For an output file FOO.html, FOO.md should be deleted if FOO.Rmd exists, and FOO.html should be deleted when FOO.Rmarkdown exists (because FOO.Rmarkdown should generate FOO.markdown instead) or neither FOO.Rmarkdown nor FOO.Rmd exists (because a plain Markdown file should not be knitted to HTML).

## Usage

clean_duplicates(preview = TRUE)

## Arguments

preview

Whether to preview the file list, or just delete the files. If you are sure the files can be safely deleted, use preview = FALSE.

## Value

For preview = TRUE, a logical vector indicating if each file was successfully deleted; for preview = FALSE, the file list is printed.