Bash script to either create or attach to a named tmux session with the given working directory.

tm

#!/bin/bash

if [ "$1" != "" ]; then
  cd $1
fi

DIR_NAME=${PWD##*/}

tmux has-session -t $DIR_NAME 2>/dev/null
if [ $? -eq 1 ]
then
   tmux new -s $DIR_NAME
else
   tmux attach -t $DIR_NAME
fi

Eg: tm ~/projects/myapp will create a new tmux session in that directory with the name myapp, or attach to one if it already exists. tm with no arguments will do the same but for the current directory.