GNU `shar' utilities
********************

This manual documents version 4.6.2 of the GNU shar utilities.

Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
2003, 2004, 2005 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.1 or any later version published by the Free Software
     Foundation; with no Invariant Sections, with no Front-Cover
     Texts, and with no Back-Cover Texts.  A copy of the license is
     included in the section entitled "GNU Free Documentation
     License".

GNU `shar' makes so-called shell archives out of many files,
preparing them for transmission by electronic mail services, while
`unshar' helps unpacking shell archives after reception.  Other tools
help using `shar' with the electronic mail system, and even allow
synchronization of remote directory trees.  This is release 4.6.2.

1 Introduction to this toolset
******************************

GNU `uuencode' and `uudecode' have an history which roots are lost in
ages, and we will not even try to trace it.  The current versions
were brought into GNU by Ian Lance Taylor, and later modernized by
Ulrich Drepper.  GNU `shar' surely has a long history, too.  All
along this long road, numerous users contributed various
improvements.  The file `THANKS' in the distribution, as far as we
know, contain the names of all contributors we could identify, and
for which email addresses are seemingly valid.

Please help us getting the history straight, for the following
information is somewhat approximative.  James Gosling wrote the
public domain `shar 1.x'.  William Davidsen rewrote it as `shar 2.x'.
Warren Tucker implemented modifications and called it `shar 3.x'.
Richard Gumpertz maintained it until 1990.  Franc,ois Pinard, from
the public domain `shar 3.49', made `GNU shar 4.x', in 1994.  Some
modules and other code sections were freely borrowed from other GNU
distributions, bringing this `shar' under the terms of the GNU
General Public License.

The few wrapper scripts and the `remsync' program have been
contributed more recently by Franc,ois Pinard, just as an attempt for
making this GNU `sharutils' toolset more useful.

Your feedback helps us to make a better and more portable product.
Mail suggestions and bug reports (including documentation errors) for
these programs to `bug-gnu-utils@prep.ai.mit.edu'.

2 The basic `shar' utilities
****************************

GNU `shar' makes so-called shell archives out of many files,
preparing them for transmission by electronic mail services.  A
"shell archive" is a collection of files that can be unpacked by
`/bin/sh'.  A wide range of features provide extensive flexibility in
manufacturing shars and in specifying shar _smartness_.  For example,
`shar' may compress files, uuencode binary files, split long files
and construct multi-part mailings, ensure correct unsharing order,
and provide simplistic checksums.  *Note shar invocation::.

GNU `unshar' scans a set of mail messages looking for the start of
shell archives.  It will automatically strip off the mail headers and
other introductory text.  The archive bodies are then unpacked by a
copy of the shell.  `unshar' may also process files containing
concatenated shell archives.  *Note unshar invocation::.

2.1 Invoking the `shar' program
===============================

The format of the `shar' command is one of:

     shar [ OPTION ] ... FILE ...
     shar -S [ OPTION ] ...

In the first form, the file list is given as command arguments.  In
the second form, the file list is read from standard input.  The
resulting archive is sent to standard output unless the `-o' option
is given.

Options can be given in any order.  Some options depend on each other:
the `-o' option is required if the `-l' or `-L' option is used.  The
`-n' option is required if the `-a' option is used.  Also see `-V'
below.

Some options are special purpose:

`--help'
     Print a help summary on standard output, then immediately exits.

`--version'
     Print the version number of the program on standard output, then
     immediately exits.

`-q'
`--quiet'
     Verbose _off_ at `shar' time.  Messages are usually issued on
     standard error to let the user follow the progress, while making
     the archives.  This option inhibits these messages.


2.1.1 Selecting files
---------------------

`-p'
`--intermix-type'
     Allow positional parameter options.  The options `-M', `-B',
     `-T', `-z' and `-Z' may be embedded, and files to the right of
     the option will be processed in the specified mode.  Without the
     `-p' option, embedded options would be interpreted as file names.
     *Note Stocking::.

`-S'
`--stdin-file-list'
     Read list of files to be packed from the standard input rather
     than from the command line.  Input must be one file name per
     line.  This switch is especially useful when the command line
     will not hold the list of files to be packed.  For example:

          find . -type f -print | \
            shar -S -o /somewhere/big.shar

     If `-p' is specified on the command line, then the options `-M',
     `-B', `-T', `-z' and `-Z' may be included in the standard input
     (on a line separate from file names).  The maximum number of
     lines of standard input, file names and options, may not exceed
     1024.


2.1.2 Splitting output
----------------------

`-o PREFIX'
`--output-prefix=PREFIX'
     Save the archive to files `PREFIX.01' through `PREFIX.NNN'
     instead of standard output.  This option _must_ be used when the
     `-l' or the `-L' switches are used.

     When PREFIX contains any `%' character, PREFIX is then
     interpreted as a `sprintf' format, which should be able to
     display a single decimal number.  When PREFIX does not contain
     such a `%' character, the string `.%02d' is internally appended.

`-l SIZE'
`--whole-size-limit=SIZE'
     Limit the output file size to SIZE times 1024 bytes but don't
     split input files.  This allows the recipient of the shell
     archives to unpack them in any order.

`-L SIZE'
`--split-size-limit=SIZE'
     Limit output file size to SIZE times 1024 bytes and split files
     if necessary.  The archives created with this option must be
     unpacked in the correct order.  If the recipient of the shell
     archives wants to put all of them in a single folder, she shall
     save them in the correct order for `unshar', used with option
     `-e', to unpack them all at once.  *Note unshar invocation::.

     For people used to saving all the shell archives into a single
     mail folder, care must be taken to save them in the appropriate
     order.  For those having the appropriate tools (like Masanobu
     Umeda's `rmailsort' package for GNU Emacs), shell archives can
     be saved in any order, then sorted by increasing date (or send
     time) before massive unpacking.


2.1.3 Controlling the shar headers
----------------------------------

`-n NAME'
`--archive-name=NAME'
     Name of archive to be included in the header of the shar files.
     Also see the `-a' switch further down.

`-s ADDRESS'
`--submitter=ADDRESS'
     The `-s' option allows for overriding the email address for the
     submitter, for when the default is not appropriate.  The
     automatically determined address looks like `USERNAME@HOSTNAME'.

`-a'
`--net-headers'
     Allows automatic generation of headers:

          Submitted-by: ADDRESS
          Archive-name: NAME/partNN

     The NAME must be given with the `-n' switch.  If name includes a
     `/', then `/part' isn't used. Thus `-n xyzzy' produces:
          xyzzy/part01
          xyzzy/part02

     while `-n xyzzy/patch' produces:
          xyzzy/patch01
          xyzzy/patch02

     and `-n xyzzy/patch01.' produces:
          xyzzy/patch01.01
          xyzzy/patch01.02

`-c'
`--cut-mark'
     Start the shar with a cut line.  A line saying `Cut here' is
     placed at the start of each output file.

`-t'
`--translate'
     Translate messages in the script.  If you have set the `LANG'
     environment variable, messages printed by `shar' will be in the
     specified language.  The produced script will still be emitted
     using messages in the lingua franca of the computer world:
     English.  This option will cause the script messages to appear
     in the languages specified by the `LANG' environment variable
     set when the script is produced.


