.tmux.conf

#
# NOTE TO MYSELF
# ---
# choose-buffer		"clipboard manager"			C-a C-p (was C-a =)
# choose-client		"attach to different sessions"		C-a D
# 			(not very useful with tmx)
# choose-tree		"show panes and windows in a tree"	C-a w
# list-keys		"show key bindings"			C-a ? (`list-keys -N`)
#								C-a / (`command-prompt ... list-keys -1N`) to find interactively
# customize-mode	"interactive settings"			C-a C (`customize-mode -Z`)
# display-panes		"identify"				-
# ---
#

#
# Basic things
#

# Vi mode
setw -g mode-keys vi
set -g status-keys vi

# Mouse
set -g mouse on

# enter copy-mode, but only if NOT mouse_any_flag (i. e. the program does not
# want mouse itself) AND NOT pane_in_mode (i. e. we are not yet entered copy mode)
# NB: `if -F` checks for non-empty string, so concatenation of the flags is an "OR" here
bind -n WheelUpPane if -Ft= '#{mouse_any_flag}#{pane_in_mode}' 'send-keys -M' 'copy-mode; send-keys -M'

# TODO: use `select-pane -t=` in Wheel{Up,Down}Pane handlers in copy-mode{,-vi} tables
#       to have scrolling focus follow mouse events

# Window titles
set -g set-titles on

# Default window title format is illegible, set it to something sane.
# #S: session name
# #h: short hostname (use #H for full hostname)
# #W: window name (set by auto-rename below, usually current command name or special mode in square brackets)
# #T: pane title (set by application running inside the pane, defaults to hostname)
# Do not show pane title (only window name) if pane title is default (== hostname).
# Likewise, do not show window name (only pane title) if pane title contains window name (== current command).
set -g set-titles-string "tmux (#S@#h): #{?#{==:#T,#H},#W,#{?#{m:*#W*,#T},#T,#W: #T}} #{session_alerts}"

setw -g automatic-rename on
setw -g allow-rename on
set -g base-index 1

#setw -g automatic-rename-format "#{?pane_title,#{pane_title},#{?pane_in_mode,[tmux],#{pane_current_command}}#{?pane_dead,[dead],}"
#setw -g set-titles-string "tmux (#S@#h): #{?#{==:#T,#H},#W,#{?#{m:*#W*,#T},#T,#W: #T}} #{session_alerts}"

# 500ms escape time is really excessive
# I use mosh where possible over slow links, so I'd like to think that it actually sends C1s as C1s
# (cf. https://unix.stackexchange.com/a/608179/21885)
set -g escape-time 10

# Forward bells from the applications to the terminal emulator
# (which will hopefully do something sane)
set -g bell-action any
set -g visual-bell off

# Set a reasonable $TERM
set -g default-terminal "tmux-256color"

# Forward focus events from the terminal emulator to the applications
set -g focus-events on

# Enable status bar
bind s set status

# Scrollback buffer
set -g history-limit 1000000

# I don't like gaps in window numbers.
set -g renumber-windows on

# enable OSC 52 support for the built-in selection/clipboard (see below)
set -g set-clipboard on
set -ag terminal-features "tmux*:clipboard:ccolour:cstyle:focus:title"
# emit OSC 52 in a form acceptable to unpatched mosh (see mobile-shell/mosh#1054)
# set -ag terminal-overrides "xterm*:Ms=\\E]52;c;%p2%s\\7"
# set -ag terminal-overrides "tmux*:Ms=\\E]52;c;%p2%s\\7"

# enable "true color" support
set -ag terminal-overrides "alacritty:RGB"
set -ag terminal-overrides "xterm*:RGB"
set -ag terminal-overrides "tmux*:RGB"

# Rebind select-pane commands to disable key repeat (really annoying)
bind Up select-pane -U
bind Down select-pane -D
bind Left select-pane -L
bind Right select-pane -R

#
# Copy mode
#

# Enter/exit
unbind [
bind Escape copy-mode

# General copy mode operations
unbind -T copy-mode-vi C-b # page-up
unbind -T copy-mode-vi C-f # page-down

bind -T copy-mode-vi C-v send-keys -X rectangle-toggle
bind -T copy-mode-vi Enter send-keys -X cancel
bind -T copy-mode-vi v send-keys -X begin-selection
bind -T copy-mode-vi V send-keys -X select-line

