pacdiff:tldr:9e532

The command "pacdiff --sudo --backup" is used in Arch Linux and its derivatives to manage .pacnew and .pacsave files, which are created during system updates or package installations when the existing configuration file needs to be replaced.

Let's break down the options and their meanings:

• "pacdiff" is the command itself, used to compare and merge changes between configuration files.
• "--sudo" runs the command with superuser privileges using sudo. This is necessary as most system configuration files are owned by the root user.
• "--backup" directs pacdiff to create backups of the original configuration files before applying any changes.

Here's what happens when you execute this command:

1. Pacdiff starts running with root privileges (obtained using sudo).
2. It checks for any modifications or new configuration files (.pacnew or .pacsave) generated during system updates or package installations.
3. For each modified configuration file found, pacdiff prompts you to compare the differences between the new and old versions.
4. If you choose to merge the changes manually, pacdiff opens a text-based comparison tool (like vimdiff) for you to review and edit the files.
5. If you choose to automatically merge the changes, pacdiff replaces the original configuration file with the new one and saves the original file with a ".pacsave" extension.
6. Additionally, pacdiff also creates a backup of the original configuration file with a ".pacsave" extension, which can be accessed later if needed.

In summary, "pacdiff --sudo --backup" helps to manage configuration files by identifying changes made during system updates, giving you the option to manually or automatically merge those changes, and creating backups to ensure you can revert to the old configuration if necessary.