Submit patches, bug reports, and enhancement requests via

			http://bugs.ntp.org

		  The ntp Distribution Base Directory

This directory and its subdirectories contain the Network Time Protocol
Version 4 (NTP) distribution for Unix and Windows/NT systems.  This release
may still work on VxWorks, too.

The contents of the base directory are given in this file. The contents of
subdirectories are given in the README files in each subdirectory.

A complete explanation of the configure, compile and install process, as
well as setting up an NTP subnet, is in the HTML pages in the ./html/
directory. For more information on NTP and how to get a working setup,
read WHERE-TO-START.

For Windows/NT, visit html/build/hints/winnt.html .

The base directory ./ contains the autoconfiguration files, source
directories and related stuff:

COPYRIGHT	Excerpt from the HTML file ./html/copyright.html. This file
		specifies copyright conditions, together with a list of
		major authors and electric addresses.

INSTALL		Generic installation instructions for autoconf-based programs.
		Unless you really know what you are doing, you should read the
		directions in the HTML pages, starting with ./html/index.html.

NEWS		What's new in this release.

README		This file.

README.bk	Instructions for folks who use the BitKeeper-repository
		version of NTP.

README.hackers	Notes to folks who want to hack on the code.

TODO            List of items the NTP developers are working on.

WHERE-TO-START	Hints on what to read in order to get a working
		configuration.

Makefile.am	Automake file configuration file. Edit only if you have the
		GNU automake and autoconf utilities installed.

Makefile.in	Autoconf make file template for Unix.

adjtimed        Directory containing the sources for the adjtime daemon
		for HP/UX systems prior to HP-UX 10.0.

authstuff       Directory containing sources for miscellaneous programs
		to test, calibrate and certify the cryptographic
		mechanisms for DES and MD5 based authentication. These
		programs do not include the cryptographic routines
		themselves, so are free of U.S. export restrictions.

build		A script to build the distribution in A.`config.guess`
		subdirectory (more or less).

clockstuff	Directory containing sources for miscellaneous programs
		to test certain auxiliary programs used with some kernel
		configurations, together with a program to calculate
		propagation delays for use with radio clocks and
		national time dissemination services such as WWV/WWVH,
		WWVB and CHU.

conf            Directory containing a motley collection of
		configuration files for various systems. For example only.

config.guess	Script used to identify the machine architecture and
		operating system.

config.h.in	Configuration file generated automatically from
		configure.in. Do not edit.

configure	Script used to configure the distribution. See the HTML pages
		(./html/index.html) for a complete description of the options
		available.

configure.in	Master configuration template. Edit only if you have the
		GNU automake and autoconf utilities installed.

dot.emacs	C-mode indentation rules for code "Just the way Dave likes it".

flock_build	(UDel only) Build the distribution on a number of
		different platforms.

html            Directory containing a complete set of documentation on
		building and configuring a NTP server or client. The
		documentation is in the form of HTML files suitable for
		browsing and contains links to additional documentation
		at various web sites. If a browser is unavailable, an
		ordinary text editor can be used.

include		Directory containing include header files used by most
		programs in the distribution.

install-sh	Script to install a program, script or data file.

kernel		Directory containing sources for kernel programs such as
		line disciplines and STREAMS modules used with the CHU
		decoder and precision PPS signals.

libntp		Directory containing library source code used by most
		programs in the distribution.

ntpdate		Directory containing sources for a program to set the
		local machine time from one or more remote machines
		running NTP.  Operates like rdate, but much more accurate.

ntpq            Directory containing sources for a utility program to
		query local and remote NTP peers for state variables and
		related timekeeping information. This program conforms
		to Appendix A of the NTP Version 3 Specification RFC 1305.

ntptrace        Directory containing sources for a utility program that
		can be used to reveal the chain of NTP peers from a
		designated peer to the primary server at the root of the
		timekeeping subnet.

parse		Directory containing files belonging to the generic
		parse reference clock driver. For reasonably simple
		clocks it is possible to get away with about 3-4Kb of
		code. additionally the SunOS 4.x/Solaris 5.3 streams
		module for parse squats here.

patches		Directory containing patches already applied to this
		distribution. These are included for record and to help
		in possible porting problems.

scripts		Directory containing scripts to build the configuration
		files in this directory and then the makefiles used in
		various dependent directories. the subdirectories
		monitoring and support hold various perl and shell
		scripts for visualizing synchronization and daemon startup.

stamp.h.in	Configuration file generated automatically from configure.in.
		Do not edit.

util            Directory containing sources for various utility and
		testing programs.