2.1.4 Selecting how files are stocked
-------------------------------------

`-T'
`--text-files'
     Treat all files as text, regardless of their contents.

`-B'
`--uuencode'
     Treat all files as binary, use `uuencode' prior to packing. This
     increases the size of the archive. The recipient must have
     `uudecode' in order to unpack.

          Use of `uuencode' is not appreciated by many on the net, because
          people like to readily see, by mere inspection of a shell archive,
          what it is about.

`-M'
`--mixed-uuencode'
     Mixed mode.  Automatically determine if the files are text or
     binary and archive correctly.  Files found to be binary are
     uuencoded prior to packing.  This option is selected by default.

     For a file is considered to be a text file, instead of a binary
     file, all the following should be true simultaneously:
       1. The file does not contain any ASCII control character
          besides <BS> (backspace), <HT> (horizontal tab), <LF> (new
          line) or <FF> (form feed).

       2. The file does not contains a <DEL> (delete).

       3. The file contains no character with its eighth-bit set.

       4. The file, unless totally empty, terminates with a <LF>
          (newline).

       5. No line in the file contains more than 200 characters.  For
          counting purpose, lines are separated by a <LF> (newline).

`-z'
`--gzip'
     Use `gzip' and `uuencode' on all files prior to packing.  The
     recipient must have `uudecode' and `gzip' (used with `-d') in
     order to unpack.

     Usage of `-z' in net shars will cause you to be flamed off the
     earth.

`-g LEVEL'
`--level-for-gzip=LEVEL'
     When doing compression, use `-LEVEL' as a parameter to `gzip'.
     The `-g' option turns on the `-z' option by default.  The
     default value is 9, that is, maximum compression.

`-j'
`--bzip2'
     Use `bzip2' and `uuencode' on all files prior to packing.  The
     recipient must have `uudecode' and `bzip2' (used with `-d') in
     order to unpack.

     Usage of `-j' in net shars will cause you to be flamed off to
     hell.

`-Z'
`--compress'
     Use `compress' and `uuencode' on all files prior to packing.
     The recipient must have `uudecode' and `compress' (used with
     `-d') in order to unpack.  Option `-C' is a synonymous for `-Z',
     but is deprecated.

     Usage of `-Z' in net shars will cause you to be flamed off the
     earth.

`-b BITS'
`--bits-per-code=BITS'
     When doing compression, use `-bX' as a parameter to `compress'.
     The `-b' option turns on the `-Z' option by default.  The
     default value is 12, foreseeing the memory limitations of some
     `compress' programs on smallish systems, at `unshar' time.


2.1.5 Protecting against transmission errors
--------------------------------------------

Transmission of shell archives is not always free of errors.  So one
should make consistency checks on the receiving site.  A very simple
(and unreliable) method is running the UNIX `wc' tool on the output
file.  This can report the number of characters in the file.

As one can guess this does not catch all errors.  Especially changing
of a character value does not change the computed check sum.  To
achieve this goal better method were invented and standardized.  One
very strong is MD5 (MD = message digests).  This is standardized in
RFC 1321.  The produced shell scripts do not force the `md5sum'
program to be installed on the system.  This is necessary because it
is not yet part of every UNIX.  The program is however not necessary
for producing the shell archive.

`-w'
`--no-character-count'
     Do _not_ check with `wc -c' after unpack.  The default is to
     check.

`-D'
`--no-md5-digest'
     Do _not_ check with `md5sum' after unpack.  The default is to
     check.

`-F'
`--force-prefix'
     Prepend the prefix character to every line even if not required.
     This option may slightly increase the size of the archive,
     especially if `-B' or `-Z' is used.  Normally, the prefix
     character is `X'.  If the parameter to the `-d' option starts
     with `X', then the prefix character becomes `Y'.

`-d STRING'
`--here-delimiter=STRING'
     Use STRING to delimit the files in the shar instead of
     `SHAR_EOF'.  This is for those who want to personalize their
     shar files.


2.1.6 Producing different kinds of shars
----------------------------------------

`-V'
`--vanilla-operation'
     This option produces "vanilla" shars which rely only upon the
     existence of `echo', `test' and `sed' in the unpacking
     environment.

     The `-V' disables options offensive to the "network cop" (or
     "brown shirt").  It also changes the default from mixed mode
     `-M' to text mode `-T'.  Warnings are produced if option `-B',
     `-z', `-j', `-Z', `-p' or `-M' is specified (any of which does
     or might require `uudecode', `gzip', `bzip2' or `compress' in
     the unpacking environment).

`-P'
`--no-piping'
     In the shar file, use a temporary file to hold the file to
     `uudecode', instead of using pipes.  This option is mandatory
     when you know the unpacking `uudecode' is unwilling to merely
     read its standard input.  Richard Marks wrote what is certainly
     the most (in)famous of these, for MSDOS :-).

     (Here is a side note from the maintainer.  Why isnt't this option
     the default?  In the past history of `shar', it was decided that
     piping was better, surely because it is less demanding on disk
     space, and people seem to be happy with this.  Besides, I think
     that the `uudecode' from Richard Marks, on MSDOS, is wrong in
     refusing to handle `stdin'.  So far that I remember, he has the
     strong opinion that a program without any parameters should give
     its `--help' output.  Besides that, should I say, his `uuencode'
     and `uudecode' programs are full-featured, one of the most
     complete set I ever saw.  But Richard will not release his
     sources, he wants to stay in control.)

`-x'
`--no-check-existing'
     Overwrite existing files without checking.  If neither `-x' nor
     `-X' is specified, when unpacking itself, the shell archive will
     check for and not overwrite existing files (unless `-c' is passed
     as a parameter to the script when unpacking).

`-X'
`--query-user'
     Interactively overwrite existing files.

     Use of `-X' produces shars which _will_ cause problems with some
     `unshar'-style procedures, particularily when used together with
     vanilla mode (`-V').  Use this feature mainly for archives to be
     passed among agreeable parties.  Certainly, `-X' is _not_ for
     shell archives which are to be submitted to Usenet or other
     public networks.

     The problem is that `unshar' programs or procedures often feed
     `/bin/sh' from its standard input, thus putting `/bin/sh' and
     the shell archive script in competition for input lines.  As an
     attempt to alleviate this problem, `shar' will try to detect if
     `/dev/tty' exists at the receiving site and will use it to read
     user replies.  But this does not work in all cases, it may
     happen that the receiving user will have to avoid using `unshar'
     programs or procedures, and call `/bin/sh' directly.  In vanilla
     mode, using `/dev/tty' is not even attempted.

`-m'
`--no-timestamp'
     Avoid generating `touch' commands to restore the file
     modification dates when unpacking files from the archive.

     When the timestamp relationship is not preserved, some files like
     `configure' or `*.info' may be uselessly remade after unpacking.
     This is why, when this option is not used, a special effort is
     made to restore timestamps,

`-Q'
`--quiet-unshar'
     Verbose _off_ at `unshar' time.  Disables the inclusion of
     comments to be output when the archive is unpacked.

`-f'
`--basename'
     Use only the last file name component of each input file name,
     ignoring any prefix directories.  This is sometimes useful when
     building a shar from several directories, or another directory.
     If a directory name is passed to `shar', the substructure of
     that directory will be restored whether `-f' is specified or not.


