Regress conf from https://raw.githubusercontent.com/lacygoill/config/master/.config/tmux/tmux.conf.

1 files changed, 1496 insertions, 0 deletions

diff --git a/regress/conf/01840240e807e837dbf76d85b4b938de.conf b/regress/conf/01840240e807e837dbf76d85b4b938de.conf
new file mode 100644
index 00000000..dcd4899e
--- /dev/null
+++ b/regress/conf/01840240e807e837dbf76d85b4b938de.conf
@@ -0,0 +1,1496 @@
+# Options {{{1
+# Server {{{2
+
+# Don't pile up more than 10 buffers (down from 50 by default).{{{
+#
+# Rationale: Keeping  a tidy  stack, with  relevant information,  could help  us
+# integrate tmux buffers in our workflow more often.
+#
+# However,  maybe we  could keep  a big  stack of  buffers, and  filter them  by
+# pressing `f` in the window opened by `choose-buffer`.
+# Alternatively,  we could  also try to  use fzf to  fuzzy search  through their
+# contents...
+#}}}
+set -s buffer-limit 10
+
+
+# What does this option control?{{{
+#
+# It sets the time in milliseconds for which tmux waits after an escape is input
+# to determine if it is part of a function or meta key sequences.
+# The default is 500 millisec onds.
+#}}}
+# Why do you reset it?{{{
+#
+# The default  value introduces lag  when we use Vim  and escape from  insert to
+# normal mode.  We want to reduce the timeout.
+#}}}
+# Why don't you set it to 0 ?{{{
+#
+# >     Some people set  it to zero but  I consider that risky  if you're connecting
+# >     over a wide-area  network or there is anything else  that might insert small
+# >     delays between the delivery of chars in such a sequence.
+#
+# Source: https://github.com/tmux/tmux/issues/353#issuecomment-294570322
+#
+# Basically, we should still  let a few ms to be sure all  the keys in a control
+# sequence will have enough time to reach tmux.
+#}}}
+set -s escape-time 10
+
+# If the terminal supports focus events, they will be requested by the tmux
+# client and passed through to the tmux server, then to the programs it runs.
+# Necessary to be able to listen to `FocusGained` and `FocusLost`.
+# Also necessary for `pane-focus-[in|out]` hooks.
+set -s focus-events on
+
+# history of tmux commands (pfx :)
+set -s history-file "$HOME/.tmux/command_history"
+
+# What does this do?{{{
+#
+# It makes  tmux sometimes  send an OSC  52 sequence –  which sets  the terminal
+# clipboard content – if  there is an `Ms` entry in  the terminfo description of
+# the outer terminal.
+#}}}
+#   What are the possible values of this option?{{{
+#
+#    - `on`
+#    - `external`
+#    - `off`
+#
+# ---
+#
+# There are 3 ways to create a tmux buffer:
+#
+#    1. invoke the `set-buffer` or `load-buffer` tmux commands
+#    2. copy text in copy mode (`send -X copy-selection`, `copy-pipe`, ...)
+#    3. send an OSC 52 sequence from an application inside tmux (e.g. `$ printf ...`)
+#
+# `1.` always creates a tmux buffer; never sets the X clipboard.
+# `2.` always creates a tmux buffer; sets the X clipboard via OSC 52 iff `set-clipboard` is not `off`.
+# `3.`        creates a tmux buffer *and* sets the X clipboard via OSC 52 iff `set-clipboard` is `on`.
+#
+# IOW, `external` makes  tmux *automatically* set the X clipboard  when you yank
+# sth in  copy mode via  OSC 52, while  `on` does the  same, but also  allows an
+# application to *manually* set a tmux buffer/the X clipboard via a OSC 52.
+#
+# Source: https://unix.stackexchange.com/a/560464/289772
+#}}}
+#   What is the possible drawback of the value `on`?{{{
+#
+# https://github.com/tmux/tmux/wiki/Clipboard#security-concerns
+#}}}
+#   How to disable OSC 52 for some terminals, but not all?{{{
+#
+#     # or use 'external'
+#     set -s set-clipboard on
+#     set -as terminal-overrides 'yourTERMname:Ms@'
+#                                                ^
+#       man terminfo /Similar Terminals/;/canceled
+#}}}
+set -s set-clipboard external
+
+# Why do you move your 'terminal-overrides' settings in another file?{{{
+#
+# It makes it easier to source the settings only when the tmux server is started;
+# not when we manually re-source `tmux.conf`.
+#}}}
+#   Why do you need them to be sourced only once?{{{
+#
+# We *append* strings to the value of the 'terminal-overrides' option.
+# I don't want to append the same strings again and again every time I re-source
+# `tmux.conf`.
+#}}}
+#   Why don't you simply reset the option before appending a value?{{{
+#
+# That would make us lose the default value of the option:
+#
+#     terminal-overrides[0] "xterm*:XT:Ms=\\E]52;%p1%s;%p2%s\\007:Cs=\\E]12;%p1%s\\007:Cr=\\E]112\\007:Ss=\\E[%p1%d q:Se=\\E[2 q"
+#     terminal-overrides[1] screen*:XT
+#
+# ---
+#
+# Besides, one of the value we append to 'terminal-overrides' depends on the value of `$TERM`.
