FAQ - tmux - Rivoreo Source Code Repositories

 tmux frequently asked questions

 ******************************************************************************
 * PLEASE NOTE: most display problems are due to incorrect TERM! Before       *
 * reporting problems make SURE that TERM settings are correct inside and     *
 * outside tmux.                                                              *
 *                                                                            *
 * Inside tmux TERM must be "screen" or similar (such as "screen-256color").  *
 * Don't bother reporting problems where it isn't!                            *
 *                                                                            *
 * Outside, it must match your terminal: particularly, use "rxvt" for rxvt    *
 * and derivatives.                                                           *
 ******************************************************************************

 * How is tmux different from GNU screen?

 tmux and GNU screen have many similarities. Some of the main differences I am
 aware of are (bearing in mind I haven't used screen for a few years now):

 - tmux uses a client-server model. Each server has single Unix domain socket in
   /tmp and within one server there are multiple sessions which may be attached
   to multiple clients (terminals).

   This has advantages, notably: windows may be linked simultaneously to
   multiple sessions; windows may be moved freely between sessions; and a client
   may be switched between sessions easily (C-b D). There is one major
   disadvantage: if the server crashes, game over, all sessions die. In
   practice, however, tmux is quite stable and gets more so as people report any
   bugs they hit :-).

   This model is different from screen, where typically each new screen instance
   is independent. tmux supports the same behaviour by using multiple servers
   with the -L option but it is not typically recommended.

 - Different command interfaces. One of the goals of tmux is that the shell
   should be easily usable as a scripting language - almost all tmux commands
   can be used from the shell and behave identically whether used from the
   shell, from a key binding or from the command prompt. Personally I also find
   tmux's command interface much more consistent and clearer, but this is
   subjective.

 - tmux calls window names (what you see in the status line) "names", screen
   calls them "titles".

 - tmux has a multiple paste buffers. Not a major one but comes in handy quite a
   lot.

 - tmux supports automatically renaming windows to the running application
   without gross hacks using escape sequences. Its even on by default.

 - tmux has a choice of vi or emacs key layouts. Again, not major, but I use
   emacs so if tmux did support only one key set it would be emacs and then all
   the vi users would get humpy. Key bindings may be completely reconfigured in
   any case.

 - tmux has an option to limit the window size.

 - tmux has search in windows (C-b f).

 - The window split (pane) model is different. tmux has two objects, windows and
   panes; screen has just windows. This difference has several implications:

   * In screen you can have a window appear in several layouts, in tmux a pane
   can only be in one window (fixing this is a big todo item but quite
   invasive).

   * tmux layouts are immutable and do not get changed unless you modify them.

   * In tmux, all panes are closed when you kill a window.

   * tmux panes do not have individual names, titles and so on.

   I think tmux's model is much easier to manage and navigate within a window,
   but breaking panes off from and joining them to windows is more clumsy.

   tmux also has support for preset pane layouts.

 - tmux's status line syntax is more readable and easier to use. I think it'd be
   hard for anyone to argue with this. tmux doesn't support running a command
   constantly and always using the last line of its output, commands must be run
   again each time.

 - tmux has modern, easily extended code. Again hard to argue screen is better
   if you have looked at the code.

 - tmux depends on libevent. I don't see this as a disadvantage: libevent is
   small and portable, and on modern systems with current package management
   systems dependencies are not an issue. libevent brings advantages in code
   simplicity and performance.

 - screen allows the window to be bigger than the terminal and can pan around
   it. tmux limits the size to the largest attached client. This is a big todo
   item for tmux but it is not trivial.

 - screen has builtin serial and telnet support; this is bloat and is unlikely
   to be added to tmux.

 - Environment handling is different.

 - tmux tends to be more demanding on the terminal so tends to show up terminal
   and application bugs which screen does not.

 - screen has wider platform support, for example IRIX, and for odd terminals.

 * I found a bug! What do I do?

 Check the latest version of tmux from Git to see if the problem is still
 reproducible.  Sometimes the length of time between releases means a lot of
 fixes can be sitting in Git and the problem might already be fixed.

 Please send bug reports by email to nicm@users.sourceforge.net or
 tmux-users@lists.sourceforge.net. Please include as much of the following
 information as possible:

 - the version of tmux you are running;
 - the operating system you are using and its version;
 - the terminal emulator you are using and the TERM setting when tmux was
   started;
 - a description of the problem;
 - if the problem is repeatable, the steps to repeat the problem;
 - for screen corruption issues, a screenshot and the output of "infocmp $TERM"
   from outside tmux are often very useful.

