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TMUX

A session / window manager for the console. Allows tracking tabs all within the same console. This is useful when connecting to remote servers, especially when connecting with something flakey like a phone.

Install tmux on the remote server:

sudo apt install tmux

from there you can launch tmux with

tmux

Once inside a tmux context, it helps to know some basic commands to navigate.

to detach

ctrl-b d # (or ctrl-p d if remapped)

tmux is controlled using a command mode that is accessed with a command prefix. By default it's set to ctrl-b but that interferes with switching buffers in emacs. I like to switch to using ctrl-p. It's similar to VS Code's command mode that way. The rest of these notes will use ctrl-p instead of the default ctrl-b.

Sessions, windows and panes

Each Session contains a group of windows.

Each window is made up of one or more panes.

On a small screen like a mobile device running Android, there isn't room for more than one pane, but sessions and windows help a lot.

This is a good guide

https://tmuxcheatsheet.com/

Sessions

to list all sessions

tmux ls

ctrl-p s

to re-attach to the previous session

tmux attach

if the previous one is not the one you want:

tmux attach-session -t 5

to cycle through sessions from within tmux

ctrl-p ( ctrl-p )

to rename a session
ctrl-p $

Windows

ctrl-p p
Previous window

ctrl-p n
Next window

ctrl-p 0 ... 9
Switch/select window by number

ctrl-p c
Create window

ctrl-p ,
Rename current window

ctrl-p &
Close current window

Panes

Panes (splits)

%  vertical split
"  horizontal split

o  swap panes
q  show pane numbers
x  kill pane
+  break pane into window (e.g. to select text by mouse to copy)
-  restore pane from window
⍽  space - toggle between layouts
`<prefix>` q (Show pane numbers, when the numbers show up type the key to goto that pane)
`<prefix>` { (Move the current pane left)
`<prefix>` } (Move the current pane right)
`<prefix>` z toggle pane zoom

Configuration

Put this at the bottom of ~/.tmux.conf
($XDG_CONFIG_HOME/tmux/tmux.conf works too):

# remap prefix to Control + p
set -g prefix C-p
unbind C-b
bind C-p send-prefix

Control + m was used previously, but it overlaps with sending 'enter' in tmux, which results in needing to press enter twice. Not using ctrl-m resolves the issue where pressing enter requires a double press.

Is ctrl-i used for tab key on the CLI. Using it as the bind key results in needing to press tab twice for auto-complete. Running out of options -- maybe ctrl-p? Similar to what is used in visual studio code

A very heavily customized and popular version of a .tmux.conf

https://github.com/gpakosz/.tmux
gpakosz/.tmux: Oh my tmux! My self-contained, pretty & versatile tmux configuration made with

https://pragprog.com/titles/bhtmux2/tmux-2/
tmux 2: Productive Mouse-Free Development by Brian P. Hogan

Other options

# force a reload of the config file
unbind r
bind r source-file ~/.tmux.conf

# quick pane cycling
unbind ^A
bind ^A select-pane -t :.+

Launch Script Template

tmux can help manage the state needed for workspaces. In this case, create a script to configure the startup.

#!/bin/bash

session="template"
tmux new-session -d -s $session
window=0
tmux rename-window -t $session:$window 'tmux'
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window 'emacs -nw tmux-start-template.sh' C-m

window=1
tmux new-window -t $session:$window -n 'git'
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window 'git status' C-m

window=2
tmux new-window -t $session:$window -n 'template'
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window 'emacs -nw instances-template.md' C-m

window=3
tmux new-window -t $session:$window -n ''
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window 'emacs -nw instances-' C-m

window=4
tmux new-window -t $session:$window -n ''
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window 'emacs -nw instances-' C-m

window=5
tmux new-window -t $session:$window -n ''
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window 'emacs -nw ' C-m

window=6
tmux new-window -t $session:$window -n ''
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window '' C-m

window=7
tmux new-window -t $session:$window -n ''
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window '' C-m

window=8
tmux new-window -t $session:$window -n ''
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window '' C-m

window=9
tmux new-window -t $session:$window -n ''
tmux send-keys -t $session:$window 'cd ~/notes/template' C-m
tmux send-keys -t $session:$window '' C-m

tmux attach-session -t template

A good reference that got me going

https://how-to.dev/how-to-create-tmux-session-with-a-script
How to create tmux session with a script

https://unix.stackexchange.com/questions/292137/tmux-script-to-launch-several-commands
scripting - tmux script to launch several commands - Unix & Linux Stack Exchange

https://duckduckgo.com/?t=ffab&q=tmux+script+to+open+multiple+sessions&ia=web
tmux script to open multiple sessions at DuckDuckGo
https://stackoverflow.com/questions/58453982/spinning-up-multiple-tmux-sessions-in-bash
Spinning up multiple tmux sessions in bash - Stack Overflow