+#
+#     if '[ "$TERM" != "st-256color" ]' 'set -as terminal-overrides ",*:Cr=\\E]112\\007"'
+#           ^----------------------^
+#
+# And the value of `$TERM` will be correct only the first time we source `tmux.conf`.
+#}}}
+
+# What's the value of `$TERM` here?{{{
+#
+# The  first time  our `tmux.conf`  is sourced,  it matches  the `$TERM`  of the
+# outer terminal;  the next  times, it's the  value of  'default-terminal' (i.e.
+# 'tmux-256color').
+#}}}
+# What's the meaning of this `if` guard?{{{
+#
+# The condition `[ "$TERM" != "tmux-256color" ]` is true only the first time our
+# `tmux.conf` is sourced.
+# So, this part of the guard means: “if this is the first time the file is sourced”.
+# This is equivalent to `has('vim_starting')` in Vim.
+#
+# The condition `[ -n "$DISPLAY" ]` is true only in a GUI environment.
+# So, this part of the guard means: “don't source the file if we are in a console”.
+# Indeed, I doubt  a linux console is  able to understand any  sequence we might
+# want to use.
+#}}}
+#   Could we use `%if` instead of `if`?{{{
+#
+# You could try this:
+#
+#     %if "#{!=:$TERM,#{default-terminal}}"
+#     source-file "$HOME/.config/tmux/terminal-overrides.conf"
+#     %endif
+#
+# But it doesn't seem to work; the guard would not prevent the file from being re-sourced.
+# I think  that's because,  in this  case, `$TERM`  refers to  the value  in the
+# environment of  the tmux  server process;  and for  the latter,  `TERM` always
+# matches the outer terminal.
+#}}}
+if '[ "$TERM" != "#{default-terminal}" -a -n "$DISPLAY" ]' { source "$HOME/.config/tmux/terminal-overrides.conf" }
+
+# Leave `default-terminal` at the end.{{{
+#
+# In my limited testing, moving it above would not cause an issue, but better be
+# safe than sorry.
+# In  particular,  I  want  to  be  sure  that  the  value  of  `$TERM`  is  not
+# 'tmux-256color'  the   first  time  our  `tmux.conf`   is  sourced;  otherwise
+# `terminal-overrides.conf` would never be sourced.
+#}}}
+# Why `-s` instead of `-g`? {{{
+#
+# Since tmux 2.1, `default-terminal` is a server option, not a session option.
+#
+# >     As a side effect this changes default-terminal  to be a server rather than a
+# >     session option.
+#
+# https://github.com/tmux/tmux/commit/7382ba82c5b366be84ca55c7842426bcf3d1f521
+# Confirmed by the  fact that `default-terminal` is described in  the section of
+# the server options in the man page.
+# Also confirmed by the fact that it's listed in the output of:
+#
+#     tmux show -s
+#
+# However, according to nicm:
+#
+# >     You do not have to use -s or -w for set-option except for user options.
+# >     tmux can work it out from the option name.
+# >     For show-option you do need it.
+#
+# So, we could omit `-s`, but I prefer to be explicit.
+#}}}
+# Why not let tmux use the default value `screen` (for `$TERM`)?{{{
+#
+# By default, most terminals set `$TERM` to `xterm` because the `xterm` entry is
+# present and set in the terminfo db of most machines.
+# tmux sets it to  `screen`, again, because it's a popular  entry (more than the
+# `tmux` one).
+# The `xterm`/`screen` value  implies that the terminal  will declare supporting
+# only 8 colors; confirmed by `$ tput colors`.
+#
+# Because of this,  the theme of some  programs might be off  (including Vim and
+# the terminal itself).  We want the terminal to declare it supports 256 colors,
+# which anyway is usually true.
+#}}}
+# Do we need `$TERM` to contain `tmux`?{{{
+#
+# Yes.  To support italics:
+#
+# The `screen-256color` entry in the terminfo db doesn't have a `sitm` field.
+# IOW, the db reports that screen is unable to support italics, which is true.
+# So, if we set `$TERM` to `screen-256color`, when an application will want to
+# make some text appear italicized, it will think it's not possible.
+# But  it *is*  possible, because  we  use tmux,  not screen.   And tmux  *does*
+# support the italics style.
+# The solution is to set `$TERM`  to `tmux-256color` so that when an application
+# queries  the terminfo  db, it  finds  the field  `sitm` with  the right  value
+# `\E[3m`.
+#
+# See also:
+# https://github.com/tmux/tmux/wiki/FAQ#i-dont-see-italics-or-italics-and-reverse-are-the-wrong-way-round
+# https://github.com/tmux/tmux/issues/175#issuecomment-152719805
+#}}}
+#   `256color`?{{{
+#
+# For a Vim color scheme to be correctly applied, no.
+# Because  it seems  that our  current theme  automatically sets  the number  of
+# colors to 256:
+#
+#     :runtime colors/seoul256.vim
+#     :echo &t_Co
+#
+# But, for the color schemes of other programs, maybe.
+#}}}
+set -s default-terminal tmux-256color
+
+# Session {{{2
+
+# Don't ring the bell in the current window.
+set -g bell-action other
+
+# Why?{{{
+#
+# If a new window is created without any command to execute, tmux reads the
+# session option `default-command` to find one.
+# By default,  its value  is an empty  string which instructs  tmux to  create a
+# *login* shell using the value of the default-shell option.
