README -- Info-ZIP UnZip
------------------------
Program version: 6.1c (BETA).
Document date: 2017-12-08
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Introduction
------------
Info-ZIP UnZip and Zip are free, portable, compressor-archiver
utility programs, which are intended to be compatible with PKZIP by
PKWARE, Inc. PKWARE and PKZIP are registered trademarks of PKWARE, Inc.
The .ZIP archive format is widely used, by these and other programs.
This document describes UnZip, the extraction program. (Zip is
described in its own README file.)
The UnZip kit includes the following programs:
UnZip The normal UnZip program.
UnZipSFX The UnZip self-extraction (SFX) program. (On most
systems, append a ZIP archive to it to make a
self-extracting archive bundle.)
ZipInfo A mode of UnZip operation ("unzip -Z"), rather than a
separate program, but it may be installed as an alias or
link to the real UnZip program.
Particular operating systems may have additional programs or variants
of these basic programs. For example:
fUnZip [Unix] Filter UnZip, a limited-capability extraction program,
intended for use in a pipeline.
ZipGrep [Unix] A Bourne shell script which uses UnZip and egrep to
search for patterns in Zip archive members.
VMS includes VMS-style CLI variants of UnZip, UnZipSFX, and ZipInfo.
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Information Sources
-------------------
Main Info-ZIP Web site: http://info-zip.org/
UnZip page: http://info-zip.org/UnZip.html
Info-ZIP forums: http://info-zip.org/phpBB3/index.php
FTP access: ftp://ftp.info-zip.org/pub/infozip/
Info-ZIP at SourceForge: https://sourceforge.net/projects/infozip/
Info-ZIP forums at SourceForge:
https://sourceforge.net/tracker/?group_id=118012
Info-ZIP programs are widely used and distributed (and often modified
and redistributed). The sources listed above provide the original
source code, and pre-built binaries for some system types. For the
software license (and disclaimers) see:
http://info-zip.org/license.html [HTML]
http://info-zip.org/license.txt [plain text]
ftp://ftp.info-zip.org/pub/infozip/license.html [HTML]
ftp://ftp.info-zip.org/pub/infozip/doc/license [plain text]
Source kits include this README file, and various other files,
including BUGS, COPYING, INSTALL, LICENSE, and ToDo. Changes are noted
in "History.610". (For changes in older versions, see other "History.*"
files.) Many OS-specific subdirectories include "INSTALL*" and/or
"README*" supplements. A "proginfo" subdirectory contains some
additional (mostly old) documentation of particular interest to
developers.
For program usage information, source kits include a "docs"
subdirectory which contains ".txt" files with formatted Unix "man"
output, and may also include ".htx" files with VMS help output.
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Description
-----------
UnZip is an extraction utility for archives in .ZIP format, in which
member files usually are compressed, and may be encrypted. Although
highly compatible both with PKWARE's PKZIP program and with Info-ZIP's
own Zip program, the primary objectives for UnZip have been portability
and non-MS-DOS functionality.
Info-ZIP programs are developed primarily on Unix (and Unix-like,
including GNU/Linux and Mac OS X), VMS, and Windows systems. Support
for other, older or less popular operating environments depends on help
from contributors outside the main Info-ZIP group, who have access to
these systems. Similarly, we don't have every available compiler on
every system type. We describe our programs as "portable", and welcome
complaints and suggestions involving their use on almost anything.
UnZip has been ported to operating systems like AmigaDOS, AOS/VS, Atari
TOS, Acorn RISC OS, BeOS, FlexOS, Human68k, IBM mainframes (MVS, VM/CMS,
z/OS), Macintosh (pre-OS-X), MS-DOS, OS/2, SMS/QDOS, Tandem NSK, and
TOPS-20. A DLL is available for OS/2 and Windows. An object library is
available on Unix, VMS, and Windows.
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Significant Behavior Changes and New Features Since UnZip 6.00
--------------------------------------------------------------
For more details on new command-line options or other features,
please see the usual Unix "man" or VMS HELP documentation.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- Behavior change: New command-line parser (like the one used by Zip).
Functional changes include:
- Addition of long options, like "--license".
- Addition of two-character short options, for example, "-so". Note
that this can make some combined one-character options ambiguous.
When in doubt, separate one-character short options like "-s -o",
instead of combining them into "-so".
- Option negation now uses a trailing "-" instead of a leading "-".
For example, "-q-" instead of "--q". Multiple levels of negation,
like "----q", are no longer supported. Use multiple negative
options, like "-q- -q- -q-", instead.
- New option "-so"/"--options" lists all available options.
- New option "-sc"/"--commandline" shows the input command line and
exits.
- New "--license" option displays the license. This allows program
distribution without additional documentation.
- Behavior change: Now, by default, date-time information is restored on
extracted files only, not on created directories. Use "-D" to restore
no date-time information. Use "-D-" to restore date-time information
on directories as well as files. (On VMS, this is not a change,
except for the new trailing-hyphen syntax for option negation.)