David L. Mills (mills@udel.edu)
21 June 1998

In order to use the BitKeeper repository version of NTP you should visit

 http://support.ntp.org/Main/SoftwareDevelopment

for important information.

If you want to submit patches, please see the README.hackers file.

Notes to hackers.

See README.patches for information about submitting patches.

---

Dave likes this code indented formatted in a consistent way.
The file "dot.emacs" has the emacs C-mode indentation style that Dave likes.

---

We'd like to see *all* system function declarations live in include/l_stdlib.h
and NEVER appear in the .c files.

---

Leap Second Smearing with NTP
-----------------------------

By Martin Burnicki
with some edits by Harlan Stenn

The NTP software protocol and its reference implementation, ntpd, were
originally designed to distribute UTC time over a network as accurately as
possible.

Unfortunately, leap seconds are scheduled to be inserted into or deleted
from the UTC time scale in irregular intervals to keep the UTC time scale
synchronized with the Earth rotation.  Deletions haven't happened, yet, but
insertions have happened over 30 times.

The problem is that POSIX requires 86400 seconds in a day, and there is no
prescribed way to handle leap seconds in POSIX.

Whenever a leap second is to be handled ntpd either:

- passes the leap second announcement down to the OS kernel (if the OS
supports this) and the kernel handles the leap second automatically, or

- applies the leap second correction itself.

NTP servers also pass a leap second warning flag down to their clients via
the normal NTP packet exchange, so clients also become aware of an
approaching leap second, and can handle the leap second appropriately.


The Problem on Unix-like Systems
--------------------------------
If a leap second is to be inserted then in most Unix-like systems the OS
kernel just steps the time back by 1 second at the beginning of the leap
second, so the last second of the UTC day is repeated and thus duplicate
timestamps can occur.

Unfortunately there are lots of applications which get confused it the
system time is stepped back, e.g. due to a leap second insertion.  Thus,
many users have been looking for ways to avoid this, and tried to introduce
workarounds which may work properly, or not.

So even though these Unix kernels normally can handle leap seconds, the way
they do this is not optimal for applications.

One good way to handle the leap second is to use ntp_gettime() instead of
the usual calls, because ntp_gettime() includes a "clock state" variable
that will actually tell you if the time you are receiving is OK or not, and
if it is OK, if the current second is an in-progress leap second.  But even
though this mechanism has been available for about 20 years' time, almost
nobody uses it.


NTP Client for Windows Contains a Workaround
--------------------------------------------
The Windows system time knows nothing about leap seconds, so for many years
the Windows port of ntpd provides a workaround where the system time is
slewed by the client to compensate the leap second.

Thus it is not required to use a smearing NTP server for Windows clients,
but of course the smearing server approach also works.


The Leap Smear Approach
-----------------------
Due to the reasons mentioned above some support for leap smearing has
recently been implemented in ntpd.  This means that to insert a leap second
an NTP server adds a certain increasing "smear" offset to the real UTC time
sent to its clients, so that after some predefined interval the leap second
offset is compensated.  The smear interval should be long enough,
e.g. several hours, so that NTP clients can easily follow the clock drift
caused by the smeared time.

During the period while the leap smear is being performed, ntpd will include
a specially-formatted 'refid' in time packets that contain "smeared" time.
This refid is of the form 254.x.y.z, where x.y.z are 24 encoded bits of the
smear value.

With this approach the time an NTP server sends to its clients still matches
UTC before the leap second, up to the beginning of the smear interval, and
again corresponds to UTC after the insertion of the leap second has
finished, at the end of the smear interval.  By examining the first byte of
the refid, one can also determine if the server is offering smeared time or
not.

