surep.sh

#!/bin/sh

# ############################################################################ #
# ############################################################################ #
# ############################################################################ #
#                                                                              #
#                   SuRep (2015-05-10 00:15:51) by Fravadona                   #
#                   Adapted for DSM6 by CoolRaoul
#                                                                              #
                                version=1.0.2
#                                                                              #
#       Send an email to notify changes made in a directory of the NAS         #
#                                                                              #
# TODO:                                                                        #
#      * option to set a minimum number of modifications before sending email  #
#      * rollback logging support                                              #
#      * demonize the script                                                   #
#      * plain text connection with telnet (it shouldn't worth it)             #
#                                                                              #
# LIMITATIONS:                                                                 #
#      * this script is not intended to monitor a directory with waaaay too    #
#        much files inside it                                                  #
#      * UTF8 and strange (but legal) ASCII email addresses may cause problems #
#      * encoding of email message may be limited                              #
#                                                                              #
# COMMENT:                                                                     #
#      * an implementation with "inotify" and "sendmail" is without a doubt a  #
#        much better approach, but DSM doesn't provide it by default           #
#                                                                              #
# ############################################################################ #
# ############################################################################ #
# ############################################################################ #

# ============================================================================ #

#IFS=' '$'\t'$'\n'
#PATH=/bin:/usr/bin:/usr/syno/bin

# ============================================================================ #

ddbfile="/tmp/SuRep-`/bin/date '+%s'`-$$.ddb"
nodfile="/tmp/SuRep-`/bin/date '+%s'`-$$.nod"

trap "exit 2" 1 2 3 15
trap "/bin/rm -f '${ddbfile}' '${nodfile}' >& /dev/null" 0

# ============================================================================ #

# ############################################################################ #
#                                                                              #
# surep_sendmail () : function for sending an email                            #
#                                                                              #
# ############################################################################ #

  surep_sendmail () {

local FNAME="surep_sendmail"

local usage="
${FNAME} -- Send an email

Usage: ${FNAME} OPTION...

OPTION:
  -h                display this help and exit
  -f  ADDRESS           from (=sender) email address
  -t  ADDRESS           to (=recipient) email address(es)
  -u  SUBJECT           message subject (def: empty)
  -m  MESSAGE           message body (def: empty)
  -s  SERVER:PORT       smtp mail relay
  -o  username=USERNAME     username for SMTP authentication
  -o  password=PASSWORD     password for SMTP authentication
  -o  fqdn=FQDN         FQDN of this computer
  -o  isp=<none|ssl|tls>    internet security protocol (def: tls)
  -o  pause=SECONDS     wait time between each SMTP command (def: 1)
"

if [ $# -eq 0 ]
then
    printf '%s\n' "${usage}"
    return 1
fi

# ---------------------------------------------------------------------------- #

local _from _to _subject _message _server _username _password _fqdn _isp _pause
local _from_email _to_email _server_fqdn _server_port

_isp='tls'
_pause=1

local OPTION OPTIND OPTARG

while getopts ":f:t:u:m:s:o:h" OPTION
do
    case "${OPTION}" in
        h)
            printf '%s\n' "${usage}"
            return 0
        ;;
        f)
            _from="${OPTARG}"
        ;;
        t)
            if [ -z ${_to} ]
            then
                _to="${OPTARG}"
            else
                _to="${_to}, ${OPTARG}"
            fi
        ;;
        u)
            _subject="${OPTARG}"
        ;;
        m)
            _message="${OPTARG}"
        ;;
        s)
            _server="${OPTARG}"
            _server_fqdn="${_server%:*}"
            _server_port="${_server#*:}"
        ;;
        o)
            case "${OPTARG}" in
                username=*)  _username="${OPTARG#username=}" ;;
                password=*)  _password="${OPTARG#password=}" ;;
                fqdn=*)      _fqdn="${OPTARG#fqdn=}" ;;
                isp=*)       _isp="${OPTARG#isp=}" ;;
                pause=*)     _pause="${OPTARG#pause=}" ;;
                *)
                    printf '%s\n' "${FNAME}: illegal option -o ${OPTARG}" >&2
                    return 1
                ;;
            esac
        ;;
        :)
            printf '%s\n' "${FNAME}: option requires an argument -${OPTARG}" >&2
            return 1
        ;;
        ?)
            printf '%s\n' "${FNAME}: illegal option -${OPTARG}" >&2
            return 1
        ;;
    esac
done