+# The default value of the latter is `$SHELL` (atm: `/usr/local/bin/zsh`).
+#
+# When we create a new window, we  want a *non*-login shell, because a login zsh
+# shell  sources `~/.zprofile`,  which  we use  to execute  code  specific to  a
+# virtual *console* (set the background to white in the console).
+# This code is not suited to a virtual *terminal*.
+#
+# More  generally, we  don't  want a  *non*-login shell  to  source login  files
+# (`.profile`, `.zprofile`, `.zlogin`).
+#
+# So, we give the value zsh to `default-command` to prevent tmux from starting a
+# login shell.
+#}}}
+set -g default-command "$SHELL"
+
+# Don't detach the client when the current session is killed.
+set -g detach-on-destroy off
+
+# display status line messages and other on-screen indicators for 1s
+# (or until a key is pressed)
+set -g display-time 1000
+# display the indicators shown by the display-panes command for 5s
+set -g display-panes-time 5000
+
+# increase scrollback buffer (2000 → 50000)
+#
+# `history-limit` has nothing to do with the history of executed tmux commands.
+# It controls the amount of lines you can scroll back when you enter copy mode.
+set -g history-limit 50000
+
+# Index options
+# When we create a new window, tmux looks for an unused index, starting from 0.{{{
+#
+# I prefer 1, because:
+#
+#    - I usually count from 1, not 0
+#    - this lets us run `:movew -t :0` to move the current window in first position
+#
+# Note that you can't  run `:movew -t :1` to move the  window in first position,
+# because 1 is already taken by the first window.
+# `:movew` expects an index which is “free” (i.e. not used by any existing window).
+#
+# Also,  note that  when  running `:movew  -t :0`,  tmux  renumbers all  windows
+# automatically from whatever value is assigned to the 'base-index' option.
+#}}}
+set -g base-index 1
+#    │
+#    └ must be applied globally to all sessions
+#
+# same thing for the panes
+set -gw pane-base-index 1
+#    ││
+#    │└ window option
+#    └ must be applied globally to all windows
+
+# make tmux capture the mouse and allow mouse events to be bound as key bindings
+set -g mouse on
+
+# use `M-space` as a prefix
+set -g prefix M-space
+
+# renumber windows, when:{{{
+#
+#    - we destroy one of them
+#    - we move the first window (index 1) at the end (index 99), by running `movew -t :99`
+#
+# to prevent holes in the sequence of indexes
+#}}}
+set -g renumber-windows on
+
+# time for repeating of a hotkey bound using the -r flag without having to type the prefix again; default: 500
+set -g repeat-time 1000
+
+# Some consoles don't like attempts to set the window title.
+# This might cause tmux to freeze the terminal when you attach to a session.
+# https://github.com/tmux/tmux/wiki/FAQ#tmux-freezes-my-terminal-when-i-attach-to-a-session-i-have-to-kill--9-the-shell-it-was-started-from-to-recover
+set -g set-titles off
+
+# update the status line every 5 seconds (instead of 15s by default)
+set -g status-interval 5
+
+# emacs key bindings in tmux command prompt (prefix + :) are better than vi keys,
+# even for vim users.
+set -g status-keys emacs
+
+# color of status line
+set -g -F status-style "bg=#{?#{==:$DISPLAY,},blue,colour138}"
+
+# Center the position of the window list component of the status line
+set -g status-justify centre
+
+# cache the number of cpu cores in `~/.ncore`, which a shell command in 'status-right' is going to need
+if '[ ! -s "${HOME}/.ncore" ]' \
+    { run "lscpu | awk '/^CPU\\(s\\):\\s*[0-9]/ { print $2 }' >\"${HOME}/.ncore\"" }
+
+# set the contents of the status line
+# What's `#[...]`?{{{
+#
+# It lets you embed some styles.
+# If you want to  apply the same style all over the left  part or the right part
+# of the status line, you can also use `status-left-style` or `status-right-style`:
+#
+#     set -g status-left '#[fg=colour15,bold] #S'
+#     ⇔
+#     set -g status-left       ' #S'
+#     set -g status-left-style '#[fg=colour15,bold]'
+#
+# However, I prefer  embedding the styles inside the value  of `status-left` and
+# `status-right`, because:
+#
+#    - it's more concise
+#    - it's more powerful: you can set the style of an arbitrary *portion* of the status line
+#
+# ---
+#
+# Note that you  can use this syntax only  in the value of an  option which sets
+# the *contents* of sth, not its style.
+# So, this is *not* a valid syntax:
+#
+#     # ✘
+#     set -g status-left-style '#[fg=colour15,bold]'
+#
+# Here, you must get rid of `#[...]`:
+#
+#     # ✔
+#     set -g status-left-style 'fg=colour15,bold'
+#}}}
+# What's `#{?...}`?{{{
+#
+# A conditional:
+#
+#     #{?test,val1,val2}
+#
+# For example:
+#
+#     {?client_prefix,#[bold],}
+#
+# This will be evaluated  into the style `bold` if the  prefix has been pressed,
+# or nothing otherwise.
+#}}}
+# Why do you use `nobold`?{{{
+#
+# We set the style `bold` for some part of the status line.
+# But a style applies to *all* the remaining text in the status line.
+# We need `nobold` to reset the style.