# Copy directly into desktop (Wayland/X11) keyboard instead of using tmux clipboard
# (tmux clipboard integrates with OSC 52 to read/write system clipboard,
#  which gnome-terminal does not support)
bind -T copy-mode-vi Y send-keys -X copy-pipe-and-cancel "clip --desktop -i"
# For reference, the original tmux selection/clipboard interface
bind -T copy-mode-vi y send-keys -X copy-selection-and-cancel
# However, nested tmux _will_ make use of OSC 52 to pass the copied selection
# to parent tmux, which will then get "stuck" in the toplevel tmux (see above)
# TODO: somehow teach tmux to react to clipboard events such that we _both_ use
#       OSC 52 to pass the selection "above" _and_ use `~/bin/clip` to write to
#       Wayland/X11 clipboard?
# HACK: add a dedicated binding to copy existing buffer into desktop clipboard
# (bind `C-y` for similarity with `y`)
bind C-y run -b "tmux show-buffer | clip --desktop -i"

# same interface can be done for mouse, but I don't like the idea that releasing mouse exits copy mode, so just get rid of it
unbind -T copy-mode-vi MouseDragEnd1Pane
#bind -T copy-mode-vi MouseDragEnd1Pane send-keys -X copy-pipe-and-cancel "clip --desktop -i"

# per the logic above, also do not exit copy mode on double/triple click
bind-key -T copy-mode-vi DoubleClick1Pane select-pane \; send-keys -X select-word
bind-key -T copy-mode-vi TripleClick1Pane select-pane \; send-keys -X select-line

# similarly, interface with the desktop (Wayland/X11) clipboard in the other direction
bind P run "clip --desktop -o | tmux load-buffer -btmp -" \; paste-buffer -p -btmp -d #\; send-keys -X cancel
# similarly, for reference, the original tmux sesection/clipboard interface
unbind ]
bind p paste-buffer -p
# HACK: add a dedicated binding to copy existing desktop clipboard into tmux buffer (with OSC 52)
# (I'd bind `C-p` for similarity with `p`, but it's taken by `choose-buffer`)
bind C-o run -b "clip --desktop -o | tmux load-buffer -w -"

# FIXME: drop `run "..."` wrapping around `tmux wait tmp` (pending release of https://github.com/tmux/tmux/commit/7339845c01727b209b3b96e5b1d917129b2c8a83)
# FIXME: drop `wait -S`/`wait` completely (pending resolution of https://github.com/tmux/tmux/issues/1517)

# Upload to 0x0 and copy the URL, else display the error
#bind -T copy-mode-vi Y send-keys -X copy-pipe-and-cancel "resp=\"\$(curl --fail-with-body -sS '-Ffile=@-;filename=stdin.log' https://0x0.st 2>&1)\" && rc=0 || rc=\$?; if (( \$rc != 0 )); then tmux set-buffer -berr \"\$resp\"; else tmux set-buffer -w \"\$resp\"; tmux delete-buffer -berr; fi; tmux wait -S tmp" \; wait tmp \; if-shell "tmux show-buffer -berr &>/dev/null" { show-buffer -berr }

# Upload to 0x0 and display the URL
bind -T copy-mode-vi X send-keys -X copy-pipe-and-cancel "curl --fail-with-body -sS '-Ffile=@-;filename=stdin.log' https://0x0.st |& tmux load-buffer -btmp -; tmux wait -S tmp" \; wait tmp \; show-buffer -btmp

#
# Main key bindings
#

# screen forever
unbind C-b
set -g prefix C-a

# misc
bind r source-file ~/.tmux.conf
bind a send-prefix # C-a-a-a-a-a-aaaaaa!
bind m send-keys C-b # I'd bind 'b' for similarity with 'a', but 'b' is taken for previous-window
bind q kill-window \; kill-session
unbind ]
bind p paste-buffer -p
unbind &
bind X confirm-before -p "kill-window #W (y/n)?" kill-window # FIXME: find a way to move binding instead of hardcoding
bind C-r respawn-pane -k
unbind =
bind C-p choose-buffer -Z

# Pane splitting
unbind %
bind v split-window -h
bind V split-window -h -f
unbind '"'
bind h split-window -v
bind H split-window -v -f
unbind o

