#!/bin/sh
# sn - select numbered screen
# Andrew Ho (andrew@tellme.com)
#
# See http://www.zeuscat.com/andrew/software/desktop_hacks/#named-screens
# for some background information about how I use this script.

ME=`basename "$0"`
USAGE="usage: $ME screen-number"

if [ "$#" -ne 1 ]; then
    echo "$ME: required screen number argument missing" 2>&1
    echo "$USAGE" 2>&1
    exit 1
fi

if [ "x$1" = "x" ]; then
    echo "$ME: invalid empty screen number argument" 2>&1
    echo "$USAGE" 2>&1
    exit 1
elif [ ! "$1" -gt 0 ]; then
    echo "$ME: invalid screen number argument: $1" 2>&1
    echo "$USAGE" 2>&1
    exit 1
fi

tmpfile="/var/tmp/$ME.tmp.$$"
screen -list | awk '/(Attached|Detached)/ { print $1 }' | sort -n > "$tmpfile"
if [ ! -f "$tmpfile" ]; then
    echo "$ME: could not create $tmpfile" 2>&1
    exit 2
fi

screenid="sn$1"
if grep "$screenid" "$tmpfile" ; then
    rm -f "$tmpfile"
    echo "$ME: reattaching to screen $screenid (detaching others)" 2>&1
    exec screen -x "$screenid"
else
    rm -f "$tmpfile"
    echo "$ME: creating new screen $screenid" 2>&1
    exec screen -S "$screenid"
fi