20.1. The Files Dictionary [CLHS-20.2]

20.1. The Files Dictionary [CLHS-20.2]
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Function `PROBE-FILE`

PROBE-FILE cannot be used to check whether a directory exists. Use functions EXT:PROBE-DIRECTORY or DIRECTORY for this.

FILE-AUTHOR always returns NIL, because the operating systems CLISP is ported to do not store a file's author in the file system. Some operating systems, such as UNIX, have the notion of a file's owner, and some other Common Lisp implementations return the user name of the file owner. CLISP does not do this, because owner and author are not the same; in particular, authorship is preserved by copying, while ownership is not.

Use OS:FILE-OWNER to find the owner of the file.

Function `EXT:PROBE-DIRECTORY`

(EXT:PROBE-DIRECTORY pathname) tests whether pathname exists and is a directory. It will, unlike PROBE-FILE or TRUENAME, not SIGNAL an ERROR if the parent directory of pathname does not exist.

Function `DELETE-FILE`

(DELETE-FILE pathname) deletes the pathname pathname, not its TRUENAME, and returns the absolute pathname it actually removed or NIL if pathname did not exist. When pathname points to a file which is currently open in CLISP, an ERROR is SIGNALed.

Function `DIRECTORY`

(DIRECTORY &OPTIONAL pathname &KEY :FULL :CIRCLE :IF-DOES-NOT-EXIST) can run in two modes:

If pathname contains no name or type component, a list of all matching directories is produced. E.g., (DIRECTORY "/etc/*/") lists all subdirectories in the directory #P"/etc/".
Otherwise a list of all matching files is returned. E.g., (DIRECTORY "/etc/*") lists all regular files in the directory #P"/etc/". If the :FULL argument is non-NIL, additional information is returned: for each matching file you get a LIST of at least four elements (file-pathname file-truename file-write-date-as-decoded-time file-length).

If you want all the files and subdirectories in the current directory, you should use (NCONC (DIRECTORY "*/") (DIRECTORY "*")). If you want all the files and subdirectories in all the subdirectories under the current directory (similar to the ls -R UNIX command), use (NCONC (DIRECTORY "**/") (DIRECTORY "**/*")).

Platform Dependent: UNIX platform only.: If the :CIRCLE argument is non-NIL, the function avoids endless loops that may result from symbolic links.

The argument :IF-DOES-NOT-EXIST controls the treatment of links pointing to non-existent files and can take the following values:

:DISCARD (default): discard the bad directory entries
:ERROR: an ERROR is SIGNALed on bad directory entries (this corresponds to the default behavior of DIRECTORY in CMU CL)
:KEEP: keep bad directory entries in the returned list (this roughly corresponds to the (DIRECTORY ... :TRUNAMEP NIL) call in CMU CL)
:IGNORE: Similar to :DISCARD, but also do not signal an error when a directory is unaccessible (contrary to the [ANSI CL] specification).

Function `EXT:DIR`

(EXT:DIR &OPTIONAL pathname) is like DIRECTORY, but displays the pathnames instead of returning them. (EXT:DIR) shows the contents of the current directory.

Function `EXT:CD`

(EXT:CD pathname) sets it, (EXT:CD) returns it.

Platform Dependent: UNIX platform only.: (EXT:CD [pathname]) manages the current directory.
Platform Dependent: Win32 platform only.: (EXT:CD [pathname]) manages the current device and the current directory.

Function `EXT:DEFAULT-DIRECTORY`

(EXT:DEFAULT-DIRECTORY) is equivalent to (EXT:CD). (SETF (EXT:DEFAULT-DIRECTORY) pathname) is equivalent to (EXT:CD pathname), except for the return value.

Function `EXT:MAKE-DIR`

(EXT:MAKE-DIR directory-pathname) creates a new subdirectory.

Function `EXT:DELETE-DIR`

(EXT:DELETE-DIR directory-pathname) removes an (empty) subdirectory.