# check mandatory arguments

local _opt
for _opt in _from _to _server _username _password _fqdn
do
    if [ -z "`eval printf '%s\n' \\${${_opt}}`" ]
    then
        case "${_opt}" in
            _from)
                printf '%s\n' "${FNAME}: option is mandatory -f" 1>&2
                return 1
            ;;
            _to)
                printf '%s\n' "${FNAME}: option is mandatory -t" 1>&2
                return 1
            ;;
            _server)
                printf '%s\n' "${FNAME}: option is mandatory -s" 1>&2
                return 1
            ;;
            _username)
                printf '%s\n' "${FNAME}: option is mandatory -o username=" 1>&2
                return 1
            ;;
            _password)
                printf '%s\n' "${FNAME}: option is mandatory -o password=" 1>&2
                return 1
            ;;
            _fqdn)
                printf '%s\n' "${FNAME}: option is mandatory -o fqdn=" 1>&2
                return 1
            ;;
        esac
    fi
done

# check server

if [ -z ${_server_fqdn} ] || \
   [ -z ${_server_port} ] || \
   [ X"${_server}" != X"${_server_fqdn}:${_server_port}" ]
then
    printf '%s\n' "${FNAME}: wrong format for option -s '${_server}'" >&2
    return 1
fi

# check protocol

case "${_isp}" in
    [tT][lL][sS])
        _isp="-starttls smtp"
    ;;
    [sS][sS][lL])
        _isp=""
    ;;
    [nN][oO][nN][eE])
        printf '%s\n' "${FNAME}: plain text connexion is not supported -o isp=none"
        return 0
    ;;
    *)
        printf '%s\n' "${FNAME}: unknown protocol for option -o isp='${_isp}'" >&2
        return 1
    ;;
esac

# ---------------------------------------------------------------------------- #

# reformat the sender string

_from=`printf '%s\n' "${_from}" | /bin/sed -e 's/</ /' -e 's/>//' \
                                           -e 's/ */ /g' \
                                           -e 's/\([^ ]*@[^ ]*\) */<\1>/' \
                                           -e 's/^ //'`

# extract the "pure" email from the sender string

_from_email=`printf '%s\n' "${_from}" | /bin/sed -e 's/[^<]*<\([^>]*\)>.*/\1/g'`

# reformat the receivers string

_to=`printf '%s\n' "${_to}" | /usr/bin/tr '\n' ','`
_to=`printf '%s\n' "${_to}" | /bin/sed -e 's/</ /g'  -e 's/>//g' \
                                       -e 's/,/, /g' -e 's/ */ /g' \
                                       -e 's/\([^ ]*@[^ ,)]*\) */<\1>/g' \
                                       -e 's/^ //'`

# extract the list of "pure" emails from the receiver string

_to_email=`printf '%s\n' "${_to}" | /bin/sed -e 's/[^<]*<\([^>]*\)>[^<]*/\1 /g' \
                                             -e 's/ $//'`

# ---------------------------------------------------------------------------- #

# create a shell pipe for communating with the SMTP client software

if [ ! -e "${nodfile}" ]
then
    /bin/mknod "${nodfile}" p
    exec 3<> "${nodfile}"
fi

# ---------------------------------------------------------------------------- #

# launch the SMTP client and send the email

eval /usr/bin/openssl s_client "${_isp}" -connect "${_server}" -crlf -quiet -ign_eof <&3 2> /dev/null &
local _pid=$!

