os/tmux/ TmuxIntermediate

See https://github.com/tmux/tmux/wiki/Advanced-Use

Socket

Tmux by default creates a socket in /tmp/tmux-$UID/default. We can change this

tmux -Lhello  -- creates/uses server and socket in /tmp/tmux-$UID/hello
tmux -Shello  -- creates/uses server and socket in file 'hello'

to see socket path within a session

:display -p '#{socket_path}'

If a socket is accidentally deleted, it can be recreated via

pkill -USR1 tmux

Session

:kill-session -C  -- clear alert flags

Working directory

By default the working directory is the directory we were in when launching tmux. This can be changed via

:attach -c/tmp

Or when creating a new session, window or pane

:new -c/tmp    -- new session with working directory /tmp
:neww -c/tmp   -- new window with working directory /tmp
:splitw -c/etc -- new pane (split one above other) with cwd=/etc
:splitw -h -c/usr -- new pane (split one beside other) with cwd=/usr

Respawning pane

By default, when the command running in a pane exits, the pane closes. We can change this

:set-option remain-on-exit

and then

:respawn-pane        -- start new process in a pane
:respawn-pane cmd    -- run cmd in (dead) pane
:respawn-pane -k cmd -- kill current process and run cmd in pane

Window sizes

:show -g default-size

:set-option window-size largest/smallest/latest/manual

Then there are keys when the window is larger than our terminal: {{Ctrl-B}} followed by

S-Up
S-Down
S-Left
S-Right
Delete -- return to tracking the cursor position

and commands

:resizew -x200 -y100        -- resize to 200x100
:resizew -A                 -- work out size from attached clients
:resizew -L20               -- adjust size left
:resizew -R20, -D20, -U20   -- same but for right, down, up

Piping pane changes

:pipe-pane 'cat > /tmp/log1' -- pipes changes to terminal to cat
:pipe-pane                   -- stop piping
:pipe-pane -I 'cat /tmp/log1'
:pipe-pane -o 'cat > /tmp/log1' -- toggles piping

Pane commands

:selectp -Tmytitle -- set title for pane

The pane title is in quotes to the lower right, the window name is next to its number, and the session name is in square brackets to the lower left.

Terminal window stuff

With e.g. xterm and friends, we can set the title using

set -g set-titles on

and change what the title is set to via

set -g set-titles-string '#{pane_title}'

where '#{pane_title}' is a format string for the title. By default this is 'session-name:window-number:window-name - pane-name'.

Format strings

For things like setting the title, the format string looks like e.g.

'#{pane_title}'

and there are a few variables we can use in here. These are

#{pane_title}                           -- pane title
#{session_name}, #{window_name}         -- names
#{pane_id}, #{window_id}, #{session_id} -- ids

For example to list ids in current window

$ tmux lsp -F '#{session_id} #{window_id} #{pane_id}'
$0 @8 %8

Addressing panes

Note that variable TMUX_PANE is set to the appropriate pane_id when spawning a pane, and is unique for that pane (it is never reused by a given tmux server).

For example

tmux send -t%22 "echo hello world" Enter -- types echo hello world and presses Enter
tmux send -t%21 -l "echo hello" Enter -- Enter is sent as text

note that this can't send e.g "\n" – that literally sends a backslash followed by n.

tmux capturep -pt%21  -- dump contents of pane %21 to stdout
... -e includes escape sequences for colours and attributes
    -C escapes nonprintable chatacters as octal sequences
    -N preserves trailing spaces at the end of lines
    -J preserves trailing spaces and joins wrapped lines

More panes

Empty pane

$ tmux splitw ''
$ echo 'hello world' | tmux splitw -I  -- takes content of new pane from stdin

Windows

A window can belong to more than one session.

Escape sequences

$ printf '\033]2;newtitle\007'  -- sets terminal title

Options

Options, set with :setw