DirectoryFile

     NAME
	  directoryfile	- rouitnes to read directory filenames

     DESCRIPTION
	  DirectoryFile	is used	to read	the entries in a file-system
	  directory. The File is open before access. Entries are
	  returend one by one.

     EXAMPLE
	    external class DirectoryFile;
	    ref(DirectoryFile) Directory;
	    text t; integer i;
	    Directory:-	new DirectoryFile(SomeName);
	    if not Directory.open the
	       error( Can't open :"& SomeName)"
	    else
	    begin
	       while Directory.NextEntry do
	       begin
		  outtext(Directory.EntryName);	outimage;
	       end;
	       Directory.close;
	    end;

     AUTHOR
	  Boris	Magnusson, Lund	University.

     SEE ALSO
	  FileStatus - routines	to access Unix filesystem info about a
	  file.

     DETAILED INTERFACE
	     class DirectoryFile(FileName);
	     text FileName;
	  After	succefully opened, the filename	of a directory can  be
	  read	sequentially  by  calling  NextEntry  to  advance  and
	  EntryName to access the name of the file.

	  This	class  only  reports  the  name	 of  the  files	 in  a
	  directory.  See the class FileStatus for getting information
	  about	the indiviual files.

	  Supers: -
	  Kind:	Instantiable
	  Init:	DF :- new DirectoryFile("aDirectoryFilename") ;
	  Sequencing: (Open (NextEntry EntryName)* Close)*

     OPERATIONS
     Open
	     Boolean procedure Open;
	  Return True if the file is a directory and can be opened for
	  reading.
     Close
	     Boolean procedure Close;
	  Returns true if the file could be closed succesfully.

     NextEntry
	     Boolean procedure NextEntry;
	  Advances to the next entry in	the directory. Returns True if
	  there	was yet	another	entry and false	when there are no more
	  entries.

     Entryname
	     text procedure Entryname;
	  Returns  the	"filename"  of	the  current  Entry   in   the
	  directory.