The unlink command removes an entry from the ESP including referenced files that are not referenced in other entries. That is useful eg to have multiple entries that use the same kernel with different options. The cleanup command removes all files that are not referenced by any entry.
System and Service Manager
Details
Most documentation is available on systemd's web site.
Assorted, older, general information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Code Map for information about this repository's layout and content.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
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Stable branches with backported patches are available in the stable repo.