2.2 Invoking the `unshar' program
=================================

The format of the `unshar' command is:

     unshar [ OPTION ] ... [ FILE ... ]

Each FILE is processed in turn, as a shell archive or a collection of
shell archives.  If no files are given, then standard input is
processed instead.

Options:

`--version'
     Print the version number of the program on standard output, then
     immediately exits.

`--help'
     Print an help summary on standard output, then immediately exits.

`-d DIRECTORY'
`--directory=DIRECTORY'
     Change directory to DIRECTORY before unpacking any files.

`-c'
`--overwrite'

`-f'
`--force'
     Passed as an option to the shar file.  Many shell archive scripts
     (including those produced by `shar' 3.40 and newer) accepts a
     `-c' argument to indicate that existing files should be
     overwritten.

     The option `-f' is provided for a more unique interface.  Many
     programs (such as `cp' and `mv') use this option to trigger the
     very same action.

`-e'
`--exit-0'
     This option exists mainly for people who collect many shell
     archives into a single mail folder.  With this option, `unshar'
     isolates each different shell archive from the others which have
     been put in the same file, unpacking each in turn, from the
     beginning of the file towards its end.  Its proper operation
     relies on the fact that many shar files are terminated by a
     `exit 0' at the beginning of a line.

     Option `-e' is internally equivalent to `-E "exit 0"'.

`-E STRING'
`--split-at=STRING'
     This option works like `-e', but it allows you to specify the
     string that separates archives if `exit 0' isn't appropriate.

     For example, noticing that most `.signatures' have a `--' on a
     line right before them, one can sometimes use `--split-at=--'
     for splitting shell archives which lack the `exit 0' line at end.
     The signature will then be skipped altogether with the headers of
     the following message.


2.3 Miscellaneous considerations
================================

Here is a place-holder for many considerations which do not fit
elsewhere, while not worth a section for themselves.

Be careful that the output file(s) are not included in the inputs or
`shar' may loop until the disk fills up.  Be particularly careful
when a directory is passed to `shar' that the output files are not in
that directory (or a subdirectory of that directory).

When a directory is passed to `shar', it may be scanned more than
once, to conserve memory.  Therefore, one should be careful to not
change the directory contents while `shar' is running.

No attempt is made to restore the protection and modification dates
for directories, even if this is done by default for files.  Thus, if
a directory is given to `shar', the protection and modification dates
of corresponding unpacked directory may not match those of the
original.

Use of the `-M' or `-B' options will slow down the archive process.
Use of the `-z' or `-Z' options may slow the archive process
considerably.

Let us conclude by a showing a few examples of `shar' usage:

     shar *.c > cprog.shar
     shar -Q *.[ch] > cprog.shar
     shar -B -l28 -oarc.sh. *.arc
     shar -f /lcl/src/u*.c > u.sh

The first shows how to make a shell archive out of all C program
sources.  The second produces a shell archive with all `.c' and `.h'
files, which unpacks silently.  The third gives a shell archive of
all uuencoded `.arc' files, into files `arc.sh.01' through to
`arc.sh.NNN'.  The last example gives a shell archive which will use
only the file names at unpack time.

3 Simple wrappers around `shar'
*******************************

3.1 The `mailshar' command and arguments
========================================

3.2 The `mail-files' command and arguments
==========================================

3.3 The `find-mailer' command and arguments
===========================================

4 Remote synchronisation of directories
***************************************

For using the `remsync' facility, besides `sharutils' of course, you
also need `perl', GNU `tar', GNU `findutils' and `gzip', all
installed.  You also need a `sum' program which is BSD-compatible,
for example the one from GNU `textutils'.

The `remsync' program tries to maintain up-to-date copies of whole
hierarchy of files over many loosely connected sites, provided there
is at least some slow electronic mail between them.  It prepares and
sends out specially packaged files called "synchronization packages",
and is able to processes them after reception.

There is no _master_ site, each site has an equal opportunity to
modify files, and modified files are propagated.  Among many other
commands, the `broadcast' command prepares and sends a
synchronization package from the current site to all others, while
the `process' command is used to apply synchronization packages
locally after reception from remote sites.  `remsync' will never send
a file to another site without being asked to with the `broadcast'
command, and besides the project synchronization state files (always
named `.remsync'), it will never modify a file locally without being
asked to with the `process' command.

The unit of transmission is a file, whatever its size may be.
Nothing less than whole files are being transmitted.  People deciding
to cooperate in keeping a synchronized set of files must have trust
each other, as each participant has the power of modifying the
contents of files at other sites.  When `remsync' is used by a single
individual travelling between many sites, as it is often the case,
this confidence problem should be easier to resolve :-).

The `process' command will modify a file without asking confirmation,
as long as there is no reason to believe that the file has been
modified at more than one place.  When some confusion arises from the
fact many people independently modified a single file, the receiving
user of conflicting files will have the duty of resolving them into a
merged version.  So, the merging has to be done at the site where the
discrepancy is observed, from where it is propagated again to others
participants.  There is no locking mechanism, so people should use
other means, like electronic mail, for telling each other what they
do, and which part of a project they are working on.

4.1 Quick start at using `remsync'
==================================

If you are in a real hurry, you can follow the recipe given here, and
postpone studying this manual further.  However, we will consider
only a simple case.  In any case, it is good to read the full example,
as it gives a good picture of the overall usage of `remsync'.

For any sizeable project, it might not be convenient to start with
one site having it all and the other site having nothing, because
this would cause the first synchronization to be huge.  It is more
practical to move over a copy of the project by other means, might it
be diskettes, tapes, or `mailshar'.  So let's presume both sites have
a copy of the project, not necessarily identical, but close.

For the following example, we presume that under the same domain
`champignac.land', there are two machines named `spirou' and
`fantasio'.  Further, the participating user on
`spirou@spirou.champignac.land' has `spirou' for a login name, and
similarily, the participating user on `fantasio.champignac.land' has
`fantasio' for a login name.  On the `spirou' machine, user `spirou'
keeps the project under his home, in directory `spirou-copy', while
on the `fantasio' machine, user `fantasio' keeps the project under
his home, in directory `fantasio-copy'.  Of course, user names might
be the same, as well as the directories containing the project.  We
use different names here just to make the example clearer.

Here is a full transcript of the initialization session, normally
executed only once, and slightly edited to make it more suitable for
this manual.  The example is broken down in little parts, allowing
explanations and comments.

     % cd ~/spirou-copy
     % remsync
     remsync (format *.*) - GNU sharutils *.*

     >> mode init

     init>> remote fantasio@fantasio.champignac.land ~/fantasio-copy
     * Directory `~/spirou-copy is not ready for synchronization
     Should I prepare it for its first time (y/n)? [y]
     Please enter a short project description: Zorglub project
     What is your full email address, here? [spirou@spirou.champignac.land]

These commands prepare the `~/spirou-copy' hierarchy for
synchronization.  You should be located at the top directory of the
hierarchy at the time the command `remsync' is called.

The `mode init' command instructs `remsync' that no files should be
sent in the synchronization package, only their checksum.  The goal
here is to inform the other site of what we have, and what we don't,
somewhat disregarding the fact the other site still looks like it has
nothing yet.

The `remote' command is the key in establishing a synchronization
link.  It has two parameters, the first being the email address of the
partner at the other site (as seen from here, if this matters), the
second being the location of the directory where the package should
reside on the remote site (as seen from there).

