The "clean" command:

Usage: fossil clean ?OPTIONS? ?PATH ...?

Delete all "extra" files in the source tree. "Extra" files are files that are not officially part of the check-out. If one or more PATH arguments appear, then only the files named, or files contained with directories named, will be removed.

If the --prompt option is used, prompts are issued to confirm the permanent removal of each file. Otherwise, files are backed up to the undo buffer prior to removal, and prompts are issued only for files whose removal cannot be undone due to their large size or due to --disable-undo being used.

The --force option treats all prompts as having been answered yes, whereas --no-prompt treats them as having been answered no.

Files matching any glob pattern specified by the --clean option are deleted without prompting, and the removal cannot be undone.

No file that matches glob patterns specified by --ignore or --keep will ever be deleted. Files and subdirectories whose names begin with "." are automatically ignored unless the --dotfiles option is used.

The default values for --clean, --ignore, and --keep are determined by the (versionable) clean-glob, ignore-glob, and keep-glob settings.

The --verily option ignores the keep-glob and ignore-glob settings and turns on --force, --emptydirs, --dotfiles, and --disable-undo. Use the --verily option when you really want to clean up everything. Extreme care should be exercised when using the --verily option.

Options:

--allckouts
Check for empty directories within any check-outs that may be nested within the current one. This option should be used with great care because the empty-dirs setting (and other applicable settings) belonging to the other repositories, if any, will not be checked.
--case-sensitive BOOL
Override case-sensitive setting
--dirsonly
Only remove empty directories. No files will be removed. Using this option will automatically enable the --emptydirs option as well.
--disable-undo
WARNING: This option disables use of the undo mechanism for this clean operation and should be used with extreme caution.
--dotfiles
Include files beginning with a dot (".")
--emptydirs
Remove any empty directories that are not explicitly exempted via the empty-dirs setting or another applicable setting or command line argument. Matching files, if any, are removed prior to checking for any empty directories; therefore, directories that contain only files that were removed will be removed as well.
-f|--force
Remove files without prompting
-i|--prompt
Prompt before removing each file. This option implies the --disable-undo option.
-x|--verily
WARNING: Removes everything that is not a managed file or the repository itself. This option implies the --force, --emptydirs, --dotfiles, and --disable-undo options. Furthermore, it completely disregards the keep-glob and ignore-glob settings. However, it does honor the --ignore and --keep options.
--clean CSG
WARNING: Never prompt to delete any files matching this comma separated list of glob patterns. Also, deletions of any files matching this pattern list cannot be undone.
--ignore CSG
Ignore files matching patterns from the comma separated list of glob patterns
--keep <CSG>
Keep files matching this comma separated list of glob patterns
-n|--dry-run
Delete nothing, but display what would have been deleted
--no-prompt
Do not prompt the user for input and assume an answer of 'No' for every question
--temp
Remove only Fossil-generated temporary files
-v|--verbose
Show all files as they are removed