# Pane (re-)creation preserving $PWD
# tmux does not support binding key sequences, sunrise by hand
bind k switch-client -T keep-cwd
# ergonomics: alleviate the need to release Ctrl in chords like C-a k C-r
bind C-k switch-client -T keep-cwd
# split-window (C-a [vV]/[hH], see above)
bind -T keep-cwd v split-window -c "#{pane_current_path}" -h 
bind -T keep-cwd V split-window -c "#{pane_current_path}" -h -f
bind -T keep-cwd h split-window -c "#{pane_current_path}" -v
bind -T keep-cwd H split-window -c "#{pane_current_path}" -v -f
# new-window (C-a c)
bind -T keep-cwd c new-window -c "#{pane_current_path}"
# respawn-pane (C-a C-r, see above)
bind -T keep-cwd C-r respawn-pane -c "#{pane_current_path}" -k

# Layouts
# mnemonic: vertical dash (pipe) for vertical split bar, horizontal dash for horizontal split bar
bind | select-layout even-horizontal
bind - select-layout even-vertical
bind = select-layout -E

# Organization
unbind .
bind . command-prompt "swap-window -t '%%'" # we use renumber-windows, default move-window is unusable in this configuration

# Mark/swap (with marked)
unbind M
bind M select-pane -m # mark
unbind S
bind S swap-pane # swap with marked

# Break/join (implicitly with marked)
unbind B
bind B break-pane
unbind J
bind J join-pane
bind C-j switch-client -T join-pane
bind -T join-pane v join-pane -h
bind -T join-pane V join-pane -h -f
bind -T join-pane h join-pane -v
bind -T join-pane H join-pane -v -f

# Bindings to move windows around
# (see below for original bindings)
bind-key -r < swap-window -t - -d
bind-key -r > swap-window -t + -d

# Pane navigation
bind z select-pane -t :.+ # switch to previous pane
bind -n C-n next-window
bind n next-window
bind -n C-b previous-window
bind b previous-window

# Focus
bind C-f run "tmux-focus c #D"
bind C-u run "tmux-focus d #D"


#
# Appearance
#

# Statusbar
set -g status-position bottom
set -g status-interval 4
set -g status-left ''
set -g status-right ''
set -g status-justify centre # center align window list

setw -g status-style ''
setw -g window-status-format '#[bg=black,fg=brightblack] #I #[blink,bg=brightblack,fg=black] #W  ' # gnome-terminal, urxvt, Linux VT (blink == bg=bright)
setw -g window-status-current-format '#[fg=brightwhite,bg=cyan] #I #[fg=cyan,bg=default] #W  '

# Panel borders
set -g pane-border-style fg=black,bg=default
set -g pane-active-border-style fg=cyan,bg=default

# Resize
setw -g aggressive-resize on

# Restore pre-3.2 behavior: when more than one shared session is looking at the same window,
# limit window size to the smallest of shared sessions (instead of playing the tug-of-war).
set -g window-size latest


#
# Names and titles
#

# 1. "Pane title" is the title of the specific pane, externally set by the
#    command that's running in the pane using the xterm "set window title" sequence
#    (in case of nested tmux, tmux's "window title" becomes this one);
# 2. "Window name" is the tmux-internal name of the window (tab), auto-updated
#    using automatic-rename.

# Okay, this is getting awkward.
# This is at the wrong side of the limits of what I can reasonably write with
# the (fugly) tmux format mini-language, so set a temporary variable to the
# beautified format string, and then set the real one to the minified string.

# this sets the tmux's own title (which becames _pane title_ in case of nesting)
# (the #{n:...} replacement counts the number of alerts in the list)
set -g @set-titles-string "
(#{user}@#{host_short})
#{?#{window_name}, #{window_name},}
#{?#{session_alerts}, (#{n:#{s/[^,]+(,|$)/./:session_alerts}} alerts),}
"
set -gF set-titles-string "#{s/\n//:#{@set-titles-string}}"

# sudo sets title to the entire command line plus trailing garbage,
# reduce it aggressively
# (the regex matches 10 chars + at most 10 chars until the next word boundary, the rest is ellipsized)
set -g @ellipsized-pane-title-sudo "#{s/^(.{10#}([^ ]{0,10#} |.{10#})).*/\\1…/:#{s/^sudo +//:#{pane_title}}}"
# this even uglier regex matches first word + at most 10 chars until the next word boundary
set -g @ellipsized-pane-title-ssh-mosh "#{s/^([^ ]+) +([^ ]{0,10#} ?).*/\\1 \\2…/:#{s/^(^ssh|mosh|mosh-client|\\[mosh\\]) +//:#{pane_title}}}"

