Tmux

tmux

tmuxA Great Terminal Multiplexer

lgfang

Alcatel-Lucent QingDao R&D

December 9, 2013

lgfang | QD R&D | December 9, 2013 1 / 47

tmux

Agenda

1 Why Tmux

2 Feature Highlight

3 Comparisons

4 Setup Terminal

5 More Usages

6 “Advanced” skills and tips

7 Q&A


tmux | Why Tmux

Agenda

1 Why Tmux


tmux | Why Tmux

The Itch

Isn’t it boring and in-efficient that

Loosing everything when the connection to server broken?

Switching among dozens of terminal windows.

Drag&Drop again and again to tile terminal windows

Can not share current terminal with others.

Connected to a console directly


tmux | Why Tmux

The Itch








tmux | Why Tmux

The Itch








tmux | Why Tmux

The Itch








tmux | Why Tmux

The Itch








tmux | Why Tmux

What is tmux

A Terminal Multiplexer capable of

detach/re-attach

remote-share, pair-working (esp. remote pair-working)

window split and tiling

grouping windows

re-sizing windows

. . .

Meanwhile, it is

Easy to use

Well defined command line interface

Well documented

BSD licensed


tmux | Why Tmux

What is tmux

A Terminal Multiplexer capable of

detach/re-attach

remote-share, pair-working (esp. remote pair-working)

window split and tiling

grouping windows

re-sizing windows

. . .

Meanwhile, it is

Easy to use

Well defined command line interface

Well documented

BSD licensed


tmux | Feature Highlight

Agenda

2 Feature Highlight



Detach, re-attach and remote share

This Page Intentionally Left Blank :)



Split at will



Split at will



Split at will



Or, preset layouts



Auto-resize when shared



Group windows according to project/work item etc.



The Simpler The Better



Easy to configure

Configure file $HOME/.tmux.conf

# default prefix ’C-b’

set-option -g prefix F12

bind-key | split-window -h

bind-key _ split-window -v



Even support mouse

set-option -g mouse-select-pane on

set-option -g mouse-resize-pane on

set-option -g mouse-select-window on

set-window-option -g mode-mouse on



Easy to use

This is enough to get you started1.

New session tmux [new -s session-name]

Attach tmux attach [-t session-name]

Detach F12 d

New window F12 c

Split vertically F12

Split horizontally F12 |

Change layout F12 space

Kill pane 2F12 x

1I bind prefix to F122Use “exit”. “kill pane” only when it does not response.



Easy to install

If you can not persuade your system administrator, install one underyour HOME.

# install libevent if not already

tar xvfz libevent -1.4.14b-stable.tar.gz

cd libevent -1.4.14b-stable

./ configure --prefix=$HOME /.local

make && make install

echo "LD_LIBRARY_PATH=$HOME /.local/bin:$LD_LIBRARY_PATH" >>

↪→~/. bash_profile

tar xvfz tmux -1.6. tar.gz && cd tmux -1.6/

./ configure --prefix=$HOME /.local \

CFLAGS="-I$HOME /.local/include" \

LDFLAGS="-L$HOME /. local/lib"

# To statically link tmux: --enable -static

make && make install

echo "PATH=$HOME /.local/bin:$PATH" >> ~/. bash_profile



Easy scripting

It is simple to control tmux in a shell script. Refer to my start up script

for an example.



Free as in “freedom”

Last but not least: it is BSD-licensed.Which means, it is free to use, modify, re-distribute, or even makeprofit from (sell) it.


tmux | Comparisons

Agenda

3 Comparisons


tmux | Comparisons

Copmared with secureCRT

I prefer (“putty + tmux + to”) since, as far as I know, secureCRT

can not detach/attach

can not group windows per projects(or bug/escalation etc.)

can not tile

can not remote share

not convenient if the host list is really long

can not jump to dest host via an intermediate server

your hot-keys is not available other PCs, or after re-install

seems it does not support UTF-8

non-free


tmux | Comparisons

Compared with gnu “screen”

As far as I know, “screen”

Is a little bit more complicated to configure

Is not as easy as tmux to split window

Can not resize window


tmux | Comparisons

Compared with VNC

The cons of VNC:

Depends on X (GUI environment)

Consume more CPU and network traffic (I think)

