.bashrc script to auto-attach screen if there is a session available on login.

autoscreen.bashrc

#/bin/bash

#set -x

: <<'END'
autoscreen.bashrc
Andrew Domaszek
project: random bits of bash

Copyright (C) September 8, 2013, Andrew Domaszek
(MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

## usage:
copy to $HOME/.bash/autoscreen.bashrc

Append to $HOME/.bashrc:
if [ -r "$HOME/.bash/autoscreen.bashrc" ]; then
  . $HOME/.bash/autoscreen.bashrc
fi

END

# if interactive and not already inside a screen
if [ ! -z "$PS1" ] && [ -z "$STY" ]
then
  old=$IFS
  IFS=$'\n'
  screens=($(screen -ls | egrep -iv '\(.*dead.*\)' | grep -e '(.*)' | awk '{print $1}'))
  IFS=$old
  if [ ${#screens[@]} -eq 1 ]; then
    # exec this shell into the only screen session
    exec screen -x "${screens[0]}"
  elif [ ${#screens[@]} -gt 1 ]; then
    # bring up a selection menu with the available screen sessions
    select opt in "${screens[@]}" "None"
    do
      if [ "$opt" != "None" ] ; then
        exec screen -x "$opt"
      else
        echo "Ok, not loading any screens"
        break;
      fi
    done;
  fi
fi