_at_top and pane_at_bottom formats.

* Make bell, activity and silence alerting more consistent by: removing the
  bell-on-alert option; adding activity-action and silence-action options with
  the same possible values as the existing bell-action; adding a "both" value
  for the visual-bell, visual-activity and visual-silence options to trigger
  both a bell and a message.

* Add a pane_pipe format to show if pipe-pane is active.

* Block signals between forking and resetting signal handlers so that the
  libevent signal handler doesn't get called in the child and incorrectly write
  into the signal pipe that it still shares with the parent. GitHub issue 1001.

* Allow punctuation in pane_current_command.

* Add -c for respawn-pane and respawn-window.

* Wait for any remaining data to flush when a pane is closed while pipe-pane is
  in use.

* Fix working out current client with no target. GitHub issue 995.

* Try to fallback to C.UTF-8 as well as en_US.UTF-8 when looking for a UTF-8
  locale.

* Add user-keys option for user-defined key escape sequences (mapped to User0
  to User999 keys).

* Add pane-set-clipboard hook.

* FAQ file has moved out of repository to online.

* Fix problem with high CPU usage when a client dies unexpectedly. GitHub issue
  941.

* Do a dance on OS X 10.10 and above to return tmux to the user namespace,
  allowing access to the clipboard.

* Do not allow escape sequences which expect a specific terminator (APC, DSC,
  OSC) to wait for forever - use a small timeout. This reduces the chance of
  the pane locking up completely when sent garbage (cat /dev/random or
  similar).

* Support SIGUSR2 to toggle logging on a running server, also generate the
  "out" log file with -vv not -vvvv.

* Make set-clipboard a three state option: on (tmux both sends to outside
  terminal and accepts from applications inside); external (tmux sends outside
  but does not accept inside); and off.

* Fix OSC 4 palette setting for bright foreground colours. GitHub issue 954.

* Use setrgbf and setrgbb terminfo(5) capabilities to set RGB colours, if they
  are available. (Tc is still supported as well.)

* Fix redrawing panes when they are resized several times but end up with the
  size unchanged (for example, splitw/resizep -Z/breakp).

* Major rewrite of choose mode. Now includes preview, sorting, searching and
  tagging; commands that can be executed directly from the mode (for example,
  to delete one or more buffers); and filtering in tree mode.

* choose-window and choose-session are now aliases of choose-tree (in the
  command-alias option).

* Support OSC 10 and OSC 11 to set foreground and background colours.

* Check the U8 capability to determine whether to use UTF-8 line drawing
  characters for ACS.

* Some missing notifications for layout changes.

* Control mode clients now do not affect session sizes until they issue
  refresh-client -C. new-session -x and -y works with control clients even if
  the session is not detached.

* All new sessions that are unattached (whether with -d or started with no
  terminal) are now created with size 80 x 24. Whether the status line is on or
  off does not affect the size of new sessions until they are attached.

* Expand formats in option names and add -F flag to expand them in option values.

* Remember the search string for a pane even if copy mode is exited and entered
  again.

* Some further BCE fixes (scroll up, reverse index).

* Improvements to how terminals are cleared (entirely or partially).

CHANGES FROM 2.4 TO 2.5, 09 May 2017

* Reset updated flag when restarting #() command so that new output is properly
  recognised. GitHub issue 922.

* Fix ECH with a background colour.

* Do not rely on the terminal not moving the cursor after DL or EL.

* Fix send-keys and send-prefix in copy-mode (so C-b C-b works). GitHub issue
  905.

* Set the current pane for rotate-window so it works in command sequences.

* Add pane_mode format.

* Differentiate M-Up from Escape+Up when possible (that is, in terminals with
  xterm(1) style function keys). GitHub issue 907.

* Add session_stack and window_stack_index formats.

* Some new control mode notifications and corresponding hooks:
  pane-mode-changed, window-pane-changed, client-session-changed,
  session-window-changed.

* Format pane_search_string for last search term while in copy mode (useful
  with command-prompt -I).

* Fix a problem with high CPU usage and multiple clients with #(). GitHub issue
  889.

* Fix UTF-8 combining characters in column 0.

* Fix reference counting so that panes are properly destroyed and their
  processes killed.

* Clamp SU (CSI S) parameter to work around a bug in Konsole.

* Tweak line wrapping in full width panes to play more nicely with terminal
  copy and paste.

* Fix when we emit SGR 0 in capture-pane -e.

* Do not change TERM until after config file parsing has finished, so that
  commands run inside the config file can use it to make decisions (typically
  about default-terminal).

* Make the initial client wait until config file parsing has finished to avoid
  racing with commands.

* Fix core when if-shell fails.

* Only use ED to clear screen if the pane is at the bottom.

* Fix multibyte UTF-8 output.

* Code improvements around target (-t) resolution.

* Change how the default target (for commands without -t) is managed across
  command sequences: now it is set up at the start and commands are required
  to update it if needed. Fixes binding command sequences to mouse keys.

* Make if-shell from the config file work correctly.

* Change to always check the root key table if no binding is found in the
  current table (prefix table or copy-mode table or whatever). This means that
  root key bindings will take effect even in copy mode, if not overridden by a
  copy mode key binding.

* Fix so that the history file works again.

* Run config file without a client rather than using the first client, restores
  previous behaviour.

* If a #() command doesn't exit, continue to read from it and use its last full
  line of output.

* Handle slow terminals and fast output better: when the amount of data
  outstanding gets too large, discard output until it is drained and we are
  able to do a full redraw. Prevents tmux sitting on a huge buffer that the
  terminal will take forever to consume.

* Do not redraw a client unless we realistically think it can accept the data -
  defer redraws until the client has nothing else waiting to write.

CHANGES FROM 2.3 TO 2.4, 20 April 2017

Incompatible Changes
====================

* Key tables have undergone major changes. Mode key tables are no longer
  separate from the main key tables. All mode key tables have been removed,
  together with the -t flag to bind-key and unbind-key.

  The emacs-edit, vi-edit, emacs-choose and vi-choose tables have been replaced
  by fixed key bindings in the command prompt and choose modes. The mode-keys
  and status-keys options remain.

  The emacs-copy and vi-copy tables have been replaced by the copy-mode and
  copy-mode-vi tables. Commands are sent using the -X and -N flags to
  send-keys. So the following:

    bind -temacs-copy C-Up scroll-up
    bind -temacs-copy -R5 WheelUpPane scroll-up

  Becomes:

    bind -Tcopy-mode C-Up send -X scroll-up
    bind -Tcopy-mode WheelUpPane send -N5 -X scroll-up

  These changes allows the full command parser (including command sequences) and
  command set to be used - for example, the normal command prompt with editing
  and history is now used for searching, jumping, and so on instead of a custom
  one. The default C-r binding is now:

    bind -Tcopy-mode C-r command-prompt -i -p'search up' "send -X search-backward-incremental '%%'"

  There are also some new commands available with send -X, such as
  copy-pipe-and-cancel.
* set-remain-on-exit has gone -- can be achieved with hooks instead.
* Hooks: before hooks have been removed and only a selection of commands now
  have after hooks (they are no longer automatic). Additional hooks have been
  added.
* The xterm-keys option now defaults to on.

Normal Changes
==============

* Support for mouse double and triple clicks.
* BCE (Background Colour Erase) is now supported.
* All occurrences of a search string in copy mode are now highlighted;
  additionally, the number of search results is displayed. The highlighting
  updates interactively with the default emacs key bindings (incremental
  search).
* source-file now understands glob patterns.
* Formats now have simple comparisons:

    #{==:a,b}
    #{!=:a,b}

* There are the following new formats:

  - #{version} -- the tmux server version;
  - #{client_termtype} -- the terminal type of the client;
  - #{client_name} -- the name of a client;
  - #{client_written} -- the number of bytes written to the client.

* The configuration file now accepts %if/%endif conditional blocks which are
  processed when it is parsed; the argument is a format string (useful with the
  new format comparison options).
* detach-client now has -E to execute a command replacing the client instead of
  exiting.
* Add support for custom command aliases, this is an array option which
  contains items of the form "alias=command". This is consulted when an
  unknown command is parsed.
* break-pane now has -n to specify the new window name.
* OSC 52 support has been added for programs inside tmux to set a tmux buffer.
* The mouse "all event" mode (1003) is now supported.
* Palette setting is now possible (OSC 4 and 104).
* Strikethrough support (a recent terminfo is required).
* Grouped sessions can now be named (new -t).
* terminal-overrides and update-environment are now array options (the previous
  set -ag syntax should work without change).
* There have been substantial performance improvements.

CHANGES FROM 2.2 TO 2.3, 29 September 2016

Incompatible Changes
====================

None.

Normal Changes
==============

* New option 'pane-border-status' to add text in the pane borders.
* Support for hooks on commands: 'after' and 'before' hooks.
* 'source-file' understands '-q' to suppress errors for nonexistent files.
* Lots of UTF8 improvements, especially on MacOS.
* 'window-status-separator' understands #[] expansions.
* 'split-window' understands '-f' for performing a full-width split.
* Allow report count to be specified when using 'bind-key -R'.
* 'set -a' for appending to user options (@foo) is now supported.
* 'display-panes' can now accept a command to run, rather than always
  selecting the pane.

CHANGES FROM 2.1 TO 2.2, 10 April 2016

Incompatible Changes
====================

* The format strings which referenced time have been removed.  Instead:

  #{t:window_activity}

can be used.

* Support for TMPDIR has been removed.  Use TMUX_TMPDIR instead.
* UTF8 detection now happens automatically if the client supports it, hence
  the:

  mouse-utf8
  utf8

  options has been removed.
* The:

  mouse_utf8_flag

  format string has been removed.
* The -I option to show-messages has been removed.  See:

  #{t:start_time}

  format option instead.

Normal Changes
==============

* Panes are unzoomed with selectp -LRUD
* New formats added:

  #{scroll_position}
  #{socket_path}
  #{=10:...} -- limit to N characters (from the start)
  #{=-10:...} -- limit to N characters (from the end)
  #{t:...} -- used to format time-based formats
  #{b:...} -- used to ascertain basename from string
  #{d:...} -- used to ascertain dirname from string
  #{s:...} -- used to perform substitutions on a string

* Job output is run via the format system, so formats work again
* If display-time is set to 0, then the indicators wait for a key to be
  pressed.
* list-keys and list-commands can be run without starting the tmux server.
* kill-session learns -C to clear all alerts in all windows of the session.
* Support for hooks (internal for now), but hooks for the following have been
  implemented:

  alert-bell
  alert-silence
  alert-activity
  client-attached
  client-detached
  client-resized
  pane-died
  pane-exited

* RGB (24bit) colour support.  The 'Tc' flag must be set in the external TERM
  entry (using terminal-overrides or a custom terminfo entry).