 * Why doesn't tmux do $x?

 Please send feature requests by email to nicm@users.sourceforge.net.

 * Why do you use the screen terminal description inside tmux? It sucks.

 It is already widely available. It is planned to change to something else such
 as xterm-xfree86 at some point, if possible.

 * I don't see any colour in my terminal! Help!

 On some platforms, common terminal descriptions such as xterm do not include
 colour. screen ignores this, tmux does not. If the terminal emulator in use
 supports colour, use a value for TERM which correctly lists this, such as
 xterm-color.

 * tmux freezes my terminal when I attach to a session. I even have to kill -9
   the shell it was started from to recover!

 Some consoles really really don't like attempts to set the window title. Tell
 tmux not to do this by turning off the "set-titles" option (you can do this
 in .tmux.conf):

      set -g set-titles off

 If this doesn't fix it, send a bug report.

 * Why is C-b the prefix key? How do I change it?

 The default key is C-b because the prototype of tmux was originally developed
 inside screen and C-b was chosen not to clash with the screen meta key. It
 also has the advantage of not interfering with the use of C-a for start-of-line
 in emacs and the shell (although it does interfere with previous-character).

 Changing is simple: change the "prefix-key" option, and - if required - move
 the binding of the "send-prefix" command from C-b (C-b C-b sends C-b by
 default) to the new key. For example:

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

 * How do I use UTF-8?

 When running tmux in a UTF-8 capable terminal, UTF-8 must be turned on in tmux;
 as of release 0.9, tmux attempts to autodetect a UTF-8-capable terminal by
 checking the LC_ALL, LC_CTYPE and LANG environment variables. list-clients may
 be used to check if this is detected correctly; if not, the -u command-line
 flag may be specified when creating or attaching a client to a tmux session:

 	$ tmux -u new

 Since the 1.0 release, tmux will turn on UTF-8 related options automatically
 (ie status-utf8, and utf8) if the above conditions are met.

 * How do I use a 256 colour terminal?

 Provided the underlying terminal supports 256 colours, it is usually sufficient
 to add the following to ~/.tmux.conf:

 	set -g default-terminal "screen-256color"

 Note that some platforms do not support "screen-256color" ("infocmp
 screen-256color" will return an error) - in this case see the next entry in
 this FAQ.

 tmux attempts to detect a 256 colour terminal both by looking at the colors
 terminfo entry and by looking for the string "256col" in the TERM environment
 variable.

 If both these methods fail, the -2 flag may be passed to tmux when attaching
 to a session to indicate the terminal supports 256 colours.

 * vim or $otherprogram doesn't display 256 colours. What's up?

 Some programs attempt to detect the number of colours a terminal is capable of
 by checking the colors terminfo or Co termcap entry. However, this is not
 reliable, and in any case is missing from the "screen" terminal description
 used inside tmux.

 There are two options (aside from using "screen-256color") to allow programs to
 recognise they are running on a 256-colour terminal inside tmux:

 - Manually force the application to use 256 colours always or if TERM is set to
   screen. For vim, you can do this by overriding the t_Co option, see
   http://vim.wikia.com/wiki/256_colors_in_vim.
 - Creating a custom terminfo file that includes colors#256 in ~/.terminfo and
   using it instead. These may be compiled with tic(1).

 * How do I make Ctrl-PgUp and Ctrl-PgDn work in vim?

 tmux supports passing through ctrl (and where supported by the client terminal,
 alt and shift) modifiers to function keys using xterm(1)-style key sequences.
 This may be enabled per window, or globally with the tmux command:

 	setw -g xterm-keys on

 Because the TERM variable inside tmux must be set to "screen", vim will not
 automatically detect these keys are available; however, the appropriate key
 sequences can be overridden in .vimrc using the following:

 	if &term == "screen"
 	set t_kN=^[[6;*~
 	set t_kP=^[[5;*~
 	endif

 And similarly for any other keys for which modifiers are desired.

 Please note that the "xterm-keys" setting may affect other programs, in the
 same way as running them in a standard xterm; for example most shells do not
 expect to receive xterm(1)-style key sequences so this setting may prevent keys
 such as ctrl-left and ctrl-right working correctly. tmux also passes through
 the ctrl (bit 5 set, for example ^[[5~ to ^[[5^) modifier in non-xterm(1) mode;
 it may be possible to configure vim to accept these, an example of how to do so
 would be welcome.

 vim users may also want to set the "ttyfast" option inside tmux.