# this sets the _window name_ (which is internal to tmux)
set -g @automatic-rename-format "
#{?pane_in_mode,
	[tmux],
	#{?#{pane_title},
		#{?#{==:#{pane_current_command},mosh-client},
			[mosh] #{E:@ellipsized-pane-title-ssh-mosh},
			#{?#{==:#{pane_current_command},ssh},
				[ssh] #{E:@ellipsized-pane-title-ssh-mosh},
				#{?#{==:#{pane_current_command},sudo},
					[sudo] #{E:@ellipsized-pane-title-sudo},
					#{?#{m/r:^#{pane_current_command}($| ),#{pane_title}},
						#{pane_title},
						#{pane_current_command} \"#{pane_title}\"
					}
				}
			}
		},
		#{pane_current_command}
	}
}
#{?pane_dead,
	\u0020
	#{?pane_dead_signal,
		[killed with #{pane_dead_signal}],
		#{?pane_dead_status,
			[exited with #{pane_dead_status}],
			[exited]
		}
	},
}
"
set -gF automatic-rename-format "#{s/\n//:#{@automatic-rename-format}}"


#
# Misc
#

# Original bindings on < an >, responsible for spawning the window and pane menus respectively
# (note that we swap the order:
#  - `C-a >` -> `C-a [` (pane),
#  - `C-a <` -> `C-a ]` (window))
# TODO: find a way to rebind those without open-coding their definitions
#       (https://unix.stackexchange.com/questions/774022/move-rebind-tmux-keybinding-to-a-different-key-without-spelling-it-out)
bind-key    -T prefix       ]                      display-menu -T "#[align=centre]#{window_index}:#{window_name}" -x W -y W "#{?#{>:#{session_windows},1},,-}Swap Left" l { swap-window -t :-1 } "#{?#{>:#{session_windows},1},,-}Swap Right" r { swap-window -t :+1 } "#{?pane_marked_set,,-}Swap Marked" s { swap-window } '' Kill X { kill-window } Respawn R { respawn-window -k } "#{?pane_marked,Unmark,Mark}" m { select-pane -m } Rename n { command-prompt -F -I "#W" { rename-window -t "#{window_id}" "%%" } } '' "New After" w { new-window -a } "New At End" W { new-window }
bind-key    -T prefix       [                      display-menu -T "#[align=centre]#{pane_index} (#{pane_id})" -x P -y P "#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Top,}" < { send-keys -X history-top } "#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Bottom,}" > { send-keys -X history-bottom } '' "#{?mouse_word,Search For #[underscore]#{=/9/...:mouse_word},}" C-r { if-shell -F "#{?#{m/r:(copy|view)-mode,#{pane_mode}},0,1}" "copy-mode -t=" ; send-keys -X -t = search-backward "#{q:mouse_word}" } "#{?mouse_word,Type #[underscore]#{=/9/...:mouse_word},}" C-y { copy-mode -q ; send-keys -l "#{q:mouse_word}" } "#{?mouse_word,Copy #[underscore]#{=/9/...:mouse_word},}" c { copy-mode -q ; set-buffer "#{q:mouse_word}" } "#{?mouse_line,Copy Line,}" l { copy-mode -q ; set-buffer "#{q:mouse_line}" } '' "#{?mouse_hyperlink,Type #[underscore]#{=/9/...:mouse_hyperlink},}" C-h { copy-mode -q ; send-keys -l "#{q:mouse_hyperlink}" } "#{?mouse_hyperlink,Copy #[underscore]#{=/9/...:mouse_hyperlink},}" h { copy-mode -q ; set-buffer "#{q:mouse_hyperlink}" } '' "Horizontal Split" h { split-window -h } "Vertical Split" v { split-window -v } '' "#{?#{>:#{window_panes},1},,-}Swap Up" u { swap-pane -U } "#{?#{>:#{window_panes},1},,-}Swap Down" d { swap-pane -D } "#{?pane_marked_set,,-}Swap Marked" s { swap-pane } '' Kill X { kill-pane } Respawn R { respawn-pane -k } "#{?pane_marked,Unmark,Mark}" m { select-pane -m } "#{?#{>:#{window_panes},1},,-}#{?window_zoomed_flag,Unzoom,Zoom}" z { resize-pane -Z }