tmux

../_images/tmux.png

Install powerline, A fancy status line for tmux

sudo pip3 install --user --break-system-packages git+https://github.com/powerline/powerline

Copy powerline config files to a locally editable place

mkdir -p ~/.config/powerline
cp -r ~/.local/lib/python3.13/site-packages/powerline/config_files/* ~/.config/powerline

Now you can edit ~/.config/powerline/themes/tmux/default.json to customize your tmux status bar. For example I don’t want to see the system uptime or load in the status bar so I remove the sys.uptime and sys.system_load blocks.

I also edit ~/.config/powerline/config.json to enable term_truecolor.

Powerline fonts

In order to see some of the symbols that powerline uses you will need a supported font. I’ve found that the Hack powerline font is easy enough on the eyes. You’ll need to install it in macOS in order to use it with iTerm2 and you’ll need to install it in Windows in order to use it with PuTTY

Configure iTerm and PuTTY to use 256 colors and the new font

You’ll want to enable 256 color support otherwise you’ll be stuck using only 16 colors and that looks terrible.

For iTerm2 you’ll need to go to Settings -> Profiles -> Terminal and change “Report Terminal Type” to xterm-256color. Then go to Settings -> Profiles -> Text and change “Font” to Hack.

For PuTTY you’ll need to go to Configuration -> Connection -> Data and change “Terminal-type string” to putty-256color. Then go to Configuration -> Window -> Appearance -> Font settings and change “Font:” to Hack.

~/.config/tmux/tmux.conf

#
# mouse support
#

set -g mouse on

#
# prefix
#

unbind C-b                   # \
set-option -g prefix C-a     #  > Change prefix from `Ctrl-b` to `Ctrl-a`
bind-key C-a send-prefix     # /
bind a send-prefix           # Make it so `Ctrl-a a` mimics bash's ctrl-a (move cursor to beginning of line)

#
# sessions
#

bind C new-session           # `Ctrl-a C` to create a new session
bind P switch-client -p      # `Ctrl-a P` for previous session
bind N switch-client -n      # `Ctrl-a N` for next session
bind S choose-tree           # `Ctrl-a S` to bring up a choose session screen
set -g detach-on-destroy off # Go to previous session instead of detaching

#
# windows
#

unbind w
unbind &
unbind '"'
bind '"' choose-window                                       # `Ctrl-a "` to bring up a choose window screen
bind A command-prompt -I "#W" "rename-window '%%'"           # `Ctrl-a A` to name your current window
bind C-a last-window                                         # `Ctrl-a Ctrl-a` to go to previous window
bind k confirm-before -p "kill window #W? (y/n)" kill-window # `Ctrl-a k` to kill (an unresponsive) window
set -g automatic-rename on                                   # Automatically name your window (unless you've manually named it)
set -g history-limit 50000                                   # Window scrollback size
set -g renumber-windows off                                  # Don't renumber windows if you close one

#
# panes
#

unbind %
bind | split-window -h                       # `Ctrl-a |` to split window vertically
bind - split-window -v                       # `Ctrl-a -` to split window horizontally
bind -n M-Left select-pane -L                # `Alt-LeftArrow` to move to pane to the left
bind -n M-Right select-pane -R               # `Alt-RightArrow` to move to pane to the right
bind -n M-Up select-pane -U                  # `Alt-UpArrow` to move to pane above
bind -n M-Down select-pane -D                # `Alt-DownArrow` to move to pane below
bind s set-window-option synchronize-panes   # `Ctrl-a s` to type in all panes at once
# Note, you can use `Ctrl-a z` to zoom into a pane (make the pane full screen).  Also to zoom out.