Of course, clients which receive the "smeared" time from an NTP server don't
have to (and even must not) care about the leap second anymore.  Smearing is
just transparent to the clients, and the clients don't even notice there's a
leap second.


Pros and Cons of the Smearing Approach
--------------------------------------
The disadvantages of this approach are:

- During the smear interval the time provided by smearing NTP servers
differs significantly from UTC, and thus from the time provided by normal,
non-smearing NTP servers.  The difference can be up to 1 second, depending
on the smear algorithm.

- Since smeared time differs from true UTC, and many applications require
correct legal time (UTC), there may be legal consequences to using smeared
time.  Make sure you check to see if this requirement affects you.

However, for applications where it's only important that all computers have
the same time and a temporary offset of up to 1 s to UTC is acceptable, a
better approach may be to slew the time in a well defined way, over a
certain interval, which is what we call smearing the leap second.


The Motivation to Implement Leap Smearing
-----------------------------------------
Here is some historical background for ntpd, related to smearing/slewing
time.

Up to ntpd 4.2.4, if kernel support for leap seconds was either not
available or was not enabled, ntpd didn't care about the leap second at all.
So if ntpd was run with -x and thus kernel support wasn't used, ntpd saw a
sudden 1 s offset after the leap second and normally would have stepped the
time by -1 s a few minutes later.  However, 'ntpd -x' does not step the time
but "slews" the 1-second correction, which takes 33 minutes and 20 seconds
to complete.  This could be considered a bug, but certainly this was only an
accidental behavior.

However, as we learned in the discussion in http://bugs.ntp.org/2745, this
behavior was very much appreciated since indeed the time was never stepped
back, and even though the start of the slewing was somewhat undefined and
depended on the poll interval.  The system time was off by 1 second for
several minutes before slewing even started.

In ntpd 4.2.6 some code was added which let ntpd step the time at UTC
midnight to insert a leap second, if kernel support was not used.
Unfortunately this also happened if ntpd was started with -x, so the folks
who expected that the time was never stepped when ntpd was run with -x found
this wasn't true anymore, and again from the discussion in NTP bug 2745 we
learn that there were even some folks who patched ntpd to get the 4.2.4
behavior back.

In 4.2.8 the leap second code was rewritten and some enhancements were
introduced, but the resulting code still showed the behavior of 4.2.6,
i.e. ntpd with -x would still step the time.  This has only recently been
fixed in the current ntpd stable code, but this fix is only available with a
certain patch level of ntpd 4.2.8.

So a possible solution for users who were looking for a way to come over the
leap second without the time being stepped could have been to check the
version of ntpd installed on each of their systems.  If it's still 4.2.4 be
sure to start the client ntpd with -x.  If it's 4.2.6 or 4.2.8 it won't work
anyway except if you had a patched ntpd version instead of the original
version.  So you'd need to upgrade to the current -stable code to be able to
run ntpd with -x and get the desired result, so you'd still have the
requirement to check/update/configure every single machine in your network
that runs ntpd.

Google's leap smear approach is a very efficient solution for this, for
sites that do not require correct timestamps for legal purposes.  You just
have to take care that your NTP servers support leap smearing and configure
those few servers accordingly.  If the smear interval is long enough so that
NTP clients can follow the smeared time it doesn't matter at all which
version of ntpd is installed on a client machine, it just works, and it even
works around kernel bugs due to the leap second.

Since all clients follow the same smeared time the time difference between
the clients during the smear interval is as small as possible, compared to
the -x approach.  The current leap second code in ntpd determines the point
in system time when the leap second is to be inserted, and given a
particular smear interval it's easy to determine the start point of the
smearing, and the smearing is finished when the leap second ends, i.e. the
next UTC day begins.

The maximum error doesn't exceed what you'd get with the old smearing caused
by -x in ntpd 4.2.4, so if users could accept the old behavior they would
even accept the smearing at the server side.

In order to affect the local timekeeping as little as possible the leap
smear support currently implemented in ntpd does not affect the internal
system time at all.  Only the timestamps and refid in outgoing reply packets
*to clients* are modified by the smear offset, so this makes sure the basic
functionality of ntpd is not accidentally broken.  Also peer packets
exchanged with other NTP servers are based on the real UTC system time and
the normal refid, as usual.