+#}}}
+# How can I include the time of the day or the hour in the status line?{{{
+#
+# Use `date(1)` and `%` items:
+#
+#     %a = day of week
+#     %d = day of month
+#     %b = month
+#     %R = hour
+#
+# See `man date`.
+#}}}
+set -g status-left ' #[fg=colour7]#{?client_prefix,#[fg=colour0],}#S#[fg=colour7]'
+
+# Which alternative could I use to get the cpu load?{{{
+#
+#     $ uptime|awk '{split(substr($0, index($0, "load")), a, ":"); print a[2]}'
+#
+# https://github.com/tmux/tmux/wiki/FAQ#what-is-the-best-way-to-display-the-load-average-why-no-l
+#}}}
+# Why don't you write the code in a script and invoke it with `#(my-script.sh)`?{{{
+#
+# A script needs another shell to be interpreted.
+# The latter adds overhead, which would almost double the time the code needs to
+# be run.
+#
+# Check this:
+#
+#     $ cat <<'EOF' >/tmp/sh.sh
+#     awk 'BEGIN { getline load <"/proc/loadavg"; getline ncore <(ENVIRON["HOME"]"/.ncore"); printf("%d", 100 * load / ncore) }'
+#     EOF
+#     $ chmod +x /tmp/sh.sh
+#
+#     $ time zsh -c 'repeat 100 /tmp/sh.sh'
+#     ... 0,420 total˜
+#     $ time zsh -c 'repeat 100 awk '\''BEGIN { getline load <"/proc/loadavg"; getline ncore <(ENVIRON["HOME"]"/.ncore"); printf("%d", 100 * load / ncore) }'\'''
+#     ... 0,193 total˜
+#}}}
+# Why do you double the percent sign in `printf("%%d", ...)`?{{{
+#
+# The code is going to be expanded inside the value of 'status-right'.
+# And the  latter is always passed  to `strftime(3)` for which  the percent sign
+# has a special meaning.
+# As a result, if you don't double the  percent sign – to make it literal – `%d`
+# will be replaced with the current day of the month (01, 02, ..., 31).
+#
+# From `man tmux /status-right`:
+#
+# >     As  with status-left,  string will  be passed  to strftime(3)  and character
+# >     pairs are replaced.
+#}}}
+cpu='awk '\''BEGIN { \
+    getline load <"/proc/loadavg"; \
+    getline ncore <(ENVIRON["HOME"]"/.ncore"); \
+    printf("%%d", 100 * load / ncore) }'\'''
+
+mem='free | awk '\''/Mem/ { total = $2; used = $3 }; \
+    END { printf("%%d", 100 * used / total) }'\'''
+# TODO: Maybe we could get rid of `free(1)`, by inspecting `/proc/meminfo`.
+# However,  I can  find the  second field  ("total") of  `free(1)` in  this file
+# (first line: "MemTotal"), but not the third one ("used").
+#
+# Update: From `man free`:
+#
+#     used   Used memory (calculated as total - free - buffers - cache)
+#
+# You would have to read 4 files to compute the `used` field.
+# Make some tests (with `time(1)`) to see whether the resulting `awk(1)` command
+# is slower than what we currently run.
+
+# TODO: Color the numbers in red if they exceed some threshold.
+# Try to capture the  output of the 2 shell commands in  tmux variables, so that
+# we can test them in a conditional.
+set -g  status-right '#[fg=colour235]M #[fg=colour15,bold]'
+set -ga status-right "#($mem) "
+set -ga status-right '#[fg=colour235,nobold]C #[fg=colour15,bold]'
+set -ga status-right "#($cpu) "
+
+setenv -gu cpu
+setenv -gu mem
+
+# Why do you want `COLORTERM` to be automatically updated?{{{
+#
+# It can be useful to detect a terminal which lies about its identity.
+# E.g., xfce4-terminal advertises  itself as `xterm-256color`, but  the value of
+# its `COLORTERM` variable is 'xfce4-terminal'.
+#
+# So, the more reliable  `COLORTERM` is, the better we can  detect that we're in
+# xfce4-terminal, and react appropriately.
+# This can be useful, for example, to prevent vim-term from sending `CSI 2 SPC q`
+# when we're leaving Vim from xfce4-terminal on Ubuntu 16.04.
+# The latter  doesn't understand this sequence,  and once sent to  the terminal,
+# tmux will regularly reprint the sequence wherever our cursor is.
+#}}}
+# Why could I be tempted to run the same command for `LESSOPEN`, `LESSCLOSE`, `LS_COLORS`?{{{
+#
+#     setenv -gu LESSOPEN
+#     setenv -gu LESSCLOSE
+#     setenv -gu LS_COLORS
+#
+# These environment variables are set in  `~/.zshenv`, but only on the condition
+# they've not been set yet.
+# The purpose of the condition is to make the shell quicker to start.
+# Indeed, setting these variables adds around 8ms to the shell's startup time.
+# However, if they are set in the tmux global environment, then they'll never be
+# reset  when  we  start a  new  shell,  because  the  condition will  never  be
+# satisfied.
+#
+# This means that we can't change the value of these variables by simply editing
+# `~/.zshenv`, which can be an issue.
+#}}}
+#   Why don't you do it?{{{
+#
+# Because it would add around 8ms to the startup time of every shell we ask tmux
+# to open.