 * How do I make ctrl and shift arrow keys work in emacs?

 The terminal-init-screen function in term/screen.el is called for new frames,
 but it doesn't configure any function keys.

 If the tmux xterm-keys option is on, it is enough to define the same keys as
 xterm. Add the following to init.el or .emacs to do this:

 (defadvice terminal-init-screen
   ;; The advice is named `tmux', and is run before `terminal-init-screen' runs.
   (before tmux activate)
   ;; Docstring.  This describes the advice and is made available inside emacs;
   ;; for example when doing C-h f terminal-init-screen RET
   "Apply xterm keymap, allowing use of keys passed through tmux."
   ;; This is the elisp code that is run before `terminal-init-screen'.
   (if (getenv "TMUX")
     (let ((map (copy-keymap xterm-function-map)))
     (set-keymap-parent map (keymap-parent input-decode-map))
     (set-keymap-parent input-decode-map map))))

 And ensure .tmux.conf contains "set -g xterm-keys on".

 Alternatively, the screen.el file can be copied to the load path and
 customized.

 * Why doesn't elinks set the window title inside tmux?

 There isn't a way to detect if a terminal supports setting the window title, so
 elinks attempts to guess by looking at the environment. Rather than looking for
 TERM=screen, it uses the STY variable to detect if it is running in screen;
 tmux does not use this so the check fails. A workaround is to set STY before
 running elinks.

 The following shell function does this, and also clears the window title on
 exit (elinks, for some strange reason, sets it to the value of TERM):

 	elinks() {
         	STY= `which elinks` $*
 	        echo -ne \\033]0\;\\007;
 	}

 * What is the proper way to escape characters with #(command)?

 When using the #(command) construction to include the output from a command in
 the status line, the command will be parsed twice. First, when it's read by the
 configuration file or the command-prompt parser, and second when the status
 line is being drawn and the command is passed to the shell. For example, to
 echo the string "(test)" to the status line, either single or double quotes
 could be used:

 	set -g status-right "#(echo \\\\(test\\\\))"
 	set -g status-right '#(echo \\\(test\\\))'

 In both cases, the status-right option will be set to the string "#(echo
 \\(test\\))" and the command executed will be "echo \(test\)".

 * tmux uses too much CPU. What do I do?

 Automatic window renaming may use a lot of CPU, particularly on slow computers:
 if this is a problem, turn it off with "setw -g automatic-rename off". If this
 doesn't fix it, please report the problem.

 * I use PuTTY and my tmux window pane separators are all qqqqqqqqq's!

 PuTTY is using a character set translation that doesn't support ACS line
 drawing. With a Unicode font, try setting PuTTY to use a different translation
 on the Window -> Translation configuration page. For example, change UTF-8 to
 ISO-8859-1 or CP437. It may also be necessary to adjust the way PuTTY treats
 line drawing characters in the lower part of the same configuration page.

 * What is the best way to display the load average? Why no #L?

 It isn't possible to get the load average portably in code and it is preferable
 not to add portability goop. The following works on at least Linux, *BSD and OS
 X:

 uptime|awk '{split(substr($0, index($0, "load")), a, ":"); print a[2]}'

 * How do I attach the same session to multiple clients but with a different
   current window, like screen -x?

 One or more of the windows can be linked into multiple sessions manually with
 link-window, or a grouped session with all the windows can be created with
 new-session -t.

 * Ctrl and arrow keys doesn't work in putty! What do I do?

 putty inverts the sense of the cursor key mode on ctrl, which is a bit hard for
 tmux to detect properly. To get ctrl keys right, change the terminfo settings
 so kUP5 (Ctrl-Up etc) are the adjusted versions, and disable smkx/rmkx so tmux
 doesn't change the mode. For example with this line in .tmux.conf (assuming you
 have TERM set to xterm):

 set -g terminal-overrides "xterm*:kLFT5=\eOD:kRIT5=\eOC:kUP5=\eOA:kDN5=\eOB:smkx@:rmkx@"

 Note that this will only work in tmux 1.2 and above.

 * How can I blank the tmux window?