The leap smear implementation is optionally available in ntp-4.2.8p3 and
later, and the changes can be tracked via http://bugs.ntp.org/2855.


Using NTP's Leap Second Smearing
--------------------------------
- Leap Second Smearing MUST NOT be used for public servers, e.g. servers
provided by metrology institutes, or servers participating in the NTP pool
project.  There would be a high risk that NTP clients get the time from a
mixture of smearing and non-smearing NTP servers which could result in
undefined client behavior.  Instead, leap second smearing should only be
configured on time servers providing dedicated clients with time, if all
those clients can accept smeared time.

- Leap Second Smearing is NOT configured by default.  The only way to get
this behavior is to invoke the ./configure script from the NTP source code
package with the --enable-leap-smear parameter before the executables are
built.

- Even if ntpd has been compiled to enable leap smearing support, leap
smearing is only done if explicitly configured.

- The leap smear interval should be at least several hours' long, and up to
1 day (86400s).  If the interval is too short then the applied smear offset
is applied too quickly for clients to follow.  86400s (1 day) is a good
choice.

- If several NTP servers are set up for leap smearing then the *same* smear
interval should be configured on each server.

- Smearing NTP servers DO NOT send a leap second warning flag to client time
requests.  Since the leap second is applied gradually the clients don't even
notice there's a leap second being inserted, and thus there will be no log
message or similar related to the leap second be visible on the clients.

- Since clients don't (and must not) become aware of the leap second at all,
clients getting the time from a smearing NTP server MUST NOT be configured
to use a leap second file.  If they had a leap second file they would apply
the leap second twice: the smeared one from the server, plus another one
inserted by themselves due to the leap second file.  As a result, the
additional correction would soon be detected and corrected/adjusted.

- Clients MUST NOT be configured to poll both smearing and non-smearing NTP
servers at the same time.  During the smear interval they would get
different times from different servers and wouldn't know which server(s) to
accept.


Setting Up A Smearing NTP Server
--------------------------------
If an NTP server should perform leap smearing then the leap smear interval
(in seconds) needs to be specified in the NTP configuration file ntp.conf,
e.g.:

 leapsmearinterval 86400

Please keep in mind the leap smear interval should be between several and 24
hours' long.  With shorter values clients may not be able to follow the
drift caused by the smeared time, and with longer values the discrepancy
between system time and UTC will cause more problems when reconciling
timestamp differences.

When ntpd starts and a smear interval has been specified then a log message
is generated, e.g.:

 ntpd[31120]: config: leap smear interval 86400 s

While ntpd is running with a leap smear interval specified the command:

 ntpq -c rv

reports the smear status, e.g.:

# ntpq -c rv
associd=0 status=4419 leap_add_sec, sync_uhf_radio, 1 event, leap_armed,
version="ntpd 4.2.8p3-RC1@1.3349-o Mon Jun 22 14:24:09 UTC 2015 (26)",
processor="i586", system="Linux/3.7.1", leap=01, stratum=1,
precision=-18, rootdelay=0.000, rootdisp=1.075, refid=MRS,
reftime=d93dab96.09666671 Tue, Jun 30 2015 23:58:14.036,
clock=d93dab9b.3386a8d5 Tue, Jun 30 2015 23:58:19.201, peer=2335,
tc=3, mintc=3, offset=-0.097015, frequency=44.627, sys_jitter=0.003815,
clk_jitter=0.451, clk_wander=0.035, tai=35, leapsec=201507010000,
expire=201512280000, leapsmearinterval=86400, leapsmearoffset=-932.087

In the example above 'leapsmearinterval' reports the configured leap smear
interval all the time, while the 'leapsmearoffset' value is 0 outside the
interval and increases from 0 to -1000 ms over the interval.  So this can be
used to monitor if and how the time sent to clients is smeared.  With a
leapsmearoffset of -.932087, the refid reported in smeared packets would be
254.196.88.176.

See README.hackers for notes on coding styles.

