Tweak export function: make the export planned

Hello,

i find a hack:

#!/bin/bash

# Settings
BACKUP_DIR=/home/toto/ftp
URL=https://www.website.com
USER=admin
PASS=passpass

COOKIES_FILE=/tmp/wp-backup.cookies

# Compute some aliases
DATE=<code>date +%Y-%m-%d</code>
BACKUP_FILE=$BACKUP_DIR/wp-backup-$DATE.xml

# Authentication
wget --keep-session-cookies --save-cookies $COOKIES_FILE  --post-data "log=$USER&pwd=$PASS&wp-submit=Connexion&testcookie=1" -O /dev/null "$URL/wp-login.php" > /dev/null

# Get the 'export' xml file
wget -O $BACKUP_FILE --load-cookies $COOKIES_FILE "$URL/wp-admin/export.php?author=all&submit=1&download=true"

chmod 777 $BACKUP_FILE

#end of file

but i have the login page in html format, in the xml backup file ??

what is wrong?

bye