CHANGES FROM 2.0 TO 2.1, 18 October 2015

Incompatible Changes
====================

* Mouse-mode has been rewritten.  There's now no longer options for:
	- mouse-resize-pane
	- mouse-select-pane
	- mouse-select-window
	- mode-mouse

  Instead there is just one option:  'mouse' which turns on mouse support
  entirely.
* 'default-terminal' is now a session option.  Furthermore, if this is set
  to 'screen-*' then emulate what screen does.  If italics are wanted, this
  can be set to 'tmux' but this is still new and not necessarily supported
  on all platforms with older ncurses installs.
* The c0-* options for rate-limiting have been removed.  Instead, a backoff
  approach is used.

Normal Changes
==============

* New formats:
	- session_activity
	- window_linked
	- window_activity_format
	- session_alerts
	- session_last_attached
	- client_pid
	- pid
* 'copy-selection', 'append-selection', 'start-named-buffer' now understand
  an '-x' flag to prevent it exiting copying mode.
* 'select-pane' now understands '-P' to set window/pane background colours.
* 'renumber-windows' now understands windows which are unlinked.
* 'bind' now understands multiple key tables.  Allows for key-chaining.
* 'select-layout' understands '-o' to undo the last layout change.
* The environment is updated when switching sessions as well as attaching.
* 'select-pane' now understands '-M' for marking a pane.  This marked pane
  can then be used with commands which understand src-pane specifiers
  automatically.
* If a session/window target is prefixed with '=' then only an exact match
  is considered.
* 'move-window' understands '-a'.
* 'update-environment' understands '-E' when attach-session is used on an
  already attached client.
* 'show-environment' understands '-s' to output Bourne-compatible commands.
* New option: 'history-file' to save/restore command prompt history.
* Copy mode is exited if the history is cleared whilst in copy-mode.
* 'copy-mode' learned '-e' to exit copy-mode when scrolling to end.

CHANGES FROM 1.9a TO 2.0, 06 March 2015

Incompatible Changes
====================

* The choose-list command has been removed.
* 'terminal-overrides' is now a server option, not a session option.
* 'message-limit' is now a server option, not a session option.
* 'monitor-content' option has been removed.
* 'pane_start_path' option has been removed.
* The "info" mechanism which used to (for some commands) provide feedback
  has been removed, and like other commands, they now produce nothing on
  success.

Normal Changes
==============

* tmux can now write an entry to utmp if the library 'utempter' is present
  at compile time.
* set-buffer learned append mode (-a), and a corresponding
  'append-selection' command has been added to copy-mode.
* choose-mode now has the following commands which can be bound:
	- start-of-list
	- end-of-list
	- top-line
	- bottom-line

* choose-buffer now understands UTF-8.
* Pane navigation has changed:
	- The old way of always using the top or left if the choice is ambiguous.
	- The new way of remembering the last used pane is annoying if the
	  layout is balanced and the leftmost is obvious to the user (because
	  clearly if we go right from the top-left in a tiled set of four we want
	  to end up in top-right, even if we were last using the bottom-right).

      So instead, use a combination of both: if there is only one possible
      pane alongside the current pane, move to it, otherwise choose the most
      recently used of the choice.
* 'set-buffer' can now be told to give names to buffers.
* The 'new-session', 'new-window', 'split-window', and 'respawn-pane' commands
  now understand multiple arguments and handle quoting problems correctly.
* 'capture-pane' understands '-S-' to mean the start of the pane, and '-E-' to
  mean the end of the pane.
* Support for function keys beyond F12 has changed.  The following explains:
	- F13-F24 are S-F1 to S-F12
	- F25-F36 are C-F1 to C-F12
	- F37-F48 are C-S-F1 to C-S-F12
	- F49-F60 are M-F1 to M-F12
	- F61-F63 are M-S-F1 to M-S-F3

 Therefore, F13 becomes a binding of S-F1, etc.
* Support using pane id as part of session or window specifier (so % means
  session-of-%1 or window-of-%1) and window id as part of session
  (so @1 means session-of-@1).
* 'copy-pipe' command now understands formats via -F
* 'if-shell'  command now understands formats via -F
* 'split-window' and 'join-window' understand -b to create the pane to the left
  or above the target pane.

CHANGES FROM 1.9 TO 1.9a, 22 February 2014

NOTE: This is a bug-fix release to address some important bugs which just
missed the 1.9 deadline, but were found afterwards.

Normal Changes
==============

* Fix crash due to uninitialized lastwp member of layout_cell
* Fix -fg/-bg/-style with 256 colour terminals.

CHANGES FROM 1.8 TO 1.9, 20 February 2014

NOTE:  This release has bumped the tmux protocol version.  It is therefore
advised that the prior tmux server is restarted when this version of tmux is
installed, to avoid protocol mismatch errors for newer clients trying to
talk to an older running tmux server.

Incompatible Changes
====================

* 88 colour support has been removed.
* 'default-path' has been removed.  The new-window command accepts '-c' to
  cater for this.  The previous value of "." can be replaced with: 'neww -c
  $PWD', the previous value of '' which meant current path of the pane can
  be specified as:  'neww -c "#{pane_current_path}"'

Deprecated Changes
==================

* The single format specifiers:  #A -> #Z (where defined) have been
  deprecated and replaced with longer-named equivalents, as listed in the
  FORMATS section of the tmux manpage.
* The various foo-{fg,bg,attr} commands have been deprecated and replaced
  with equivalent foo-style option instead.  Currently this is still
  backwards-compatible, but will be removed over time.

Normal Changes
==============

* A new environment variable TMUX_TMPDIR is now honoured, allowing the
  socket directory to be set outside of TMPDIR (/tmp/ if not set).
* If -s not given to swap-pane the current pane is assumed.
* A #{pane_synchronized} format specifier has been added to be a conditional
  format if a pane is in a synchronised mode (c.f. synchronize-panes)
* Tmux now runs under Cygwin natively.
* Formats can now be nested within each other and expanded accordingly.
* Added 'automatic-rename-format' option to allow the automatic rename
  mechanism to use something other than the default of
  #{pane_current_command}.
* new-session learnt '-c' to specify the starting directory for that session
  and all subsequent windows therein.
* The session name is now shown in the message printed to the terminal when
  a session is detached.
* Lots more format specifiers have been added.
* Server race conditions have been fixed; in particular commands are not run
  until after the configuration file is read completely.
* Case insensitive searching in tmux's copy-mode is now possible.
* attach-session and switch-client learnt the '-t' option to accept a window
  and/or a pane to use.
* Copy-mode is only exited if no selection is in progress.
* Paste key in copy-mode is now possible to enter text from the clipboard.
* status-interval set to '0' now works as intended.
* tmux now supports 256 colours running under fbterm.
* Many bug fixes!

CHANGES FROM 1.7 TO 1.8, 26 March 2013

Incompatible Changes
====================

* layout redo/undo has been removed.

Normal Changes
==============

* Add halfpage up/down bindings to copy mode.
* Session choosing fixed to work with unattached sessions.
* New window options window-status-last-{attr,bg,fg} to denote the last
  window which was active.
* Scrolling in copy-mode now scrolls the region without moving the mouse
  cursor.
* run-shell learnt '-t' to specify the pane to use when displaying output.
* Support for middle-click pasting.
* choose-tree learns '-u' to start uncollapsed.
* select-window learnt '-T' to toggle to the last window if it's already
  current.
* New session option 'assume-paste-time' for pasting text versus key-binding
  actions.
* choose-* commands now work outside of an attached client.
* Aliases are now shown for list-commands command.
* Status learns about formats.
* Free-form options can be set with set-option if prepended with an '@'
  sign.
* capture-pane learnt '-p' to send to stdout, and '-e' for capturing escape
  sequences, and '-a' to capture the alternate screen, and '-P' to dump
  pending output.
* Many new formats added (client_session, client_last_session, etc.)
* Control mode, which is a way for a client to send tmux commands.
  Currently more useful to users of iterm2.
* resize-pane learnt '-x' and '-y' for absolute pane sizing.
* Config file loading now reports errors from all files which are loaded via
  the 'source-file' command.
* 'copy-pipe' mode command to copy selection and pipe the selection to a
  command.
* Panes can now emit focus notifications for certain applications
  which use those.
* run-shell and if-shell now accept formats.
* resize-pane learnt '-Z' for zooming a pane temporarily.
* new-session learnt '-A' to make it behave like attach-session.
* set-option learnt '-o' to prevent setting an option which is already set.
* capture-pane and show-options learns '-q' to silence errors.
* New command 'wait-for' which blocks a client until woken up again.
* Resizing panes will now reflow the text inside them.
* Lots and lots of bug fixes, fixing memory-leaks, etc.
* Various manpage improvements.

CHANGES FROM 1.6 TO 1.7, 13 October 2012

* tmux configuration files now support line-continuation with a "\" at the
  end of a line.
* New option status-position to move the status line to the top or bottom of
  the screen.
* Enforce history-limit option when clearing the screen.
* Give each window a unique id, like panes but prefixed with @.
* Add pane id to each pane in layout description (while still accepting
  the old form).
* Provide defined ways to set the various default-path possibilities: ~
  for home directory, . for server start directory, - for session start
  directory and empty for the pane's working directory (the default). All
  can also be used as part of a relative path (eg -/foo). Also provide -c
  flags to neww and splitw to override default-path setting.
* Add -l flag to send-keys to send input literally (without translating
  key names).
* Allow a single option to be specified to show-options to show just that
  option.
* New command "move-pane" (like join-pane but allows the same window).
* join-pane and move-pane commands learn "-b" option to place the pane to
  the left or above.
* Support for bracketed-paste mode.
* Allow send-keys command to accept hex values.
* Add locking around "start-server" to avoid race-conditions.
* break-pane learns -P/-F arguments for display formatting.
* set-option learns "-q" to make it quiet, and not print out anything.
* copy mode learns "wrap-search" option.
* Add a simple form of output rate limiting by counting the number of
  certain C0 sequences (linefeeds, backspaces, carriage returns) and if it
  exceeds a threshold (current default 250/millisecond), start to redraw
  the pane every 100 milliseconds instead of making each change as it
  comes. Two configuration options - c0-change-trigger and
  c0-change-interval.
* find-window learns new flags:  "-C", "-N", "-T" to match against either or
  all of a window's content, name, or title.  Defaults to all three options
  if none specified.
* find-window automatically selects the appropriate pane for the found
  matches.
* show-environment can now accept one option to show that environment value.
* Exit mouse mode when end-of-screen reached when scrolling with the mouse
  wheel.
* select-layout learns -u and -U for layout history stacks.
* kill-window, detach-client, kill-session all  learn "-a" option for
  killing all but the current thing specified.
* move-window learns "-r" option to renumber window sequentially in a
  session.
* New session option "renumber-windows" to automatically renumber windows in
  a session when a window is closed.  (see "move-window -r").
* Only enter copy-mode on scroll up.
* choose-* and list-* commands all use "-F" for format specifiers.
* When spawning external commands, the value from the "default-shell" option
  is now used, rather than assuming /bin/sh.
* New choose-tree command to render window/sessions as a tree for selection.
* display-message learns new format options.
* For linked-windows across sessions, all flags for that window are now
  cleared across sessions.
* Lots and lots of bug fixes, fixing memory-leaks, etc.
* Various manpage improvements.

