delete-file

(delete-file pathname)

Deletes the named file and returns t. Anything that leaves the file in place is an error -- including "it was not there to begin with", which Common Lisp also makes a file-error. Probe first with probe-file when a missing file should be tolerated, or wrap the call in ignore-errors.

Works on all four backends. Both WASM backends unlink through the path_unlink_file WASI import (Preview 1 directly, --component through wasi:filesystem's unlink-file-at); a missing file answers the same file-error everywhere. Removing a directory still signals on WASM: the unlink call cannot remove directories.

(with-open-file (out "notes.txt" :direction :output)
  (write-line "draft" out))
(delete-file "notes.txt")   ; => T
(probe-file "notes.txt")    ; => NIL
(delete-file "notes.txt")   ; signals: DELETE-FILE: cannot delete notes.txt