Scripts ending in .php will be executed with php-cgi.

Changing PHP options

Many PHP configurable options can be set by setting their values in a .user.ini file located in the directory where you want things changed. From the PHP Manual's list of php.ini directives, you can change any listed where the "Changeable" column says either "PHP_INI_PERDIR" or "PHP_INI_ALL". For example, your .user.ini might contain:

upload_max_filesize = “30M”

Choosing a version of PHP

PHP 5.5 will be retired on December 17, 2019.

Breaking changes might occurr at this time, particularly if a site contains custom database code. See the information on updating your site from PHP 5.5.

You can choose among multiple versions of PHP, depending on which silk platform version your account is hosted on:

Silk platform PHP version Command-line path Sunset Date
silkv1 5.5 (default) /opt/remi/php55/root/usr/bin/php December 17, 2019
silkv2 5.5 /opt/remi/php55/root/usr/bin/php December 17, 2019
silkv2 7.2 (default) /opt/remi/php72/root/usr/bin/php November 30, 2020
silkv2 7.3 /opt/remi/php73/root/usr/bin/php December 6, 2021

If you need to switch PHP versions, you can do so by creating or editing your site's .silk.ini file (for example ~/www-root/.silk.ini) and adding the version to the [php] section:

version = 7.3

Valid version choices are default, any of the versions listed in the table above, or newest (which provides the newest available on the system).

Your PHP processes should restart with any version changes within a few minutes. If you would like changes to take effect immediately, type pkill -u <myusername> php-cgi.

PHP versions from the command-line and scheduled tasks

Since multiple version of PHP are available, make sure you call the intended version. The version of PHP you call by default from the command-line should be the version specified in your ~/www-root/.silk.ini file. To call another version, or to call the correct one from a scheduled task, use its full path, listed in the table above.

Upgrading from PHP 5.3

PHP 5.3 was retired on May 24, 2019.

Some changes of note when updating PHP to a newer version:

  • The mysql database library no longer supports the original form of MySQL authentication. You will need to update your WebDB accounts to use modern authentication, reset their password, and update your site with the new password. Note that other sites using the same WebDB accounts will stop working if you do this unless also updated. If you need temporary additional credentials during migration in order to support old and modern authentication simultaneously, contact SAA for assistance.
  • Magic quotes are no longer supported.
  • Other updates might be required. Check your error log file for new warnings and errors after updating PHP.

For a complete list of changes between PHP 5.3 and 5.5, check out Migrating from PHP 5.3.x to PHP 5.4.x and Migrating from PHP 5.4.x to PHP 5.5.x in the PHP documentation. In particular, note the list of backward incompatible changes.

Upgrading from PHP 5.5


PHP versions newer than 5.5 are available only on silkv2 servers.

You can test or permanently change your site to use a different PHP version whenever convenient.

Database code changes might be necessary, as PHP's original MySQL library (mysql) has been retired:

Other updates might be required. Check your error log file for new warnings and errors after updating PHP.

For a complete list of changes between PHP 5.5 and 7.2, check the following:

In particular, note the list of backward incompatible changes.

Composer Packages

Composer is a popular library dependency manager for PHP. Once you declare what packages your project needs, it can help you get them installed and keep them up to date. You can check out composer and see what packages are available at Packagist.

PEAR Packages


PEAR will no longer be included with PHP after PHP 7.3. You should consider using Composer instead.

You may need to use the older PEAR package manager to obtain PHP extensions for your application. If so, you'll need to initialize and maintain your own PEAR repository, and refer to it from within your application.

You can create your own local PEAR repository in ~/pear with:

pear config-create ~/ ~/.pearrc

After this, you can manage your PEAR modules with the pear command. For example:

pear install MDB2