drush

PHP's create_function() was:

DEPRECATED as of PHP 7.2.0, and REMOVED as of PHP 8.0.0

As the docs say, its use is highly discouraged.

PHP 7 is no longer supported by the upstream developers, but it'll still be around for a while longer (because, for example, popular linux distributions provide support for years beyond the upstream End of Life).

This is a simple trick which (unless my googlefu simply failed me) I didn't find described anywhere when I had a quick look:

$ drush ev '$file = file_load(21749); var_dump(file_delete($file, TRUE));'
bool(true)

I recently found myself trying to use drush to set up a Drupal 6 install on a server where I did not have root access. I kept getting errors along the lines of this:

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 1234 bytes)

I didn't have permission to edit the php.ini file for php_cli, so I had to find another workaround. The solution's pretty simple and comes courtesy of the drushrc.php file.