arc521.doc

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                          ARC

                 File Archive Utility
                     Version 5.20

























                 (C)COPYRIGHT 1985,86
                          by
          System Enhancement Associates, Inc.
                  ALL RIGHTS RESERVED





This document describes version 5.20 of the ARC file
utility, which was created by System Enhancement
Associates, Inc. in October of 1986.


       TABLE OF CONTENTS



Section                                           Page


Introduction  ....................................   1
Using ARC  .......................................   3
ARC commands  ....................................   5
    Adding files  ................................   5
    Extracting files  ............................   7
    Deleting files  ..............................   8
    Listing archive entries  .....................   8
    Running files  ...............................  10
    Printing files  ..............................  11
    Testing an archive  ..........................  11
    Converting an archive  .......................  12
ARC options  .....................................  13
    Suppressing compression  .....................  13
    Backup retention  ............................  14
    Message suppression  .........................  15
    Encryption/Decryption  .......................  17
RAMdisk support  .................................  18
MARC  ............................................  19
ARCE  ............................................  20
Version numbers  .................................  21
Common questions and answers  ....................  22
Maintenance contracts  ...........................  24
Revision history  ................................  25
    Changes in version 3  ........................  25
    Changes in version 4  ........................  25
    Changes in version 4.1  ......................  26
    Changes in version 4.3  ......................  26
    Changes in version 4.4  ......................  27
    Changes in version 4.5  ......................  27
    Changes in version 5.0  ......................  28
    Changes in version 5.1  ......................  29
    Changes in version 5.2  ......................  30
Program history and credits  .....................  31
Bulletin boards  .................................  33
Site licenses  ...................................  34













         INTRODUCTION



ARC is the copyrighted property of System Enhancement
Associates, Inc.  You are granted a limited license to
use ARC, and to copy it and distribute it, provided
that the following conditions are met:

1) No fee may be charged for such copying and
   distribution.

2) ARC may ONLY be distributed in its original,
   unmodified state.

3) ARC may *not* be distributed, in whole or in part, as
   part of any commercial product or service without
   the express written permission of System
   Enhancement Associates.


Contributions for the use of this program will be
appreciated, and should be sent to:

          System Enhancement Associates, Inc.
             21 New Street, Wayne NJ 07470

You may not use this product in a commercial
environment or a governmental organization without
paying a license fee of $35.  Site licenses and
commercial distribution licenses are available.  A
program disk and printed documentation are available
for $50.  See the order form enclosed with this manual
for more details.



ARC is user supported software.  This means that you
may copy it freely and give the copies away to anyone
you wish, at no cost.  They are in turn requested to
send in a contribution if they decide to use it.

The user supported software concept (often referred to
as "shareware") is an attempt to provide software at low
cost.  The cost of offering a new product by
conventional means is staggering, and hence dissuades
many independent authors and small companies from
developing and promoting their ideas.  User supported
software is an attempt to develop a new marketing
channel, where products can be introduced at low cost.




ARC                                              Page 1
If user supported software works, then everyone will
benefit.  The user will benefit by receiving quality
products at low cost, and by being able to "test
drive" software thoroughly before purchasing it.  The
author benefits by being able to enter the commercial
software arena without first needing large sources of
venture capital.

But it can only work with your support.  We're not
just talking about ARC here, but about all user
supported software.  If you obtain a user supported
program from a friend or colleague, and are still
using it after a couple of weeks, then it is obviously
worth something to you, and a contribution should be
sent.



And now, back to ARC:

ARC is used to create and maintain file archives.  An
archive is a group of files collected together into
one file in such a way that the individual files may
be recovered intact.

ARC is different from other archive and library
utilities in that it automatically compresses the
files being archived, so that the resulting archive
takes up a minimum amount of space.

When ARC is used to add a file to an archive it
analyzes the file to determine which of three storage
methods will result in the greatest savings.  These
three methods are:

1) No compression; the file is stored as is.

2) Repeated-character compression; repeated sequences
   of the same byte value are collapsed into a three-
   byte code sequence.

3) Dynamic Lempel-Zev compression;  the file is stored
   as a series of variable size bit codes which
   represent character strings, and which are created
   "on the fly".

Note that since one of the three methods involves no
compression at all, the resulting archive entry will
never be larger than the original file.





ARC                                              Page 2
           USING ARC



ARC is invoked with a command of the following format:

    ARC <x> <arcname> [<template> . . .]

Where:

    <x> is an ARC command letter (see below), in
    either upper or lower case.

    <arcname> is the name of the archive to act on,
    with or without an extension.  If no extension is
    supplied, then ".ARC" is assumed.  The archive
    name may include path and drive specifiers.

    <template> is one or more file name templates.
    The "wildcard" characters "*" and "?" may be used.
    A file name template may include a path or drive
    specifier, though it isn't always meaningful.


If ARC is invoked with no arguments (by typing "ARC",
and pressing "enter"), then a brief command summary is
displayed.