#
# _auth : base64 authentification string for SMTP server
#
local _auth=`printf '\000%s\000%s' "${_username}" "${_password}" \
           | /usr/bin/openssl enc -base64 -A 2>/dev/null`

local _email=

printf '%s\n' "EHLO ${_server_fqdn}"        >&3 ; /bin/sleep ${_pause}
printf '%s\n' "AUTH PLAIN ${_auth}"         >&3 ; /bin/sleep ${_pause}
printf '%s\n' "HELO ${_fqdn}"               >&3 ; /bin/sleep ${_pause}
printf '%s\n' "MAIL FROM: <${_from_email}>" >&3 ; /bin/sleep ${_pause}
for _email in ${_to_email}
do
    printf '%s\n' "RCPT TO: <${_email}>"    >&3 ; /bin/sleep ${_pause}
done
printf '%s\n' "DATA"                        >&3 ; /bin/sleep ${_pause}
printf '%s\n' "\
Date: `/bin/date --rfc-2822`
Subject: ${_subject}
From: ${_from}
To: ${_to}
${_message}
."                                          >&3 ; /bin/sleep ${_pause}
printf '%s\n' "QUIT"                        >&3 ; /bin/sleep ${_pause}

wait ${_pid}

}

# ############################# (surep_sendmail) ############################# #

# ============================================================================ #

#
# surep_snapshot_header : first bytes of a snapshot file
#
surep_snapshot_header="SuRep snapshot format 1"

# ============================================================================ #

# ############################################################################ #
#                                                                              #
# surep_mksnapshot () : function that takes a snapshot of a directory          #
#                                                                              #
# ############################################################################ #

  surep_mksnapshot () {

local FNAME="surep_mksnapshot"

local usage="
${FNAME} -- Take a snapshot of the files in a directory

Usage: ${FNAME} DIR...

Take a snapshot of all the files in DIR(s) with the following format :

file size blocks mode uid gid devid inode hard major minor access modify change iob

Where :

file   = File name encoded in base64
size   = File size in bytes
blocks = Number of used blocks
mode   = File type and ACLs
uid    = Owner UID
gid    = Owner GID
devid  = Device number
inode  = Inode number
hard   = Number of hardlinks referencing the file
major  = Major number
Minor  = Minor number
access = Last access date in second since Epoch
modify = Last modify date in second since Epoch
change = Last change date in second since Epoch
iob    = Block size in bytes
"

if [ $# -eq 0 ]
then
    printf '%s\n' "${usage}"
    return 1
fi

# ---------------------------------------------------------------------------- #

printf '%s\n' "${surep_snapshot_header}"

/usr/bin/find "${@}" -type f -print0 | /usr/bin/xargs -0 /bin/sh -c '
for file in "${0}" "${@}"
do
    stat=$(/bin/stat -t "${file}")
    stat=${stat#"${file} "}
    file=$(printf "%s" "${file}" | /usr/bin/openssl enc -base64 -A 2> /dev/null)
    printf "%s %s\n" "${file}" "${stat}"
done' | /usr/bin/sort

}

# ############################ (surep_mksnapshot) ############################ #

# ============================================================================ #

#
# surep_diffdb_header : first bytes of a SuRep diff database file
#
surep_diffdb_header="SQLite format 3"

# ============================================================================ #

# ############################################################################ #
#                                                                              #
# surep_mkdiffdb () : function that compares two snapshots and stores the      #
#                     the differences in a database                            #
#                                                                              #
# ############################################################################ #

  surep_mkdiffdb () {

local FNAME="surep_mkdiffdb"

local usage="
${FNAME} -- Make a database of differences between snapshots

Usage: ${FNAME} DIFFDB SNAPSHOT SNAPSHOT

Create a database file DIFFDB filled with the non matching lines between the
two SNAPSHOT files
"

if [ $# -ne 3 ]
then
    printf '%s\n' "${usage}"
    return
fi

# ---------------------------------------------------------------------------- #

local _diffdb="${1}"
local _snap_1="${2}"
local _snap_2="${3}"

# verify DIFFDB

if [ -s "${_diffdb}" ]
then
    if [ ! -f "${_diffdb}" ] || [ X"`/usr/bin/head -c ${#surep_diffdb_header} "${_diffdb}" 2> /dev/null`" != X"${surep_diffdb_header}" ]
    then
        printf '%s\n' "${FNAME}: ${_diffdb}: not a diffdb file" 1>&2
        return 1
    fi
else
    if [ -n "${_diffdb%/*}" ]
    then
        /bin/mkdir -p "${_diffdb%/*}" 2> /dev/null
        if [ $? -ne 0 ]
        then
            printf '%s\n' "${FNAME}: can't create diffdb file '${_diffdb}': Permission denied" 1>&2
            return 1
        fi
    fi
    /bin/touch "${_diffdb}" 2> /dev/null
    if [ $? -ne 0 ]
    then
        printf '%s\n' "${FNAME}: can't create diffdb file '${_diffdb}': Permission denied" 1>&2
        return 1
    fi
fi