Scrolling

Using a terminal multiplexer, you lose the ability to use your system terminal's built in scrolling mechanism, if any. On something like a phone, this is not an issue, but on desktop contexts it may be limiting?

See Also

Screen

Screen is a similar tool to TMUX that has been around for a long time

On some systems it may be the only tool available.

Launch a new screen session for long running jobs

screen

Once in a screen session, run the script:

time python3 my_job_that_takes_a_long_time.py

detach from the session using Clrl+A and then press d.

screen -ls

screen -r [number]

to reattach

https://duckduckgo.com/?t=ffab&q=bash+screen&ia=web
bash screen at DuckDuckGo
https://www.howtogeek.com/662422/how-to-use-linuxs-screen-command/
How to Use Linux’s screen Command
https://duckduckgo.com/?t=ffab&q=screen+vs+tmux&ia=web
screen vs tmux at DuckDuckGo
https://superuser.com/questions/236158/tmux-vs-screen
tmux vs. screen - Super User

https://tmuxcheatsheet.com/
Tmux Cheat Sheet & Quick Reference

https://duckduckgo.com/?t=ffab&q=screen+terminal+disconnect&ia=web
screen terminal disconnect at DuckDuckGo

https://medium.com/swlh/how-to-use-screen-on-linux-to-detach-and-reattach-your-terminal-2f52755ff45e
How to Use Screen on Linux to Detach and Reattach Your Terminal | by Zubair Ahmed | The Startup | Medium

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

attach:

tmux a  #  (or at, or attach)

attach to named:

tmux a -t myname

list sessions:

tmux ls

kill session:

tmux kill-session -t myname

Kill all the tmux sessions:

tmux ls | grep : | cut -d. -f1 | awk '{print substr($1, 0, length($1)-1)}' | xargs kill

In tmux, hit the prefix ctrl-p and then:

Misc

d  detach
t  big clock
?  list shortcuts
:  prompt

Sessions

:new`<CR>`  new session
s  list sessions
$  name session

Windows (tabs)

c  create window
w  list windows
n  next window
p  previous window
f  find window
,  name window
&  kill window

Panes (splits)

%  vertical split
"  horizontal split

o  swap panes
q  show pane numbers
x  kill pane
+  break pane into window (e.g. to select text by mouse to copy)
-  restore pane from window
⍽  space - toggle between layouts
`<prefix>` q (Show pane numbers, when the numbers show up type the key to goto that pane)
`<prefix>` { (Move the current pane left)
`<prefix>` } (Move the current pane right)
`<prefix>` z toggle pane zoom

Sync Panes

You can do this by switching to the appropriate window, typing your Tmux prefix (commonly Ctrl-B or Ctrl-A) and then a colon to bring up a Tmux command line, and typing:

:setw synchronize-panes

You can optionally add on or off to specify which state you want; otherwise the option is simply toggled. This option is specific to one window, so it won’t change the way your other sessions or windows operate. When you’re done, toggle it off again by repeating the command. tip source

Resizing Panes

You can also resize panes if you don’t like the layout defaults. I personally rarely need to do this, though it’s handy to know how. Here is the basic syntax to resize panes:

PREFIX : resize-pane -D (Resizes the current pane down)
PREFIX : resize-pane -U (Resizes the current pane upward)
PREFIX : resize-pane -L (Resizes the current pane left)
PREFIX : resize-pane -R (Resizes the current pane right)
PREFIX : resize-pane -D 20 (Resizes the current pane down by 20 cells)
PREFIX : resize-pane -U 20 (Resizes the current pane upward by 20 cells)
PREFIX : resize-pane -L 20 (Resizes the current pane left by 20 cells)
PREFIX : resize-pane -R 20 (Resizes the current pane right by 20 cells)
PREFIX : resize-pane -t 2 20 (Resizes the pane with the id of 2 down by 20 cells)
PREFIX : resize-pane -t -L 20 (Resizes the pane with the id of 2 left by 20 cells)

Copy mode:

Pressing PREFIX [ places us in Copy mode. We can then use our movement keys to move our cursor around the screen. By default, the arrow keys work. we set our configuration file to use Vim keys for moving between windows and resizing panes so we wouldn’t have to take our hands off the home row. tmux has a vi mode for working with the buffer as well. To enable it, add this line to .tmux.conf:

setw -g mode-keys vi

With this option set, we can use h, j, k, and l to move around our buffer.

