probe-file pathspec => truename
Arguments and Values:
pathspec---a pathname designator.
truename---a physical pathname or nil.
probe-file tests whether a file exists.
probe-file returns false if there is no file named pathspec, and otherwise returns the truename of pathspec.
If the pathspec designator is an open stream, then probe-file produces the truename of its associated file. If pathspec is a stream, whether open or closed, it is coerced to a pathname as if by the function pathname.
The host computer's file system.
An error of type file-error is signaled if pathspec is wild.
An error of type file-error is signaled if the file system cannot perform the requested operation.
truename, open, ensure-directories-exist, pathname, logical-pathname, Section 20.1 (File System Concepts), Section 20.1.2 (File Operations on Open and Closed Streams), Section 19.1.2 (Pathnames as Filenames)