CHANGES FROM 1.5 TO 1.6, 23 January 2012

* Extend the mode-mouse option to add a third choice which means the mouse
  does not enter copy mode.
* Add a -r flag to switch-client to toggle the client read-only flag.
* Add pane-base-index option.
* Support \ for line continuation in the configuration file.
* Framework for more powerful formatting of command output and use it for
  list-{panes,windows,sessions}. This allows more descriptive replacements
  (such as #{session_name}) and conditionals.
* Mark dead panes with some text saying they are dead.
* Reject $SHELL if it is not a full path.
* Add -S option to refresh-client to redraw status line.
* Add an else clause for if-shell.
* Try to resolve relative paths for loadb and saveb (first, using client
  working directory, if any, then default-path or session working directory).
* Support for \e[3J to clear the history and send the corresponding
  terminfo code (E3) before locking.
* When in copy mode, make repeat count indicate buffer to replace, if used.
* Add screen*:XT to terminal-overrides for tmux-in-tmux.
* Status-line message attributes added.
* Move word-separators to be a session rather than window option.
* Change the way the working directory for new processes is discovered. If
  default-path isn't empty, it is used. Otherwise, if a new window is created
  from the command-line, the working directory of the client is used. If not,
  platform specific code is used to retrieve the current working directory
  of the process in the active pane. If that fails, the directory where the
  session was created is used, instead.
* Do not change the current pane if both mouse-select-{pane,window} are
  enabled.
* Add \033[s and \033[u to save and restore cursor position.
* Allow $HOME to be used as default-path.
* Add CNL and CPL escape sequences.
* Calculate last position correctly for UTF-8 wide characters.
* Add an option allow-rename to disable the window rename escape sequence.
* Attributes for each type of status-line alert (ie bell, content and
  activity) added. Therefore, remove the superfluous options
  window-status-alert-{attr,bg,fg}.
* Add a -R flag to send-keys to reset the terminal.
* Add strings to allow the aixterm bright colours to be used when
  configuring colours.
* Drop the ability to have a list of keys in the prefix in favour of two
  separate options, prefix and prefix2.
* Flag -2 added to send-prefix to send the secondary prefix key.
* Show pane size in top right of display panes mode.
* Some memory leaks plugged.
* More command-prompt editing improvements.
* Various manpage improvements.
* More Vi mode improvements.

CHANGES FROM 1.4 TO 1.5, 09 July 2011

* Support xterm mouse modes 1002 and 1003.
* Change from a per-session stack of buffers to one global stack. This renders
  copy-buffer useless and makes buffer-limit now a server option.
* Fix most-recently-used choice by avoiding reset the activity timer for
  unattached sessions every second.
* Add a -P option to new-window and split-window to print the new window or
  pane index in target form (useful to pass it into other commands).
* Handle a # at the end of a replacement string (such as status-left)
  correctly.
* Support for UTF-8 mouse input (\033[1005h) which was added in xterm 262.
  If the new mouse-utf8 option is on, UTF-8 mouse input is enabled for all
  UTF-8 terminals. The option defaults to on if LANG etc are set in the same
  manner as the utf8 option.
* Support for HP-UX.
* Accept colours of the hex form #ffffff and translate to the nearest from the
  xterm(1) 256-colour set.
* Clear the non-blocking IO flag (O_NONBLOCK) on the stdio file descriptors
  before closing them (fixes things like "tmux ls && cat").
* Use TMPDIR if set.
* Fix next and previous session functions to actually work.
* Support -x and -y for new-session to specify the initial size of the window
  if created detached with -d.
* Make bind-key accept characters with the top-bit-set and print them as octal.
* Set $TMUX without the session when background jobs are run.
* Simplify the way jobs work and drop the persist type, so all jobs are
  fire-and-forget.
* Accept tcgetattr/tcsetattr(3) failure, fixes problems with fatal() if the
  terminal disappears while locked.
* Add a -P option to detach to HUP the client's parent process (usually causing
  it to exit as well).
* Support passing through escape sequences to the underlying terminal by using
  DCS with a "tmux;" prefix.
* Prevent tiled producing a corrupt layout when only one column is needed.
* Give each pane created in a tmux server a unique id (starting from 0), put it
  in the TMUX_PANE environment variable and accept it as a target.
* Allow a start and end line to be specified for capture-pane which may be
  negative to capture part of the history.
* Add -a and -s options to lsp to list all panes in the server or session
  respectively. Likewise add -s to lsw.
* Change -t on display-message to be target-pane for the #[A-Z] replacements
  and add -c as target-client.
* The attach-session command now prefers the most recently used unattached
  session.
* Add -s option to detach-client to detach all clients attached to a session.
* Add -t to list-clients.
* Change window with mouse wheel over status line if mouse-select-window is on.
* When mode-mouse is on, automatically enter copy mode when the mouse is
  dragged or the mouse wheel is used. Also exit copy mode when the mouse wheel
  is scrolled off the bottom.
* Provide #h character pair for short hostname (no domain).
* Don't use strnvis(3) for the title as it breaks UTF-8.
* Use the tsl and fsl terminfo(5) capabilities to update terminal title and
  automatically fill them in on terminals with the XT capability (which means
  their title setting is xterm-compatible).
* Add a new option, mouse-resize-pane. When on, panes may be resized by
  dragging their borders.
* Fix crash by resetting last pane on {break,swap}-pane across windows.
* Add three new copy-mode commands - select-line, copy-line, copy-end-of-line.
* Support setting the xterm clipboard when copying from copy mode using the
  xterm escape sequence for the purpose (if xterm is configured to allow it).
* Support xterm(1) cursor colour change sequences through terminfo(5) Cc
  (set) and Cr (reset) extensions.
* Support DECSCUSR sequence to set the cursor style with two new terminfo(5)
  extensions, Cs and Csr.
* Make the command-prompt custom prompts recognize the status-left option
  character pairs.
* Add a respawn-pane command.
* Add a couple of extra xterm-style keys that gnome terminal provides.
* Allow the initial context on prompts to be set with the new -I option to
  command-prompt. Include the current window and session name in the prompt
  when renaming and add a new key binding ($) for rename session.
* Option bell-on-alert added to trigger the terminal bell when there is an
  alert.
* Change the list-keys format so that it shows the keys using actual tmux
  commands which should be able to be directly copied into the config file.
* Show full targets for lsp/lsw -a.
* Make confirm-before prompt customizable with -p option like command-prompt
  and add the character pairs #W and #P to the default kill-{pane,window}
  prompts.
* Avoid sending data to suspended/locked clients.
* Small memory leaks in error paths plugged.
* Vi mode improvements.

CHANGES FROM 1.3 TO 1.4, 27 December 2010

* Window bell reporting fixed.
* Show which pane is active in the list-panes output.
* Backoff reworked.
* Prevent the server from dying when switching into copy mode when already
  in a different mode.
* Reset running jobs when the status line is enabled or disabled.
* Simplify xterm modifier detection.
* Avoid crashing in copy mode if the screen size is too small for the
  indicator.
* Flags -n and -p added to switch-client.
* Use UTF-8 line drawing characters on UTF-8 terminals, thus fixing some
  terminals (eg putty) which disable the vt100 ACS mode switching sequences
  in UTF-8 mode. On terminals without ACS, use ASCII equivalents.
* New server option exit-unattached added.
* New session option destroy-unattached added.
* Fall back on normal session choice method if $TMUX exists but is invalid
  rather than rejecting.
* Mark repeating keys with "(repeat)" in the key list.
* When removing a pane, don't change the active pane unless the active pane
  is actually the one being removed.
* New command last-pane added.
* AIX fixes.
* Flag -a added to unbind-key.
* Add XAUTHORITY to update-environment.
* More info regarding window and pane flags is now shown in list-*.
* If VISUAL or EDITOR contains "vi" configure mode-keys and status-key to vi.
* New window option monitor-silence and session option visual-silence added.
* In the built-in layouts distribute the panes more evenly.
* Set the default value of main-pane-width to 80 instead of 81.
* Command-line flag -V added.
* Instead of keeping a per-client prompt history make it global.
* Fix rectangle copy to behave like emacs (the cursor is not part of the
  selection on the right edge but on the left it is).
* Flag -l added to switch-client.
* Retrieve environment variables from the global environment rather than
  getenv(3), thus allowing them to be updated during the configuration file.
* New window options other-pane-{height,width} added.
* More minor bugs fixed and manpage improvements.

CHANGES FROM 1.2 TO 1.3, 18 July 2010

* New input parser.
* Flags to move through panes -UDLR added to select-pane.
* Commands up-pane, and down-pane removed, since equivalent behaviour is now
  available through the target flag (-t:+ and -t:-).
* Jump-forward/backward in copy move (based on vi's F, and f commands).
* Make paste-buffer accept a pane as a target.
* Flag -a added to new-window to insert a window after an existing one, moving
  windows up if necessary.
* Merge more mode into copy mode.
* Run job commands explicitly in the global environment (which can be modified
  with setenv -g), rather than with the environment tmux started with.
* Use the machine's hostname as the default title, instead of an empty string.
* Prevent double free if the window option remain-on-exit is set.
* Key string conversions rewritten.
* Mark zombie windows as dead in the choose-window list.
* Tiled layout added.
* Signal handling reworked.
* Reset SIGCHLD after fork to fix problems with some shells.
* Select-prompt command removed. Therefore, bound ' to command-prompt -p index
  "select-window -t:%%" by default.
* Catch SIGHUP and terminate if running as a client, thus avoiding clients from
  being left hanging around when, for instance, a SSH session is disconnected.
* Solaris 9 fixes (such as adding compat {get,set}env(3) code).
* Accept none instead of default for attributes.
* Window options window-status-alert-{alert,bg,fg} added.
* Flag -s added to the paste-buffer command to specify a custom separator.
* Allow dragging to make a selection in copy mode if the mode-mouse option is
  set.
* Support the mouse scroll wheel.
* Make pipe-pane accept special character sequences (eg #I).
* Fix problems with window sizing when starting tmux from .xinitrc.
* Give tmux sockets (but not the containing folder) group permissions.
* Extend the target flags (ie -t) to accept an offset (for example -t:+2), and
  make it wrap windows, and panes.
* New command choose-buffer added.
* New server option detach-on-destroy to set what happens to a client when the
  session it is attached to is destroyed. If on (default), the client is
  detached. Otherwise, the client is switched to the most recently active of
  the remaining sessions.
* The commands load-buffer, and save-buffer now accept a dash (-) as the file
  to read from stdin, or write to stdout.
* Custom layouts added.
* Additional code reduction, bug fixes, and manpage enhancements.

