Files

The file management utilities are:

• (file-exists? path) returns #t if a file (not a directory) path exists, #f otherwise. Unlike some other procedures that take a path argument, this procedure never raises the exn:i/o:filesystem:username exception.
• (link-exists? path) returns #t if a link path exists (Unix and MacOS), #f otherwise. Note that the predicates file-exists? or directory-exists? work on the final destination of a link or series of links, while link-exists? only follows links to resolve the base part of path (i.e., everything except the last name in the path). This procedure never raises the exn:i/o:filesystem:username exception.
• (delete-file path) deletes the file with pathname path if it exists, returning void if a file was deleted successfully, otherwise the exn:i/o:filesystem:file exception is raised. If path is a link, the link is deleted rather than the destination of the link.
• (rename-file-or-directory old new) renames the file or directory with pathname old -- if it exists -- to the pathname new. If the file or directory is renamed successfully, void is returned, otherwise the exn:i/o:filesystem:rename exception is raised. This procedure can be used to move a file/directory to a different directory (on the same disk) as well as rename a file/directory within a directory. The pathname new cannot refer to an existing file or directory. If old is a link, the link is renamed rather than the destination of the link.
• (file-or-directory-modify-seconds path) returns the file or directory's last modification date as platform-specific seconds (see also section 11.4). If no file or directory path exists, the exn:i/o:filesystem:file exception is raised.
• (file-or-directory-permissions path) returns a list containing 'read, 'write, and/or 'execute for the given file or directory path. If no such file or directory exists, the exn:i/o:filesystem:file exception is raised.
• (file-size path) returns the (logical) size of the specified file. (Under MacOS, this is the sum of the data fork and resource fork sizes.) If no such file exists, , the exn:i/o:filesystem:file exception is raised.
• (copy-file src dest) creates the file dest as a copy of src. If the file is successfully copied, void is returned, otherwise the exn:i/o:filesystem:rename exception is raised. If dest already exists, the copy will fail. File permissions are preserved in the copy. Under MacOS, the resource fork is also preserved in the copy.