bukkit.sh

#!/bin/bash

#  Author: TBC_x
# Created: 10-27-2011 15:34:17
# License: You can do whatever you want with this script, respecting laws
# of your country. But if you'll mess up your system, it's YOUR fault!

# This script was created for simple preparation GNU screen for run bukkit
# server. This allows to share bukkit console with more users. Users should
# be added in /home/bukkit/.xscreenrc and members of bukkitadmin group.
# Pass user names as arguments. If you want additional changes, do it by hand.

# For smooth run /var/run/screen must have mode 755 and GNU screen bust be run
# with SUID bit set. It's disadvantage is less security. When GNU screen with
# SUID can be exploited and do bad stuff (no remote exploits though). So when
# you're using encrypted SSH access your own machine, this shouldn't be any obstacle.

# When executed just run 'su -c "screen -AdmS Minecraft /path/to/start/script"
# bukkit'. I'm recommending add it as init script.

# Manually adding users: add line in /home/bukkit/.screenrc "acladd USERNAME"
# and add that user in group bukkitadmin too.

basedir="/home"
username="bukkit"
groupname="bukkitadmin"
shell="/bin/bash"
users=$@

# ===================================================
# === DON'T TOUCH THIS, IT WILL SNAP YOUR HAND!!! ===
# ===================================================

function creationtime {

groupadd $groupname
useradd -s $shell -mb $basedir -g $groupname $username

# Creating base configuration for screen

cat > "$basedir/$username/.screenrc" << EOF
defshell $shell
multiuser on
EOF

# Adding users from argument

for user in $users; do
  if (id $user &> /dev/null); then        # Checking for presence of users in system
    usermod -a -G $groupname $user
    echo acladd $user >> $basedir/$username/.screenrc
  else
    echo "Warning: user $user doesn't exist!"
  fi
done

# This is very useful, hopefully you won't experience permissions problems anymore!

echo "umask 007" >> $basedir/$username/.bashrc
chown -R $username:$groupname $basedir/$username
chmod -R 770 $basedir/$username

}

# Some basic checks, testing, if the script can be run.

if   [ ! $1 ]; then
    echo "  Usage: bukkit.sh [Users]"
    echo "Example: bukkit.sh bob jack"
    exit 0

elif [[ $USER != "root" ]]; then
  echo "You aren't root, this won't work, if you aren't root."
  exit 1

elif (id $username &> /dev/null); then
  echo "User $username exists! Stopping..."
  exit 1
fi



creationtime

exit 0