CHANGES FROM 1.1 TO 1.2, 10 March 2010

* Switch to libevent.
* Emulate the ri (reverse index) capability, ergo allowing tmux to at least
  start on Sun consoles (TERM=sun, or sun-color).
* Assign each entry a number, or lowercase letter in choose mode, and accept
  that as a shortcut key.
* Permit top-bit-set characters to be entered in the status line.
* Mark no-prefix keys with (no prefix), rather than [] in list-keys.
* New command show-messages (alias showmsgs), and new session option
  message-limit, to show a per-client log of status lines messages up to the
  number defined by message-limit.
* Do not interpret #() for display-message to avoid leaking commands.
* New window options window-status-format, and window-status-current-format to
  control the format of each window in the status line.
* Add a -p flag to display-message to print the output, instead of displaying
  it in the status line.
* Emulate il1, dl1, ich1 to run with vt100 feature set.
* New command capture-pane (alias capturep) to copy the entire pane contents
  to a paste buffer.
* Avoid duplicating code by adding a -w flag to set-option, and show-options to
  set, and show window options. The commands set-window-option, and
  show-window-options are now aliases.
* Panes can now be referred to as top, bottom, top-left, etc.
* Add server-wide options, which can be set with set-option -s, and shown with
  show-options -s.
* New server option quiet (like -q from the command line).
* New server option escape-time to set the timeout used to detect if escapes
  are alone, part of a function key, or meta sequence.
* New session options pane-active-border-bg, pane-active-border-fg,
  pane-border-bg, and pane-border-fg to set pane colours.
* Make split-window accept a pane target, instead of a window.
* New command join-pane (alias joinp) to split, and move an existing pane into
  the space (the opposite of break-pane), thus simplifying calls to
  split-window, followed by move-window.
* Permit S- prefix on keys for shift when the terminal/terminfo supports them.
* Window targets (-t flag) can now refer to the last window (!), next (+), and
  previous (-) window by number.
* Mode keys to jump to the bottom/top of history, end of the next word, scroll
  up/down, and reverse search in copy mode.
* New session option display-panes-active-colour to display the active pane in
  a different colour with the display-panes command.
* Read the socket path from $TMUX if it's present, and -L, and -S are not
  given.
* Vi-style mode keys B, W, and E to navigate between words in copy mode.
* Start in more mode when configuration file errors are detected.
* Rectangle copy support added.
* If attach-session was specified with the -r flag, make the client read-only.
* Per-window alternate-screen option.
* Make load-buffer work with FIFOs.
* New window option word-separators to set the characters considered as word
  separators in copy mode.
* Permit keys in copy mode to be prefixed by a repeat count, entered with [1-9]
  in vi mode, or M-[1-9] in emacs mode.
* utf8 improvements.
* As usual, additional code reduction, bug fixes, and manpage enhancements.

CHANGES FROM 1.0 TO 1.1, 05 November 2009

* New run-shell (alias run) command to run an external command without a
  window, capture it's stdout, and send it to output mode.
* Ability to define multiple prefix keys.
* Internal locking mechanism removed. Instead, detach each client and run the
  external command specified in the new session option lock-command (by default
  lock -np), thus allowing the system password to be used.
* set-password command, and -U command line flag removed per the above change.
* Add support for -c command line flag to execute a shell command.
* New lock-client (alias lockc), and lock-session (alias locks) commands to
  lock a particular client, or all clients attached to a session.
* Support C-n/C-p/C-v/M-v with emacs keys in choice mode.
* Use : for goto line rather than g in vi mode.
* Try to guess which client to use when no target client was specified. Finds
  the current session, and if only one client is present, use it. Otherwise,
  return the most recently used client.
* Make C-Down/C-Up in copy mode scroll the screen down/up one line without
  moving the cursor.
* Scroll mode superseded by copy mode.
* New synchronize-panes window option to send all input to all other panes in
  the same window.
* New lock-server session option to lock, when off (on by default), each
  session when it has been idle for the lock-after-time setting. When on, the
  entire server locks when all sessions have been idle for their individual
  lock-after-time setting.
* Add support for grouped sessions which have independent name, options,
  current window, but where the linked windows are synchronized (ie creating,
  killing windows are mirrored between the sessions). A grouped session may be
  created by passing -t to new-session.
* New mouse-select-pane session option to select the current pane with the
  mouse.
* Queue, and run commands in the background for if-shell, status-left,
  status-right, and #() by starting each once every status-interval. Adds the
  capability to call some programs which would previously cause the server to
  hang (eg sleep/tmux). It also avoids running commands excessively (ie if used
  multiple times, it will be run only once).
* When a window is zombified and automatic-rename is on, append [dead] to the
  name.
* Split list-panes (alias lsp) off from list-windows.
* New pipe-pane (alias pipep) to redirect a pane output to an external command.
* Support for automatic-renames for Solaris.
* Permit attributes to be turned off in #[] by prefixing with no (eg nobright).
* Add H/M/L in vi mode, and M-R/M-r in emacs to move the cursor to the top,
  middle, and bottom of the screen.
* -a option added to kill-pane to kill all except current pane.
* The -d command line flag is now gone (can be replaced by terminal-overrides).
  Just use op/AX to detect default colours.
* input/tty/utf8 improvements.
* xterm-keys rewrite.
* Additional code reduction, and bug fixes.

CHANGES FROM 0.9 TO 1.0, 20 September 2009

* Option to alter the format of the window title set by tmux.
* Backoff for a while after multiple incorrect password attempts.
* Quick display of pane numbers (C-b q).
* Better choose-window, choose-session commands and a new choose-client command.
* Option to request multiple responses when using command-prompt.
* Improved environment handling.
* Combine wrapped lines when pasting.
* Option to override terminal settings (terminal-overrides).
* Use the full range of ACS characters for drawing pane separator lines.
* Customisable mode keys.
* Status line colour options, with embedded colours in status-left/right, and
  an option to centre the window list.
* Much improved layouts, including both horizontal and vertical splitting.
* Optional visual bell, activity and content indications.
* Set the utf8 and status-utf8 options when the server is started with -u.
* display-message command to show a message in the status line, by default some
  information about the current window.
* Improved current process detection on NetBSD.
* unlink-window -k is now the same as kill-window.
* attach-session now works from inside tmux.
* A system-wide configuration file, /etc/tmux.conf.
* A number of new commands in copy mode, including searching.
* Panes are now specified using the target (-t) notation.
* -t now accepts fnmatch(3) patterns and looks for prefixes.
* Translate \r into \n when pasting.
* Support for binding commands to keys without the prefix key
* Support for alternate screen (terminfo smcup/rmcup).
* Maintain data that goes off screen after reducing the window size, so it can
  be restored when the size is increased again.
* New if-shell command to test a shell command before running a tmux command.
* tmux now works as the shell.
* Man page reorganisation.
* Many minor additions, much code tidying and several bug fixes.

CHANGES FROM 0.8 TO 0.9, 01 July 2009

* Major changes to build infrastructure: cleanup of makefiles and addition
  of a configure script.
* monitor-content window option to monitor a window for a specific fnmatch(3)
  pattern. The find-window command also now accepts fnmatch(3) patterns.
* previous-layout and select-layout commands, and a main-horizontal layout.
* Recreate the server socket on SIGUSR1.
* clear-history command.
* Use ACS line drawing characters for pane separator lines.
* UTF-8 improvements, and code to detect UTF-8 support by looking at
  environment variables.
* The resize-pane-up and resize-pane-down commands are now merged together
  into a new resize-pane command with -U and -D flags.
* confirm-before command to request a yes/no answer before executing dangerous
  commands.
* Status line bug fixes, support for UTF-8 (status-utf8 option), and a key to
  paste from the paste buffer.
* Support for some additional escape sequences and terminal features, including
  better support for insert mode and tab stops.
* Improved window resizing behaviour, modelled after xterm.
* Some code reduction and a number of miscellaneous bug fixes.

================================================================================

On 01 June 2009, tmux was imported into the OpenBSD base system. From this date
onward changes are logged as part of the normal CVS commit message to either
OpenBSD or SourceForge CVS. This file will be updated to contain a summary of
major changes with each release, and to mention important configuration or
command syntax changes during development.

The list of older changes is below.

================================================================================

21 May 2009

* stat(2) files before trying to load them to avoid problems, for example
  with "source-file /dev/zero".

19 May 2009

* Try to guess if the window is UTF-8 by outputting a three-byte UTF-8 wide
  character and seeing how much the cursor moves. Currently tries to figure out
  if this works by some stupid checks on the terminal, these need to be
  rethought. Also might be better using a width 1 character rather than width 2.
* If LANG contains "UTF-8", assume the terminal supports UTF-8, on the grounds
  that anyone who configures it probably wants UTF-8. Not certain if this is
  a perfect idea but let's see if it causes any problems.
* New window option: monitor-content. Searches for a string in a window and if
  it matches, highlight the status line.

18 May 2009

* main-horizontal layout and main-pane-height option to match vertical.
* New window option main-pane-width to set the width of the large left pane with
  main-vertical (was left-vertical) layout.
* Lots of layout cleanup. manual layout is now manual-vertical.

16 May 2009

* select-layout command and a few default key bindings (M-0, M-1, M-2, M-9) to
  select layouts.
* Recreate server socket on SIGUSR1, per SF feature request 2792533.

14 May 2009

* Keys in status line (p in vi mode, M-y in emacs) to paste the first line
  of the upper paste buffer. Suggested by Dan Colish.
* clear-history command to clear a pane's history.
* Don't force wrapping with \n when asked, let the cursor code figure it out.
  Should fix terminals which use this to detect line breaks.
* Major cleanup and restructuring of build infrastructure. Still separate files
  for GNU and BSD make, but they are now hugely simplified at the expense of
  adding a configure script which must be run before make. Now build and
  install with:

	$ ./configure && make && sudo make install

04 May 2009

* Use ACS line drawing characters for pane separator lines.