The master copy of this information can be found at:

 http://support.ntp.org/Dev/MaintainerIssues#How_to_work_on_a_bug_using_BitKe

If you are going to patch both ntp-stable and ntp-dev
please do it this way:

 > cd ntp-stable
 > (make and test your changes to ntp-stable first)
 > (commit your changes to ntp-stable)
 > cd ../ntp-dev
 > bk pull ../ntp-stable	(get your changes from ntp-stable)
 > (resolve any problems and test your changes)
 > (commit your changes to ntp-dev)

With the current release of bitkeeper it is *much* easier to move changes
from ntp-stable to ntp-dev than it is to move changes from ntp-dev to
ntp-stable.

If you make your changes in the above order and then submit them,
it will be trivial to apply your patches.

Otherwise, it will be much more difficult to apply your patches.

You are pretty much done now if your repos are on pogo.udel.edu.

If these patches are for a bugzilla issue, mark the issue as Resolved/READY
with a comment of "Please pick up the patches in pogo:/wherever"

---

Please read (and follow) the previous section if you want to submit
patches for both ntp-stable and ntp-dev.

If you cannot easily get your patches to pogo, you may submit patches
via the 'bk send' command:

 > cd REPO
 > bk citool	(or bk ci ... ;  bk commit ... )
 > bk pull	# make sure your repo is up-to-date
 > bk send -d -ubk://www.ntp.org/home/bk/REPO - > file-containing-the-patch
 > bk receive -vv -a < file-containing-the-patch
		# Sanity check.

 # Open a bugzilla item at <http://bugzilla.ntp.org>

 # After the bug is opened, visit the bug and attach file-containing-the-patch

See README.hackers for notes on coding styles.

The NTP project's github repository is at https://github.com/ntp-project/ntp.

There are two branches, master and stable.

The stable branch is the current supported production code branch, the
ntp-stable code (even 2nd number).

The master branch is for new development, also known as ntp-dev (which
has an odd 2nd number).

If you have some work you'd like to add, then if there is any interest
in seeing that work in the current production release then base your work
on the stable branch, and pull your work into a master copy to allow for
publishing your changes in the ntp-dev or master branch.

If there is no expectation that your work will be included in the
current stable release (the ntp-stable code) then it's better to do your
work on a copy of the master branch.

Make sure that any changes you make to stable pull cleanly into master.

It's possible that after pulling your changes from stable to master that
some additional cleanup will be required in master.  Please do this.

If you follow this method, then if you submit a pull request for either
master or for master+stable, it will be easy for us to evaluate and
incorporate your work.

Please also note that your submissions will be able to be evaluated and
handled sooner if the repo that contains your pull requests also includes
test cases.

The general workflow is as follows:

1) If you haven't, create a fork of ntp-project/ntp with your github account.
   i) Log on to github.com with your github account.
       - If you don't have one, create one first. (read: https://help.github.com/articles/signing-up-for-a-new-github-account)
       - Make sure you also have a SSH key associated with your github account.
         (read: https://help.github.com/articles/generating-ssh-keys/)
   ii) Go to https://github.com/ntp-project/ntp
   iii) On the top right corner, right below the header bar, there is
        a button labeled "Fork".  Click on it.  This will fork the current
	ntp master to your own account. Once done, it will go to your account's
	version of the ntp repository. (Your fork of ntp source)
   iv) Clone a local version of your fork.
        - git clone git@github.com:<your_username>/ntp

2) Look through the bugs listed in the bug tracker: http://bugs.ntp.org/

3) Once you've found a bug to work on:

   i) Create a branch off your own master branch of your local fork.
      (the <branchname> can be any valid short string that will tell you
       what you're working on)
      - git checkout -b <branchname>

   ii) Start working on the bug.
   iii) When you create changes in the source, it would help you to
        keep track of your changes by committing to your local repo.
	(This way, every small change is tracked and when you've
	 made a mistake, you can always go back.)
	 - git commit -a -m "description of change"
   iv) Once you are satisfied, you can push to your github account's
       repository.
         - git push origin <branchname>
    v) (go to step iii).

4) Once you feel you've fixed the bug (and tested it), you need to
   create a pull request on your branch on github.  (Read up on
   pull requests @ https://help.github.com/articles/using-pull-requests)

    i) Create your pullrequest by following the instructions @
       https://help.github.com/articles/creating-a-pull-request/

5) Your pull request will be reviewed by committers and when it
   passes review, it will be merged by the reviewer/allowed committer.

