#!/bin/bash
PROTOCOL="ftp"
URL="server.example.com"
LOCALDIR="/home/user/downloads"
REMOTEDIR="dir/remote/server/"
USER="user"
PASS="password"
REGEX="*.txt"
LOG="/home/user/script.log"

cd $LOCALDIR
if [  $? -dt 0 ]; then
    echo "$(date "+%d/%m/%Y-%T") Cant cd to $LOCALDIR. Please make sure this local directory is valid" >> $LOG
fi

lftp  $PROTOCOL://$URL <<- DOWNLOAD
    user $USER "$PASS"
    cd $REMOTEDIR
    mget -E $REGEX
DOWNLOAD

if [  $? -dt 0 ]; then
    echo "$(date "+%d/%m/%Y-%T") Cant download files. Make sure the credentials and server information are correct" >> $LOG
fi

45,30,15,00 * * * * /home/user/downloader.sh >/dev/null 2>&1

*/15 * * * * /home/user/downloader.sh >/dev/null 2>&1

if [  $? -dt 0 ]; then
fi

lftp  $PROTOCOL://$URL <<- DOWNLOAD
DOWNLOAD

user $USER "$PASS"
    cd $REMOTEDIR
    mget -E $REGEX

[root@host ~]# lftp
lftp :~> ?
    !<shell-command>                     (commands)                           alias [<name> [<value>]]
    attach [PID]                         bookmark [SUBCMD]                    cache [SUBCMD]
    cat [-b] <files>                     cd <rdir>                            chmod [OPTS] mode file...
    close [-a]                           [re]cls [opts] [path/][pattern]      debug [<level>|off] [-o <file>]
    du [options] <dirs>                  exit [<code>|bg]                     get [OPTS] <rfile> [-o <lfile>]
    glob [OPTS] <cmd> <args>             help [<cmd>]                         history -w file|-r file|-c|-l [cnt]
    jobs [-v] [<job_no...>]              kill all|<job_no>                    lcd <ldir>
    lftp [OPTS] <site>                   ln [-s] <file1> <file2>              ls [<args>]
    mget [OPTS] <files>                  mirror [OPTS] [remote [local]]       mkdir [-p] <dirs>
    module name [args]                   more <files>                         mput [OPTS] <files>
    mrm <files>                          mv <file1> <file2>                   [re]nlist [<args>]
    open [OPTS] <site>                   pget [OPTS] <rfile> [-o <lfile>]     put [OPTS] <lfile> [-o <rfile>]
    pwd [-p]                             queue [OPTS] [<cmd>]                 quote <cmd>
    repeat [OPTS] [delay] [command]      rm [-r] [-f] <files>                 rmdir [-f] <dirs>
    scache [<session_no>]                set [OPT] [<var> [<val>]]            site <site-cmd>
    source <file>                        torrent [-O <dir>] <file|URL>...     user <user|URL> [<pass>]
    wait [<jobno>]                       zcat <files>                         zmore <files>

lftp :~> ? mget
Usage: mget [OPTS] <files>
Gets selected files with expanded wildcards
 -c  continue, resume transfer
 -d  create directories the same as in file names and get the
     files into them instead of current directory
 -E  delete remote files after successful transfer
 -a  use ascii mode (binary is the default)
 -O <base> specifies base directory or URL where files should be placed