Because there is no `.remsync' file in the project's top-level
directory,  `remsync' concludes this is a first synchronization, and
so, ask a few questions, often telling in square brackets what answer
would be implied by a mere <Return> or <Enter>.  If the default reply
seems inappropriate, just give the correct information.

     init>> broadcast

       Broadcasting to address `fantasio@fantasio.champignac.land'
       Studying local files for their signature
       Registering file `file1'
       Registering file `file2'
       Registering file `file3'
     * There were new registrations, please check them
     Should I resume the current command (y/n)? [y]
     Mailing shar to fantasio@fantasio.champignac.land
     Message queued
       Command `broadcast' done

     init>> quit

     %

The `broadcast' command produces an inventory of the project's files
at this end, and mail it to the other partners.  But before doing so,
because some new files were registered into the synchronization, the
user is given the opportunity of interrupting the command, if it is
felt that some registered file should really not be there.

The `quit' command exits `remsync', but only once it created the
`.remsync' file on disk.

_Then_, on `fantasio.champignac.land', user `fantasio' will receive
the synchronization package, easily recognizable by the fact the
string `.remsync.tar.gz' appears in the `Subject' header of the
message.  Let's assume `fantasio' saves the whole message as file
`/tmp/synchro-message'.  Then, `fantasio' might use the following
recipe:

     % cd /tmp
     % unshar synchro-message
     uudecoding file .remsync.tar.gz
     % remsync process
       Exploding archive `/tmp/.remsync.tar.gz'

       Package being received:
         from address `spirou@spirou.champignac.land'
         for project `Zorglub project'
       Visiting directory `~/fantasio-copy', remote was `~/spirou-copy'
       Initializing file `.remsync' from received information
       Studying local files for their signature
       Command `process' done

In that `remsync process' call, the `process' command is being given
non-interactively, so `remsync' avoids unneeded interactions and
exits right away once the command is done.  But equivalently,
`remsync' might be called without arguments, the `process' command
given interactively, and a `quit' command later required to get out
of `remsync'.

When receiving a synchronization package, `remsync' should be
executed in the directory where the file `.remsync.tar.gz' has been
unpacked, which might be quite unrelated to the project itself.
Here, `fantasio' executed `remsync' in `/tmp/', while the project
resides in `~/fantasio-project'.  The synchronization package itself
contains enough information for `remsync' to automatically visit the
proper directory.

After this operation, `fantasio.champignac.land' has a `.remsync'
file in `~/fantasio-copy', and the remote synchronization
initialization is completed.  Either `spirou' or `fantasio' may then
modify files on their respective machine.  If `spirou' modifies
`file2' in the project, `spirou' may execute:

     % cd ~/spirou-copy
     % remsync broadcast
       Reading configuration for project `Zorglub project'

       Broadcasting to address `fantasio@fantasio.champignac.land'
       Studying local files for their signature
       Packaging file `file2'
     shar: Saving file2 (gzipped)
     Mailing shar to fantasio@fantasio.champignac.land
     Message queued
       Command `broadcast' done

In fact, any time a participant later feel like sending modified files
to all partners, s/he just have to change the directory to the top of
the project hierarchy, then call `remsync broadcast'.  Any time a
synchronization package is later received, at either end, the
receiving user should apply `unshar' to related electronic messages
for reconstructing the synchronization package `.remsync.tar.gz', then
call `remsync process' in the directory containing this package.

4.2 The `remsync' command and arguments
=======================================

At the shell prompt, calling the command `remsync' without any
parameters initiates an interactive dialog, in which the user types
commands and receives feedback from the program.

The command `remsync', given at the shell prompt, may have arguments,
in which case these arguments taken together form one `remsync'
interactive command.  However, `--help' and `--version' options are
interpreted especially, with their usual effect in GNU.  Once this
command has been executed, no more commands are taken from the user
and `remsync' terminates execution.  This allows for using `remsync'
in some kind of batch mode.  It is unwise to redirect `remsync'
standard input, because user interactions might often be needed in
ways difficult to predict in advance.

The two most common usages of `remsync' are the commands:

     remsync b
     remsync p

The first example executes the `broadcast' command, which sends
synchronization packages to all connected remote sites for the current
local directory tree.

The second example executes the `process' command, which studies and
complies with a synchronisation package saved in the current
directory (not necessarily into the synchronized directory tree),
under the usual file name `remsync.tar.gz'.

4.3 Automatic mechanisms in the `remsync' program
=================================================

The following points apply to many of the `remsync' commands.  We
describe them here once and for all.

   * The file `.remsync' describes the various properties for the
     current synchronization.  It is kept right in the top directory
     of a synchronized directory tree.  Some commands may be executed
     without any need for this file.  The program waits as far as
     possible before reading it.

   * If the `.remsync' file is not found when required, and only then,
     the user is interactively asked to fill a questionnaire about it.

   * If the `.remsync' file has been logically modified after having
     been read, or if it just has been created, the program will save
     it back on disk.  But it will do so only before reading another
     `.remsync' file, or just before exit.  A preexisting `.remsync'
     will be renamed to `.remsync.bak' before it is rewritten, when
     this is done, any previous `.remsync.bak' file is discarded.

   * Many commands refer to previously entered information by
     repeating this information.  For example, one can refer to a
     particular `scan' statement by entering the wildcard to be
     scanned by this statement.  An alternative method of specifying
     a statement consists in using the decimal number which appears
     between square brackets in the result of a `list' command.

   * Whenever a site list must be given, it is a space separated list
     of remote sites.  If the list is preceeded by a bang (<!>), the
     list is complemented, that is, the sites that will be operated
     upon are all those _not_ appearing in the list.  As a special
     case, if the site list is completely empty, then all sites are
     selected.


4.4 Commands for `remsync'
==========================

Program commands to `remsync' may be given interactively by the user
sitten at a terminal.  They can come from the arguments of the
`remsync' call at the shell level.  Internally, the `process' command
might obey many sub-commands found in a received synchronization
package.

Program commands are given one per line.  Lines beginning with a sharp
(<#>) and white lines are ignored, they are meant to increase clarity
or to introduce user comments.  With only a few exceptions, commands
are introduced by a keyword and often contains other keywords.  In
all cases, the keywords specific to `remsync' may be abbreviated to
their first letter.  When there are many keywords in succession, the
space separating them may be omitted.  So the following commands are
all equivalent:

     list remote
     l remote
     list r
     l r
     listremote
     lr

while the following are not legal:

     l rem
     lisremote

Below, for clarity, keywords are written in full and separated by
spaces.  Commands often accept parameters, which are then separated by
spaces.  All available commands are given in the table.  The first few
commands do not pre-require the file `.remsync'.  The last three
commands are almost never used interactively, but rather automatically
triggered while `process''ing received synchronization packages.

`?'
     Display a quick help summary of available commands.

`!' [ SHELL-COMMAND ]
     If SHELL-COMMAND has been given, execute it right now as a shell
     command.  When not given, rather start an interactive shell.
     Exiting from the shell will return to this program.  The started
     shell is taken from the `SHELL' environment variable if set,
     else `sh' is used.

`quit'
     Leave the program normally and return to the shell.

`abort'
     Leave the program with a nonzero exit status and return to the
     shell.  No attempt is made to save a logically modified
     `.remsync' file.