6) You have fixed a bug.  Goto step #2.

If these patches are for a bugzilla issue, mark the issue as Resolved/READY
with a comment of "Please pick up the patches from XXX" where XXX is
something like:

 hostname:~user/path	if it's a machine the reviewers have access to, or
 github-pull-request-URI

---

This is a list of the #define REFCLK_* stuff.

If you want to add a new refclock let us know and we'll assign you a number.

Should this list also include the name of the party responsible for the
refclock?

LOCALCLOCK	1	/* external (e.g., lockclock) */
GPS_TRAK	2	/* TRAK 8810 GPS Receiver */
WWV_PST		3	/* PST/Traconex 1020 WWV/H */
SPECTRACOM	4	/* Spectracom (generic) Receivers */
TRUETIME	5	/* TrueTime (generic) Receivers */
IRIG_AUDIO	6	/* IRIG-B/W audio decoder */
CHU_AUDIO	7	/* CHU audio demodulator/decoder */
PARSE		8	/* generic driver (usually DCF77,GPS,MSF) */
GPS_MX4200	9	/* Magnavox MX4200 GPS */
GPS_AS2201	10	/* Austron 2201A GPS */
GPS_ARBITER	11	/* Arbiter 1088A/B/ GPS */
IRIG_TPRO	12	/* KSI/Odetics TPRO-S IRIG */
ATOM_LEITCH	13	/* Leitch CSD 5300 Master Clock */
MSF_EES		14	/* EES M201 MSF Receiver */
GPSTM_TRUE	15	/* OLD TrueTime GPS/TM-TMD Receiver */
IRIG_BANCOMM	16	/* Bancomm GPS/IRIG Interface */
GPS_DATUM	17	/* Datum Programmable Time System */
NIST_ACTS	18	/* NIST Auto Computer Time Service */
WWV_HEATH	19	/* Heath GC1000 WWV/WWVH Receiver */
GPS_NMEA	20	/* NMEA based GPS clock */
GPS_VME		21	/* TrueTime GPS-VME Interface */
ATOM_PPS	22	/* 1-PPS Clock Discipline */
PTB_ACTS	NIST_ACTS
USNO		NIST_ACTS
GPS_HP		26	/* HP 58503A Time/Frequency Receiver */
ARCRON_MSF	27	/* ARCRON MSF radio clock. */
SHM		28	/* clock attached thru shared memory */
PALISADE	29	/* Trimble Navigation Palisade GPS */
ONCORE		30	/* Motorola UT Oncore GPS */
GPS_JUPITER	31	/* Rockwell Jupiter GPS receiver */
CHRONOLOG	32	/* Chrono-log K WWVB receiver */
DUMBCLOCK	33	/* Dumb localtime clock */
ULINK		34	/* Ultralink M320 WWVB receiver */
PCF		35	/* Conrad parallel port radio clock */
WWV_AUDIO	36	/* WWV/H audio demodulator/decoder */
FG		37	/* Forum Graphic GPS */
HOPF_SERIAL	38	/* hopf DCF77/GPS serial line receiver */
HOPF_PCI	39	/* hopf DCF77/GPS PCI receiver */
JJY		40	/* JJY receiver */
TT560		41	/* TrueTime 560 IRIG-B decoder */
ZYFER		42	/* Zyfer GPStarplus receiver */
RIPENCC		43	/* RIPE NCC Trimble driver */
???????		44	Claas Hilbrecht (20020711)

NTP uses A.B.C - style release numbers.

At the moment:

 A is 4, for ntp V4.
 B is the major release number.
 C is the minor release number.  Even numbers are 'stable' releases and
 odd numbers are "development" releases.

Following the release number may be the letter 'p' followed by a number.
This indicates a point (or patch) release.

Release candidates have -RC in the release number.

Here are some recent versions numbers as an example:

 4.2.2		A production release (from the ntp-stable repository)
 4.2.2p2	A production release (from the ntp-stable repository)
 4.2.3p12	A development release
 4.2.3p15-rc1	A release candidate for 4.2.4

Note that after the ntp-dev repo produces a production release it will
be copied into the ntp-stable and the cycle will repeat.

