Preface to the Fourth (2002) Edition
Plan 9 continues to grow and adapt.
The fourth major release of the system
incorporates a number of changes, but the most central
is the conversion to a new version of the 9P file system
This new version was motivated by a desire to support
files with name elements longer than 27 bytes (the old
but the opportunity was taken to change a number of other things
about the protocol,
making it more efficient, more flexible, and easier to encapsulate.
One simple but indispensable new feature made possible by the protocol
change is that the system now records the user who last modified a file;
to identify the culprit.
Many aspects of system security have been improved.
The new security agent
maintains user passwords, while
keeps them safe and enables single sign-on to multiple domains and machines
using a variety of secure protocols and services.
Throughout the system, components have been rewritten and interfaces
modified to eliminate restrictions, improve performance, and clarify design.
The full list is too long to include here, but significant changes have occurred
in a number of system calls
the thread library
(many pages in section 2, including
and many others.
The changes are sweeping and are accompanied by many new programs, tools,
See the manual pages and the accompanying documents for more information.
Computing Science Research Center
Murray Hill NJ
Copyright © 2002 Lucent Technologies Inc. All rights reserved.