# verify SNAPSHOT 1

if [ ! -e "${_snap_1}" ]
then
    printf '%s\n' "${FNAME}: ${_snap_1}: no such file" 1>&2
    return 1
fi
if [ ! -r "${_snap_1}" ]
then
    printf '%s\n' "${FNAME}: ${_snap_1}: permission denied" 1>&2
    return 1
fi
if [ ! -f "${_snap_1}" ] || [ X"`/usr/bin/head -c ${#surep_snapshot_header} "${_snap_1}" 2> /dev/null`" != X"${surep_snapshot_header}" ]
then
    printf '%s\n' "${FNAME}: ${_snap_1}: not a snapshot file" 1>&2
    return 1
fi

# verify SNAPSHOT 2

if [ ! -e "${_snap_2}" ]
then
    printf '%s\n' "${FNAME}: ${_snap_2}: no such file" 1>&2
    return 1
fi
if [ ! -r "${_snap_2}" ]
then
    printf '%s\n' "${FNAME}: ${_snap_2}: permission denied" 1>&2
    return 1
fi
if [ ! -f "${_snap_2}" ] || [ X"`/usr/bin/head -c ${#surep_snapshot_header} "${_snap_2}" 2> /dev/null`" != X"${surep_snapshot_header}" ]
then
    printf '%s\n' "${FNAME}: ${_snap_2}: not a snapshot file" 1>&2
    return 1
fi

# ---------------------------------------------------------------------------- #

# create tables in database

/usr/bin/sqlite3 "${_diffdb}" <<EOF

drop table if exists T_PLUS;

create table T_PLUS (
  file text,      -- file name (base64 encoded)
  size integer,   -- size in bytes
  blocks integer, -- number of blocks
  type integer,   -- file type
  acl integer,    -- access control list (sugo)
  uid integer,    -- user id of owner
  gid integer,    -- group id of owner
  devid integer,  -- device id
  inode integer,  -- inode number
  hard integer,   -- number of hard hard pointing to this file
  major integer,  -- major number
  minor integer,  -- minor number
  access integer, -- last access date
  modify integer, -- last modify date
  change integer, -- last change date
  iob integer     -- size of blocks
);

drop table if exists T_MINUS;

create table T_MINUS (
  file text,      -- file name (base64 encoded)
  size integer,   -- size in bytes
  blocks integer, -- number of blocks
  type integer,   -- file type
  acl integer,    -- access control list (sugo)
  uid integer,    -- user id of owner
  gid integer,    -- group id of owner
  devid integer,  -- device id
  inode integer,  -- inode number
  hard integer,   -- number of hard hard pointing to this file
  major integer,  -- major number
  minor integer,  -- minor number
  access integer, -- last access date
  modify integer, -- last modify date
  change integer, -- last change date
  iob integer     -- size of blocks
);

EOF

# ---------------------------------------------------------------------------- #

# right order for reading the lines of surep_mksnapshot

local _file _size _blocks _mode _uid _gid _devid _inode _hard _major _minor _access _modify _change _iob
local _type _acl _table

# inserting the file stats in the diff database

while read _file _size _blocks _mode _uid _gid _devid _inode _hard _major _minor _access _modify _change _iob
do
    if [ -z "${_file}" ]
    then
        continue
    fi

    case "${_file}" in
        -*) _table=T_MINUS
        ;;
        +*) _table=T_PLUS
        ;;
    esac