 GNU screen has a feature whereby it will blank the screen after a period of
 inactivity. To do the same thing in tmux, use the lock-command setting, for
 example (with GNU bash):

 set -g lock-command 'tput civis && read -s -n1'

 This will remove the cursor and tell the shell to quit once a key has been
 pressed. For zsh, use "read -s -k1".

 In addition, it's possible to have both blanking and locking (for instance via
 lock(1) or vlock(1)) by using the following:

 bind x set lock-command '/usr/bin/vlock' \; lock-client \; set lock-command 'tput civis && read -s -n1'

 * vim displays reverse video instead of italics, while less displays italics
   (or just regular text) instead of reverse. What's wrong?

 Screen's terminfo description lacks italics mode and has standout mode in its
 place, but using the same escape sequence that urxvt uses for italics. This
 means applications (like vim) looking for italics will not find it and might
 turn to reverse in its place, while applications (like less) asking for
 standout will end up with italics instead of reverse. To make applications
 aware that tmux supports italics and to use a proper escape sequence for
 standout, you'll need to create a new terminfo file with modified sgr, smso,
 rmso, sitm and ritm entries:

 	$ mkdir $HOME/.terminfo/
 	$ screen_terminfo="screen"
 	$ infocmp "$screen_terminfo" | sed \
 	  -e 's/^screen[^|]*|[^,]*,/screen-it|screen with italics support,/' \
 	  -e 's/%?%p1%t;3%/%?%p1%t;7%/' \
 	  -e 's/smso=[^,]*,/smso=\\E[7m,/' \
 	  -e 's/rmso=[^,]*,/rmso=\\E[27m,/' \
 	  -e '$s/$/ sitm=\\E[3m, ritm=\\E[23m,/' > /tmp/screen.terminfo
 	$ tic /tmp/screen.terminfo

 And tell tmux to use it in ~/.tmux.conf:

 	set -g default-terminal "screen-it"

 If your terminal supports 256 colors, use:

 	$ screen_terminfo="screen-256color"

 instead of "screen". See the FAQ entry about 256 colors support for more info.
 Also note that tmux will still display reverse video on terminals that do not
 support italics.

 If your urxvt cannot display italics at all, make sure you have an italics
 capable font enabled, for example, add to ~/.Xdefaults:

 	urxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true

 * How can I make tmux use my terminal's scrollback buffer?

 Normally, tmux enables the terminal's "alternate screen". Most terminals (such
 as xterm) do not save scrollback for the alternate screen. You might prefer
 tmux to use the normal screen, so it uses your terminal's scrollback
 buffer. This way, you can access the scrollback buffer as usual, for example
 using the mouse wheel - although there is no guarantee output inside tmux will
 always (or ever) be added to the scrollback.

 You can make tmux use the normal screen by telling it that your terminal does
 not have an alternate screen. Put the following in ~/.tmux.conf:

         set -ga terminal-overrides ',xterm*:smcup@:rmcup@'

 Adjust if your $TERM does not start with xterm.

 tmux will still emulate the alternate screen for applications run under tmux,
 so you don't really lose anything with this setting. The only disadvantage is
 that when you exit tmux, it will not restore whatever was there before you
 started.

 * How do I see the default configuration?

 Show the default session options by starting a new tmux server with no
 configuration file:

         $ tmux -Lfoo -f/dev/null start\; show -g

 Or the default window options:

         $ tmux -Lfoo -f/dev/null start\; show -gw

 * How do I copy a selection from tmux to the system's clipboard?

 When running in xterm(1), tmux can automatically send copied text to the
 clipboard. This is controlled by the set-clipboard option and also needs this
 X resource to be set:

 	XTerm*disallowedWindowOps: 20,21,SetXprop

 For rxvt-unicode (urxvt), there is an unofficial Perl extension here:

         http://anti.teamidiot.de/static/nei/*/Code/urxvt/

 Otherwise a key binding for copy mode using xclip (or xsel) works:

 	bind -temacs-copy C-y copy-pipe "xclip -i >/dev/null"

 Or for inside and outside copy mode with the prefix key:

         bind C-y run -b "tmux save-buffer - | xclip -i"

 On OS X, reattach-to-usernamespace lets pbcopy/pbpaste work:

         https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard

 * Why do I see dots around a session when I attach to it?

 tmux limits the size of the window to the smallest attached session. If
 it didn't do this then it would be impossible to see the entire window.
 The dots mark the size of the window tmux can display.