+#}}}
+#     Isn't this an issue?{{{
+#
+# No.
+# If you want to modify one of these variables, and if you want the change to be
+# applied immediately without  restarting the tmux server, do it  in the context
+# of the tmux global environment:
+#
+#     $ tmux setenv -g LESSOPEN new_value
+#}}}
+if '[ "$TERM" != "#{default-terminal}" ]' { set -ga update-environment COLORTERM }
+# TODO: We have several similar `if` conditions.  Maybe we should write only one,
+# and put inside all the commands we want to run.
+# This would make tmux start a little faster.
+
+# display a message when activity is detected in a window
+# Why?{{{
+#
+# We  haven't customized  the  status line  to include  an  indicator when  some
+# activity is detected in a window, because by default we don't monitor activity
+# ('monitor-activity' is off).
+# Indeed, generally, most windows will produce some output and have some activity.
+# Seeing a lot of indicators in the status line, all the time, is meaningless.
+#
+# But we do  have a key binding to temporarily  toggle 'monitor-activity' in the
+# current window; so, we  need a way to be notified when  some activity is later
+# detected in it.
+#}}}
+set -g visual-activity on
+
+# Window {{{2
+
+# Use vi key bindings in copy mode.
+set -gw mode-keys vi
+
+# colors of *borders* of focused and non-focused panes
+set -gw pane-active-border-style 'fg=colour138,bg=#cacaca'
+set -gw pane-border-style        'fg=colour138,bg=#cacaca'
+
+# How to insert the index of a window?{{{
+#
+# Use the alias `#I`.
+#}}}
+# How to insert its flags, like `Z` for a zoomed window?{{{
+#
+# Use the alias `#F`.
+#}}}
+# Set what to display for the current window (then for the other ones), and how,
+# in the status line window list.
+# See: https://github.com/tmux/tmux/issues/74#issuecomment-129130023
+set -gw window-status-current-format '#[fg=colour232,bg=colour253]#W#F#{?window_zoomed_flag, #[fg=blue]#P/#{window_panes},}'
+set -gw window-status-format '#[fg=colour232#,bg=colour248]#W#F#[bg=default]'
+
+# Pane {{{2
+
+# colors of focused and non-focused panes
+# Because we use `-gw`, the colors will affect any pane.{{{
+#
+# But, at runtime, you could use `-p` to set the color of a given pane when it's
+# (un)focused differently.
+#}}}
+set -gw window-active-style 'bg=#dbd6d1'
+set -gw window-style        'bg=#cacaca'
+# }}}1
+# Key Bindings {{{1
+# root {{{2
+
+# `F1`, ..., `F10` are used in `htop(1)`.
+# `F11` and `F12` are used in WeeChat to scroll in the nicklist bar.
+bind -T root S-F8 run -b 'tmux_log'
+
+# Why do you rebind `command-prompt` to `pfx + ;`?  It's already bound to `pfx + :`...{{{
+#
+# We  often press  the prefix  key by  accident, then  press `:`  to open  Vim's
+# command-line.  As a result, we open tmux command-line; it's distracting.
+#}}}
+bind ';' command-prompt
+unbind :
+# Do *not* bind `command-prompt` to `M-:`; we press it by accident too frequently.
+
+# focus next/previous window
+# I'm frequently pressing these key bindings in Vim's insert mode.  It's distracting!{{{
+#
+# Idea1: Use `pfx w` to focus an  arbitrary window, and supercharge `pfx h/l` to
+# focus the next/previous pane or window.
+#
+#     bind -r h if -F '#{pane_at_left}' 'prev' 'selectp -L'
+#     bind -r l if -F '#{pane_at_right}' 'next' 'selectp -R'
+#
+# Idea2: Use `M-h/l` twice when the current pane is running Vim.
+#
+#     set -g @foo 0
+#     bind -T root M-l if -F '#{m:*vim,#{pane_current_command}}' { if -F '#{@foo}' { set -g @foo 0 ; next } { set -g @foo 1 } } { next }
+#     bind -T root M-h if -F '#{m:*vim,#{pane_current_command}}' { if -F '#{@foo}' { set -g @foo 0 ; prev } { set -g @foo 1 } } { prev }
+#
+# Idea3: Make tmux send `M-h` or `M-l` when  Vim is running in the current pane,
+# and let Vim decide what to do, based on whether we're in insert mode or normal
+# mode.
+#
+#     noremap! <expr> <m-h> <sid>m_hl('h')
+#     noremap! <expr> <m-l> <sid>m_hl('l')
+#     nno <expr> <m-h> <sid>m_hl('h')
+#     nno <expr> <m-l> <sid>m_hl('l')
+#     xno <expr> <m-h> <sid>m_hl('h')
+#     xno <expr> <m-l> <sid>m_hl('l')
+#
+#     fu s:m_hl(seq) abort
+#         if mode() =~# '^[ic]$'
+#             return ''
+#         endif
+#         call system('tmux '..(a:seq is# 'l' ? 'next' : 'prev'))
+#         return ''
+#     endfu
+#     bind -T root M-l if -F '#{m:*vim,#{pane_current_command}}' 'send M-l' 'next'
+#     bind -T root M-h if -F '#{m:*vim,#{pane_current_command}}' 'send M-h' 'prev'
+#
+# Problem: When we're running Vim without config (`-Nu NONE`), we can't focus another tmux window.
