duti:tldr:5bb29

The command 'duti -x ${ext}' is used to remove the default file association for a specific file extension on macOS.

Here's a breakdown of the command:

• 'duti' is the command-line tool used for managing the default file associations on macOS.
• '-x' is an option for the 'duti' command, which is used to remove the default association.
• '${ext}' is a placeholder that should be replaced with the specific file extension you want to remove the default association for.

For example, if you want to remove the default association for the file extension ".txt", you would replace '${ext}' with '.txt', resulting in the command:

duti -x .txt

Executing this command would remove the default app associated with files having the ".txt" extension, so that the system will no longer automatically open those files with a specific application.