 To avoid this, detach all other clients when attaching:

 	$ tmux attach -d

 Or from inside tmux by detaching individual clients with C-b D or all
 using:

 	C-b : attach -d

 $Id$
	tmux frequently asked questions

	******************************************************************************
	* PLEASE NOTE: most display problems are due to incorrect TERM! Before *
	* reporting problems make SURE that TERM settings are correct inside and *
	* outside tmux. *
	* *
	* Inside tmux TERM must be "screen" or similar (such as "screen-256color"). *
	* Don't bother reporting problems where it isn't! *
	* *
	* Outside, it must match your terminal: particularly, use "rxvt" for rxvt *
	* and derivatives. *
	******************************************************************************

	* How is tmux different from GNU screen?

	tmux and GNU screen have many similarities. Some of the main differences I am
	aware of are (bearing in mind I haven't used screen for a few years now):

	- tmux uses a client-server model. Each server has single Unix domain socket in
	/tmp and within one server there are multiple sessions which may be attached
	to multiple clients (terminals).

	This has advantages, notably: windows may be linked simultaneously to
	multiple sessions; windows may be moved freely between sessions; and a client
	may be switched between sessions easily (C-b D). There is one major
	disadvantage: if the server crashes, game over, all sessions die. In
	practice, however, tmux is quite stable and gets more so as people report any
	bugs they hit :-).

	This model is different from screen, where typically each new screen instance
	is independent. tmux supports the same behaviour by using multiple servers
	with the -L option but it is not typically recommended.

	- Different command interfaces. One of the goals of tmux is that the shell
	should be easily usable as a scripting language - almost all tmux commands
	can be used from the shell and behave identically whether used from the
	shell, from a key binding or from the command prompt. Personally I also find
	tmux's command interface much more consistent and clearer, but this is
	subjective.

	- tmux calls window names (what you see in the status line) "names", screen
	calls them "titles".

	- tmux has a multiple paste buffers. Not a major one but comes in handy quite a
	lot.

	- tmux supports automatically renaming windows to the running application
	without gross hacks using escape sequences. Its even on by default.

	- tmux has a choice of vi or emacs key layouts. Again, not major, but I use
	emacs so if tmux did support only one key set it would be emacs and then all
	the vi users would get humpy. Key bindings may be completely reconfigured in
	any case.

	- tmux has an option to limit the window size.

	- tmux has search in windows (C-b f).

	- The window split (pane) model is different. tmux has two objects, windows and
	panes; screen has just windows. This difference has several implications:

	* In screen you can have a window appear in several layouts, in tmux a pane
	can only be in one window (fixing this is a big todo item but quite
	invasive).

	* tmux layouts are immutable and do not get changed unless you modify them.

	* In tmux, all panes are closed when you kill a window.

	* tmux panes do not have individual names, titles and so on.

	I think tmux's model is much easier to manage and navigate within a window,
	but breaking panes off from and joining them to windows is more clumsy.

	tmux also has support for preset pane layouts.

	- tmux's status line syntax is more readable and easier to use. I think it'd be
	hard for anyone to argue with this. tmux doesn't support running a command
	constantly and always using the last line of its output, commands must be run
	again each time.

	- tmux has modern, easily extended code. Again hard to argue screen is better
	if you have looked at the code.

	- tmux depends on libevent. I don't see this as a disadvantage: libevent is
	small and portable, and on modern systems with current package management
	systems dependencies are not an issue. libevent brings advantages in code
	simplicity and performance.

	- screen allows the window to be bigger than the terminal and can pan around
	it. tmux limits the size to the largest attached client. This is a big todo
	item for tmux but it is not trivial.

	- screen has builtin serial and telnet support; this is bloat and is unlikely
	to be added to tmux.

	- Environment handling is different.

	- tmux tends to be more demanding on the terminal so tends to show up terminal
	and application bugs which screen does not.

	- screen has wider platform support, for example IRIX, and for odd terminals.

	* I found a bug! What do I do?

	Check the latest version of tmux from Git to see if the problem is still
	reproducible. Sometimes the length of time between releases means a lot of
	fixes can be sitting in Git and the problem might already be fixed.

	Please send bug reports by email to nicm@users.sourceforge.net or
	tmux-users@lists.sourceforge.net. Please include as much of the following
	information as possible:

	- the version of tmux you are running;
	- the operating system you are using and its version;
	- the terminal emulator you are using and the TERM setting when tmux was
	started;
	- a description of the problem;
	- if the problem is repeatable, the steps to repeat the problem;
	- for screen corruption issues, a screenshot and the output of "infocmp $TERM"
	from outside tmux are often very useful.