    _file=${_file#?}
    _type=${_mode%???}
     _acl=${_mode#?}

    printf "insert into ${_table} values ('%s',%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d);\n" \
           "${_file}"    \
           "${_size}"    \
           "${_blocks}"  \
           "0x${_type}"  \
           "0x${_acl}"   \
           "${_uid}"     \
           "${_gid}"     \
           "0x${_devid}" \
           "${_inode}"   \
           "${_hard}"    \
           "${_major}"   \
           "${_minor}"   \
           "${_access}"  \
           "${_modify}"  \
           "${_change}"  \
           "${_iob}"

done <<EOF | /usr/bin/sqlite3 "${_diffdb}"
`/usr/bin/diff -U 0 "${_snap_1}" "${_snap_2}" | /bin/grep -v -e '^[@+-][@+-]'`
EOF

}

# ############################# (surep_mkdiffdb) ############################# #

# ============================================================================ #

# ############################################################################ #
#                                                                              #
# surep_lsdiffdb () : function for displaying different views of the content   #
#                     of a diff database                                       #
#                                                                              #
# ############################################################################ #

  surep_lsdiffdb () {

local FNAME="surep_lsdiffdb"

local usage="
Usage: ${FNAME} [OPTION]... DIFFDB

Extract various views from the DIFFDB database file

OPTIONS
  -h       display this help and exit
  -n       display new files
  -d       display deleted files
  -m       display modified files
  -r       display renamed files
  -x       display new files excluding the renamed ones
"

local _view=

local OPTION OPTIND OPTARG

while getopts ":hndmrx" OPTION
do
    case "${OPTION}" in
        h)
            printf '%s\n' "${usage}"
            return 0
        ;;
        n)
            _view="${_view} n"
        ;;
        d)
            _view="${_view} d"
        ;;
        m)
            _view="${_view} m"
        ;;
        r)
            _view="${_view} r"
        ;;
        x)
            _view="${_view} x"
        ;;
        :)
            printf '%s\n' "${FNAME}: option requires an argument -${OPTARG}" >&2
            return 1
        ;;
        ?)
            printf '%s\n' "${FNAME}: illegal option -${OPTARG}" >&2
            return 1
        ;;
    esac
done
shift `/usr/bin/expr ${OPTIND} - 1`

if [ $# -ne 1 ]
then
    printf '%s\n' "${usage}" 1>&2
    return 1
fi

# ---------------------------------------------------------------------------- #

local _diffdb="${1}"

# verify DIFFDB

if [ ! -e "${_diffdb}" ]
then
     printf '%s\n' "${FNAME}: ${_diffdb}: no such file" 1>&2
     return 1
fi
if [ ! -r "${_diffdb}" ]
then
     printf '%s\n' "${FNAME}: ${_diffdb}: permission denied" 1>&2
     return 1
fi
if [ ! -f "${_diffdb}" ] || [ X"`/usr/bin/head -c ${#surep_diffdb_header} "${_diffdb}" 2> /dev/null`" != X"${surep_diffdb_header}" ]
then
    printf '%s\n' "${FNAME}: ${_diffdb}: not a diffdb file" 1>&2
    return 1
fi

# ---------------------------------------------------------------------------- #

# We suppose that two files with the same Name, Inode, ModDate and Size
# are identical (rsync algorithm)

local _file

for _view in ${_view}
do
    case ${_view} in

        n)  # display new files

/usr/bin/sqlite3 "${_diffdb}" <<SQLITE
.separator " "
select file from T_PLUS where file not in (select file from T_MINUS);
SQLITE
        ;;

        d)  # display deleted files

/usr/bin/sqlite3 "${_diffdb}" <<SQLITE
.separator " "
select file from T_MINUS where file not in (select file from T_PLUS);
SQLITE
        ;;

        m)  # display modified files

/usr/bin/sqlite3 "${_diffdb}" <<SQLITE
.separator " "
select P.file from T_PLUS P left join T_MINUS M
on P.file = M.file
where P.inode != M.inode or P.modify != M.modify or P.size != M.size ;
SQLITE
        ;;

        r)  # display renamed files (not 100% accurate because an inode may
            #                        be recycled and allocated for a file of
            #                        the same size and modification time)

