#!/usr/bin/env bash

function usage () {

   if [ -n "$1" ];then
      echo -e "\nError: $1"
   fi

cat<<EOF


Usage: `basename $0`  [-r] <-u username> [-g groupname] <pathname>

`basename $0` proofs ownership of the given pathname, and change it to the given username
if needed. If flag "-g" is given, also group membership will be changed.

If pathname is a directory, all regular files inside will be proofed and also changed
if needed. If flag "-r" is present, also subdirectories will be considered.

Mandytory Options:

   -u username
          name of the user, that should own the given file(s)


Optinal Control Options:

   -h
          print that help text
         

   -g groupname
          name of the group, the given file(s) should be member of.
          

   -r
          means recursive. script also traverses into subdirectories


Example:

   /root/bin/check_ownership.sh -u amavis -g amavis /var/lib/amavis/.spamassassin

EOF
exit

}


recursiv=false
while getopts d:g:hru: opt ; do
   case $opt in
      h) usage ;;
      u)
         user="$OPTARG" 
         ;;
      g) group="$OPTARG" ;;
      r) recursiv=true ;;
      \?) usage ;;
   esac
done

shift `expr $OPTIND - 1`

path=$1


if [ -z "$path" ];then
   usage "Es wurde kein Verzeichnis angegeben"
fi

if [ ! -d "$path" -a ! -f "$path" ];then 
   usage "\"$path\" is neither a directory nor a regular File"
fi

if [ -z "$user" ];then
   usage "Benutzername (-u) muss angegeben werden"
fi

[ $# -ne "1" ] && usage "wrong number of arguments"


if [ -z "$group" ] ; then
   _ownership=$user
   check_group=false
else
   _ownership="$user:$group"
   check_group=true
fi


function check_owner () {
   _path=$1
   change_ownership=false

   if [ -d $_path -o -f $_path ]; then
      _u=`stat -c "%U" $_path`
      _o="$_u"
      if [ "$_u" != "$user" ]; then
         change_ownership=true
      fi
      if $check_group ; then
         _g=`stat -c "%G" $_path`
         _o="${_u}:$_g"
         if [ "$_g" != "$group" ]; then
            change_ownership=true
         fi
      fi

      if $change_ownership ; then
         echo
         echo "$_path has wrong ownership ($_o)." 
         echo -en "\tChange to ownership $_ownership.."
         chown $_ownership $_path > /dev/null 2>&1
         if [ "$?" = "0" ];then
            echo "   [ Ok ]"
         else
            echo "   [ Failed ]"
         fi
         echo
            
      fi

      if [ -d $_path ]; then
         for _file in $_path/* ; do
            if [ -d $_file ] && $recursiv ; then
               check_owner $_file
            elif [ -f $_file ]; then
               check_owner $_file
            fi
         done
      fi
   fi
}
   

check_owner $path

exit 0