.tmux.conf

# ~/.tmux.conf

# Copyright (C) 2021 Maciej Delmanowski <drybjed@gmail.com>
# SPDX-License-Identifier: GPL-3.0-only


# -- Environment --------------------------------------------------------{{{1

# Copy specified variables from the environment when a new tmux session is
# created or existing session is attached
set-option -g update-environment \
    "DBUS_SESSION_BUS_ADDRESS \
     DESKTOP_SESSION \
     DISPLAY \
     GNOME_KEYRING_CONTROL \
     GNOME_KEYRING_PID \
     GPG_AGENT_INFO \
     ORIGCOLORTERM \
     ORIGTERM \
     SESSION_MANAGER \
     SSH_AGENT_PID \
     SSH_AUTH_SOCK \
     SSH_CONNECTION \
     WINDOWID \
     XAUTHORITY \
     XDG_SESSION_COOKIE \
     XDG_SESSION_PATH"

# Set tmux version in the environment to be used by the version-specific
# commands
# Source: https://stackoverflow.com/questions/35016458/
run-shell 'tmux setenv -g TMUX_VERSION $(tmux -V | \
                            sed -En "s/^tmux ([0-9]+(.[0-9]+)?).*/\1/p")'


# -- Keybindings --------------------------------------------------------{{{1

# Send prefix character into the client when pressed twice
bind-key ` send-prefix
bind-key C-b send-prefix

# Enable and disable custom prefix in case of paste issues
bind-key F7 set-option -g prefix C-b
bind-key F8 set-option -g prefix `

# <prefix> \ or v: split window vertically
bind-key \ split-window -h
bind-key v split-window -h

# <prefix> - or b: split window horizontally
bind-key - split-window -v
bind-key b split-window -v

# <prefix> i or o: select prev/next pane
bind-key i select-pane -t :.-
bind-key o select-pane -t :.+

# <prefix> vi motions: switch panes
bind-key h select-pane -L
bind-key j select-pane -D
bind-key k select-pane -U
bind-key l select-pane -R

# <prefix> <Meta> + vi motions: resize panes
bind-key -r -T prefix M-h resize-pane -L 8
bind-key -r -T prefix M-j resize-pane -D 4
bind-key -r -T prefix M-k resize-pane -U 4
bind-key -r -T prefix M-l resize-pane -R 8

# <prefix> <Meta> + <Shift> + vi motions: resize panes more
bind-key -r -T prefix M-H resize-pane -L 32
bind-key -r -T prefix M-J resize-pane -D 16
bind-key -r -T prefix M-K resize-pane -U 16
bind-key -r -T prefix M-L resize-pane -R 32

# <Meta> + vi motions: switch panes
bind-key -n M-h select-pane -L
bind-key -n M-j select-pane -D
bind-key -n M-k select-pane -U
bind-key -n M-l select-pane -R

# <Meta> + <Shift> + vi motions: move panes spatially
bind-key -n M-H select-pane -L \; swap-pane -ds '!'
bind-key -n M-J select-pane -D \; swap-pane -ds '!'
bind-key -n M-K select-pane -U \; swap-pane -ds '!'
bind-key -n M-L select-pane -R \; swap-pane -ds '!'

# <Meta> + Left/Right: switch to left/right window
# (doesn't work on console)
bind-key -n M-Left  previous-window
bind-key -n M-Right next-window

# <Meta> + , or .: switch to left/right window
# (doesn't work on console)
bind-key -n M-, previous-window
bind-key -n M-. next-window

# <Meta> + < or >: move current window left or right
# (doesn't work on console)
bind-key -n M-< swap-window -t -1
bind-key -n M-> swap-window -t +1

# <Meta> + /: enter copy or search mode
bind-key -n M-/ copy-mode

# <prefix> /: switch to the previous window
bind-key / last-window

# <Meta> + f: switch fullscreen mode of the current pane
bind-key -n M-f resize-pane -Z

# <prefix> r: reload tmux configuration file
bind-key r source-file ~/.tmux.conf


# https://zserge.com/posts/tmux/
# Linux system clipboard
bind -T copy-mode-vi Enter send-keys -X copy-pipe-and-cancel "xclip -in -selection clipboard"
bind-key -T copy-mode-vi MouseDragEnd1Pane send -X copy-pipe-and-cancel "xclip -in -selection clipboard"


# -- Options ------------------------------------------------------------{{{1

# Enable mouse mode on older tmux versions
if-shell -b '[ "$(echo "$TMUX_VERSION < 2.1" | bc)" = 1 ]' " \
    set -g mouse-select-pane on; set -g mode-mouse on; \
    set -g mouse-resize-pane on; set -g mouse-select-window on"

# In version 2.1 "mouse" replaced the previous 4 mouse options
if-shell -b '[ "$(echo "$TMUX_VERSION >= 2.1" | bc)" = 1 ]' \
    "set -g mouse on"

# UTF8 is autodetected in 2.2 onwards, but errors if explicitly set
if-shell -b '[ "$(echo "$TMUX_VERSION < 2.2" | bc)" = 1 ]' \
    "set -g utf8 on; set -g status-utf8 on; set -g mouse-utf8 on"

# Set the default tmux prefix character
set-option -g prefix `

# Use vi keyboard shortcuts by default
set-window-option -g mode-keys vi

# Set the start index of tmux windows, keeping it at 1 makes switching using
# M-<number> easier
set-option -g base-index 1

# Set the start of the pane index, to make it similar to the window index
set-option -g pane-base-index 1

# Renumber all windows when a window is closed
set-option -g renumber-windows on

# Don't wait after <Escape> is pressed to check if a meta-key is pressed
set-option -s escape-time 0

# Rename windows automatically if a custom name has not been set. The name will
# based on the current process name.
set-window-option -g automatic-rename on
set-window-option -g automatic-rename-format '#{pane_current_command}'

# Allow programs to rename windows via ANSI escape sequences
set-window-option -g allow-rename on

# Increase the scrollback size
set-option -g history-limit 65536

# Define the value of the $TERM environment variable
set-option -g default-terminal "screen-256color"


# -- Window/pane activity monitoring ------------------------------------{{{1

# Monitor windows and panes for activity
set-window-option -g monitor-activity on

# Monitor window and panes for bells (^G) sent by applications
if-shell -b '[ "$(echo "$TMUX_VERSION >= 2.6" | bc)" = 1 ]' \
    "set-window-option -g monitor-bell on"

# Define which windows should create activity events
if-shell -b '[ "$(echo "$TMUX_VERSION >= 2.6" | bc)" = 1 ]' \
    "set-option -g activity-action other"

# Define which windows should create bell events
set-option -g bell-action any

# Define custom window title style on activity
set-window-option -g window-status-activity-style fg='red,underscore'

# Define custom window title style on bell
set-window-option -g window-status-bell-style fg='red,underscore'


# -- X window title -----------------------------------------------------{{{1

# Try setting the X window title using ANSI sequences
set-option -g set-titles on

# The string that defines the X window title, used by default
set-option -g set-titles-string "`#S -- tmux"

# If a SSH session is detectd, use a more desciptive string as X window title
if-shell '[ -n "$SSH_CONNECTION" ]' 'set-option -g set-titles-string "ssh!#(whoami)@#H`#S -- tmux"'


# -- Messages, command line ---------------------------------------------{{{1

# Configure the style of tmux messages and the command prompt
set-option -g message-style fg='yellow,bold',bg='blue,bold'

# Set message display time in miliseconds
set-option -g display-time 2000


# -- Left status bar ----------------------------------------------------{{{1

# Set the maximum length of the left status bar
set-option -g status-left-length 50

# The default status, used in X window session
#   `<session-name>
set-option -g status-left '#[fg=black,bold]--#[default] #[fg=yellow,bold]#[bg=blue,bold]#{?client_prefix,`#S#[default],#[fg=black,bold]#[bg=default]`#[fg=yellow,nobold]#S#[default]} #[fg=black,bold]--#[default] '