/usr/bin/sqlite3 "${_diffdb}" <<SQLITE
.separator " "
select P.file from T_PLUS P left join T_MINUS M
on M.inode = P.inode
where M.file != P.file and M.modify = P.modify and M.size = P.size;
SQLITE
        ;;

        x)  # display new file excluding the renamed ones

/usr/bin/sqlite3 "${_diffdb}" <<SQLITE
.separator " "
select file from T_PLUS where file not in (select file from T_MINUS)
except
select P.file from T_PLUS P left join T_MINUS M
on M.inode = P.inode
where M.file != P.file and M.modify = P.modify and M.size = P.size;
SQLITE
        ;;
    esac
done

}

# ############################# (surep_lsdiffdb) ############################# #

# ============================================================================ #

SCRIPTNAME="${0##*/}"

usage="
Usage: ${SCRIPTNAME} -c CONFIG
"

while getopts ":c:h" OPTION
do
    case "${OPTION}" in
        h)
            printf '%s\n' "${usage}"
            exit 0
        ;;
        c)
            config="${OPTARG}"
        ;;
        :)
            printf '%s\n' "${FNAME}: option requires an argument -${OPTARG}" 1>&2
            return 1
        ;;
        ?)
            printf '%s\n' "${FNAME}: illegal option -${OPTARG}" 1>&2
            return 1
        ;;
    esac
done
shift `/usr/bin/expr ${OPTIND} - 1`

# ============================================================================ #

# check if configuration file is correct

if [ ! -e "${config}" ]
then
    printf '%s\n' "${SCRIPTNAME}: ${config}: no such configuration file" 1>&2
    exit 1
fi
if [ ! -f "${config}" ]
then
    printf '%s\n' "${SCRIPTNAME}: ${config}: not a configuration file" 1>&2
    exit 1
fi
if [ ! -r "${config}" ]
then
    printf '%s\n' "${SCRIPTNAME}: ${config}: permission denied" 1>&2
    exit 1
fi

# load the configuration file

. "${config}"

# verify compatibility of the configuration

if [ -z "${conf_compat}" ] || [ X"${version%.*}" != X"${conf_compat}" ]
then
    printf '%s\n' "${SCRIPTNAME}: ${config}: incompatible configuration file" 1>&2
    exit 1
fi

# verify nas_dir

if [ ! -d "${nas_dir}" ]
then
    printf '%s\n' "${SCRIPTNAME}: ${nas_dir}: no such directory" 1>&2
    exit 1
fi

# verify snapshot_dir

if [ ! -d "${snapshot_dir}" ]
then
    /bin/mkdir -p "${snapshot_dir}" 2> /dev/null
    if [ $? -ne 0 ]
    then
        printf '%s\n' "${SCRIPTNAME}: ${snapshot_dir}: cannot create snapshot directory" 1>&2
        exit 1
    fi
fi

# ============================================================================ #

/bin/date '+[%Y-%m-%d %H:%M:%S] launched SuRep'

# snapshot_id : unique identifier for the snapshots of this nas_dir
snapshot_id="`printf '%s\n' "${nas_dir}" | /usr/bin/openssl enc -base64 -A 2> /dev/null`"

# snapshot_file: file containing the snapshot
snapshot_file="${snapshot_dir}/${snapshot_id}.ss"

# save previous snapshot file

if [ -e "${snapshot_file}" ]
then
    /bin/mv "${snapshot_file}" "${snapshot_file}.0"
fi

# make a new snapshot of nas_dir

/bin/date "+[%Y-%m-%d %H:%M:%S] taking a new snapshot of '${nas_dir}'"

surep_mksnapshot "${nas_dir}" > "${snapshot_file}"

/bin/date "+[%Y-%m-%d %H:%M:%S] snapshot done"

# is that the first run for 'nas_dir' ?

if [ ! -e "${snapshot_file}.0" ]
then
    /bin/date "+[%Y-%m-%d %H:%M:%S] detected initial run, see you next time !"
    exit 0
fi

# ============================================================================ #

# generating a temporary diff database

/bin/date "+[%Y-%m-%d %H:%M:%S] creating diff database by comparing snapshots"

surep_mkdiffdb "${ddbfile}" "${snapshot_file}.0" "${snapshot_file}"

/bin/date "+[%Y-%m-%d %H:%M:%S] diff database generated"