30 April 2009

* Support command sequences without a space before the semicolon, for example
  "neww; neww" now works as well as "neww ; neww". "neww;neww" is still an
  error.
* previous-layout command.
* Display the layout name in window lists.
* Merge resize-pane-up and resize-pane-down into resize-pane with -U and -D
  flags.

29 April 2009

* Get rid of compat/vis.* - only one function was used which is easily
  replaced,and less compat code == good.

27 April 2009

* Avoid using the prompt history when the server is locked, and prevent any
  input entered from being added to the client's prompt history.
* New command, confirm-before (alias confirm), which asks for confirmation
  before executing a command. Bound "&" and "x" by default to confirm-before
  "kill-window" and confirm-before "kill-pane", respectively.

23 April 2009

* Support NEL, yet another way of making newline. Fixes the output from some
  Gentoo packaging thing. Reported by someone on SF then logs that allowed a
  fix sent by tcunha.
* Use the xenl terminfo flag to detect early-wrap terminals like the FreeBSD
  console. Many thanks for a very informative email from Christian Weisgerber.

21 April 2009

* tmux 0.8 released.

17 April 2009

* Remove the right number of characters from the buffer when escape then
  a cursor key (or other key prefixed by \033) is pressed. Reported by
  Stuart Henderson.

03 April 2009

* rotate-window command. -U flag (default) for up, -D flag for down.

02 April 2009

* Change scroll/pane redraws to only redraw the single pane affected rather
  than the entire window.
* If redrawing the region would mean redrawing > half the pane, just schedule
  to redraw the entire window. Also add a flag to skip updating the window any
  further if it is scheduled to be redrawn. This has the effect of batching
  multiple redraws together.

01 April 2009

* Basic horizontal splitting and layout management. Still some redraw and other
  issues - particularly, don't mix with manual pane resizing, be careful when
  viewing from multiple clients and don't expect shell windows to redraw very
  well after the layout is changed; generally cycling the layout a few times
  will fix most problems. Getting this in for testing while I think about how
  to deal with manual mode.

  Split window as normal and cycle the layouts with C-b space. Some of the
  layouts will work better when swap-pane comes along.

31 March 2009

* AIX port, thanks to cmihai for access to a box. Only tested on 6.1 with xlc
  10.1 (make sure CC is set). Needs GNU make and probably ncurses (didn't try
  plain curses). Also won't build with DEBUG, so comment the FDEBUG=1 line in
  GNUmakefile.
* Draw a vertical line on the right when the window size is less than the
  terminal size. This is partly to shake out any horizontal limit bugs on the
  way to horizontal splitting/pane tiling. Currently a bit slow since it has to
  do a lot of redrawing but hopefully that will improve as I get some better
  ideas for how to do it.
* Fix remaining problems with copy and paste and UTF-8.

28 March 2009

* Better UTF-8 support, including combined characters. Unicode data is now
  stored as UTF-8 in a separate array, the code does a lookup into this every
  time it gets to a UTF-8 cell. Zero width characters are just appended onto
  the UTF-8 data for the previous cell. This also means that almost no bytes
  extra are wasted non-Unicode data (yay).

  Still some oddities, such as copy mode skips over wide characters in a
  strange way, and the code could do with some tidying.
* Key repeating is now a property of the key binding not of the command.
  Repeat is turned on when the key is bound with the -r flag to bind-key.
  next/previous-window no longer repeat by default as it turned out to annoy
  me.

27 March 2009

* Clear using ED when redrawing the screen. I foolishly assumed using spaces
  would be equivalent and terminals would pick up on this, but apparently not.
  This fixes copy and paste in xterm/rxvt.
* Sockets in /tmp are now created in a subdirectory named, tmux-UID, eg
  tmux-1000. The default socket is thus /tmp/tmux-UID/default. To start a
  separate server, the new -L command line option should be used: this creates
  a socket in the same directory with a different name ("-L main" will create
  socket called "main"). -S should only be used to place the socket outside
  /tmp. This makes sockets a little more secure and a bit more convenient to
  use multiple servers.

21 March 2009

* New session flag "set-remain-on-exit" to set remain-on-exit flag for new
  windows created in that session (like "remain-by-default" used to do). Not
  perfectly happy about this, but until I can think of a good way to introduce
  it generically (maybe a set of options in the session) this will do. Fixes
  SF request 2527847.

07 March 2009

* Support for 88 colour terminals.
* break-pane command to create a new window using an existing pane.

02 March 2009

* Make escape key timer work properly so escape+key can be used without
  lightning fast key presses.

13 February 2009

* Redo mode keys slightly more cleanly and apply them to command prompt
  editing. vi or emacs mode is controlled by the session option status-keys.

12 February 2009

* Looking up argv[0] is expensive, so just use p_comm for the window name which
  is good enough. Also increase name update time to 500 ms.

11 February 2009

* Only use ri when actually at the top of the screen; just move the cursor up
  otherwise.
* FreeBSD's console wraps lines at $COLUMNS - 1 rather than $COLUMNS (the
  cursor can never be beyond $COLUMNS - 1) and does not appear to support
  changing this behaviour, or any of the obvious possibilities (turning off
  right margin wrapping, insert mode). This is irritating, most notably because
  it impossible to write to the very bottom-right of the screen without
  scrolling. To work around this, if built on FreeBSD and run with a "cons"
  $TERM, the bottom-right cell on the screen is omitted.
* Emulate scroll regions (slowly) to support the few terminals which don't have
  it (some of which don't really have any excuse).

10 February 2009

* No longer redraw the status line every status-interval unless it has actually
  changed.

08 February 2009

* Don't treat empty arguments ("") differently when parsing configuration
  file/command prompt rather than command line.
* tmux 0.7 released.

03 February 2009

* New command, copy-buffer (alias copyb), to copy a session paste buffer to
  another session.

01 February 2009

* The character pair #(command) may now contain (escaped) right parenthesis.

30 January 2009

* . now bound to "command-prompt 'move-window %%'" by default, from joshe.

29 January 2009

* Window options to set status line fg, bg and attributes for a single
  window. Options are: window-status-fg, window-status-bg,
  window-status-attr. Set to "default" to use the session status colours.

  This allows quite neat things like:

	$ cat ~/bin/xssh
	#!/bin/sh

	if [ ! -z "$TMUX" ]; then
	case "$1" in
    	natalya)
	        tmux setw window-status-fg red >/dev/null
		;;
	natasha)
        	tmux setw window-status-fg yellow >/dev/null
		;;
	esac
	fi
	ssh "$@"
	[ ! -z "$TMUX" ] && tmux setw -u window-status-fg >/dev/null
	$ alias ssh="~/bin/xssh"

* Support #(command) in status-left, and status-right, which is displayed as
  the first line of command's output (e.g. set -g status-right
  "#(whoami)@#(hostname -s)"). Commands with )s aren't supported.

28 January 2009

* Support mouse in copy mode to move cursor. Can't do anything else at the
  moment until other mouse modes are handled.
* Better support for at least the most common variant of mouse input: parse it
  and adjust for different panes. Also support mouse in window/session choice
  mode.

27 January 2009

* Bring back the fancy window titles with session/window names: it is easy to
  work around problems with elinks (see FAQ).
* -u flag to scroll-mode and copy-mode to start scrolled one page
  up. scroll-mode -u is bound to prefix,page-up (ppage) by default.
* Allow status, mode and message attributes to be changed by three new options:
  status-attr, mode-attr, message-attr. A comma-separated list is accepted
  containing: bright, dim, underscore, blink, reverse, hidden, italics, for
  example:

	set -g status-attr bright,blink

  From Josh Elsasser, thanks!

26 January 2009

* Be more clever about picking the right process to create the window name.
* Don't balls up the terminal on UTF-8 combined characters. Don't support them
  properly either - they are just discarded for the moment.

25 January 2009

* load-buffer command

23 January 2009

* Use reverse colours rather than swapping fg and bg for message, mode and
  status line. This makes these usable on black and white terminals.
* Better error messages when creating a session or window fails.
* Oops. Return non-zero on error. Reported by Will Maier.

21 January 2009

* Handle SIGTERM (and kill-server which uses it), a bit more neatly - tidy
  up properly and print a nicer message. Same effect though :-).
* new-window now supports -k to kill target window if it exists.
* Bring back split-window -p and -l options to specify the height a percentage
  or as a number of lines.
* Make window and session choice modes allow you to choose items in vi keys
  mode (doh!). As a side-effect, this makes enter copy selection (as well
  as C-w/M-w) when using emacs keys in copy mode. Reported by merdely.

20 January 2009

* Darwin support for automatic-rename from joshe; Darwin doesn't seem to have
  a sane method of getting argv[0] and searching for the precise insane way
  is too frustrating, so this just uses the executable name.
* Try to change the window title to match the command running it in. This is
  done by reading argv[0] from the process group leader of the group that owns
  the tty (tcgetpgrp()). This can't be done portably so some OS-dependent code
  is introduced (ugh); OpenBSD, FreeBSD and Linux are supported at the moment.

  A new window flag, automatic-rename, is available: if this is set to off, the
  window name is not changed. Specifying a name with the new-window,
  new-session or rename-window commands will automatically set this flag to off
  for the window in question. To disable it entirely set the option to off
  globally (setw -g automatic-rename off).

19 January 2009

* Fix various stupid issues when the status line is turned off. Grr.
* Use reverse attributes for clock and cursor, otherwise they do not
  appear on black and white terminals.
* An error in a command sequence now stops execution of that sequence.
  Internally, each command code now passes a return code back rather than
  talking to the calling client (if any) directly.
* attach-session now tries to start the server if it isn't already started - if
  no sessions are created in .tmux.conf this will cause an error.
* Clean up starting server by making initial client get a special socketpair.

18 January 2009

* Unbreak UTF-8.
* -a flag to next-window and previous-window to select the next or previous
  window with activity or bell. Bound to M-n and M-p.
* find-window command to search window names, titles and visible content (but
  not history) for a string. If only one is found, the window is selected
  otherwise a choice list is shown. This (as with the other choice commands)
  only works from a key. Bound to "f" by default.
* Cleaned up command printing code, also enclose arguments with spaces in "s.
* Added command sequences. These are entered by separating each argument by a ;
  argument (spaces on both sides), for example:

	lsk ; lsc

  To use a literal ; as the argument prefix it with \, for example:

	bind x lsk \; lsc

  Commands are executed from left to right. Also note that command sequences do
  not support repeat-time repetition unless all commands making up the sequence
  support it.
* suspend-client command to suspend a client. Don't try to background it
  though...
* Mark attached sessions in sessions lists. Suggested by Simon Kuhnle.