- Behavior change: Now, by default, permission/protection information is
restored on Unix(-like) and VMS systems, but limited by the user's
Unix umask or VMS default protection. Use -k/--keep-permissions
(/RESTORE = PROTECTION = ORIGINAL) to ignore the umask or default
protection, and get the old default behavior. Use -k- (/RESTORE =
NOPROTECTION) to ignore the archived permissions, leaving only the
umask or default protection.
- Behavior change: Now, on Unix(-like) and VMS systems,
-X/--restore-owner (/RESTORE = OWNER) controls only restoration of
Unix UID/GID or VMS UIC. On VMS, -ka/--keep-acl (/RESTORE = ACL)
controls restoration of ACLs.
- Behavior change: ZipInfo report format changes:
- Headers and totals summary formats have been changed. New option:
-mc/--member_counts.
- "-v" report includes some raw hexadecimal values along with the old
descriptions/interpretations.
- Behavior change: Interactive queries to resolve file-system conflicts
("replace XXX ? [y]es, [n]o, [A]ll, [N]one, [r]ename:") were buggy.
Previously, on some system types, the path/name shown in the query
could be an archive path/name, not a file-system path/name. Also, a
"-d exdir" extraction directory could be added to a user-specified
"rename" path/name, which may already have included it. Now, the
query should always show the file-system path/name which has the
conflict (including the effects of any "-d exdir" or "-j[=N]"
options), and a user-specified "rename" (file-system) path/name should
be used as specified.
- Behavior change (possible): New -da/--auto-extract-dir option to
specify a destination directory for extracted files which is derived
from the base name of the archive. For example, with -da, extraction
of "fred.zip" is done into subdirectory "fred" instead of into the
current directory. (On VMS, subdirectory "[.fred]".) Previously
(with the old command-line parser), "-da" would be interpreted as
equivalent to "-d a", which would extract into the destination
directory "a".
- Optional support for WinZip-compatible AES encryption (compression
method 99). See aes_wg/README_AES_WG.txt for more information.
- Optional support for compression methods LZMA (14) and PPMd (98).
See szip/README_SZIP.txt for more information.
- Better Unicode support for Windows
- New -I and -O options for ISO and OEM character set conversion,
respectively, using iconv. See INSTALL (or unix/Makefile) for details
on enabling/disabling iconv support. (The unix/configure script
should enable it automatically, by default, where it appears to work.)
- -j/--junk-dirs option now accepts an optional value, the number of
directory levels to discard. As before, plain "-j" discards all
directory names. "-j=N" discards only the top "N" directory levels.
- Initial support for AppleDouble storage of Finder info, resource fork
data, and extended attributes on Macintosh (Mac OS X) systems.
Intended to be compatible with Apple "ditto".
- Initial support for an UnZip object library on Unix and VMS, providing
a callable UnZip interface. Comments in an example main program
source module, libiz/izunzip_example.c, explain some usage details.
Currently, only a simple .a or .OLB object library is offered, not a
.so shared object or .EXE shareable image.
- Acorn port updated.
- The Unix builders (unix/configure, unix/Makefile) have been changed
substantially. See INSTALL and unix/Makefile for details.
Highlights:
- More consistent with Zip.
- Use "CC=gcc" to specify GCC. "make" targets "*_gcc" are gone.
- Use "PROD=subdir" to put product files (objects, executables, ...)
into a subdirectory, rather than ".".
- Windows MinGW support.
- Minor changes to accommodate BAE Systems STOP OS.
- Output from unix/configure script (used by "make generic") is more
informative.
- VMS CLI changes:
- /[NO]CASE_INSENSITIVE (for -C) is now deprecated, replaced by new
/MATCH = CASE = {BLIND|SENSITIVE}.
- /[NO]TIMES (for -T) is now deprecated, replaced by new
/[NO]DECIMAL_TIME.
- /JUNK_DIRS (-j) now has an optional (integer) value.
- New qualifiers/values: /[NO]AUTO_DIRECTORY (-da), /JAR (--jar),
/LICENSE (--license), /RESTORE = ACL (-ka),
/RESTORE = [NO]PROTECTION = [LIMITED|ORIGINAL] (-k),
/RESTORE = OWNER (-X), /VERBOSE = COMMAND (-sc). Optional:
/MATCH = [NO]WILD_MATCH_SLASH (-W).
- New Windows builders for Microsoft Visual Studio (Visual C++) 2010
have more options, fewer projects. (Service Pack 1 may be needed for
VS 2010. VS 2012 (and newer?) should be compatible.) Look for
"vc10/" directory under "win32/" and "windll/".
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Distribution
------------
If you have a question regarding redistribution of Info-ZIP software,
whether as-is, as packaging for a commercial product, or as an integral
part of a commercial product, please read the Frequently Asked Questions
(FAQ) section of the included COPYING.OLD file. All Info-ZIP releases
are now covered by the Info-ZIP license. See the file LICENSE. The
most current license should be available at:
http://info-zip.org/license.html
ftp://ftp.info-zip.org/pub/infozip/license.html
The Info-ZIP group lacks access to many supported system types
(and/or C compilers), so others may wish to provide pre-built
executables for various environments. In general, there is no problem
with this. We require only that such distributions include this README
file, the LICENSE file (which includes copyright and redistribution
information, and any appropriate documentation files (unzip.txt and/or
unzip.1 for UnZip, and so on).