	* Why doesn't tmux do $x?

	Please send feature requests by email to nicm@users.sourceforge.net.

	* Why do you use the screen terminal description inside tmux? It sucks.

	It is already widely available. It is planned to change to something else such
	as xterm-xfree86 at some point, if possible.

	* I don't see any colour in my terminal! Help!

	On some platforms, common terminal descriptions such as xterm do not include
	colour. screen ignores this, tmux does not. If the terminal emulator in use
	supports colour, use a value for TERM which correctly lists this, such as
	xterm-color.

	* tmux freezes my terminal when I attach to a session. I even have to kill -9
	the shell it was started from to recover!

	Some consoles really really don't like attempts to set the window title. Tell
	tmux not to do this by turning off the "set-titles" option (you can do this
	in .tmux.conf):

	set -g set-titles off

	If this doesn't fix it, send a bug report.

	* Why is C-b the prefix key? How do I change it?

	The default key is C-b because the prototype of tmux was originally developed
	inside screen and C-b was chosen not to clash with the screen meta key. It
	also has the advantage of not interfering with the use of C-a for start-of-line
	in emacs and the shell (although it does interfere with previous-character).

	Changing is simple: change the "prefix-key" option, and - if required - move
	the binding of the "send-prefix" command from C-b (C-b C-b sends C-b by
	default) to the new key. For example:

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

	* How do I use UTF-8?

	When running tmux in a UTF-8 capable terminal, UTF-8 must be turned on in tmux;
	as of release 0.9, tmux attempts to autodetect a UTF-8-capable terminal by
	checking the LC_ALL, LC_CTYPE and LANG environment variables. list-clients may
	be used to check if this is detected correctly; if not, the -u command-line
	flag may be specified when creating or attaching a client to a tmux session:

	$ tmux -u new

	Since the 1.0 release, tmux will turn on UTF-8 related options automatically
	(ie status-utf8, and utf8) if the above conditions are met.

	* How do I use a 256 colour terminal?

	Provided the underlying terminal supports 256 colours, it is usually sufficient
	to add the following to ~/.tmux.conf:

	set -g default-terminal "screen-256color"

	Note that some platforms do not support "screen-256color" ("infocmp
	screen-256color" will return an error) - in this case see the next entry in
	this FAQ.

	tmux attempts to detect a 256 colour terminal both by looking at the colors
	terminfo entry and by looking for the string "256col" in the TERM environment
	variable.

	If both these methods fail, the -2 flag may be passed to tmux when attaching
	to a session to indicate the terminal supports 256 colours.

	* vim or $otherprogram doesn't display 256 colours. What's up?

	Some programs attempt to detect the number of colours a terminal is capable of
	by checking the colors terminfo or Co termcap entry. However, this is not
	reliable, and in any case is missing from the "screen" terminal description
	used inside tmux.

	There are two options (aside from using "screen-256color") to allow programs to
	recognise they are running on a 256-colour terminal inside tmux:

	- Manually force the application to use 256 colours always or if TERM is set to
	screen. For vim, you can do this by overriding the t_Co option, see
	http://vim.wikia.com/wiki/256_colors_in_vim.
	- Creating a custom terminfo file that includes colors#256 in ~/.terminfo and
	using it instead. These may be compiled with tic(1).

	* How do I make Ctrl-PgUp and Ctrl-PgDn work in vim?

	tmux supports passing through ctrl (and where supported by the client terminal,
	alt and shift) modifiers to function keys using xterm(1)-style key sequences.
	This may be enabled per window, or globally with the tmux command:

	setw -g xterm-keys on

	Because the TERM variable inside tmux must be set to "screen", vim will not
	automatically detect these keys are available; however, the appropriate key
	sequences can be overridden in .vimrc using the following:

	if &term == "screen"
	set t_kN=^[[6;*~
	set t_kP=^[[5;*~
	endif

	And similarly for any other keys for which modifiers are desired.

	Please note that the "xterm-keys" setting may affect other programs, in the
	same way as running them in a standard xterm; for example most shells do not
	expect to receive xterm(1)-style key sequences so this setting may prevent keys
	such as ctrl-left and ctrl-right working correctly. tmux also passes through
	the ctrl (bit 5 set, for example ^[[5~ to ^[[5^) modifier in non-xterm(1) mode;
	it may be possible to configure vim to accept these, an example of how to do so
	would be welcome.

	vim users may also want to set the "ttyfast" option inside tmux.

