#!/bin/sh
# 
# (c) 2009 Michael Wojciechowski
#
# Show a list of screen sessions belonging to the current user.
#
# For each session show PID of the screen process and the name of
# innermost child process.
#
# When a session is selected and the user presses <enter>, "screen -r
# -d" is executed to attach to this session.
#

DIALOG="/usr/bin/dialog"
MENU_DIM_WIDTH=80
MENU_DIM_HEIGHT=40
TEMP="/tmp/sscr-$USER"
SP=`ps -C screen -o pid=`
LASTPID=-1
FollowPid ()
{
  newpid=`ps --ppid $1 -o pid=`
  if [ -n "$newpid" ]
  then
    FollowPid $newpid
  else
    LASTPID=$1
  fi
}
if [ ! -x "${DIALOG}" ]
then
  echo "This script needs ${DIALOG} to function. Abort."
  exit -1
fi
ENTRIES=""
COUNT=0

ENTRIES="$ENTRIES -1 Create"
COUNT=`expr $COUNT + 1`

for PID in `echo $SP`
do
	FollowPid $PID

	NAME=`ps -p $LASTPID -o comm=`

	if [ "$NAME" != "screen" ]
	then
	    ENTRIES="$ENTRIES $PID $NAME"
	    COUNT=`expr $COUNT + 1`
	fi
done

if [ "$COUNT" -eq 0 ]
then
  echo "No screen sessions to show."
  exit 0
fi

${DIALOG} --title "Which screen session?" --menu "Select screen session" $MENU_DIM_WIDTH $MENU_DIM_HEIGHT $COUNT $ENTRIES 2> $TEMP
STATUS=$?

case $STATUS in
  "0") 
     ;; # pressed ok.
  *)
     echo "Script aborted by user ($STATUS)."
     rm -f $TEMP
     exit
esac

SESSION=`cat $TEMP|sed -e "s/\"//g"`
rm -f $TEMP

if [ "$SESSION" -eq "-1" ]
then
    screen -d -m
    exec $0
fi

exec screen -r -d $SESSION