Following is a brief summary of the available ARC
commands:

    a   = add files to archive
    m   = move files to archive
    u   = update files in archive
    f   = freshen files in archive
    d   = delete files from archive
    x,e = extract files from archive
    r   = run files from archive
    p   = copy files from archive to standard output
    l   = list files in archive
    v   = verbose listing of files in archive
    t   = test archive integrity
    c   = convert entry to new packing method









ARC                                              Page 3
Following is a brief summary of the available ARC
options, which may alter how a command works:

    b   = retain backup copy of archive
    s   = suppress compression (store only)
    w   = suppress warning messages
    n   = suppress notes and comments
    o   = overwrite existing files when extracting
    g   = encode or decode archive entry













































ARC                                              Page 4
         ARC COMMANDS



This section describes each of the commands.  ARC will
accept any one command at a time.  If no commands are
given, then a brief command list is displayed.



ADDING FILES

Files are added to an archive using the "A" (Add), "M"
(Move), "U" (Update), or "F" (Freshen) commands.  Add
always adds the file.  Move differs from Add in that
the source file is deleted once it has been added to
the archive.

Update differs from Add in that the file is only added
if it is not already in the archive, or if it is newer
that the corresponding entry in the archive.

Freshen is similar to Update, except that new files
are not added to the archive; only files already in
the archive are updated.


For example, if you wish to add a file named
"TEST.DAT" to an archive named "MY.ARC", you would use
a command of the form:

    ARC a my test.dat

If you wanted to add all files with a ".C" extension,
and all files named "STUFF" to an archive named
"JUNK.ARC", you could type:

    ARC a junk *.c stuff.*

If you wanted to move all files in your current
directory into an archive named "SUM.ARC", you could
use a command of the form:

    ARC m sum *.*

If you have an archive named "TEXT.ARC", and you
wanted to add to it all of your files with an
extension of ".TXT" which have been created or changed
since they were last archived, then you would type:

    ARC u text *.txt



ARC                                              Page 5
If you have a bunch of files in your current
directory, with backup copies being stored in an
archive named "SAFE.ARC", then if you wanted to make
sure that every file in the archive is the latest
version of that file, you would type:

    ARC f safe


A word about Update and Freshen:  These are similar in
that they look at the date and time of last change on
the file, and only add it if the file has been changed
since it was last archived.  They differ in that
Update will add new files, while Freshen will not.

In other words, Update looks for the files on disk,
and adds them if they are new or have changed, while
Freshen looks in the archive, and tries to update the
files which are already there.


Archive entries are always maintained in alphabetic
order.  Archive entries may not have duplicate names.
If you add a file to an archive that already contains
a file by that name, then the existing entry in the
archive is replaced.  Also, the archive itself and its
backup will not be added.

You may also add a file which is in a directory other
than your current directory.  For example, it is
perfectly legal to type:

    ARC a junk c:\dustbin\stuff.txt

You cannot add two files with the same name.  In other
words, if you have a file named "C:\DUSTBIN\STUFF.TXT"
and another file named "C:\BUCKET\STUFF.TXT", then
typing:

    arc a junk c:\dustbin\*.* c:\bucket\*.*

will not work.


ARC does not save the path name.  In other words, if
you specify a drive and/or path when adding a file,
only the actual file name is stored in the archive.







ARC                                              Page 6
ARC will never add an archive to itself, nor will it
add the temporary copy or a backup copy of the
archive.


An interesting note:  It has been brought to our
attention that BASIC programs compress to a smaller
size when they are *not* tokenized.  If you are more
concerned with space than speed, you may wish to
convert your BASIC programs to ASCII form before
adding them to an archive.  Your BASIC manual should
give instructions on how to do this.



EXTRACTING FILES

Archive entries are extracted with the "E" (Extract)
and "X" (eXtract) commands.  For example, if you had
an archive named "JUNK.ARC", and you wanted all files
in it with an extension of ".TXT" or ".DOC" to be
recreated on your disk, you could type:

    ARC x junk *.txt *.doc

If you wanted to extract all of the files in an
archive named "JUNK.ARC", you could simply type:

    ARC x junk

Whatever method of file compression was used in
storing the files is reversed, and uncompressed copies
are created in the current directory.

You can also specify a path name, in which case the
decompressed copy is placed in the specified
directory.  For example, if you had an archive named
"JUNK.ARC", and you wanted all files in it with an
extension of ".TXT" to be placed in the directory
"C:\WASTE\LAND", then you could type:

    ARC x junk c:\waste\land\*.txt

If you wanted to put the file "TRASH.TXT" on your A:
drive, and the file "LITTER.TXT" on your B: drive, you
could type:

    ARC x junk a:trash.txt b:litter.txt






ARC                                              Page 7
If you give more than one path for a file, then only
the first one is used.  For example, if you typed:

    ARC x junk a:trash.txt b:trash.txt

then TRASH.TXT will be placed on your A: drive.



DELETING FILES

Archive entries are deleted with the "D" (Delete)
command.  For example, if you had an archive named
"JUNK.ARC", and you wished to delete all entries in it
with a filename extension of ".C", you could type:

    ARC d junk *.c



LISTING ARCHIVE ENTRIES

You can obtain a list of the contents of an archive by
using the "L" (List) command or the "V" (Verbose list)
command.  For example, to see what is in an archive
named "JUNK.ARC", you could type:

    ARC l junk

If you are only interested in files with an extension
of ".DOC", then you could type: