tmux

tmux stands for «Terminal MUltipleXer». It is one of the few indispensable tools in our toolchain.

tmux enables a number of terminals to be created, accessed, and controlled from a single screen. tmux may be detached from a screen and continue running in the background, then later reattached.

This is the .tmux.conf config file we use on our servers:

#################
# tmux settings #
#################

# many sources of inspiration:
# http://www.hamvocke.com/blog/a-guide-to-customizing-your-tmux-conf/
# https://www.tmuxcheatsheet.com/
# https://github.com/raxod502/radian/blob/master/.tmux.conf


# Prevent tmux from messing up keybindings
set-option -g xterm-keys on
set-window-option -g xterm-keys on

# Increase the scrollback buffer size from 2000 to an effectively unlimited size
set-option -g history-limit 10000000

# # Update the status bar every second, instead of the default 15
# # seconds. It doesn't look like it's possible to update more than
# # once per second.
set-option -g status-interval 1

# focus events enabled for terminals that support them
set-option -g focus-events on

# very useful when using "grouped sessions" and multi-monitor setup:
# when a smaller terminal connects to a tmux client, it shrinks to fit it. The
# clients attached with bigger displays see this constrained view.
# aggressive-resize makes it such that the window is only resized if the smaller
# client is actively looking at it.
set-window-option -g aggressive-resize on

# Enable mouse support
# http://www.hamvocke.com/blog/a-guide-to-customizing-your-tmux-conf/
set-option -g mouse on


# * keybindings
################################################################################

# use Emacs keybindings, see:
# http://stackoverflow.com/q/18240683/3538165
# http://stackoverflow.com/a/18247437/3538165
set-option -g status-keys emacs
set-window-option -g mode-keys emacs

# easier and faster switching between next/prev window
bind C-p previous-window
bind C-n next-window

# swap to last used window with C-b C-b
bind-key C-b last-window

# use more sensible keys to split vertical and horizonal
bind | split-window -h
bind - split-window -v
unbind '"'
unbind %

# swap adjacent windows
bind-key < swap-window -t -1
bind-key > swap-window -t +1

# reload .tmux.conf, as suggested in `man tmux`
bind R source-file ~/.tmux.conf \; display "Finished sourcing ~/.tmux.conf ."

# Prevent tmux from waiting half a second before processing the ESC key, see:
# http://unix.stackexchange.com/a/25638/176805
set -s escape-time 0


# It is better to give tmux windows custom names using the , key. This
# helps naming windows according to the context they’re focusing
# on. By default tmux will update the window title automatically
# depending on the last executed command within that window. In order
# to prevent tmux from overriding wisely chosen window names we want
# to suppress this behavior:

# don't rename windows automatically
set-option -g allow-rename off

# switch panes using Alt-arrow without prefix
bind -n M-Left select-pane -L
bind -n M-Right select-pane -R
bind -n M-Up select-pane -U
bind -n M-Down select-pane -D

# Turn off repeatability for moving between panes. Otherwise, if you split
# horizontally and switch panes, you will have to wait for the 'repeat period'
# to expire before you can use <Up> and <Down> to page through shell history.
#
# Doing it this way instead of using 'set-option -g repeat-time 0' makes it
# so that Control+Arrows and Meta+Arrows (for resizing panes) are still
# repeatable.
#
# See: http://superuser.com/a/325579/326239
bind-key Up select-pane -U
bind-key Down select-pane -D
bind-key Left select-pane -L
bind-key Right select-pane -R

# Keybinding for inserting a window:
# Adapted from http://superuser.com/a/704551/326239
bind-key I command-prompt -p 'Insert window at:' '      \
    run-shell "                                     \
	if tmux select-window -t %1; then           \
	    tmux new-window -a;                     \
	    tmux swap-window -s %1 -t \$((%1+1));   \
	else                                        \
	    tmux new-window;                        \
	    tmux move-window -t %1;                 \
	fi;                                         \
	tmux select-window -t #{window_id};         \
	tmux select-window -t %1;                   \
    "'


# * Appearance
################################################################################

# panes
set -g pane-border-fg black
set -g pane-active-border-fg brightred

## Status bar design
# status line
set -g status-justify left
set -g status-bg default
set -g status-fg colour12
set -g status-interval 2

# messaging
set -g message-fg black
set -g message-bg yellow
set -g message-command-fg blue
set -g message-command-bg black

#window mode
setw -g mode-bg colour6
setw -g mode-fg colour0

# window status
setw -g window-status-format " #F#I:#W#F "
setw -g window-status-current-format " #F#I:#W#F "
setw -g window-status-format "#[fg=magenta]#[bg=black] #I #[bg=cyan]#[fg=colour8] #W "
setw -g window-status-current-format "#[bg=brightmagenta]#[fg=colour8] #I #[fg=colour8]#[bg=colour14] #W "
setw -g window-status-current-bg colour0
setw -g window-status-current-fg colour11
setw -g window-status-current-attr dim
setw -g window-status-bg green
setw -g window-status-fg black
setw -g window-status-attr reverse

# Info on left (I don't have a session display for now)
set -g status-left ''

# loud or quiet: audible and visual bells
set-option -g visual-activity off
set-option -g visual-bell on
set-option -g visual-silence off
set-option -g bell-action none
set-option -g bell-on-alert off

# Show an indicator in the status bar on windows with unseen activity.
set-window-option -g monitor-activity off

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

# The modes {
setw -g clock-mode-colour colour135
setw -g mode-attr bold
setw -g mode-fg colour196
setw -g mode-bg colour238

# }
# The panes {

set -g pane-border-bg colour235
set -g pane-border-fg colour238
set -g pane-active-border-bg colour236
set -g pane-active-border-fg colour51

# }
# The statusbar {

set -g status-position bottom
set -g status-bg colour234
set -g status-fg colour137
set -g status-attr dim
set -g status-left ''
set -g status-right '#[fg=colour233,bg=colour241,bold] %d/%m #[fg=colour233,bg=colour245,bold] %H:%M:%S '
set -g status-right-length 50
set -g status-left-length 20

setw -g window-status-current-fg colour81

# Highlight active window
setw -g window-status-current-bg colour238

setw -g window-status-current-attr bold
setw -g window-status-current-format ' #I#[fg=colour250]:#[fg=colour255]#W#[fg=colour50]#F '

setw -g window-status-fg colour138
setw -g window-status-bg colour235
setw -g window-status-attr none
setw -g window-status-format ' #I#[fg=colour237]:#[fg=colour250]#W#[fg=colour244]#F '

setw -g window-status-bell-attr bold
setw -g window-status-bell-fg colour255
setw -g window-status-bell-bg colour1

# }
# The messages {

set -g message-attr bold
set -g message-fg colour232
set -g message-bg colour166

# }

# * Miscellaneous
################################################################################

# When the current session is killed, switch to another session instead of
# detaching.
set-option -g detach-on-destroy off

# Show messages until they are dismissed, instead of for 750 milliseconds(!).
# Actually it is only for an hour, because it doesn't seem like you can turn
# off the time limit.
set-option -g display-time 36000000

# Automatically renumber windows when one is deleted, see:
# http://unix.stackexchange.com/a/51879/176805
set-option -g renumber-windows on

# Number windows and panes from 1, instead of 0; see:
# http://unix.stackexchange.com/a/35932/176805
set-option -g base-index 1
set-window-option -g pane-base-index 1

# Attempt to set the title of the terminal emulator.
set-option -g set-titles on

# local overrides
if-shell "[[ -f ~/.tmux.local.conf ]]" "source ~/.tmux.local.conf"