+# This is because those custom mappings are not installed then.
+#}}}
+# Why do you inspect these window flags?{{{
+#
+# To prevent the commands from wrapping around the edges.
+# They do that by default, and that bothers me at the moment.
+#
+# For example, I often want to focus  the next window, and press `¹` by accident
+# instead of  `²`.  It  still works,  because we  only have  2 windows,  but that
+# prevents me from learning to press the correct keys.
+#
+# Once you're confident that those keys are well-chosen, and they've passed into
+# your muscle memory, you could just install:
+#
+#     bind -T root ¹ prev
+#     bind -T root ² next
+#}}}
+bind -T root ¹ if -F '#{window_start_flag}' {} { prev }
+bind -T root ² if -F '#{window_end_flag}' {} { next }
+# TODO: Sometimes, we press these keys by accident.  Find better ones?{{{
+#
+# In particular,  when we press  `[ox` (where `x`  is some character)  to toggle
+# some Vim setting, we  need to press `AltGr` to produce  `[`; but sometimes, we
+# don't release the key before pressing `o`.
+# As a  result, we  press `AltGr  + o`  which produce  `²`; tmux  intercepts the
+# keypress, and tries to visit the  previous window, while in reality, we wanted
+# to toggle some Vim setting.
+#}}}
+
+# `M-s` to enter copy mode
+# Do *not* bind `M-s` to anything while in copy mode!{{{
+#
+# This would  make you lose  an interesting  feature of the  `copy-mode` command
+# while you're already in copy mode, reading  the output of some command such as
+# `list-keys`.
+#
+# The default behavior makes tmux show you the contents of the original window:
+#
+#     # you're reading a file
+#     :list-keys
+#     :copy-mode
+#     # the window shows again the file you were reading
+#     # press `q`, and you get back the output of `:list-keys`
+#
+# I don't know where this is documented.
+# And I don't  know why the `copy-mode`  command is invoked when  we press `M-s`
+# while in copy mode.
+# We only  have one key  binding using `M-s`  as its lhs,  and it's in  the root
+# table, not in the copy-mode table.
+#
+# Note that this feature is not specific to our `M-s` key binding.
+# I can reproduce with no config (and `C-b [` instead of `M-s`).
+#}}}
+bind -T root M-s copy-mode
+
+bind -T root M-z resize-pane -Z
+bind -T root M-Z lastp \; resize-pane -Z
+
+# Do *not* exit copy mode when when we reach the bottom of the scrollback buffer.{{{
+#
+# We remove the `-e` flag which is  passed to `copy-mode` by default, so that if
+# we enter  copy mode by scrolling  the mouse wheel  upward, and we press  a key
+# which reaches the bottom of the scrollback buffer, we don't quit copy mode.
+#
+# If you leave `-e` in the default key binding, here's what could happen:
+# you  scroll the  wheel upward  to  enter copy  mode;  at one  point, you  keep
+# pressing `C-d` to scroll toward the  bottom; once you reach the bottom, you'll
+# quit copy mode, and `C-d` will close the shell if the command-line is empty.
+#}}}
+# Where did you find the code?{{{
+#
+#     $ tmux -Lx -f/dev/null start \; lsk | grep 'root.*WheelUpPane'
+#}}}
+bind -T root WheelUpPane \
+    if -F -t= '#{mouse_any_flag}' \
+        { send -M } \
+        { if -Ft= '#{pane_in_mode}' 'send -M' 'copy-mode -t=' }
+
+# But *do* exit copy mode if we scroll downward with the mouse wheel and reach the bottom of the buffer.
+bind -T copy-mode-vi WheelDownPane \
+    selectp \; \
+    send -X -N 5 scroll-down \; \
+    if -F '#{scroll_position}' '' 'send -X cancel'
+
+# copy-mode-vi {{{2
+
+bind -T copy-mode-vi C-Space send -X set-mark
+# actually, it should be named "exchange-point-and-mark"...
+bind -T copy-mode-vi C-x send -X jump-to-mark
+
+# jump Back to the Beginning of the previous shell command{{{
+#
+# Look  for the  previous shell  prompt, to  get to  the beginning  of the  last
+# command output.  After  pressing the key binding, you can  visit all the other
+# prompts by pressing `n` or `N`.
+#
+# Inspiration: https://www.youtube.com/watch?v=uglorjY0Ntg
+#}}}
+bind -T copy-mode-vi ! send -X start-of-line \; send -X search-backward '٪'
+
+# Make  tmux use the  prefix 'buf_' instead of  'buffer' when naming  the buffer
+# storing the copied selection.
+bind -T copy-mode-vi Enter send -X copy-selection-and-cancel 'buf_'
+
+bind -T copy-mode-vi g switchc -T g-prefix
+bind -T g-prefix     g send -X history-top
+# Open a visually selected text (filepath or url) by pressing `gf` or `gx`.
+# TODO: The key binding will break if the file name contains double quotes.{{{
+#
+# Find a way to escape special characters.
+#
+# I tried `$ tmux display -p '#{q:#(tmux pasteb)}'`, but it doesn't work.
+# You probably need `q:`,  but a modifier needs to be followed by  the name of a
+# replacement variable and `#(tmux pasteb)` is not one.
+#
+# Update:
+# I don't think you should use `q:`.
