Browse Prior Art Database

Push And Pop Subdirectory Commands

IP.com Disclosure Number: IPCOM000102110D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 3 page(s) / 101K

Publishing Venue

IBM

Related People

Normington, G: AUTHOR

Abstract

Two operating system commands for manipulating subdirectories on a directory-structured data storage device are disclosed. Although the commands are applicable to any data storage system having a tree-structured set of subdirectories stemming from a root directory, they relate in particular to subdirectory structures on write-once-read-many ("WORM") devices such as optical disk drives.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Push And Pop Subdirectory Commands

       Two operating system commands for manipulating
subdirectories on a directory-structured data storage device are
disclosed.  Although the commands are applicable to any data storage
system having a tree-structured set of subdirectories stemming from a
root directory, they relate in particular to subdirectory structures
on write-once-read-many ("WORM") devices such as optical disk drives.

      It is common for stored data records to be organized into a
hierarchical directory structure under the control of an operating
system.  An example of such a directory structure is that used by the
DOS operating system in which a master directory, known as the root
directory, has a tree structured of subdirectories beneath it.  A
simple structure is shown in the accompanying figure.  In the figure,
the root directory is shown by the abbreviation " ", and a
subdirectory of root is shown as " subdirectory_name ".  In the
example shown, root has the subdirectory " text ".  A third level of
the tree structure is shown: text  has two further subdirectories
denoted by " text letters " and " text reports ".

      It is often possible for a user to define a present working
directory ("pwd").  This is the default subdirectory name which will
be assumed by the operating system if a particular command does not
specify a subdirectory.

      The two operating system commands to be described will be
referred to as the "push" and "pop" commands.  However, it will be
appreciated that the function of the commands is more important than
the particular choice of command names or syntax used in this
description.

      Push Command
a)   If the present working directory is root,  , then the command
"push new_name" will cause  new_name to be appended to the front of
all existing directory and subdirectory names, and a new root
directory to be created.  For example, if the pwd is root in the
structure shown in the figure, the command "push backup" will result
in the new set of directories  ,  backup ,  backup text ,  backup
text letters , and backup text reports .
b)   If the pwd is not root, but ends in  new_name , then the command
"push new_name" simply changes the pwd to the parent directory of the
current pwd.  For example if, in the figure, the pwd is  text letters
, then the command "push letters" will change the pwd to  text .
c)   If the pwd is not root, and the pwd does not end in new_name
, then the com...