	* How do I make ctrl and shift arrow keys work in emacs?

	The terminal-init-screen function in term/screen.el is called for new frames,
	but it doesn't configure any function keys.

	If the tmux xterm-keys option is on, it is enough to define the same keys as
	xterm. Add the following to init.el or .emacs to do this:

	(defadvice terminal-init-screen
	;; The advice is named `tmux', and is run before `terminal-init-screen' runs.
	(before tmux activate)
	;; Docstring. This describes the advice and is made available inside emacs;
	;; for example when doing C-h f terminal-init-screen RET
	"Apply xterm keymap, allowing use of keys passed through tmux."
	;; This is the elisp code that is run before `terminal-init-screen'.
	(if (getenv "TMUX")
	(let ((map (copy-keymap xterm-function-map)))
	(set-keymap-parent map (keymap-parent input-decode-map))
	(set-keymap-parent input-decode-map map))))

	And ensure .tmux.conf contains "set -g xterm-keys on".

	Alternatively, the screen.el file can be copied to the load path and
	customized.

	* Why doesn't elinks set the window title inside tmux?

	There isn't a way to detect if a terminal supports setting the window title, so
	elinks attempts to guess by looking at the environment. Rather than looking for
	TERM=screen, it uses the STY variable to detect if it is running in screen;
	tmux does not use this so the check fails. A workaround is to set STY before
	running elinks.

	The following shell function does this, and also clears the window title on
	exit (elinks, for some strange reason, sets it to the value of TERM):

	elinks() {
	STY= `which elinks` $*
	echo -ne \\033]0\;\\007;
	}

	* What is the proper way to escape characters with #(command)?

	When using the #(command) construction to include the output from a command in
	the status line, the command will be parsed twice. First, when it's read by the
	configuration file or the command-prompt parser, and second when the status
	line is being drawn and the command is passed to the shell. For example, to
	echo the string "(test)" to the status line, either single or double quotes
	could be used:

	set -g status-right "#(echo \\\\(test\\\\))"
	set -g status-right '#(echo \\\(test\\\))'

	In both cases, the status-right option will be set to the string "#(echo
	\\(test\\))" and the command executed will be "echo \(test\)".

	* tmux uses too much CPU. What do I do?

	Automatic window renaming may use a lot of CPU, particularly on slow computers:
	if this is a problem, turn it off with "setw -g automatic-rename off". If this
	doesn't fix it, please report the problem.

	* I use PuTTY and my tmux window pane separators are all qqqqqqqqq's!

	PuTTY is using a character set translation that doesn't support ACS line
	drawing. With a Unicode font, try setting PuTTY to use a different translation
	on the Window -> Translation configuration page. For example, change UTF-8 to
	ISO-8859-1 or CP437. It may also be necessary to adjust the way PuTTY treats
	line drawing characters in the lower part of the same configuration page.

	* What is the best way to display the load average? Why no #L?

	It isn't possible to get the load average portably in code and it is preferable
	not to add portability goop. The following works on at least Linux, *BSD and OS
	X:

	uptime\|awk '{split(substr($0, index($0, "load")), a, ":"); print a[2]}'

	* How do I attach the same session to multiple clients but with a different
	current window, like screen -x?

	One or more of the windows can be linked into multiple sessions manually with
	link-window, or a grouped session with all the windows can be created with
	new-session -t.

	* Ctrl and arrow keys doesn't work in putty! What do I do?

	putty inverts the sense of the cursor key mode on ctrl, which is a bit hard for
	tmux to detect properly. To get ctrl keys right, change the terminfo settings
	so kUP5 (Ctrl-Up etc) are the adjusted versions, and disable smkx/rmkx so tmux
	doesn't change the mode. For example with this line in .tmux.conf (assuming you
	have TERM set to xterm):

	set -g terminal-overrides "xterm*:kLFT5=\eOD:kRIT5=\eOC:kUP5=\eOA:kDN5=\eOB:smkx@:rmkx@"

	Note that this will only work in tmux 1.2 and above.

	* How can I blank the tmux window?

	GNU screen has a feature whereby it will blank the screen after a period of
	inactivity. To do the same thing in tmux, use the lock-command setting, for
	example (with GNU bash):

	set -g lock-command 'tput civis && read -s -n1'

	This will remove the cursor and tell the shell to quit once a key has been
	pressed. For zsh, use "read -s -k1".