Can not resize the desktop

Does not tile3

The pros of VNC:

Uses dedicated password instead of login/password for sharing

Supports X applications

3To be accurate, you can start a tiling WM in vnc. Average engineers just don’tbother to do that.lgfang | QD R&D | December 9, 2013 22 / 47

tmux | Setup Terminal

Agenda

4 Setup Terminal



Server Side

TERM and color

TERM=xterm-256color to indicate tmux to support 256 colors.4

Or, force 256 color with tmux attach -2

Ensure your locale is utf8.For instance: LC ALL=en US.utf8

4TERM=xterm only supports 8 colorslgfang | QD R&D | December 9, 2013 24 / 47


Setup PuTTY

To cope with UTF8 chars correctly.

To not intercept hot-keys sent to tmux.

A way to not send keys to application.

Here is an example:

Example (Seting up putty)

Window → Translation → Received data ... character set : UTF-8 a

Terminal → Keyboard → The Function keys and keypad : XtermR6

Window → Selection → Shift overrides applications use of mouse

ayour putty can receive and display Chinese characters(UTF-8) now


tmux | More Usages

Agenda

5 More Usages


tmux | More Usages

You are ready to get started already. However, you may find followingslides useful.


tmux | More Usages

Eye candy


tmux | More Usages

Copy mode

Entering “copy mode” to view,search and copy screen output.

Entering copy mode F12 [ ( or F12 PageUp )

Scroll up/down: PageUp /PageDown (or emacs/vi key bindings ormouse).

Search: Ctrl +s then n / N (for mode-keys emacs)

Paste: F12 ]

Show “clip board”: F12 =

set-window-option -g mode-keys emacs

set-option -g history-limit 600000


tmux | More Usages

Panes

Select pane F12 Tab (or one of ← ↑ → ↓ )

Swap two adjacent panes F12 {

Break current pane to a new window F12 !

Join a pane to current window F12 j x.y

Swap with pane y of window x F12 m x.y

Toggle Synchronize mode5 F12 Ctrl + s

bind-key Tab select-pane -t:.+

bind-key BTab select-pane -t:.-

set-option -g display-time 3000

bind-key j command-prompt "join-pane -s ’%1’"

bind-key m command-prompt -p "move (swap) current pane with: "

↪→"swap-pane -s %1"

bind-key C-s setw synchronize-panes

5Duplicate input (key-stokes) to all panes in the same windowlgfang | QD R&D | December 9, 2013 30 / 47

tmux | More Usages

Windows

To rename a window: F12 , new name

Ways to select certain window

Last Window F12 l will select last (previous “current”)window.

Using index F12 0 - 9

Next window F12 n

Previous window F12 p


tmux | More Usages

Sessions within tmux client

New session F12 :new-session -s name

Choose(switch) session F12 s

move window among sessions F12 :move-window -t sessionName


tmux | More Usages

Run Complicated Commands

Command mode: F12 : source-file .tmux.conf

Command line command: tmux source-file .tmux.conf


tmux | More Usages

Apply Configuration

F12 :source-file .tmux.conf

Why “restart” tmux does not make new configure take effect?You just “restart” a session, not the tmux server.

What does “-g” in “set-option -g” mean?Without “-g”, the option applies to current session only.


tmux | “Advanced” skills and tips

Agenda

6 “Advanced” skills and tips



Log Screen Outputs

When you want screen log of current pane, save it with: F12 Ctrl + h

bind-key C-h command-prompt -p "save log to:" "copy-mode; send-keys

↪→’M->’ C-e C-space ’M-<’ C-a C-w; save-buffer %%"

# # if "set-window-option -g mode-keys vi", use this one:

# bind-key C-h command-prompt -p "save log to:" "copy-mode; send-keys

↪→g ’space’ G ’enter’; save-buffer %%"



Another Way to Log Screen Outputs

Though I do not prefer this one, here it is:

Start logging F12 h

Stop logging F12 H6

# for mode-keys emacs

bind-key h pipe-pane "cat >>$HOME/#S-#I-#P.log" \; display-message

↪→"Start logging($HOME/#S-#I-#P.log)"

bind-key H pipe-pane \; display-message "Stop logging(#S-#I-#P.log)"

6shift + h



Nested tmux

There are sometimes nested tmux sessions (refer to my start up script ).