`visit' DIRECTORY
     Select another synchronized directory tree for any subsequent
     operation.  DIRECTORY is the top directory of the synchronized
     directory tree.

`process' [ FILE ]

`list' [ TYPE ]
     List all known statements about some information TYPE.  Allowable
     keywords for TYPE are `local', `remote', `scan', `ignore' and
     `files'.  The keyword `files' asks for all empty statements (see
     later).  If TYPE is omitted, then list all known statements for
     all types, except those given by `files'.

[ `create' ] TYPE VALUE
     Create a new statement introducing a VALUE for a given TYPE.
     Allowable keywords for TYPE are `remote', `scan' and `ignore'.
     The `create' keyword may be omitted.

     For `create' `ignore', when the pattern is preceeded by a bang
     (<!>), the condition is reversed.  That is, only those files
     which do match the pattern will be kept for synchronization.

`delete' TYPE VALUE
     Delete an existing statement supporting some VALUE for a given
     TYPE.  Allowable keywords for TYPE are `remote', `scan' and
     `ignore'.

`email' REMOTE VALUE
     Modify the electronic mail address associated with some REMOTE
     site, giving it a new VALUE.  The special `local' keyword for
     REMOTE may be used to modify the local electronic mail address.

`home' REMOTE VALUE
     Modify the top directory of the synchronized directory tree
     associated with some REMOTE site, giving it a new VALUE.  The
     special `local' keyword for REMOTE may be used to modify the
     local top directory.

`broadcast' SITE_LIST
     Send by electronic mail an update package to all sites from
     SITE_LIST, containing for each site all and only those files
     which are known to be different between the remote site and here.

`version' VERSION
     This command is not meant for interactive use.  It establishes
     the `remsync' version needed to process the incoming commands.

`from' SITE_LIST
     This command is not really meant for interactive use.  The first
     site from the SITE_LIST is the remote site which originated the
     synchronization package.  All the others are all the sites,
     including here, which were meant to be synchronized by the
     `broadcast' command that was issued at the originating remote
     site.

`sum' FILE CHECKSUM
     This command is not really meant for interactive use.  It
     declares the CHECKSUM value of a particular FILE at the
     originating remote site.  Also, if at least one `sum' command is
     received, then it is guaranteed that the originating remote site
     sent one `sum' command for each and every file to be
     synchronized, so any found local file which was not subject of
     any `sum' command does not exist remotely.

`if' FILE CHECKSUM PACKAGED
     This command is not really meant for interactive use.  It
     directs the `remsync' program to check if a local FILE has a
     given CHECKSUM.  If the checksum agrees, then the local file
     will be replaced by the PACKAGED file, as found in the received
     synchronization invoice.


4.5 How `remsync' works
=======================

How does `remsync' keep track of what is in sync, and what isn't?
*Note Xremsync::, for a the documentation on the `.remsync' file
format.  I understand that a mere description of the format does not
replace an explanation, but in the meantime, you might guess from the
format how the program works.

All files are summarized by a checksum, computed by the `sum' program.
There are a few variants of `sum' computing checksums in incompatible
ways, under the control of options.  `remsync' attempts to retrieve on
each site a compatible way to do it, and complains if it cannot.

`remsync' does not compare dates or sizes.  Experience shown that the
best version of a file is not necessarily the one with the latest
timestamp.  The best version for a site is the current version on this
site, as decided by its maintainer there, and this is this version
that will be propagated.

Each site has an idea of the checksum of a file for all other sites.
These checksums are not necessarily identical, for sites do not
necessarily propagate to all others, and the propagation network maybe
incomplete or asymmetrical in various ways.

Propagation is never done unattended.  The user on a site has to call
`remsync broadcast' to issue synchronization packages for other sites.
If this is never done, the local modifications will never leave the
site.  The user also has to call `remsync process' to apply received
synchronization packages.  Applying a package does not automatically
broadcast it further (maybe this could change?).

If a site A propagates some files to sites B and D, but not C, site B
is informed that site D also received these files, and site D is
informed that site B also received these files, so they will not
propagate again the same files to one another.  However, both site B
and D are susceptible to propagate further the same files to site C.

It may happen that a site refuses to update a file, or modifies a file
after having been received, or merges versions, or whatever.  So,
sites may have a wrong opinion of the file contents on other sites.
These differences level down after a few exchanges, and it is very
unlikely that a file would not be propagated when it should have.

This scheme works only when the various people handling the various
files have confidence in one each other.  If site B modifies a file
after having received it from site A, the file will eventually be
propagated back to site A.  If the original file stayed undisturbed
on site A, that is, if `remsync' proves that site B correctly knew
the checksum of the original file, then the file will be replaced on
site A without any user confirmation.  So, the user on site A has to
trust the changes made by the user on site B.

If the original file on site A had been modified after having been
sent in a synchronization package, than it is the responsibility of
the user on site A to correctly merge the local modifications with the
modifications observed in the file as received from site B.  This
responsibility is real, since the merged file will later be propagated
to the other sites in an authoritative way.

4.6 Related file formats
========================

4.7 Format of the `.remsync' file
=================================

The `.remsync' file saves all the information a site needs for
properly synchronizing a directory tree with remote sites.  Even if it
is meant to be editable using any ASCII editor, it has a very precise
format and one should be very careful while modifying it directly, if
ever.  The `.remsync' file is better handled through the `remsync'
program and commands.

The `.remsync' file is made up of statements, one per line.  Each
line begins with a statement keyword followed by a single <TAB>, then
by one or more parameters.  The keyword may be omitted, in this case,
the keyword is said to be _empty_, and the line begins immediately
with the <TAB>.  After the <TAB>, if there are two parameters or
more, they should all be separated with a single space.  There should
not be any space between the last parameter and the end of line
(unless there are explicit empty parameters).

The following table gives the possible keywords.  Their order of
presentation in the table is also the order of appearance in the
`.remsync' file.

`remsync'
     This statement identifies the `.remsync' format.  The only
     parameter states the file format version.

`local'
     This statement should appear exactly once, and has exactly two
     parameters.  The first parameter gives the electronic mail
     address the other sites should use for sending synchronization
     packages here.  The second parameter gives the name of the local
     directory tree to synchronize, in absolute notation.

`remote'
     This statement may appear zero, one or more times.  Each
     occurrence connects the synchronized directory tree to another
     tree on a remote site.  The first parameter gives one electronic
     mail address where to send remote synchronization packages.  The
     second parameter gives the name of the corresponding directory
     tree for this remote electronic mail address, in absolute
     notation.

`scan'
     This statement may appear zero, one or more times.  When it does
     not appear at all, the whole local directory tree will always be
     scanned, searching for files to synchronize.  When the statement
     appears at least once, the whole local directory tree will not
     be scanned, but only those files or directories appearing in one
     of these statements.  Each `scan' statement has exactly one
     parameter, giving one file or directory to be studied.  These
     are usually given relative to top directory of the local
     synchronization directory tree.  Shell wildcards are acceptable.

`ignore'
     This statement may appear zero, one or more times.  Each
     occurrence has one parameter giving a regular expression,
     according to Perl syntax for regular expressions.  These REGEXPs
     are applied against each file resulting from the scan.  If any
     of the `ignore' expression matches one of resulting file, the
     file is discarded and is not subject to remote synchronization.


