I want to always run tumx

.bashrc

#!/usr/bin/env bash

_() {
  test -e "${HOME}/.bash-no-tmux" && return
  command -v tmux >/dev/null || return
  test -z "$SSH_CONNECTION" || return
  [[ ! $TERM =~ screen && -z $TMUX ]] || return

  local session="term-$$"
  local noCloseFile="/dev/shm/.${session}-no-close"

  tmux new -s "$session"
  while tmux attach -t "$session" >/dev/null 2>&1 ; do : ; done

  if [ -e "$noCloseFile" ]
  then
    rm -f -- "$noCloseFile"
  else
    exit
  fi
} && _

# ...