1 Start a tmux session on local Linux box.

2 From that tmux session, ssh to a server and run another tmuxsession.

To send prefix to

nested tmux session Press F11 .

outer tmux session F12 .

tmux session nested twice F11 C-b

one more layer7 of nest F11 C-b C-b .

bind-key -n F11 send-prefix

bind-key C-b send-prefix

7do you really want a nested nested nested ... session?lgfang | QD R&D | December 9, 2013 38 / 47


Ways to bind-key

Normal:bind-key Tab select-pane -t:.+

Repeatable: bind-key -r Space next-layout

Without prefix: bind-key -n F11 send-prefix



“Maximize” a pane

Use cases:

Show more in the pane for a little while

Maximize, Copy (drag mouse) and Restore

# from http://superuser.com/questions/238702/maximizing-a-pane-in-tmux

unbind +

bind-key + run "if [[ $(tmux list-window) =~ MAX ]]; then \

tmux last-window;\

tmux swap-pane -s MAX.0; \

tmux kill-window -t MAX; \

else tmux new-window -d -n MAX; \

tmux swap-pane -s MAX.0; \

tmux select-window -t MAX;fi"



Shell Scripting Tmux

This script starts tmux sessions, creates windows and run commands inthem.

#!/bin/bash

# Created: Fang lungang 2011; Modified: Fang lungang 07/08/2013 16:44>

SESSION_NAME=daily;SVR="135.252.41.248"

tmux has -session -t $SESSION_NAME 2>/dev/null && exec tmux attach -t $SESSION_NAME

tmux new -session -d -s $SESSION_NAME

if hostname | grep -q "$ lgfang \| lungang $"; then # On my local PC

if ping -c 1 -W 1 $SVR; then

tmux new -window -d -n qdbbuild2 -t $SESSION_NAME :9 \

"ssh -t lungangfang@$SVR ’source .bash_profile; .local/bin/tmux -go.sh’"

tmux select -window -t $SESSION_NAME :9

# make it feels like I’m working on SVR locally

tmux set -option -g -t $SESSION_NAME status off

tmux set -option -g -t $SESSION_NAME prefix F11

fi

else # on servers , a window for emacs (start it if needed).

tmux new -window -d -n emacsclient -t $SESSION_NAME :9 \

"emacsclient -t || (emacs --daemon && emacsclient -t)"

fi

exec tmux attach -t $SESSION_NAME



Command Line Auto-complete

if [ -n "$BASH_VERSION" -a -f

↪→$HOME /.local/bin/bash_completion_tmux.sh ]; then

source $HOME /.local/bin/bash_completion_tmux.sh

fi

# -n $BASH_VERSION ==> we are in bash



auto-login and hot-keys

Some can not live without

auto-login: the emulators remember hostip/username/password.

auto-hotkey: a windows software enable you to define your ownhotkeys.

Do not worry, I wrote “to” in expect, which is (IMHO) moreconvenient.



Share Sessions among Users 8

To share all:

Find corresponding socket by echo $TMUX in the sessionMake it readable/writable to others chmod 777 /path/to/socket

Others attach with tmux -S /path/to/socket attach

To separate shared sessions from others:

tmux -S /path/to/mySocketName [new -session -s

↪→session_name]

8Seems to me the only benefit is that you do not share your passwordlgfang | QD R&D | December 9, 2013 44 / 47

tmux | Q&A

Agenda

7 Q&A


tmux | Q&A

Q&A

Questions?Thanks


tmux | Appendix

Reference card according to my configure

List Keys F12 ?

Detach F12 d

New window F12 c

Split vertically F12

Split horizontally F12 |

Change layout F12 space

Kill pane F12 x

Select window F12 0 - 9

Last window F12 l

Rename window F12 , new name

Save log F12 Ctrl + h

Select pane F12 Tab (or one of ← ↑ → ↓ )

Break current pane F12 !

Join a pane F12 j x.y

Swap two panes F12 {


Tmux

Technology

tmux comparisonscompared

tmux comparisonscopmared

willlgfang qd rd

tmux feature highlightsplit

betterlgfang qd rd

qalgfang qd rd

vlgfang qd rd

sharedlgfang qd rd