After all the statements beginning by the previous keywords, the
`.remsync' file usually contains many statements having the empty
keyword.  The empty keyword statement may appear zero, one or more
times.  Each occurrence list one file being remotely synchronized.
The first parameter gives an explicit file name, usually given
relative to the top directory of the local synchronized directory
tree.  Shell wildcards are _not_ acceptable.

Besides the file name parameter, there are supplementary parameters to
each empty keyword statement, each corresponding to one remote
statement in the `.remsync' file.  The second parameter corresponds
to the first remote, the third parameter corresponds to the second
remote, etc.  If there are more remote statements than supplementary
parameters, missing parameters are considered to be empty.

Each supplementary parameter usually gives the last known checksum
value for this particular file, as computed on its corresponding
_remote_ site.  The parameter contains a dash `-' while the remote
checksum is unknown.  The checksum value for the _local_ copy of the
file is never kept anywhere in the `.remsync' file.  The special
value `666' indicates a checksum from hell, used when the remote file
is known to exist, but for which contradictory information has been
received from various sources.

4.8 Format of synchronisation packages
======================================

Each synchronisation package is transmitted as a file named
`.remsync.tar.gz', which has the format of a `tar' archive, further
compressed with the `gzip' program.  This archive always contains a
file named `.remsync-work/orders', and zero or more files named
`.remsync-work/1', `.remsync-work/2', etc.  It contains no other
files.  Each numbered file is actually a full, non-modified file
pertaining to the hierarchy of the project, as sent from the remote
site.

The `.remsync-work/orders' file drives the processing of the received
synchronization package.  This ASCII file format quite closely
resembles the `.remsync' format, which we do not explain again here.
Only the keywords and their associated parameters are different, and
there is no empty keyword.  The following table gives the possible
keywords, in the order where they normally appear.

`format'
`title'
`here'
`remote'
`ignore'
`scan'
     All those keywords are used exactly the same way as within the
     `.remsync' file, and their format is not explained again here.
     They state the file format, project title, local and possibly
     many remote identifications and directories, zero or more
     ignores, zero or more scans; all of these exactly as known to
     the remote site who created the synchronization package.  In
     particular, the `here' line states the originating site of the
     package rather than the receiving one; the receiving site should
     still be described by one of the `remote' lines.

`visit'
     This statement appears exactly once, and has one numeric
     parameter.  It specifies the zero-based index in the list of
     remote lines above.  The index identifies the receiving site,
     that is, the site to which this package was sent.

`copy'
     This statement appears exactly once, and has one or more numeric
     parameters.  Each specifies a zero-based index in the list of
     remote lines above.  All indices specify the set of all sites
     who where broadcasted simultaneously, at the time this
     synchronization package was issued.  The index specified by the
     `visit' line should also be one of the indices of the `copy'
     lines.  The order in which the indices are given is important,
     as it also establishes the order in which file signatures are
     listed on the `check' lines below.

`check'
     This statement may appear zero, one or more times.  Each
     occurrence describes one file known to the project at the
     originating site, and there is exactly one occurrence for each
     known file in the project.  Each `check' line has exactly N+2
     parameters, where N is the number of parameters of the `copy'
     command.  The first parameter gives a file name, relative to the
     top directory.  The second parameter gives the file signature
     for this file, as computed at the originating site.  For each
     remote site presented in the `copy' command, and exactly in the
     same order, each supplementary parameter gives the originator's
     idea of the signature for the said file at this remote site.  A
     dash (`-') replaces the signature for a file known _not_ to
     exist.

`update'
     This statement may appear zero, one or more times.  Each
     occurrence describes what to do with one of the `.remsync-work/N'
     files, distributed within the synchronization package.  In fact,
     there should be exactly as many `update' lines that there are
     numbered files in the synchronization package.  Usually, each
     `update' line immediately follows the corresponding `check'
     line, and has exactly three parameters.  The first parameter
     gives a file name in the project, relative to the top level
     directory of the hierarchy.  The second parameter gives a file
     signature which the said file should have at the receiving site,
     for it to be replaced safely, with no questions asked (this is
     the originator's idea of what the file signature _was_, on the
     receiving site, prior to its replacement).  A dash (`-')
     replaces this signature for a file known _not_ to exist.  The
     third parameter is the number N, which indicates the file
     `.remsync-work/N' in the synchronization package distribution
     which should replace the corresponding project file at the
     receiving site.


4.9 Other means to synchronization
==================================

One correspondent thinks that perhaps the news distribution mechanism
could be pressed into service for this job.  I could have started
from C-news, say, instead of from scratch, and have progressively
bent C-news to behave like I wanted.

My feeling is that the route was shorter as I did it, from scratch,
that it would have been from C-news.  Of course, I could have removed
the heavy administrative details of C-news: the history and `expire',
the daemons, the `cron' entries, etc., then added the interactive
features and specialized behaviors, but all this clean up would
certainly have took energies.  Right now, non counting the subsidiary
scripts and shar/unshar sources, the heart of the result is a single
(1200 lines) script written in Perl, which I find fairly more smaller
and maintainable than a patched C-news distribution would have been.

4.10 Documentation for obsolete scripts
=======================================

This is merely a place holder for previous documentation, waiting
that I clean it up.  You have no interest in reading further down.

4.10.1 mailsync
---------------

     Usage: mailsync [ OPTION ] ... [ EMAIL_ADDRESS ] [ DIRECTORY ]
        or: mailsync [ OPTION ] ... SYNC_DIRECTORY

Option -i simply sends a `ihave' package, with no bulk files.  Option
-n inhibits any destructive operation and mailing.

In the first form of the call, find a synchronisation directory in
DIRECTORY aimed towards some EMAIL_ADDRESS, then proceed with this
synchronisation directory.  EMAIL_ADDRESS may be the name of a file
containing a distribution list.  If EMAIL_ADDRESS is not specified,
all the synchronisation directories at the top level in DIRECTORY are
processed in turn.  If DIRECTORY is not specified, the current
directory is used.

In the second form of the call, proceed only with the given
synchronisation directory SYNC_DIRECTORY.

For proceeding with a synchronisation directory, whatever the form of
the call was, this script reads the `ident' files it contains to set
the local user and directory and the remote user and directory.  Then,
selected files under the local directory which are modified in regard
to the corresponding files in the remote directory are turned into a
synchronisation package which is mailed to the remote user.

The list of selected files or directories to synchronize from the
local directory are given in the `list' file in the synchronisation
directory.  If this `list' file is missing, all files under the local
directory are synchronized.

What I usually do is to `cd' at the top of the directory tree to be
synchronized, then to type `mailsync' without parameters.  This will
automatically prepare as many synchronisation packages as there are
mirror systems, then email multipart shars to each of them.  Note that
the synchronisation package is not identical for each mirror system,
because they do not usually have the same state of synchronisation.

`mailsync' will refuse to work if anything needs to be hand cleaned
from a previous execution of `mailsync' or `resync'.  Check for some
remaining `_syncbulk' or `_synctemp' directory, or for a `_syncrm'
script.

     TODO:
     - interrogate the user if `ident' file missing.
     - automatically construct the local user address.
     - create the synchronisation directory on the fly.
     - avoid duplicating work as far as possible for multiple sends.
     - have a quicker mode, depending on stamps, not on checksums.
     - never send core, executables, backups, `.nsf*', `*/_synctemp/*', etc.