# clean old snapshot

/bin/rm -f "${snapshot_file}.0"

# ============================================================================ #

# what are we asked to display ?

/bin/date "+[%Y-%m-%d %H:%M:%S] getting the requested file list from the diff database"

case ${notify_level} in

    0)  # new - renamed          files
        filelist="`surep_lsdiffdb -x "${ddbfile}"`"
    ;;

    1)  # new                    files
        filelist="`surep_lsdiffdb -n "${ddbfile}"`"
    ;;

    2)  # new - renamed + edited files
        filelist="`surep_lsdiffdb -x -m "${ddbfile}"`"
    ;;
    3)  # new           + edited files
        filelist="`surep_lsdiffdb -n -m "${ddbfile}"`"
    ;;
esac

# filter the result

if [ -z "${exclude_filter}" ] && [ -z "${include_filter}" ]
then
    filtlist="${filelist}"
else
    filtlist=

    while read file64
    do
        file=`printf '%s\n' "${file64}" | /usr/bin/openssl enc -base64 -d -A 2>/dev/null`
        filt=
        if [ ! -z "${exclude_filter}" ] && [ ! -z "${include_filter}" ]
        then
            filt=`eval "case \"\${file}\" in
                              ${exclude_filter}) ;;
                              ${include_filter}) printf '%s\n' \"\${file64}\" ;;
                        esac"`
        elif [ ! -z "${exclude_filter}" ]
            then
            filt=`eval "case \"\${file}\" in
                              ${exclude_filter}) ;;
                              *) printf '%s\n' \"\${file64}\" ;;
                        esac"`
        else
        #    [ ! -z "${include_filter}" ]
            filt=`eval "case \"\${file}\" in
                              ${include_filter}) printf '%s\n' \"\${file64}\" ;;
                          esac"`
        fi
        if [ -n "${filt}" ]
        then
            filtlist="${filtlist}"$'\n'"${filt}"
        fi
    done <<EOF
${filelist}
EOF
    filtlist="${filtlist#?}"
fi

# is there something to display ?

if [ -z "${filtlist}" ]
then
    /bin/date "+[%Y-%m-%d %H:%M:%S] no changes to report, see you next time !"
    exit 0
fi

# ============================================================================ #

# convert the file list from base64 to human language and apply the user view

viewlist=

while read file64
do
    file=`printf '%s\n' "${file64}" | /usr/bin/openssl enc -base64 -d -A 2>/dev/null`
    if [ ! -z ${message_nasdir+x} ]
    then
        file="${message_nasdir}${file#${nas_dir}}"
    fi
    viewlist="${viewlist}"$'\n'"${file}"
done <<EOF
${filtlist}
EOF

viewlist="${viewlist#?}"

# ============================================================================ #

# replace @FILELIST@ with the file list in the email message

case "${message_body}" in
    *@FILELIST@*)
        message_head=${message_body%@FILELIST@*}
        message_tail=${message_body#*@FILELIST@}
        message_body="${message_head}${viewlist}${message_tail}"
    ;;
esac

# ============================================================================ #

#
# nas_fqdn : NAS Full Qualified Domain Name (extracted from the NAS url)
#
nas_fqdn="`printf '%s\n' "${nas_url}" |  /bin/sed -e 's#^.*://\([^/: ]*\).*#\1#'`"

# send the email

/bin/date "+[%Y-%m-%d %H:%M:%S] sending notification email :"
printf '--------------------------------------------------\n'
printf '%s\n' "${message_body}"
printf '--------------------------------------------------\n'

surep_sendmail -f "${sender_email}" \
               -t "${recipient_email}" \
               -u "${message_subject}" \
               -m "${message_body}" \
               -s "${smtp_server}" \
               -o username="${smtp_username}" \
               -o password="${smtp_password}" \
               -o fqdn="${nas_fqdn}" \
               -o isp="${smtp_isp}" \
               -o pause="${smtp_cmdwait}"

/bin/date "+[%Y-%m-%d %H:%M:%S] a notification should have been sent by email, goodbye !"

# ############################################################################ #
# ############################################################################ #
# ############################################################################ #