# Change the status on Linux console to show more relevant details
#   <user>@<host>:<tty>`<session-name>
if-shell '[ -z "$DISPLAY" -a -z "$SSH_CONNECTION" ]' \
    'set-option -g status-left "#[fg=black,bold]--#[default] #[fg=green]#(whoami)#[fg=black,bold]@#[default]#[fg=cyan]#H#[fg=black,bold]:#[fg=magenta,nobold]#{s|/dev/||:client_tty}#[fg=yellow,bold]#[bg=blue,bold]#{?client_prefix,`#S#[default],#[fg=black,bold]#[bg=default]`#[fg=yellow,nobold]#S#[default]} #[fg=black,bold]--#[default] "'

# Change the status when SSH connection is detected to show more relevant
# details
#   ssh!<user>@<host>`<session-name>
if-shell '[ -n "$SSH_CONNECTION" ]' \
    'set -g status-left "#[fg=black,bold]--#[default] #[fg=yellow,nobold]ssh#[fg=black,bold]!#[fg=green,nobold]#(whoami)#[fg=black,bold]@#[default]#[fg=cyan,bold]#H#[fg=yellow,bold]#[bg=blue,bold]#{?client_prefix,`#S#[default],#[fg=black,bold]#[bg=default]`#[fg=yellow,nobold]#S#[default]} #[fg=black,bold]--#[default] "'


# -- Middle status bar (window list) ------------------------------------{{{1

# Align the window list to the left
set-option -g status-justify left

# Configure the style of the middle status bar
set-option -g status-style fg='#999999',bg=default

# Set the style and format of the inactive windows
set -g window-status-format ' #[fg=magenta]#I#[fg=black,bold]:#[fg=white,nobold,dim]#W#[fg=green,nobold,nodim]#F '
set -g window-status-style fg='#777777',bg='default'

# Set the style and format of the currently active window
set -g window-status-current-format '#[fg=cyan,bold]╰╴#[fg=magenta,bold]#I#[fg=black,bold]:#[fg=white]#W#[fg=green,bold]#F#[fg=cyan,bold]╶╯'
set -g window-status-current-style fg='white,bold',bg='default'

# Use non-Unicode characters for the active window on Linux console
if-shell '[ -z "$DISPLAY" -a -z "$SSH_CONNECTION" ]' \
    'set -g window-status-current-format "#[fg=cyan,bold]└─ #[fg=magenta,bold]#I#[fg=black,bold]:#[fg=white]#W#[fg=green,bold]#F#[fg=cyan,bold] ─┘"'


# -- Right status bar ---------------------------------------------------{{{1

# Display simple status bar in X window session
set -g status-right ' #[fg=black,bold]--'

# In Linux console or SSH session, show current load average and time
if-shell '[ -z "$DISPLAY" -o -n "$SSH_CONNECTION" ]' \
    'set -g status-right " #[fg=black,bold]-- #[default]#[fg=yellow]#(cat /proc/loadavg | cut -d \" \" -f 1,2,3) #[fg=black,bold]-- #[fg=cyan,bright]%H:%M #[fg=black,bold]--"'


# -- Pane style ---------------------------------------------------------{{{1

# The style of the inactive pane border
set -g pane-border-style fg='#444444',bg=default

# The style of the active pane border
set -g pane-active-border-style fg='#888888',bg=default

# The style of the inactive pane border on Linux console
if-shell '[ -z "$DISPLAY" -a -z "$SSH_CONNECTION" ]' \
    'set-option -g pane-border-style fg="brightblack",bg=default'

# The style of the active pane border on Linux console
if-shell '[ -z "$DISPLAY" -a -z "$SSH_CONNECTION" ]' \
    'set-option -g pane-active-border-style fg="white",bg=default'