4.10.2 resync
-------------

     Usage: resync [ OPTION ]... TAR_FILE
        or: resync [ OPTION ]... UNTARED_DIRECTORY

Given a tar file produced by mailsync at some remote end and already
reconstructed on this end using unshar, or a directory containing the
already untared invoice, apply the synchronization package locally.

Option -n inhibits destroying or creating files, but does everything
else.  It will in particular create a synchronization directory if
necessary, produce the `_syncbulk' directory and the `_syncrm' script.

The synchronization directory for the package is automatically
retrieved or, if not found, created and initialized.  `resync' keeps
telling you what it is doing.

There are a few cases when a resync should not complete without manual
intervention.  The common case is that several sites update the very
same files differently since they were last resync'ed, and then
mailsync to each other.  The prerequisite checksum will then fail, and
the files are then kept into the `_syncbulk' tree, which has a shape
similar to the directory tree in which the files where supposed to go.
For GNU Emacs users, a very handy package, called emerge, written by
Dale Worley <drw@kutta.mit.edu>, helps reconciling two files
interactiveley.  The `_syncbulk' tree should be explicitely deleted
after the hand synchronisation.

Another case of human intervention is when files are deleted at the
mailsync'ing site.  By choice, all deletions on the receiving side are
accumulated in a `_syncrm' script, which is not executed
automatically.  Explicitely executed, `_syncrm' will remove any file
in the receiving tree which does not exist anymore on the sender
system.  I often edit `_syncrm' before executing it, to remove the
unwanted deletions (beware the double negation :-).  The script
removes itself.

All the temporary files, while resynchronizing, are held in
`_synctemp', which is deleted afterwards; if something goes wrong,
this directory should also be cleaned out by hand.  `resync' will
refuse to work if anything remains to be hand cleaned.

     TODO:
     - interrogates the user if missing receiving directory in `ident'.
     - allow `remote.sum' to be empty or non-existent.

Appendix A GNU Free Documentation License
*****************************************

                       Version 1.1, March 2000
     Copyright (C) 2000  Free Software Foundation, Inc.
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA

     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

  0. PREAMBLE

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     other written document "free" in the sense of freedom: to assure
     everyone the effective freedom to copy and redistribute it, with
     or without modifying it, either commercially or noncommercially.
     Secondarily, this License preserves for the author and
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     considered responsible for modifications made by others.

     This License is a kind of "copyleft", which means that derivative
     works of the document must themselves be free in the same sense.
     It complements the GNU General Public License, which is a
     copyleft license designed for free software.

     We have designed this License in order to use it for manuals for
     free software, because free software needs free documentation: a
     free program should come with manuals providing the same
     freedoms that the software does.  But this License is not
     limited to software manuals; it can be used for any textual
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  1. APPLICABILITY AND DEFINITIONS

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  2. VERBATIM COPYING

     You may copy and distribute the Document in any medium, either
     commercially or noncommercially, provided that this License, the
     copyright notices, and the license notice saying this License
     applies to the Document are reproduced in all copies, and that
     you add no other conditions whatsoever to those of this License.
     You may not use technical measures to obstruct or control the
     reading or further copying of the copies you make or distribute.
     However, you may accept compensation in exchange for copies.
     If you distribute a large enough number of copies you must also
     follow the conditions in section 3.

     You may also lend copies, under the same conditions stated
     above, and you may publicly display copies.

  3. COPYING IN QUANTITY

     If you publish printed copies of the Document numbering more
     than 100, and the Document's license notice requires Cover
     Texts, you must enclose the copies in covers that carry, clearly
     and legibly, all these Cover Texts: Front-Cover Texts on the
     front cover, and Back-Cover Texts on the back cover.  Both
     covers must also clearly and legibly identify you as the
     publisher of these copies.  The front cover must present the
     full title with all words of the title equally prominent and
     visible.  You may add other material on the covers in addition.
     Copying with changes limited to the covers, as long as they
     preserve the title of the Document and satisfy these conditions,
     can be treated as verbatim copying in other respects.

     If the required texts for either cover are too voluminous to fit
     legibly, you should put the first ones listed (as many as fit
     reasonably) on the actual cover, and continue the rest onto
     adjacent pages.

     If you publish or distribute Opaque copies of the Document
     numbering more than 100, you must either include a
     machine-readable Transparent copy along with each Opaque copy,
     or state in or with each Opaque copy a publicly-accessible
     computer-network location containing a complete Transparent copy
     of the Document, free of added material, which the general
     network-using public has access to download anonymously at no
     charge using public-standard network protocols.  If you use the
     latter option, you must take reasonably prudent steps, when you
     begin distribution of Opaque copies in quantity, to ensure that
     this Transparent copy will remain thus accessible at the stated
     location until at least one year after the last time you
     distribute an Opaque copy (directly or through your agents or
     retailers) of that edition to the public.

     It is requested, but not required, that you contact the authors
     of the Document well before redistributing any large number of
     copies, to give them a chance to provide you with an updated
     version of the Document.

  4. MODIFICATIONS

     You may copy and distribute a Modified Version of the Document
     under the conditions of sections 2 and 3 above, provided that
     you release the Modified Version under precisely this License,
     with the Modified Version filling the role of the Document, thus
     licensing distribution and modification of the Modified Version
     to whoever possesses a copy of it.  In addition, you must do
     these things in the Modified Version:

     A. Use in the Title Page (and on the covers, if any) a title
     distinct    from that of the Document, and from those of
     previous versions    (which should, if there were any, be listed
     in the History section    of the Document).  You may use the
     same title as a previous version    if the original publisher of
     that version gives permission.
     B. List on the Title Page, as authors, one or more persons or
     entities    responsible for authorship of the modifications in
     the Modified    Version, together with at least five of the
     principal authors of the    Document (all of its principal
     authors, if it has less than five).
     C. State on the Title page the name of the publisher of the
     Modified Version, as the publisher.
     D. Preserve all the copyright notices of the Document.
     E. Add an appropriate copyright notice for your modifications
     adjacent to the other copyright notices.
     F. Include, immediately after the copyright notices, a license
     notice    giving the public permission to use the Modified
     Version under the    terms of this License, in the form shown in
     the Addendum below.
     G. Preserve in that license notice the full lists of Invariant
     Sections    and required Cover Texts given in the Document's
     license notice.
     H. Include an unaltered copy of this License.
     I. Preserve the section entitled "History", and its title, and
     add to    it an item stating at least the title, year, new
     authors, and    publisher of the Modified Version as given on
     the Title Page.  If    there is no section entitled "History" in
     the Document, create one    stating the title, year, authors,
     and publisher of the Document as    given on its Title Page,
     then add an item describing the Modified    Version as stated in
     the previous sentence.
     J. Preserve the network location, if any, given in the Document
     for    public access to a Transparent copy of the Document, and
     likewise    the network locations given in the Document for
     previous versions    it was based on.  These may be placed in
     the "History" section.     You may omit a network location for a
     work that was published at    least four years before the
     Document itself, or if the original    publisher of the version
     it refers to gives permission.
     K. In any section entitled "Acknowledgements" or "Dedications",
      preserve the section's title, and preserve in the section all
     the    substance and tone of each of the contributor
     acknowledgements    and/or dedications given therein.
     L. Preserve all the Invariant Sections of the Document,
     unaltered in their text and in their titles.  Section numbers
     or the equivalent are not considered part of the section titles.
     M. Delete any section entitled "Endorsements".  Such a section
     may not be included in the Modified Version.
     N. Do not retitle any existing section as "Endorsements"    or
     to conflict in title with any Invariant Section.
     If the Modified Version includes new front-matter sections or
     appendices that qualify as Secondary Sections and contain no
     material copied from the Document, you may at your option
     designate some or all of these sections as invariant.  To do
     this, add their titles to the list of Invariant Sections in the
     Modified Version's license notice.  These titles must be
     distinct from any other section titles.

