Helper function for DIRECTORY-PATHNAME-P which checks whether VALUE is neither NIL nor the keyword :UNSPECIFIC.

Returns NIL if PATHSPEC (a pathname designator) does not designate a directory, PATHSPEC otherwise. It is irrelevant whether file or directory designated by PATHSPEC does actually exist.

Converts the non-wild pathname designator PATHSPEC to directory form.

Returns a wild pathname designator that designates all files within the directory named by the non-wild pathname designator DIRNAME.

Returns a fresh list of pathnames corresponding to the truenames of all files within the directory named by the non-wild pathname designator DIRNAME. The pathnames of sub-directories are returned in directory form - see PATHNAME-AS-DIRECTORY.

Converts the non-wild pathname designator PATHSPEC to file form.

Checks whether the file named by the pathname designator PATHSPEC exists and returns its truename if this is the case, NIL otherwise. The truename is returned in `canonical' form, i.e. the truename of a directory is returned as if by PATHNAME-AS-DIRECTORY.

Checks whether the file named by the pathname designator PATHSPEC exists and if it is a directory. Returns its truename if this is the case, NIL otherwise. The truename is returned in directory form as if by PATHNAME-AS-DIRECTORY.

Recursively applies the function FN to all files within the directory named by the non-wild pathname designator DIRNAME and all of its sub-directories. FN will only be applied to files for which the function TEST returns a true value. If DIRECTORIES is not NIL, FN and TEST are applied to directories as well. If DIRECTORIES is :DEPTH-FIRST, FN will be applied to the directory's contents first. If DIRECTORIES is :BREADTH-FIRST and TEST returns NIL, the directory's content will be skipped. IF-DOES-NOT-EXIST must be one of :ERROR or :IGNORE where :ERROR means that an error will be signaled if the directory DIRNAME does not exist.

Copies into TO (a stream) from FROM (also a stream) until the end of FROM is reached. The streams should have the same element type.

Copies the file designated by the non-wild pathname designator FROM to the file designated by the non-wild pathname designator TO. If OVERWRITE is true overwrites the file designtated by TO if it exists.

Recursively deletes all files and directories within the directory designated by the non-wild pathname designator DIRNAME including DIRNAME itself. IF-DOES-NOT-EXIST must be one of :ERROR or :IGNORE where :ERROR means that an error will be signaled if the directory DIRNAME does not exist.