17 January 2009

* tmux 0.6 released.

15 January 2009

* Support #H for hostname and #S for session name in status-left/right.
* Two new commands, choose-window and choose-session which work only when bound
  to a key and allow the window or session to be selected from a list. These
  are now bound to "w" and "s" instead of the list commands.

14 January 2009

* Rework the prefix-time stuff. The option is now called repeat-time and
  defaults to 500 ms. It only applies to a small subset of commands, currently:
  up-pane, down-pane, next-window, previous-window, resize-pane-up,
  resize-pane-down. These are the commands for which it is obviously useful,
  having it for everything else was just bloody annoying.
* The alt-up and alt-down keys now resize a pane by five lines at a time.
* switch-pane is now select-pane and requires -p to select a pane. The
  "o" key binding is changed to down-pane.
* up-pane and down-pane commands, bound to arrow up and down by default.
* Multiple vertical window splitting. Minimum pane size is four lines, an
  (unhelpful) error will be shown if attempting to split a window with less
  that eight lines. If the window is resized, as many panes are shown as can
  fit without reducing them below four lines. There is (currently!) not a way
  to show a hidden pane without making the window larger.

  Note the -p and -l options to split-window are now gone, these may reappear
  once I think them through again.
* Server locking on inactivity (lock-after-time) is now disabled by default.

13 January 2009

* kill-pane command.

12 January 2009

* command-prompt now accepts a single argument, a template string. Any
  occurrences of %% in this string are replaced by whatever is entered at the
  prompt and the result is executed as a command. This allows things like (now
  bound by default):

  	 bind , command-prompt "rename-window %%"

  Or my favourite:

         bind x command-prompt "split-window 'man %%'"

* Option to set prefix time, allowing multiple commands to be entered without
  pressing the prefix key again, so long as they each typed within this time of
  each other.
* Yet more hacks for key handling. Think it is just about working now.
* Two commands, resize-pane-up and resize-pane-down to resize a pane.
* Make the window pane code handle panes of different sizes, and add a -l
  and -p arguments to split-window to specify the new window size in lines
  or as a percentage.

11 January 2009

* Vertical window splitting. Currently can only split a window into two panes.
  New split-window command splits (bound to ") and switch-pane command (bound to
  o) switches between panes.

  close-pane, swap-pane commands are to follow. Also to come are pane resizing,
  >2 panes, the ability to break a pane out to a full window and vice versa and
  possibly horizontal splitting.

  Panes are subelements of windows rather than being windows in their own
  right. I tried to make them windows (so the splitting was at the session or
  client level) but this rapidly became very complex and invasive. So in the
  interests of having something working, I just made it so each window can have
  two child processes instead of one (and it still took me 12 hours straight
  coding). Now the concept is proven and much of the support code is there,
  this may change in future if more flexibility is needed.
* save-buffer command, from Tiago Cunha.

10 January 2009

* New option, lock-after-time. If there is no activity in the period specified
  by this option (in seconds), tmux will lock the server. Default is 1800 (30
  minutes), set to 0 to disable.
* Server locking. Two new commands: set-password to set a password (a
  preencrypted password may be specified with -c); and lock-server to lock the
  server until the password is entered. Also an additional command line flag,
  -U, to unlock from the shell. The default password is blank (any password
  accepted). If specifying an encrypted password from encrypt(1) in .tmux.conf
  with -c, don't forget to enclose it in single-quotes (') to prevent shell
  variable expansion.
* If a window is created from the command line, tmux will now use the same
  current working directory for the new process. A new default-path option to
  sets the working directory for processes created from keys or interactively
  from the prompt.
* New mode to display a large clock. Entered with clock-mode command (bound to
  C-b t by default); two window options: clock-mode-colour and clock-mode-style
  (12 or 24). This will probably be used as the basis for window locking.
* New command, server-info, to show some server information and terminal
  details.

09 January 2009

* Stop using ncurses variables and instead build a table of the codes we want
  into an array for each terminal type. This makes the code a little more
  untidy in places but gets rid of the awful global variables and calling
  setterm all the time, and shoves all the ncurses-dependent mess into a single
  file, tty-term.c. It also allows overriding single terminal codes, this is
  used to fix rxvt on some platforms (where it is missing dch) and in future
  may allow user customisation a la vim.
* Update key handling code. Simplify, support ctrl properly and add a new
  window option (xterm-keys) to output xterm key codes including ctrl and,
  if available, alt and shift.

08 January 2009

* If built without DEBUG (the release versions), don't cause a fatal error if
  the grid functions notice an input error, just log and ignore the
  request. This might mean me getting shouted at less often when bugs kill
  long-running sessions, at least in release versions.
* Hopefully fix cursor out-of-bounds checking when writing to grid. When I
  wrote the code I must have forgotten that the cursor can be one cell off the
  right of the screen (yes, I know), so there were number of out-of-bounds/
  overflow problems.

07 January 2009

* New flag to set and setw, -u, to unset an option (allowing it to inherit from)
  the global options again.
* Added more info messages for options changes.
* A bit of tidying and reorganisation of options code.

06 January 2009

* Don't crash when backspacing if cursor is off the right of the screen,
  reported by David Chisnall.
* Complete words at any point inside command in prompt, also use option name
  as well as command names.
* Per-client prompt history of up to 100 items.
* Use a splay tree for key bindings instead of an array. As a side-effect this
  sorts them when listed.

22 December 2008

* Use the right keys for home and end.

20 December 2008

* Add vim mode for tmux configuration file to examples/, from Tiago Cunha.

15 December 2008

* New command, source-file (alias source), to load a configuration
  file. Written by Tiago Cunha, many thanks.

13 December 2008

* Work around lack of dch. On Linux, the rxvt termcap doesn't have it (it is
  lying, but we can't really start disbelieving termcaps...). This is a bit
  horrible - I can see no way to do it without pretty much redrawing the whole
  line, but it works...

10 December 2008

* glibc's getopt(3) is useless: it is not POSIX compliant without jumping
  through non-portable hoops, and the method of resetting it is unclear (the
  man page on my system says set optind to 1, but other sources say 0). So,
  import OpenBSD's getopt_long.c into compat/ for use on Linux and use the
  clearly documented optreset = optind = 1 method. This fixes some strange
  issues with command parsing (getting the syntax wrong would prevent any
  further commands being parsed).

06 December 2008

* Bring set/setw/show/showw into line with other commands. This means that by
  default they now affect the current window (if any); the new -g flag must be
  passed to set the global options. This changes the behaviour of set/show and
  WILL BREAK CURRENT CONFIGURATIONS.

  In summary, whether in the configuration file, the command prompt, or a key
  binding, use -g to set a global option, use -t to specify a particular window
  or session, or omit both to try and use the current window or session.

  This makes set/show a bit of a pain but is the correct behaviour for
  setw/showw and is the same as every other command, so we can put up with a
  bit of pain for consistency.
* Redo window options. They now work in the same way to session options with a
  global options set. showw/setw commands now have similar syntax to show/set
  (including the ability to use abbreviations).

  PLEASE NOTE this includes the following configuration-breaking changes:

  - remain-by-default is now GONE, use "setw -g remain-on-exit" to apply the
    global window option instead;
  - mode-keys is now a window option rather than session - use "setw [-g]
    mode-keys" instead of set.

  There are also some additions:

  - message-fg and message-bg session options to control status line message
    colours;
  - mode-fg and mode-bg window options to set colours in window modes such as
    copy mode.

  The options code still a mess and now there is twice as much of it :-(.

02 December 2008

* Add support for including the window title in status-left or status-right
  strings by including the character pair "#T". This may be prefixed with
  a number to specify a maximum length, for example "#24T" to use at most
  24 characters of the title.
* Introduce two new options, status-left-length and status-right-length,
  control the maximum length of left and right components of the status bar.
* elinks (and possibly others) bypass the terminal and talk directly to X to
  restore the window title when exiting. tmux can't know about this particular
  bit of stupidity so the title ends up strange - the prefix isn't terribly
  important and elinks is quite useful so just get rid of it.

27 November 2008

* Tweaks to support Dragonfly.

17 November 2008

* tmux 0.5 released.

16 November 2008

* New window option: "utf8"; this must be on (it is off by default) for UTF-8
  to be parsed. The global/session option "utf8-default" controls the setting
  for new windows.

  This means that by default tmux does not handle UTF-8. To use UTF-8 by
  default it is necessary to a) "set utf8-default on" in .tmux.conf b) start
  tmux with -u on any terminal which support UTF-8.

  It seems a bit unnecessary for this to be a per-window option but that is
  the easiest way to do it, and it can't do any harm...
* Enable default colours if op contains \033[39;49m, based on a report from
  fulvio ciriaco.

12 November 2008

* Keep stack of last windows rather than just most recent; based on a diff from
  joshe.

04 November 2008

* Don't try to redraw status line when showing a prompt or message; if it does,
  the status timer is never reset so it redraws on every loop. Spotted by
  joshe.

09 October 2008

* Translate 256 colours into 16 if 256 is not available, same as screen does.
* Better support for OSC command (only to set window title now), and also
  support using APC for the same purpose (some Linux default shell profiles do
  this).

25 September 2008

* Large internal rewrite to better support 256 colours and UTF-8. Screen data
  is now stored as single two-way array of structures rather than as multiple
  separate arrays. Also simplified a lot of code.

  Only external changes are three new flags, -2, -d and -u, which force tmux to
  assume the terminal supports 256 colours, default colours (useful for
  xterm-256color which lacks the AX flag), or UTF-8 respectively.

10 September 2008

* Split off colour conversion code from screen code.

09 September 2008

* Initial UTF-8 support. A bit ugly and with a limit of 4096 UTF-8
  characters per window.

08 September 2008

* 256 colour support. tmux attempts to autodetect the terminal by looking
  both at what ncurses reports (usually wrong for xterm) and checking if
  the TERM contains "256col". For xterm TERM=xterm-256color is needed (as
  well as a build that support 256 colours); this seems to work for rxvt
  as well. On non-256 colour terminals, high colours are translated to white
  foreground and black background.

28 August 2008

* Support OS X/Darwin thanks to bsd-poll.c from OpenSSH. Also convert
  from clock_gettime(2) to gettimeofday(2) as OS X doesn't support the
  former; microsecond accuracy will have to be sufficient ;-).

07 August 2008

* Lose some unused/useless wrapper functions.