	In addition, it's possible to have both blanking and locking (for instance via
	lock(1) or vlock(1)) by using the following:

	bind x set lock-command '/usr/bin/vlock' \; lock-client \; set lock-command 'tput civis && read -s -n1'

	* vim displays reverse video instead of italics, while less displays italics
	(or just regular text) instead of reverse. What's wrong?

	Screen's terminfo description lacks italics mode and has standout mode in its
	place, but using the same escape sequence that urxvt uses for italics. This
	means applications (like vim) looking for italics will not find it and might
	turn to reverse in its place, while applications (like less) asking for
	standout will end up with italics instead of reverse. To make applications
	aware that tmux supports italics and to use a proper escape sequence for
	standout, you'll need to create a new terminfo file with modified sgr, smso,
	rmso, sitm and ritm entries:

	$ mkdir $HOME/.terminfo/
	$ screen_terminfo="screen"
	$ infocmp "$screen_terminfo" \| sed \
	-e 's/^screen[^\|]\|[^,],/screen-it\|screen with italics support,/' \
	-e 's/%?%p1%t;3%/%?%p1%t;7%/' \
	-e 's/smso=[^,]*,/smso=\\E[7m,/' \
	-e 's/rmso=[^,]*,/rmso=\\E[27m,/' \
	-e '$s/$/ sitm=\\E[3m, ritm=\\E[23m,/' > /tmp/screen.terminfo
	$ tic /tmp/screen.terminfo

	And tell tmux to use it in ~/.tmux.conf:

	set -g default-terminal "screen-it"

	If your terminal supports 256 colors, use:

	$ screen_terminfo="screen-256color"

	instead of "screen". See the FAQ entry about 256 colors support for more info.
	Also note that tmux will still display reverse video on terminals that do not
	support italics.

	If your urxvt cannot display italics at all, make sure you have an italics
	capable font enabled, for example, add to ~/.Xdefaults:

	urxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true

	* How can I make tmux use my terminal's scrollback buffer?

	Normally, tmux enables the terminal's "alternate screen". Most terminals (such
	as xterm) do not save scrollback for the alternate screen. You might prefer
	tmux to use the normal screen, so it uses your terminal's scrollback
	buffer. This way, you can access the scrollback buffer as usual, for example
	using the mouse wheel - although there is no guarantee output inside tmux will
	always (or ever) be added to the scrollback.

	You can make tmux use the normal screen by telling it that your terminal does
	not have an alternate screen. Put the following in ~/.tmux.conf:

	set -ga terminal-overrides ',xterm*:smcup@:rmcup@'

	Adjust if your $TERM does not start with xterm.

	tmux will still emulate the alternate screen for applications run under tmux,
	so you don't really lose anything with this setting. The only disadvantage is
	that when you exit tmux, it will not restore whatever was there before you
	started.

	* How do I see the default configuration?

	Show the default session options by starting a new tmux server with no
	configuration file:

	$ tmux -Lfoo -f/dev/null start\; show -g

	Or the default window options:

	$ tmux -Lfoo -f/dev/null start\; show -gw

	* How do I copy a selection from tmux to the system's clipboard?

	When running in xterm(1), tmux can automatically send copied text to the
	clipboard. This is controlled by the set-clipboard option and also needs this
	X resource to be set:

	XTerm*disallowedWindowOps: 20,21,SetXprop

	For rxvt-unicode (urxvt), there is an unofficial Perl extension here:

	http://anti.teamidiot.de/static/nei/*/Code/urxvt/

	Otherwise a key binding for copy mode using xclip (or xsel) works:

	bind -temacs-copy C-y copy-pipe "xclip -i >/dev/null"

	Or for inside and outside copy mode with the prefix key:

	bind C-y run -b "tmux save-buffer - \| xclip -i"

	On OS X, reattach-to-usernamespace lets pbcopy/pbpaste work:

	https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard

	* Why do I see dots around a session when I attach to it?

	tmux limits the size of the window to the smallest attached session. If
	it didn't do this then it would be impossible to see the entire window.
	The dots mark the size of the window tmux can display.

	To avoid this, detach all other clients when attaching:

	$ tmux attach -d

	Or from inside tmux by detaching individual clients with C-b D or all
	using:

	C-b : attach -d

	$Id$