+# Maybe you should  try to find a shell utility  which quotes special characters
+# in a given text.
+# Does such a tool exist?
+# If it does, maybe you could try: `#(magic_tool $(tmux pasteb))`.
+#
+# Update:
+# `#{}` can be used for a user option (`@foo`).
+# You could temporarily  set a user option with the  the filepath/url, and quote
+# it with `q:`.
+#
+# Make some tests on that:
+#
+#     http://example.org/foo/bar"baz.html
+#     http://example.org/foo/bar'baz.html
+#     https://www.reddit.com/r/Fantasy/
+#
+#     bind -T copy-mode-vi x send -X copy-selection-and-cancel \; \
+#         run 'tmux set @copied_url "$(tmux showb)"' \; \
+#         run 'xdg-open "#{q:@copied_url}"'
+#
+# For  some reason,  we need  2 `run-shell`,  otherwise, it  seems that  the key
+# binding doesn't update the url, when we try a new one.
+#
+# For some reason, when we try to open this:
+#
+#     http://example.org/a'b.html
+#
+# tmux opens this instead:
+#
+#     http://example.org/a/'b.html
+#                         ^
+#                         ✘
+#
+# For some reason, when we try to open this:
+#
+#     http://example.org/a"b.html
+#
+# tmux doesn't escape the double quote.
+#
+#     Text ended before matching quote was found for ".˜
+#     (The text was '/usr/bin/firefox "http://example.org/foo/bar"baz.html"')˜
+#
+#     $ tmux set @foo "a'b" \; display -p '#{q:@foo}'
+#     a\'b˜
+#
+#     $ tmux set @foo "a'b" \; run 'echo #{q:@foo}'
+#     a'b˜
+#
+# Why doesn't `run-shell` expand the `#{q:}` format?
+#
+# Update: you need to quote the format:
+#
+#     $ tmux set @foo "a'b" \; run 'echo "#{q:@foo}"'
+#     a\'b˜
+#
+# Update:
+# I don't think it's possible.
+# Try to open the urls via `urlscan(1)`.
+# The latter fails for the first urls.
+# If a specialized tool fails, I doubt we can do better.
+#}}}
+# FIXME: `gf` fails to open a file path starting with `~/`.
+bind -T g-prefix f send -X pipe "xargs -I {} tmux run 'xdg-open \"{}\"'"
+bind -T g-prefix x send -X pipe "xargs -I {} tmux run 'xdg-open \"{}\"'"
+
+bind -T copy-mode-vi  v    if -F '#{selection_present}' { send -X clear-selection } { send -X begin-selection }
+bind -T copy-mode-vi  V    if -F '#{selection_present}' { send -X clear-selection } { send -X select-line }
+bind -T copy-mode-vi  C-v  if -F '#{selection_present}' \
+    { if -F '#{rectangle_toggle}' \
+        { send -X rectangle-toggle ; send -X clear-selection } \
+        { send -X rectangle-toggle } \
+    } { send -X begin-selection ; send -X rectangle-toggle }
+
+# set -s copy-command 'xsel -i'
+# if there's a selection, make `y` yank it
+# without selection, make `yy` yank the current line and `yiw` the current word
+bind -T copy-mode-vi y if -F '#{selection_present}' \
+    { send -X copy-pipe-and-cancel 'xsel -i -b' 'buf_' } \
+    { switchc -T operator-pending-and-cancel }
+# y**y**
+bind -T operator-pending-and-cancel y send -X copy-line 'buf_'
+# y**iw**
+bind -T operator-pending-and-cancel i switchc -T text-object-and-cancel
+# Do *not* use `select-word`: https://github.com/tmux/tmux/issues/2126
+bind -T text-object-and-cancel w \
+    { send -X cursor-right
+      send -X previous-word
+      send -X begin-selection
+      send -X next-word-end
+      send -X copy-selection-and-cancel 'buf_' }
+
+bind -T copy-mode-vi . run "zsh -c \"tmux source =(sed -n '/^# #{@dot_command}/,/^$/p' $HOME/.config/tmux/repeat.conf)\""
+
+# **"A**yiw  **"A**yy  v_**"A**y
+bind -T copy-mode-vi '"' switchc -T specify-register
+bind -T specify-register A switchc -T operate-on-register
+# Why the `if 'tmux showb'`?{{{
+#
+# `append-selection` doesn't accept the optional prefix buffer name argument.
+# If there's no buffer, `append-selection` will  create a buffer with the prefix
+# name `buffer`; we want the prefix `buf_`.
+#}}}
+# "A**y**iw  "A**y**y  v_"A**y**
+bind -T operate-on-register y if -F '#{selection_present}' \
+    { if 'tmux showb' { send -X append-selection } { send -X copy-selection 'buf_' }} \
+    { switchc -T operator-pending }
+# "Ay**i**w
+bind -T operator-pending i switchc -T text-object
+# "Ay**y**
+bind -T operator-pending y { run "zsh -c \"tmux source =(sed -n '/^# yy/,/^$/p' $HOME/.config/tmux/repeat.conf)\"" }
+
+# v**i**w
+bind -T copy-mode-vi i switchc -T text-object
+# Why pass a second command to the first `if`?{{{
+#
+# To support `"Ayiw`.
