Copyright (C) 1990-1992 Mark Adler, Richard B. Wales, Jean-loup Gailly,
Kai Uwe Rommel and Igor Mandrichenko.
Permission is granted to any individual or institution to use, copy, or
redistribute this software so long as all of the original files are included
unmodified, that it is not sold for profit, and that this copyright notice
Zip 1.9 is a compression and file packaging utility. It is analogous to a
combination of tar and compress and is compatible with PKZIP 1.93a
(Phil Katz ZIP) for MSDOS systems. There is a companion to zip called
unzip (of course) which you should be able to find the same place you
got zip. (See the file 'where' for details on ftp sites and mail
This version of zip has been ported to a wide array of Unix and other
mainframes, minis, and micros including VMS, OS/2, Minix, MSDOS,
Windows NT, Atari, and Macintosh (the latter two have not been tested
recently). Although highly compatible with PKware's PKZIP and PKUNZIP
utilities of MSDOS fame, our primary objective has been one of
portability and other-than-MSDOS functionality. Features not found in
the PKWare version include creation of zip files in a pipe or on a
device, VMS and OS/2 extended file attributes, conversion from Unix to
MSDOS text file format; and, of course, the ability to run on most of
your favorite operating systems. And it's free.
If you got this file from zip19.zip, you can extract the rest only
with unzip 5.0 or pkzip 1.93a. See the file 'Where' if you do not
have them already.
Please read the file install.doc for information on how to compile and
install zip, zipsplit and zipnote. Please read the file zip.doc for
information on how to use them. The file "contents" is a complete
list of the files you should have in this distribution. Also, if you
are using MSDOS, you should read the note on file formats at the end
of the contents file.
This version supports encryption, but the encryption code is distributed
separately because of the US export regulations. See the file 'Where'
for access to the encryption code. Decryption can be made with unzip 5.0
or later, or with zipcloak (which is provided in the encryption supplement).
All bug reports and patches should go to [email protected]
suggestions for new features can be sent to info[email protected]
(although we don't promise to use all suggestions). Patches should be
sent as context diffs only (diff -c).
If you're considering a port, please check in with zip-bugs FIRST,
since the code is constantly being updated behind the scenes. We'll
arrange to give you access to the latest source. The alternative is the
possibility that your hard work will be tucked away in a sub-archive
and pretty much ignored. A port to VM/CMS would be welcome.
If you'd like to keep up to date with our zip (and companion unzip utility)
development, join the ranks of BETA testers, add your own thoughts and
contributions, etc., send your request to [email protected]
you will be added to the Info-ZIP newsletter mailing list.
- pkzip 1.93a is only an alpha version (see historical notes below). If
you wish to create zip files compatible with the official version of
pkzip (1.10), you must use zip 1.0. zip 1.9 cannot create files
with the old compression method (implosion).
- zip 1.9 is is compatible with pkzip 1.93a, except when two features
are used: encryption or zip file created in a pipe or on a non
seekable device. pkzip versions of 2.0 will support such files, and
unzip 5.0 already supports them. (Thanks to Phil Katz for accepting
our suggested minor changes to the zip file format.)
- the ports to the Macintosh and the Atari ST have been provided in
the hope that they can be useful, but they have been adapted from an
older version of zip (1.0) and are still completely untested. A
makefile is still missing for the Mac. Another Macintosh port is
being made by Johnny Lee but it requires
more substantial changes so it will be distributed separately.
- Please read the file zip.doc, and in particular its list of known bugs
at the end.
At the time of release of zip 1.9, the official released version of
PKZIP is version 1.10. PKZIP 1.93a is only an alpha version, which was
released in October 1991. It was supposed to be replaced soon after
with an official release of pkzip 2.0. However, Phil Katz has not yet
announced a release date at the time of writing (Aug 19th, 1992).
Beta versions of zip compatible with pkzip 1.93a have been available
since February 1992 to the info-zip group (see the file 'history').
The zip authors would have preferred to release zip 2.0 only after
pkzip 2.0(*), to ensure full compatibility in case of archive format
changes between pkzip 1.93a and 2.0. However we feel that we cannot
delay any further the release of zip 1.9, since all the major features
that we wanted to put in are now available and well tested by the
(*) The version number for the new pkzip was planned to be 2.00, but may
be increased to a number greater than 2.2 to prevent confusion with
several bogus versions, which may destroy all the data on your hard
disk if you run them.