upgrade php5 to php7 centos 6 code example

Example: upgrade php 7.3 centos 7

sudo yum -y install http://rpms.remirepo.net/enterprise/remi-release-7.rpm 
sudo yum -y install epel-release yum-utils

sudo yum-config-manager --disable remi-php54
sudo yum-config-manager --enable remi-php73
  
sudo yum update  

chmod -R 777 vendor
php artisan view:clear
php artisan config:cache

sudo chgrp www-data storage -R (Note: www-data is apache on Centos 7)
sudo chmod g+rwx storage -R


if still doesn't work try:
sudo setfacl -R -d -m g::rwx storage