How to change PHP settings for one domain or all domains in Plesk using command line?

Question

How to change PHP settings for one or all domains via command line(cli)?

Answer

1. Connect to Plesk server using SSH as root user.
2. Copy system php.ini to a new location:

   # cp -a /etc/php.ini /var/custom-php-settings.ini

3. Edit new file /var/custom-php-settings.ini and set desired options.
4. Create backup of Plesk database:

   # plesk db dump psa > /root/psa.`date +%F.%s`.sql

5. Apply custom-php-settings.ini file. 
   For one domain:
   

   # plesk bin site --update-php-settings example.com -settings /var/custom-php-settings.ini

   For all domains:
   

   Note: depending on number of domains this command can require long time to finish (more than 20 minutes).

   # mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa -e"select name from domains" | grep -v name |while read i; do plesk bin site --update-php-settings $i -settings /var/custom-php-settings.ini; done

   Note: To register additional directives, add them to a separate file (e.g. add.ini) and apply it via the command below:

   # plesk bin site --update-php-settings example.com -additional-settings /var/add.ini