Shell commands to kill detached (unattached) tmux sessions

tmux-kill-unattached.sh

#!/bin/bash

TMUX_UNATTACHED=$(tmux ls | grep -E -v '\(attached\)$')
while read session; do
  tmux kill-session -t "${line%%:*}"
done <<< $TMUX_UNATTACHED

Alternatively, append the following lines to the system shell configuration file (i.e..~/.bashrc, ~/.zshrc, etc.):

tmux-kill-unattached() {
  TMUX_UNATTACHED=$(tmux ls | grep -E -v '\(attached\)$')

  while read session; do
    tmux kill-session -t "${line%%:*}"
  done <<< $TMUX_UNATTACHED
}

and run source ~/.bashrc to refresh the current terminal session. Change .bashrc if you are using different shell config files.

Then, enter tmux-kill-unattached to execute the function.

This way is preferred since the first method requires users to specify the path to the tmux-kill-unattached.sh.