25 July 2008

* Shell variables may now be defined and used in configuration file. Define
  variables with:

	VAR=1

  And use with:

        renamew ${VAR}
	renamew "x${VAR}x"

 Also some other fixes to make, for example, "abc""abc" work similarly to
 the shell.

24 July 2008

* Finally lose inconsistently-used SCREEN_DEF* defines.
* If cursor mode is on, switch the arrow keys from \033[A to \033OA.
* Support the numeric keypad in both application and numbers mode. This is
  different from screen which always keeps it in application mode.

19 July 2008

* Unbreak "set status" - tmux thought it was ambiguous, reported by rivo nurges.

02 July 2008

* Split vi and emacs mode keys into two tables and add an option (mode-keys)
  to select between them. Default is emacs, use,

     tmux set mode-keys vi

  to change to vi.

  vi mode uses space to start selection, enter to copy selection and escape
  to clear selection.

01 July 2008

* Protocol versioning. Clients which identify as a different version from the
  server will be rejected.
* tmux 0.4 released.

29 June 2008

* Zombie windows. These are not closed when the child process dies. May be
  set for a window with the new "remain-on-exit" option; the default setting
  of this flag for new windows may be set with the "remain-by-default" session
  option.

  A window may be restarted with the respawn-window command:

  	respawn-window [-k] [command]

  If -k is given, any existing process running in the window is killed;
  if command is omitted, the same command as when the window was first
  created is used.

27 June 2008

* Handle nonexistent session or client to -t properly.

25 June 2008

* select-prompt command to allow a window to be selected at a prompt. Only
  windows in the current session may be selected. Bound to ' by default.
  Suggested by merdely.
* move-window command. Requested by merdely.
* Support binding alt keys (prefixed with M-). Change default to use
  C- for ctrl keys (^ is still accepted as an alternative).
* Slim down default key bindings: support lowercase only.
* Handle escaped keys properly (parse eg \033b into a single key code) and
  use this to change copy mode next/previous work to M-f and M-b to match
  emacs.

24 June 2008

* Next word (C-n/w) and previous word (C-b/b) in copy mode.

23 June 2008

* list-commands command (alias lscm).
* Split information about options into a table and use it to parse options
  on input (allowing abbreviations) and to print them with show-options
  (meaning that bell-action gets a proper string). This turned out a bit ugly
  though :-/.

22 June 2008

* Do not translate black and white into default if the terminal supports
  default colours. This was nice to force programs which didn't use default
  colours to be properly transparent in rxvt/aterm windows with a background
  image, but it causes trouble if someone redefines the default foreground and
  background (to have black on white or something).

21 June 2008

* Naive tab completion in the command prompt. This only completes command
  names if a) they are at the start of the text b) the cursor is at
  the end of the text c) the text contains no spaces.
* Only attempt to set the title where TERM looks like an xterm (contains
  "xterm", "rxvt" or is "screen"). I hate this but I don't see a better way:
  setting the title actually kills some other terminals pretty much dead.
* Strip padding out of terminfo(5) strings. Currently the padding is just
  ignored, this may need to be altered if there are any software terminals
  out there that actually need it.

20 June 2008

* buffer-limit option to set maximum size of buffer stack. Default is 9.
* Initial buffer improvements. Each session has a stack of buffers and each
  buffer command takes a -b option to manipulate items on the stack. If -b
  is omitted, the top entry is used. The following commands are currently
  available:

	set-buffer [-b index] [-t target-session] string
	paste-buffer [-d] [-b index] [-t target-window]
	delete-buffer [-b index] [-t target-session]
	show-buffers [-t target-session]
	show-buffer [-b index] [-t target-session]

  -d to paste-buffer deletes the buffer after pasting it.
* New option, display-time, sets the time status line messages stay on screen
  (unless a key is pressed). Set in milliseconds, default is 750 (0.75 seconds).
  The timer is only checked every 100 ms or so.

19 June 2008

* Use "status" consistently for status line option, and prefix for "prefix" key
  option.
* Allow commands to be entered at a prompt. This is triggered with the
  command-prompt command, bound to : by default.
* Show status messages properly, without blocking the server.

18 June 2008

* New option, set-titles. On by default, this attempts to set the window title
  using the \e]2;...\007 xterm code.

  Note that elinks requires the STY environment variable (used by screen) to be
  set before it will set the window title. So, if you want window titles set by
  elinks, set STY before running it (any value will do). I can't do this for all
  windows since setting it to an invalid value breaks screen.
* Show arrows at either end of status line when scrolled if more windows
  exist. Highlight the arrow if a hidden window has activity or bell.
* Scroll the status line to show the current window if necessary. Also handle
  windows smaller than needed better (show a blank status line instead of
  hanging or crashing).

17 June 2008

* tmux 0.3 released.

16 June 2008

* Add some information messages when window options are changed, suggested by
  Mike Erdely. Also add a -q command-line option to suppress them.
* show-window-options (showw) command.

15 June 2008

* show-options (show) command to show one or all options.

14 June 2008

* New window options: force-width and force-height. This will force a window
  to an arbitrary width and height (0 for the default unlimited). This is
  neat for emacs which doesn't have a sensible way to force hard wrapping at 80
  columns. Also, don't try to be clever and use clr_eol when redrawing the
  whole screen, it causes trouble since the redraw functions are used to draw
  the blank areas too.
* Clear the blank area below windows properly when they are smaller than client,
  also add an indicator line to show the vertical limit.
* Don't die on empty strings in config file, reported by Will Maier.

08 June 2008

* Set socket mode +x if any sessions are attached and -x if not.

07 June 2008

* Make status-interval actually changeable.

06 June 2008

* New window option: aggressive-resize. Normally, windows are resized to the
  size of the smallest attached session to which they are linked. This means a
  window only changes size when sessions are detached or attached, or they are
  linked or unlinked from a session. This flag changes a window to be the size
  of the smallest attached session for which it is the current window - it is
  resized every time a session changes to it or away from it. This is nice for
  things that handle SIGWINCH well (like irssi) and bad for things like shells.
* The server now exits when no sessions remain.
* Fix bug with inserting characters with TERM=xterm-color.

05 June 2008

* Completely reorganise command parsing. Much more common code in cmd-generic.c
  and a new way of specifying windows, clients or sessions. Now, most commands
  take a -t argument, which specifies a client, a session, or a window target.
  Clients and sessions are given alone (sessions are fnmatch(3)d and
  clients currently not), windows are give by (client|session):index. For
  example, if a user is in session "1" window 0 on /dev/ttypi, these should all
  be equivalent:

	tmux renamew newname			(current session and window)
	tmux renamew -t: newname		(current session and window)
	tmux renamew -t:0 newname		(current session, window 0)
	tmux renamew -t0 newname		(current session, window 0)
	tmux renamew -t1:0 newname		(session 1, window 0)
	tmux renamew -t1: newname		(session 1's current window)
	tmux renamew -t/dev/ttypi newname	(client /dev/ttypi's current
						 session and window)
	tmux renamew -t/dev/ttypi: newname	(client /dev/ttypi's current
						 session and window)
	tmux renamew -t/dev/ttypi:0 newname	(client /dev/ttypi's current
						 session, window 0)

  This does have some downsides, for example, having to use -t on selectw,

	tmux selectw -t7

  is annoying. But then using non-flagged arguments would mean renaming the
  current window would need to be something like:

	tmux renamew : newname

  It might be better not to try and be so consistent; comments to the usual
  address ;-).
* Infrastructure for printing arguments in list-keys output. Easy ones only for
  now.

04 June 2008

* Add some vi(1) key bindings in copy mode, and support binding ^[, ^\, ^]
  ^^ and ^_. Both from/prompted by Will Maier.
* setw monitor-activity and set status without arguments now toggle the current
  value; suggested by merdely.
* New command set-window-option (alias setw) to set the single current window
  option: monitor-activity to determine whether window activity is shown in
  the status bar for that window (default off).
* Change so active/bell windows are inverted in status line.
* Activity monitoring - window with activity are marked in status line. No
  way to disable this/filter windows yet.
* Brought select-window command into line with everything else; it now uses
  -i for the window index.
* Strings to display on the left and right of the status bar may now be set
  with the status-left and status-right options. These are passed through
  strftime(3) before being displayed. The status bar is automatically updated
  at an interval set by the status-interval option. The default is to display
  nothing on the left and the date and time on the left; the default update
  interval is 15 seconds.

03 June 2008

* Per session options. Setting options without specifying a session sets the
  global options as normal (global options are inherited by all sessions);
  passing -c or -s will set the option only for that session.
* Because a client has a session attached, any command needing a session can
  take a client and use its session. So, anything that used to accept -s now
  accepts -c as well.
* -s to specify session name now supports fnmatch(3) wildcards; if multiple
  sessions are found, or if no -s is specified, the most newly created is used.
* If no command is specified, assume new-session. As a byproduct, clean up
  command default values into separate init functions.
* kill-server command.

02 June 2008

* New command, start-server (alias "start"), to start the tmux server and do
  nothing else. This is good if you have a configuration file which creates
  windows or sessions (like me): in that case, starting the server the first
  time tmux new is run is bad since it creates a new session and window (as
  it is supposed to - starting the server is a side-effect).

  Instead, I have a little script which does the equivalent of:

  	tmux has -s0 2>/dev/null || tmux start
  	tmux attach -d -s0

  And I use it to start the server if necessary and attach to my primary
  session.
* Basic configuration file in ~/.tmux.conf or specified with -f. This is file
  contains a set of tmux commands that are run the first time the server is
  started. The configuration commands are executed before any others, so
  if you have a configuration file that contains:

	new -d
	neww -s0

  And you do the following without an existing server running:

	tmux new

  You will end up with two sessions, session 0 with two windows (created by
  the configuration file) and your client attached to session 1 with one
  window (created by the command-line command). I'm not completely happy with
  this, it seems a little non-obvious, but I haven't yet decided what to do
  about it.

  There is no environment variable handling or other special stuff yet.

  In the future, it might be nice to be able to have per-session configuration
  settings, probably by having conditionals in the file (so you could, for
  example, have commands to define a particular window layout that would only
  be invoked if you called tmux new -smysession and mysession did not already
  exist).
* BIG CHANGE: -s and -c to specify session name and client name are now passed
  after the command rather than before it. So, for example:

	tmux -s0 neww

  Becomes:

	tmux neww -s0

  This is to allow them to be used in the (forthcoming) configuration file
  THIS WILL BREAK ANY CURRENT SCRIPTS OR ALIASES USING -s OR -c.

