Upgrading Nextcloud from CLI.
/var/www/html/owncloud/ - Nextcloud installation directory
apache - HTTP server service user
cd /var/www/html/
wget https://download.nextcloud.com/server/prereleases/nextcloud-12.0.1RC4.zip
service httpd stop
rm owncloud-old/ -rf
mv owncloud/ owncloud-old/
unzip nextcloud-12.0.1RC4.zip
mv nextcloud/ owncloud/
mv owncloud-old/data/ owncloud/data/
cp owncloud-old/config/config.php owncloud/config/config.php
chown apache: owncloud/ -R
cd owncloud
sudo -u apache php occ upgrade
service httpd start
wget https://download.nextcloud.com/server/prereleases/nextcloud-12.0.1RC4.zip
service httpd stop
rm owncloud-old/ -rf
mv owncloud/ owncloud-old/
unzip nextcloud-12.0.1RC4.zip
mv nextcloud/ owncloud/
mv owncloud-old/data/ owncloud/data/
cp owncloud-old/config/config.php owncloud/config/config.php
chown apache: owncloud/ -R
cd owncloud
sudo -u apache php occ upgrade
service httpd start