     You may add a section entitled "Endorsements", provided it
     contains nothing but endorsements of your Modified Version by
     various parties-for example, statements of peer review or that
     the text has been approved by an organization as the
     authoritative definition of a standard.

     You may add a passage of up to five words as a Front-Cover Text,
     and a passage of up to 25 words as a Back-Cover Text, to the end
     of the list of Cover Texts in the Modified Version.  Only one
     passage of Front-Cover Text and one of Back-Cover Text may be
     added by (or through arrangements made by) any one entity.  If
     the Document already includes a cover text for the same cover,
     previously added by you or by arrangement made by the same
     entity you are acting on behalf of, you may not add another; but
     you may replace the old one, on explicit permission from the
     previous publisher that added the old one.

     The author(s) and publisher(s) of the Document do not by this
     License give permission to use their names for publicity for or
     to assert or imply endorsement of any Modified Version.

  5. COMBINING DOCUMENTS

     You may combine the Document with other documents released under
     this License, under the terms defined in section 4 above for
     modified versions, provided that you include in the combination
     all of the Invariant Sections of all of the original documents,
     unmodified, and list them all as Invariant Sections of your
     combined work in its license notice.

     The combined work need only contain one copy of this License, and
     multiple identical Invariant Sections may be replaced with a
     single copy.  If there are multiple Invariant Sections with the
     same name but different contents, make the title of each such
     section unique by adding at the end of it, in parentheses, the
     name of the original author or publisher of that section if
     known, or else a unique number.  Make the same adjustment to the
     section titles in the list of Invariant Sections in the license
     notice of the combined work.

     In the combination, you must combine any sections entitled
     "History" in the various original documents, forming one section
     entitled "History"; likewise combine any sections entitled
     "Acknowledgements", and any sections entitled "Dedications".
     You must delete all sections entitled "Endorsements."

  6. COLLECTIONS OF DOCUMENTS

     You may make a collection consisting of the Document and other
     documents released under this License, and replace the
     individual copies of this License in the various documents with
     a single copy that is included in the collection, provided that
     you follow the rules of this License for verbatim copying of
     each of the documents in all other respects.

     You may extract a single document from such a collection, and
     distribute it individually under this License, provided you
     insert a copy of this License into the extracted document, and
     follow this License in all other respects regarding verbatim
     copying of that document.

  7. AGGREGATION WITH INDEPENDENT WORKS

     A compilation of the Document or its derivatives with other
     separate and independent documents or works, in or on a volume
     of a storage or distribution medium, does not as a whole count
     as a Modified Version of the Document, provided no compilation
     copyright is claimed for the compilation.  Such a compilation is
     called an "aggregate", and this License does not apply to the
     other self-contained works thus compiled with the Document, on
     account of their being thus compiled, if they are not themselves
     derivative works of the Document.

     If the Cover Text requirement of section 3 is applicable to these
     copies of the Document, then if the Document is less than one
     quarter of the entire aggregate, the Document's Cover Texts may
     be placed on covers that surround only the Document within the
     aggregate.  Otherwise they must appear on covers around the
     whole aggregate.

  8. TRANSLATION

     Translation is considered a kind of modification, so you may
     distribute translations of the Document under the terms of
     section 4.  Replacing Invariant Sections with translations
     requires special permission from their copyright holders, but
     you may include translations of some or all Invariant Sections
     in addition to the original versions of these Invariant
     Sections.  You may include a translation of this License
     provided that you also include the original English version of
     this License.  In case of a disagreement between the translation
     and the original English version of this License, the original
     English version will prevail.

  9. TERMINATION

     You may not copy, modify, sublicense, or distribute the Document
     except as expressly provided for under this License.  Any other
     attempt to copy, modify, sublicense or distribute the Document
     is void, and will automatically terminate your rights under this
     License.  However, parties who have received copies, or rights,
     from you under this License will not have their licenses
     terminated so long as such parties remain in full compliance.

 10. FUTURE REVISIONS OF THIS LICENSE

     The Free Software Foundation may publish new, revised versions
     of the GNU Free Documentation License from time to time.  Such
     new versions will be similar in spirit to the present version,
     but may differ in detail to address new problems or concerns.
     See http://www.gnu.org/copyleft/.

     Each version of the License is given a distinguishing version
     number.  If the Document specifies that a particular numbered
     version of this License "or any later version" applies to it,
     you have the option of following the terms and conditions either
     of that specified version or of any later version that has been
     published (not as a draft) by the Free Software Foundation.  If
     the Document does not specify a version number of this License,
     you may choose any version ever published (not as a draft) by
     the Free Software Foundation.


ADDENDUM: How to use this License for your documents
====================================================

To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and
license notices just after the title page:


       Copyright (C)  YEAR  YOUR NAME.
       Permission is granted to copy, distribute and/or modify this document
       under the terms of the GNU Free Documentation License, Version 1.1
       or any later version published by the Free Software Foundation;
       with the Invariant Sections being LIST THEIR TITLES, with the
       Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
       A copy of the license is included in the section entitled ``GNU
       Free Documentation License''.
If you have no Invariant Sections, write "with no Invariant
Sections" instead of saying which ones are invariant.  If you have no
Front-Cover Texts, write "no Front-Cover Texts" instead of
"Front-Cover Texts being LIST"; likewise for Back-Cover Texts.

If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License, to
permit their use in free software.

Table of Contents
*****************

GNU `shar' utilities
1 Introduction to this toolset
2 The basic `shar' utilities
  2.1 Invoking the `shar' program
    2.1.1 Selecting files
    2.1.2 Splitting output
    2.1.3 Controlling the shar headers
    2.1.4 Selecting how files are stocked
    2.1.5 Protecting against transmission errors
    2.1.6 Producing different kinds of shars
  2.2 Invoking the `unshar' program
  2.3 Miscellaneous considerations
3 Simple wrappers around `shar'
  3.1 The `mailshar' command and arguments
  3.2 The `mail-files' command and arguments
  3.3 The `find-mailer' command and arguments
4 Remote synchronisation of directories
  4.1 Quick start at using `remsync'
  4.2 The `remsync' command and arguments
  4.3 Automatic mechanisms in the `remsync' program
  4.4 Commands for `remsync'
  4.5 How `remsync' works
  4.6 Related file formats
  4.7 Format of the `.remsync' file
  4.8 Format of synchronisation packages
  4.9 Other means to synchronization
  4.10 Documentation for obsolete scripts
    4.10.1 mailsync
    4.10.2 resync
Appendix A GNU Free Documentation License
  ADDENDUM: How to use this License for your documents


