Improved rscreen from autossh

rscreen

#!/bin/sh
#
# sample script to use autossh to open up a remote screen
# session, or reconnect to an existing one. 
#
# $Id: rscreen,v 1.4 2002/05/07 17:54:13 harding Exp $
#
if [ "X$1" = "X" ]; then
  echo "usage: `basename $0` <host>"
  exit 1
fi

if [ "X$SSH_AUTH_SOCK" = "X" ]; then
  eval `ssh-agent -s`
  ssh-add $HOME/.ssh/id_rsa
fi

#AUTOSSH_POLL=600
#AUTOSSH_PORT=20000
#AUTOSSH_GATETIME=30
#AUTOSSH_LOGFILE=$HOST.log
#AUTOSSH_DEBUG=yes 
#AUTOSSH_PATH=/usr/local/bin/ssh

lp=null

# find a free listening port
for port in $(seq 20000 20020); do
  lsof -i -n -P |grep LISTEN |grep -q ":${port}"
  [ $? -eq 1 ] && { lp=$port; break; }
done
[ "$lp" = "null" ] && { echo "no free local ports available"; return 2; }

export AUTOSSH_POLL AUTOSSH_LOGFILE AUTOSSH_DEBUG AUTOSSH_PATH AUTOSSH_GATETIME AUTOSSH_PORT

autossh -M $port -t $1 "screen -D -R $2"