tat

#!/bin/sh
#
# Attach or create tmux session named the same as current directory.

session_name="$(basename "$PWD" | tr . -)"

session_exists() {
  tmux list-sessions | sed -E 's/:.*$//' | grep -q "^$session_name$"
}

not_in_tmux() {
  [ -z "$TMUX" ]
}

if not_in_tmux; then
  tmux new-session -As "$session_name"
else
  if ! session_exists; then
    (TMUX='' tmux new-session -Ad -s "$session_name")
  fi
  tmux switch-client -t "$session_name"
fi