+#}}}
+# vi**w**  "Ayi**w**
+bind -T text-object w if -F '#{selection_present}' \
+    { send -X stop-selection
+      send -X cursor-right
+      send -X previous-word
+      send -X begin-selection
+      send -X next-word-end } \
+    { run "zsh -c \"tmux source =(sed -n '/^# yiw/,/^$/p' $HOME/.config/tmux/repeat.conf)\"" }
+
+bind -T copy-mode-vi Y send -X copy-end-of-line 'buf_'
+
+# Why don't you pass `-b` to run?{{{
+#
+# There's no need to.
+# `pipe-and-cancel` doesn't block.
+# The shell command passed as an argument is forked.
+#}}}
+bind -T copy-mode-vi S send -X pipe-and-cancel \
+    "xargs -I {} tmux run 'xdg-open \"https://www.startpage.com/do/dsearch?query={}\"'"
+
+# Why? {{{
+#
+# `search-backward-incremental`  is  better  than `search-forward`,  because  it
+# highlights  all the  matches as  you  type (like  in Vim  when 'hlsearch'  and
+# 'incsearch' are both set); you need to pass `-i` to `command-prompt` for it to work.
+#
+# Also, these key bindings make the prompt less noisy (`/` is shorter than `search down`).
+#
+# Inspired from the default emacs key bindings in copy mode.
+# }}}
+bind -T copy-mode-vi / command-prompt -ip '/' { send -X search-forward-incremental '%%' }
+bind -T copy-mode-vi ? command-prompt -ip '?' { send -X search-backward-incremental '%%' }
+
+bind -T copy-mode-vi % send -X next-matching-bracket
+bind -T copy-mode-vi _ send -X start-of-line
+
+# move current window position forward/backward
+# Why not using `h` and `l`, or `j` and `k`?{{{
+#
+# `M-C-[jk]` could  be more  useful for something  else (WeeChat?),  and doesn't
+# match a horizontal motion.
+# `M-C-[hl]` conflicts with our window manager (move virtual desktop).
+# `M-C-[HL]` is hard to press.
+#}}}
+bind -r > if -F '#{window_end_flag}' { movew -t :0 } { swapw -t :+ ; selectw -n }
+bind -r < if -F '#{window_start_flag}' { movew -t :99 } { swapw -t :- ; selectw -p }
+# If you don't like `:99`, you could write this instead:{{{
+#
+#     bind -r < if -F '#{window_start_flag}' \
+#         { run 'tmux movew -t:$((#{W:#{?window_end_flag,#I,}}+1))' } \
+#         { swapw -t :- ; selectw -p }
+#}}}
+
+# prefix {{{2
+
+# NOTE: `C-\` is free.
+
+# cycle through predefined layouts
+# Do *not* pass `-r` to `bind`!{{{
+#
+# We use Space in Vim as a prefix key.
+# If you use  `-r` here, when you're in  Vim there's a risk that  when you press
+# Space as a prefix key, it's consumed by tmux to run `nextl` instead.
+#}}}
+bind Space nextl
+
+# focus last pane, without breaking the zoomed state of the window
+bind M-Space lastp -Z
+
+# display short description for the next keypress (inspired from a default key binding)
+bind M-h command-prompt -k -p key { lsk -1N '%%' }
+#                       ├┘              ├─┘{{{
+#                       │               └ -N instead show keys and attached notes in the root and prefix key tables;
+#                       │                 with -1 only the first matching key and note is shown
+#                       └ -k is like -1 but the key press is translated to a key name
+#}}}
+# What is the side effect of `-1`?{{{
+#
+# Not only does it limit the output of the command to the first matching key and
+# note, but it also redirects where it's displayed.
+# Without `-1`, it's displayed on the terminal in copy-mode.
+# With `-1`, it's displayed as a message on the tmux status line.
+#}}}
+
+# display short description for the next 2 keypresses
+bind M-l command-prompt -1p 'key1,key2' \
+    { run "tmux lsk | awk '/-T prefix\s+%1\s+/ { print \$NF }' | xargs -I {} tmux lsk -1N -P 'M-Space %1 ' -T {} '%2'" }
+
+# repeat last shell command in last active pane
+# Warning: This overrides a default key binding:{{{
+#
+#     bind-key -T prefix . command-prompt -T target "move-window -t '%%'"
+#}}}
+bind . if -F -t '{last}' '#{m:*sh,#{pane_current_command}}' { send -t '{last}' Up Enter }
+
+# copy clipboard selection into tmux buffer
+# Why `run`?{{{
+#
+# To make the shell evaluate the command substitution.
+#}}}
+#   `--`?{{{
+#
+# The evaluation of the substitution command could start with a hyphen.
+# And  if that  happens,  tmux could  parse  the  text as  an  option passed  to
+# `set-buffer` (i.e. `-a`, `-b`, or `-n`).
+#}}}
+#   `-o`?{{{
+#
+# To make `xsel(1x)` output something.
+#}}}
+bind b switchc -T buffer
+bind -T buffer -N 'copy clipboard into tmux buffer' > run 'tmux setb -- "$(xsel -ob)"' \; display 'clipboard copied into tmux buffer'
+bind -T buffer -N 'copy tmux buffer into clipboard' < choose-buffer -F '#{buffer_sample}' \
+    { run 'tmux showb -b "%%" | xsel -ib' ; display 'tmux buffer copie