#!/bin/bash
#
# homerights - script to change access rights and owner of
# home directories
#
# 2005 by Florian Harbich (doc.nice)
#
# created after a request of ??? (danimalz) on www.linuxquestions.org
# credits for fixes and improvements to
# - Rick (archtoad6)
# - ??? (anomie)
# - ??? (fotoguy)
#
# this script can be freely copied, as long as the orginal
# author(s) remain mentioned.


######################################################
# USERCONFIG SECTION
######################################################

# base dir for home directories
HOMEBASE="/home"

# group name if no group called after the username exists
COMMONGRP="users"

# rights for home directories with common group
# the rights for the user directory are reset to 0000 before
# appying this string to be able to use X together
# with --recursive without keeping an old x right
COMMONGRPRIGHTS="u=rwX,g-rwXs,o-rwxt"

# rights for home directories with individual group
# the rights for the user directory are reset to 0000 before
# appying this string to be able to use X together
# with --recursive without keeping an old x right
USERGRPRIGHTS="u=rwX,g=rwXs,o=t"

# extra options for chown (i.e. --recursive)
CHOWNOPTS=""

# extra options for chmod (i.e.--recursive)
# this is normally not needed, without access to the directory
# one also can't access the file therein.
CHMODOPTS=""

######################################################
# END OF USERCONFIG SECTION
# do not edit below this line
######################################################

# fix variables and set sensible defaults if unset

HOMEBASE="${HOMEBASE:=/home}"
HOMEBASE="${HOMEBASE%/}"
COMMONGROUP="${COMMONGROUP:=users}"
COMMONRPRIGHTS="${COMMONGRPRIGHTS:=u+rwX,g+rwX,o-rwx}"
USERGRPRIGHTS="${USERGRPRIGHTS:=u+rwX,g+rwX,o-rwx}"

if [ \( "$1" == "-h" \) -o \( "$1" == "--help" \) ]; then
  cat >&2 <<EOF
Aufruf: $(basename $0) [-h] [-r]

script to change access rights and owner of home directories

-h      --help          show this help
-r      --really        without this switch, the script will ony
                        show what would happen, but doesn't really
                        perform the actions.


Will change all user directories in ${HOMEBASE}.
The owners will be changed to be the same as the
directory name and the group will be the same if
it exists, else it will be set to ${COMMONGRP}.
Rights for directories with individual group will
be changed to ${USERGRPRIGHTS}
rights for directories with common groups will
be set to ${COMMONGRPRIGHTS}.

EOF
  exit 0
fi

# sanity checks
if [ -z "$(grep "^${COMMONGRP}:" /etc/group)" ]; then
  # common group not in group auth file
  echo "common group ${COMMONGRP} doesn't exist! aborting." >&2
  exit 1
fi

if [ ! -d "${HOMEBASE}" ]; then
  # base directory not found
  echo "base directory ${HOMEBASE} not found! aborting." >&2
  exit 1
fi

if [ \( "$1" == "-r" \) -o \( "$1" == "--really" \) ]; then
  # really perform changes
  REALACTION="dontbelazy"
else
  # only show changes, but don't perform
  REALACTION=""
fi

[ "${REALACTION}" ] && echo "$1 specified, changes are really applied!" >&2

# main part
for DIR in $(ls -d -1 --quoting-style=escape ${HOMEBASE}/*/); do
  DIR="$(basename "${DIR}")"
  echo "setting rights for ${DIR}"
  if grep -q "^${DIR}:" /etc/passwd; then
    # user with directory name found
    if grep -q "^${DIR}:" /etc/group; then
      # group with directory name found,
      # use individual group mode for this directory
      echo "  user has its own group, setting individual mode"
      if [ "${REALACTION}" ]; then
        chown ${CHOWNOPTS} ${DIR}:${DIR} "${HOMEBASE}/${DIR}"
        # fix for X and recursive mode, see in CONFIG section
        chmod 0000 "${HOMEBASE}/${DIR}"
        chmod ${CHMODOPTS} ${USERGRPRIGHTS} "${HOMEBASE}/${DIR}"
      else
        echo "chown ${CHOWNOPTS} ${DIR}:${DIR} \"${HOMEBASE}/${DIR}\"" 
        echo "chmod ${CHMODOPTS} ${USERGRPRIGHTS} \"${HOMEBASE}/${DIR}\""
      fi
    else
      # no group with directory name found,
      # use common group mode for this directory
      echo "  user has no own group, setting common mode"
      if [ "${REALACTION}" ]; then
        chown ${CHOWNOPTS} ${DIR}:${COMMONGRP} "${HOMEBASE}/${DIR}"
        # fix for X and recursive mode, see in CONFIG section
        chmod 0000 "${HOMEBASE}/${DIR}"
        chmod ${CHMODOPTS} ${COMMONGRPRIGHTS} "${HOMEBASE}/${DIR}"
      else
        echo "chown ${CHOWNOPTS} ${DIR}:${COMMONGRP} \"${HOMEBASE}/${DIR}\"" 
        echo "chmod ${CHMODOPTS} ${COMMONGRPRIGHTS} \"${HOMEBASE}/${DIR}\""
      fi
    fi
  else
    # no user with directory name found,
    # ignore this directory
    echo "  no username for this directory, skipping..."
  fi
done

if [ -z "${REALACTION}" ]; then
  echo "no changes were made to your filesystem," >&2
  echo "use -r  or --really to really apply" >&2
fi