01 June 2008

* Bug fix: don't die if -k passed to link-window and the destination doesn't
  exist.
* New command, send-keys, will send a set of keys to a window.

31 May 2008

* Fix so tmux doesn't hang if the initial window fails for some reason. This
  was highlighted by problems on Darwin, thanks to Elias Pipping for the report
  and access to a test account. (tmux still won't work on Darwin since its
  poll(2) is broken.)

02 January 2008

* Don't attempt to reset the tty on exit if it has been closed externally.

06 December 2007

* Restore checks for required termcap entries and add a few more obvious
  emulations.
* Another major reorganisation, this time of screen handling. A new set of
  functions, screen_write_*, are now used to write to a screen and a tty
  simultaneously. These are used by the input parser to update the base
  window screen and also by the different modes which now interpose their own
  screen.

30 November 2007

* Support \ek...\e\ to set window name.

27 November 2007

* Enable/disable mouse when asked, if terminal claims to support it. Mouse
  sequences are just passed through unaltered for the moment.
* Big internal reorganisation. Rather than leaving control of the tty solely in
  the client and piping all data through a socket to it, change so that the
  server opens the tty again and reads and writes to it directly. This avoids
  a lot of buffering and copying. Also reorganise the redrawing stuff so that
  everything goes through screen_draw_* - this makes the code simpler, but
  still needs broken up more, and all the ways of writing to screens should be
  more consistent.

26 November 2007

* Rather than shifting up one line at a time once the history is full,
  shift by 10% of the history each time. This is faster.
* Add ^A and ^E to copy mode to move to start-of-line/end-of-line.

24 November 2007

* Support for alt charset mode (VT100 graphics characters).

23 November 2007

* Mostly complete copy & paste. Copy mode entered with C-b [ (copy-mode
  command). In copy mode, arrow keys/page up/page down/hjkl/C-u/C-f navigate,
  space or C-space starts selection, and enter or C-w copies and (important!)
  exits copy mode. C-b ] (paste-buffer) pastes into current window. No
  extra utility keys (bol/eol/clear selection/etc), only one single buffer,
  and no buffer manipulation commands (clear/view/etc) yet. The code is also
  fugly :-(.
* history-limit option to set maximum history. Does not apply retroactively to
  existing windows! Lines take up a variable amount of space, but a reasonable
  guess for an 80-column terminal is 250 KB per 1000 lines (of history used,
  an empty history takes no space).

21 November 2007

* Create every line as zero length and only expand it as data is written,
  rather than creating at full size immediately.
* Make command output (eg list-keys) go to a scrollable window similar to
  scroll mode.
* Redo screen redrawing so it is a) readable b) split into utility functions
  that can be used outside screen.c. Use these to make scroll mode only
  redraw what it has to which gets rid of irritating flickering status box and
  makes it much faster.
* Full line width memory and horizontal scrolling in history.
* Initial support for scroll history. = to enter scrolling mode, and then
  vi keys or up/down/pgup/pgdown to navigate. Q to exit. No horizontal history
  yet (need per-line sizes) and a few kinks to be worked out (resizing while in
  history mode will probably cause trouble).

20 November 2007

* Fix format string error with "must specify a client" message. Also
  sprinkle some printflike tags.
* tmux 0.1 released.

17 November 2007

* (nicm) Add -k option to link-window to kill target window if it exists.

16 November 2007

* (nicm) Split in-client display into two columns. This is a hack but not a lot
  more so than that bit is already and it helps with lots of keys.
* (nicm) switch-client command to switch client between different sessions. This
  is pretty cool:

	$ tmux bind q switch 0
	$ tmux bind w switch 1

  Then you can switch between sessions 0 and 1 with a key :-).
* (nicm) Accept "-c client-tty" on command line to allow client manipulation
  commands, and change detach-/refresh-session to detach-/refresh-client (this
  loses the -a behaviour, but at some point -session versions may return, and
  -c will allow fnmatch(3)).
* (nicm) List available commands on ambiguous command.

12 November 2007

* (nicm) If the terminal supports default colours (AX present), force black
  background and white foreground to default. This is useful on transparent
  *terms for programs which don't do it themselves (like most(1)).
* (nicm) Fill in the rest of the man page.
* (nicm) kill-session command.

09 November 2007

* (nicm) C-space is now "^ " not "^@".
* (nicm) Support tab (\011).
* (nicm) Initial man page outline.
* (nicm) -V to show version.
* (nicm) rename-session command.

08 November 2007

* (nicm) Check for required terminal capabilities on start.

31 October 2007

* (nicm) Linux port.

30 October 2007

* (nicm) swap-window command. Same as link-window but swaps windows.

26 October 2007

* (nicm) Saving scroll region on \e7 causes problems with ncmpc so I guess
  it is not required.
* (nicm) unlink-window command.
* (nicm) link-window command to link an existing window into another session
  (or another index in the same session). Syntax:

	tmux -s dstname link-window [-i dstidx] srcname srcidx

* (nicm) Redo window data structures. The global array remains, but each per-
  session list is now a RB tree of winlink structures. This disassociates the
  window index from the array size (allowing arbitrary indexes) which still
  allowing windows to have multiple indexes.

25 October 2007

* (nicm) has-session command: checks if session exists.

24 October 2007

* (nicm) Support for \e6n to request cursor position. resize(1) now works.
* (nicm) Support for \e7, \e8 save/restore cursor and attribute sequences.
  Currently don't save mode (probably should). Also change some cases where
  out-of-bound values are ignored to limit them to within range (there are
  others than need to be checked too).

23 October 2007

* (nicm) Lift limit on session name passed with -s.
* (nicm) Show size in session/window lists.
* (nicm) Pass tty up to server when client identifies and add a list-clients
  command to list connected clients.

20 October 2007

* (nicm) Add default-command option and change default to be $SHELL rather than
  $SHELL -l. Also try to read shell from passwd db if $SHELL isn't present.

19 October 2007

* (nicm) -n on new-session is now -s, and -n is now the initial window name.
  This was documented but not implemented :-/.
* (nicm) kill-window command, bound to & by default (because it should be hard
  to hit accidentally).
* (nicm) bell-style option with three choices: "none" completely ignore bell;
  "any" pass through a bell in any window to current; "current" ignore bells
  except in current window. This applies only to the bell terminal signal,
  the status bar always reflects any bells.
* (nicm) Refresh session command.

12 October 2007

* (nicm) Add a warning if $TMUX exists on new/attach.
* (nicm) send-prefix command. Bound to C-b by default.
* (nicm) set status, status-fg, status-bg commands. fg and bg are as a number
  from 0 to 8 or a string ("red", "blue", etc). status may be 1/0, on/off,
  yes/no.
* (nicm) Make status line mark window in yellow on bell.

04 October 2007

* (nicm) -d option to attach to detach all other clients on the same session.
* (nicm) Partial resizing support. Still buggy. A C-b S and back sometimes fixes
  it when it goes wonky.
* (mxey) Added my tmux start script as an example (examples/start-tmux.sh).
* (mxey) New sessions can now be given a command for their first window.
* (mxey) Fixed usage statement for new-window.
* (nicm) attach-session (can't believe I forgot it until now!) and list-windows
  commands.
* (nicm) rename-window and select-window commands.
* (nicm) set-option command (alias set): "tmux set-option prefix ^A".
* (nicm) Key binding and unbinding is back.

03 October 2007

* (nicm) {new,next,last,previous}-window.
* (nicm) Rewrite command handling so commands are much more generic and the
  same commands are used for command line and keys (although most will probably
  need to check how they are called). Currently incomplete (only new/detach/ls
  implemented). Change: -s is now passed before command again!
* (nicm) String number arguments. So you can do: tmux bind ^Q create "blah".
* (nicm) Key binding. tmux bind key command [argument] and tmux unbind key.
  Key names are in a table in key-string.c, plus A is A, ^A is ctrl-A.
  Possible commands are in cmd.c (look at cmd_bind_table).
* (nicm) Move command parsing into the client. Also rename some messages and
  tidy up a few bits. Lots more tidying up needed :-/.

02 October 2007

* (nicm) Redraw client status lines on rename.
* (nicm) Error on ambiguous command.

01 October 2007

* (nicm) Restore window title handling.
* (nicm) Simple uncustomisable status line with window list.

30 September 2007

* (nicm) Window info command for debugging, C-b I.

29 September 2007

* (nicm) Deleting/inserting lines should follow scrolling region. Fix.
* (nicm) Allow creation of detached sessions: "tmux new-session -d".
* (nicm) Permit error messages to be passed back for transient clients like
  rename. Also make rename -i work.
* (nicm) Pass through bell in any window to current.

28 September 2007

* (nicm) Major rewrite of input parser:
	- Lose the old weirdness in favour of a state machine.
	- Merge in parsing from screen.c.
	- Split key parsing off into a separate file.
  This is step one towards hopefully allowing a status line. It requires
  that we output data as if the terminal had one line less than it really does -
  a serious problem when it comes to things like scrolling. This change
  consolidates all the range checking and limiting together which should make
  it easier.
* (mxey) Added window renaming, like "tmux rename [-s session] [-i index] name"

27 September 2007

* Split "tmux list" into "tmux list-sessions" (ls) and "list-windows" (lsw).
* New command session selection:
	- if name is specified, look for it and use it if it exists, otherwise
	  error
	- if no name specified, try the current session from $TMUX
	- if $TMUX doesn't exist, and there is only one session, use it,
	  otherwise error

26 September 2007

* Add command aliases, so "ls" is an alias for "list".
* Rename some commands and alter syntax to take options after a la CVS. Also
  change some flags. So:

	tmux -s/socket -nabc new

  Becomes:

	tmux -S/socket new -sabc

* Major tidy and split of client/server code.

22 September 2007

* Window list command (C-b W). Started by Maximilian Gass, finished by me.

20 September 2007

* Specify meta via environment variable (META).
* Record last window and ^L key to switch to it. Largely from Maximilian Gass.
* Reset ignored signals in child after forkpty, makes ^C work.
* Wrap on next/previous. From Maximilian Gass.

19 September 2007

* Don't renumber windows on close.

28 August 2007

* Scrolling region (\e[r) support.

27 August 2007

* Change screen.c to work more logically and hopefully fix heap corruption.

09 July 2007

* Initial import to CVS. Basic functions are working, albeit with a couple of
  showstopper memory bugs and many missing features. Detaching, reattaching,
  creating new sessions, listing sessions work acceptably for using with shells.
  Simple curses programs (top, systat, tetris) and more complicated ones (mutt,
  emacs) that don't require scrolling regions (ESC[r) mostly work fine
  (including mutt, emacs). No status bar yet and no key remapping or other
  customisation.