To get out of Copy mode, we just press the ENTER key. Moving around one character at a time isn’t very efficient. Since we enabled vi mode, we can also use some other visible shortcuts to move around the buffer.

For example, we can use "w" to jump to the next word and "b" to jump back one word. And we can use "f", followed by any character, to jump to that character on the same line, and "F" to jump backwards on the line.

   Function                vi             emacs
   Back to indentation     ^              M-m
   Clear selection         Escape         C-g
   Copy selection          Enter          M-w
   Cursor down             j              Down
   Cursor left             h              Left
   Cursor right            l              Right
   Cursor to bottom line   L
   Cursor to middle line   M              M-r
   Cursor to top line      H              M-R
   Cursor up               k              Up
   Delete entire line      d              C-u
   Delete to end of line   D              C-k
   End of line             $              C-e
   Goto line               :              g
   Half page down          C-d            M-Down
   Half page up            C-u            M-Up
   Next page               C-f            Page down
   Next word               w              M-f
   Paste buffer            p              C-y
   Previous page           C-b            Page up
   Previous word           b              M-b
   Quit mode               q              Escape
   Scroll down             C-Down or J    C-Down
   Scroll up               C-Up or K      C-Up
   Search again            n              n
   Search backward         ?              C-r
   Search forward          /              C-s
   Start of line           0              C-a
   Start selection         Space          C-Space
   Transpose chars                        C-t

Configurations Options:

# Mouse support - set to on if you want to use the mouse
* setw -g mode-mouse off
* set -g mouse-select-pane off
* set -g mouse-resize-pane off
* set -g mouse-select-window off

# Set the default terminal mode to 256color mode
set -g default-terminal "screen-256color"

# enable activity alerts
setw -g monitor-activity on
set -g visual-activity on

# Center the window list
set -g status-justify centre

# Maximize and restore a pane
unbind Up bind Up new-window -d -n tmp \; swap-pane -s tmp.1 \; select-window -t tmp
unbind Down
bind Down last-window \; swap-pane -s tmp.1 \; kill-window -t tmp

Cheatsheet

From here, it helps to learn some basics. Here are a few good guides:

https://thoughtbot.com/blog/a-tmux-crash-course

For all keybindings, press ctrl-p first, then press the key you want.
key 	what it does
ctrl-p, % 	split the screen in half from left to right
ctrl-p, " 	split the screen in half from top to bottom
ctrl-p, x 	kill the current pane
ctrl-p, `<arrow key>` 	switch to the pane in whichever direction you press
ctrl-p, d 	detach from tmux, leaving everything running in the background

This is an incomplete list; a more exhaustive list is available here

https://www.ocf.berkeley.edu/~ckuehl/tmux/

Tiling Window Managers

There is a lot of conceptual overlap with tmux and tiling windows managers

Window Managers

where are these notes? wayland.txt

https://www.slant.co/topics/1902/~best-tiling-window-managers-for-linux
https://www.reddit.com/r/i3wm/comments/66ho9z/why_you_use_tmux_when_already_using_i3/
https://www.slant.co/options/1288/~awesome-review
https://www.slant.co/options/1287/~xmonad-review

Launchers / dmenu

dmenu is a fast and lightweight dynamic menu for X. It reads arbitrary text from stdin, and creates a menu with one item for each line. The user can then select an item, through the arrow keys or typing a part of the name, and the line is printed to stdout. dmenu_run is a wrapper that ships with the dmenu distribution that allows its use as an application launcher

https://wiki.archlinux.org/index.php/dmenuhttps://tools.suckless.org/dmenu/

2019.08.26 17:31:24

getting started with learning tmux for managing command line sessions

this may be able to help when termux on android gets closed and the state is lost.

2019.08.27 15:04:50

tmux seems similar in functionality to emacs... multiple buffers showing on one terminal. but it's probably better to abstract that out of the editor