Any commonly used kit scheme for the target system may be used, such
as a tar+gzip kit for Unix, a BACKUP save set for VMS, a disk image, and
so on. Plain Zip archives work if some kind of compatible unzipping
program is easily available on the target system. If the target system
provides a way to make self-extracting archives, in which both the
executables and text files can be stored together, then that's often a
good way. (Info-ZIP UnZipSFX is normally suitable, for example.) If a
bare UnZip executable is supplied, then a separate Zip archive
containing the remaining text and binary files should also be supplied.
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Talk to Info-ZIP -- Bug Reports, Feature Requests, ...
------------------------------------------------------
Info-ZIP offers two discussion forums for UnZip and related programs,
our own forums:
http://info-zip.org/phpBB3/index.php
and SourceForge forums:
https://sourceforge.net/tracker/?group_id=118012
Reports of bugs and documentation problems, and other complaints, are
welcome, as are feature requests and other suggestions, and even general
usage questions (ideally on topics which are not already well explained
in the existing documentation).
This is especially true for UnZip 6.1c, because of the extent of the
changes made since UnZip 6.10b.
The developers also use an internal e-mail discussion forum, with a
Web-form submission gateway ("Info-ZIP Bug Report") at:
http://info-zip.org/zip-bug.html
We may never see discussions on other, OS- or application-specific
forums, unless someone directs us to them.
As with most such forums, these are subject to abuse. We try to
reduce this on our own forums by requiring users to register, and by
moderating postings. (The resulting delays may be annoying, but the
noise was more annoying.) The bug-report Web form also blocks any
message which contains a URI/URL, so some useful information may need to
be omitted there, at least until the discussion gets going. Similarly,
if a test case involves private data, a discussion which begins on a
forum can move to private e-mail when appropriate.
In all cases, a program problem report should include some basic
information, like:
Computer type and operating system (and version).
Program version. (Ideally, a whole "unzip -v" or "zip -v"
report, although you might need to edit out any URLs to get it
through the bug-report Web form.)
What you did, and what happened when you did it. Showing actual
commands with their actual output is usually more helpful than a
vague description or interpretation.
Actual patches ("diff -u") to the code are welcome, but it's usually
wise to discuss suggested changes before doing the extra work. It's
often helpful to base patches on a recent internal-development source
kit, rather than on a recent full release (or even the latest public
beta kit, if it's getting old). Similarly, anyone trying to port these
programs to a new system type will probably benefit by starting with a
recent internal-development source kit. (Ask, and you are likely to
receive.) Any such work should begin with a reading of the (old, but
still useful) proginfo/ZipPorts file.
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Contributions
-------------
Info-ZIP programs are the result of much work by many people, as
suggested by the list in the proginfo/CONTRIBS file, but the number of
active developers is rather small (as the pace of recent releases might
suggest). A to-do list is kept in the file ToDo, which is a reasonable
place to start for anyone wishing to contribute. There are many
projects, small and large (some, _very_ large), listed there. New
contributors are welcome.
We try to acknowledge contributions in the release notes (History.*,
and so on), but sometimes we fail. If you deserve credit for some
contribution but don't see it, please let us know, and we'll try again
in the next release.
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Apology
-------
Too much time has passed between the releases of UnZip versions 6.10b
and 6.1c. UnZip 6.1c lacks support for some new features in Zip 3.1d.
We'll try to get the missing features into UnZip 6.1d, and to get the
final UnZip 6.1 released in a more timely way.
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WARNING
-------
The Info-ZIP AES_WG source kit (iz_aes_wg.zip), and the UnZip and
Zip source kits which include it, are subject to US export control
laws. BEFORE downloading or using any version of any of these
kits, read the following Encryption Notice. You agree to follow
these terms (as well as the terms of the Info-ZIP license) when
you download and/or use any of these source kits.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Encryption Notice
-----------------
This software kit includes encryption software. The country or
other jurisdiction where you are may restrict the import,
possession, use, and/or re-export to another country, of
encryption software. BEFORE using any encryption software, please
check all applicable laws, regulations, and policies concerning
the import, possession, use, and re-export of encryption software,
to see if these are permitted. Some helpful information may be
found at: http://www.wassenaar.org/
Export and re-export of this software from the US are governed by
the US Department of Commerce, Bureau of Industry and Security
(BIS). This is open-source ("publicly available") software.
Info-ZIP has submitted the required notification to the BIS. The
details are:
Export Commodity Control Number (ECCN) 5D002
License Exception: Technology Software Unrestricted (TSU)
(Export Administration Regulations (EAR) Section 740.13)
A copy of the required BIS notification is available in the file
aes_wg/USexport_aes_wg.msg in the source kits, and at:
ftp://ftp.info-zip.org/pub/infozip/crypt/USexport_AES_WG.msg
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