Feel free to suggest improvements...

AT&T Freeware Year 2000 Certification
====================================

This is the "readme" file for the freeware application which has
been certified by AT&T Labs as part of the "Freeware Y2K
Certification Project".

DISCLAIMER
----------
    For its own internal business purposes AT&T Labs has
    assessed various programs obtained from the Internet for
    Year-2000 (Y2K) readiness that were not sufficiently certified
    for AT&T's needs.  As a service to the computing community
    AT&T Labs is freely releasing this information to the
    public as a series of "Y2K Application Updates", one update
    for what AT&T Labs considers an "application".

    For use outside of AT&T, AT&T Labs is not certifying this
    information is correct, that any software, including repairs
    and tests, will help others in any way, survive the year
    2000, nor work with current applications. Nor is AT&T
    taking any responsibility for repairing any Y2K problems
    that were overlooked nor repairing any bugs in any
    "Y2K Application Update". All risk of using this Y2K
    Application Update remains with the user who is expected
    to test that this update meets their needs.

    LICENSE TO USE
    AT&T's intent is to ensure these Y2K patches are freely
    available to the public but will not maintain a public web site
    for their distribution. Any copyright claims only only apply to
    the specific changes made by Y2K to the code. Any original
    copyright holders retain rights to unchanged code. Wherever
    possible patches will be returned to the current owner(s) of the code.

    Owners and publishers are free to incorporate appropriate patches,
    upgrades, and tests within legal future distributions as long as
    they include the credit:

      Various Y2K updates and tests provided by AT&T Labs.
      Copyright 1999 AT&T.

    and any AT&T "comments" on the changed code remain intact.

    Any distributions of the updates must keep the entire update
    intact, without any change, including copyright and disclaimer
    information.  If integrated with the original application items
    not needed for an integrated release may be omitted. When
    distributed on the same media as the original application there
    must be no charge for this "Y2k Application Update".

    CONTACTS
    If you find any overlooked Y2K problems, or have other strictly Y2K
    repairs for the software, please E-mail:

            y2k@y2k.labs.att.com

    This address is strictly reserved for the topic at hand.
    AT&T makes no commitments to answer any E-mail
    to this address.  AT&T is free to use any submissions,
    including publishing in future Y2K related release notes,
    without payment or advance notice to the submitting person or
    persons... appropriate credit will be given in any future
    publications to the first person submitting something that
    AT&T uses.


======================================================================

Perl  ver - 4.036
No. of Repairs: 2 Repairs
Compilation of Patches Required: No
OS Tested: Solaris 2.6

======================================================================

ORGANIZATION OF THE "Y2KFixes" DIRECTORY

The "Y2KFixes" directory has been included in the archive to give
you information about the Y2K testing that was conducted and their
results.

The Y2KFixes directory contains at least the following three files:
|----> NOTES.y2kfixes    -- Technical details about the Y2K Testing
|----> Readme.y2kfixes   -- this Readme file
|----> Results.y2kfixes  -- The results of Y2K Environment Tests

The directory may contain additional files and/or directories, as
appropriate to the application, to provide the exact snapshots.


======================================================================

INSTALLING THE "PATCHES"

If you have downloaded a "patch", then you may install it as follows:

    At the same level as the source directory, invoke:

	patch -p < *.patches

The patch file contains a header which has a manifest of changed files.

======================================================================

ADDITIONAL INSTRUCTIONS:


1) Extract the patches into perl-4.036 directory which is top level directory
   for the perl4 source.

2) cd to Y2KFixes.

3) It will have y2k directory which contains regression tests for Y2K testing.

4) now cd to ../t which contains TEST file for running this regression tests.

5) run TEST, see the results  & apply patches.

6) Once you apply the patch, you need to run a shell script in x2p/find2perl.SH
   which will generate find2perl.


======================================================================

SUPPORT

See http://y2k.labs.att.com/freeware.  There will be no ongoing
support for the project. But if you have some very important issue,
you may email us at: y2k@y2k.labs.att.com