Utility for switching between Unix screens.

scr

#!/bin/sh
# Utility for switching between Unix screens. Gives you a warning if you
# try to attach to a screen while already attached.
# Note that when you create a screen, you can give it a name with the -S option.
# Usage:
# scr          -- Get a list of existing screens.
# scr foo      -- Attach to a screen with name matching "foo" e.g. 23560.myfooscreen.

if [ "$#" -eq 0 ] ; then
  # Get a list of existing screens.
  screen -ls
else
  # Are we already attached to a screen?
  screen -ls | grep \(Attached\)$
  if [ $? -eq 0 ] ; then
    echo "You are attached to a screen, please detach first by hitting Control-A d"
    exit 3
  fi
  # In the following line, the first $1 refers to the first argument of this script,
  # the second $1 is an Awk argument referring to the first field in the matching line.
  screen -r $(screen -ls | awk "/$1/{print \$1}")
fi