#
# term
#

# Set tmux-256color for tmux for reasons: https://github.com/tmux/tmux/wiki/FAQ
set -g default-terminal "tmux-256color"

# Make sure true color capability "Tc" is set for xterm
set -ga terminal-overrides ",xterm*:Tc"

#
# powerline
#

source /lib/python3.10/site-packages/powerline/bindings/tmux/powerline.conf

Color test script

Here’s a script to make sure your terminal is working with true color. You may want to run this script both before and after running tmux to verify colors are working correctly. The end result should be a color bar that smoothly draws from read to blue. If it’s chunky or looks like blocks, True Color isn’t working.

awk -v term_cols="${width:-$(tput cols || echo 80)}" 'BEGIN{
    s="/\\";
    for (colnum = 0; colnum<term_cols; colnum++) {
        r = 255-(colnum*255/term_cols);
        g = (colnum*510/term_cols);
        b = (colnum*255/term_cols);
        if (g>255) g = 510-g;
        printf "\033[48;2;%d;%d;%dm", r,g,b;
        printf "\033[38;2;%d;%d;%dm", 255-r,255-g,255-b;
        printf "%s\033[0m", substr(s,colnum%2+1,1);
    }
    printf "\n";
}'

Compiling tmux

I used to have to work on an old bastion host that was controlled by our security team and didn’t have sudo or root access. Which is odd, considering I had full root access to over 30,000 servers. It had an ancient version of tmux. The version of ncurses was so old that it didn’t come with the tmux-256color terminfo. It also didn’t have the libssl-dev package installed. Oddly enough, the server had gcc installed, so here’s how I was able to get the latest version of tmux installed into my home directory:

Make sure $HOME/.local exists

mkdir -p $HOME/.local

Setup some shell variables, add the following to your startup scripts (eg .bashrc or .zshrc)

export PATH=$HOME/.local/bin:$PATH
export LD_LIBRARY_PATH=$HOME/.local/lib:$LD_LIBRARY_PATH
export MANPATH=$HOME/.local/share/man:$MANPATH

Install pkg-config

wget https://pkgconfig.freedesktop.org/releases/pkg-config-0.29.2.tar.gz
tar -xvf pkg-config-0.29.2.tar.gz
cd pkg-config-0.29.2
./configure --prefix=$HOME/.local --with-internal-glib
make && make install

Install m4

wget https://ftp.gnu.org/gnu/m4/m4-1.4.19.tar.xz
tar -xvf m4-1.4.19.tar.xz
cd m4-1.4.19.tar.xz
./configure --prefix=$HOME/.local
make && make install

Install autoconf

wget http://ftp.gnu.org/gnu/autoconf/autoconf-2.72.tar.xz
tar -xvf autoconf-2.72.tar.xz
cd autoconf-2.72
./configure --prefix=$HOME/.local
make && make install

Install automake

wget https://ftp.gnu.org/gnu/automake/automake-1.17.tar.xz
tar -xvf automake-1.17.tar.xz
cd automake-1.17
./configure --prefix=$HOME/.local
make && make install

Install ncurses

wget https://ftp.gnu.org/pub/gnu/ncurses/ncurses-6.5.tar.gz
tar -xvf ncurses-6.5.tar.gz
cd ncurses-6.5
./configure --prefix=$HOME/.local --with-shared --with-termlib --enable-pc-files --with-pkg-config-libdir=$HOME/.local/lib/pkgconfig
make && make install

Install libevent

wget https://github.com/libevent/libevent/releases/download/release-2.1.12-stable/libevent-2.1.12-stable.tar.gz
tar -xvf libevent-2.1.12-stable.tar.gz
cd libevent-2.1.12-stable
./configure --prefix=$HOME/.local --enable-shared --disable-openssl
make && make install

Install bison (yacc)

wget https://ftp.gnu.org/gnu/bison/bison-3.8.2.tar.xz
tar -xvf bison-3.8.2.tar.xz
cd bison-3.8.2
./configure --prefix=$HOME/.local
make && make install

Install tmux

git clone https://github.com/tmux/tmux.git
cd tmux
sh autogen.sh
./configure --prefix=$HOME/.local
make && make install