file-directory-p

Arguments: pathname &key (follow-symbolic-links t)

Returns t if pathname names a directory and nil if it names a file. nil is also returned if pathname does not exist.

It was intended to change this function so that an error would be signaled if pathname does not exist and for a while the documentation was changed to reflect that, but that change was in fact never made.

The behavior when the pathname argument names a symbolic link depends on the follow-symbolic-links argument. When true (the default), symbolic links are followed and t or nil is returned as the resolved link is or is not a directory. When follow-symbolic-links is nil and pathname names a symbolic link, nil is returned regardless of what the link resolves to (since pathname is a symbolic link, not a directory).

Symbolic link example

;; Suppose we have:
$ ls -ld foo tmp
lrwxrwxrwx  1 ueer ftp    3 Feb  4 14:48 foo -< tmp/
drwxr-xr-x. 7 user ftp 4096 Feb  1 12:47 tmp/
$ 

;; In Lisp we have:
;;
cl-user(3): (file-directory-p "foo" :follow-symbolic-links nil)
nil
cl-user(4): (file-directory-p "foo" :follow-symbolic-links t)
t
;; :follow-symbolic-links defaults to t:
cl-user(5): (file-directory-p "foo") 
t

Copyright (c) 1998-2022, Franz Inc. Lafayette, CA., USA. All rights reserved.
This page was not revised from the 10.0 page.
Created 2019.8.20.