UnZip is an extraction utility for archives compressed in .zip format (also called "zipfiles"). Although highly compatible both with PKWARE's PKZIP and PKUNZIP utilities for MS-DOS and with Info-ZIP's own Zip program, our primary objectives have been portability and non-MSDOS functionality.
UnZip will list, test, or extract files from a .zip archive, commonly found on MS-DOS systems. The default behavior (with no options) is to extract into the current directory (and subdirectories below it) all files from the specified zipfile. A companion program, Zip, creates .zip archives; both programs are compatible with archives created by PKZIP and PKUNZIP for MS-DOS, but in many cases the program options or default behaviors differ. (For example, UnZip recreates the stored directory structure by default; PKUNZIP unpacks all files in the current directory by default.)
|The Unix port of UnZip 5.52 is reported to have a race-condition vulnerability, whereby a local attacker could change the permissions of the user's files during unpacking. (This has been assigned CVE #CAN-2005-2475.)|
|All versions of UnZip through 5.50 have a number of directory-traversal vulnerabilities, and version 5.50 also has a textmode data-corruption bug that affects 16-bit ports such as MS-DOS. See the FAQ page for details.|
New features in UnZip 5.52, released 27 February 2005:
The next major release will be version 6.0, adding compatibility with PKWARE's large-file-support kludge. (Ideally the zipfile format itself should be overhauled, with clean support for large files, large file systems, and real timestamps. But that would have its own compatibility problems, of course.) It will probably also include multi-part archive support--something we've been begged to implement for years (and something that we would have, had we not been interrupted by far too many other eventful things)--since Zip 3.0 will. But if not, that will likely show up in a 6.1 release a few months later.
It is somewhat questionable whether there will be a subsequent major release, but on the off-chance that there is, it will probably be version 7.0, with a much-improved and unified DLL interface and possibly better file system support for the MVS and VM/CMS ports, assuming that doesn't happen sooner. And then perhaps version 8.0 will be released, with full filter support (that is, able to read and extract a zipfile from standard input like fUnZip does now), but now we're really dreaming. While we're at it, though, a tcl/tk or Python/PIL graphical interface might be nice--but see the related-links section for a pointer to TkZip, which already exists (and has for a long time).
NEW RELEASE: Most binaries are contributed by third parties, so there's no fixed schedule for when any of them might appear. Those binaries typically provided by Info-ZIP team members (DOS, Win32, OS/2, Linux, FreeBSD, VMS) have already started showing up and should be fully available within a few weeks, though we make no promises. Please be patient, and feel free to grab the sources and compile your own!
NOTE: If you find a broken link, please tell us about it. Thanks!
Ready-to-run binary versions of UnZip are available for numerous platforms and operating systems.
Info-ZIP's portable C source code for Zip, UnZip, WiZ and MacZip (including encryption code) is freely available from:
Note that version 1.0 of the encryption/decryption code is available only from the Netherlands site and works only with Zip 1.1. Version 2.9 works with Zip 2.3. (UnZip 5.51 includes decryption support in the main source archive.)
Source code to IBM's UnZip DLL for OS/2 (distributed with the Warp BonusPak, WebExplorer, TCP/IP, etc.) is also available. This is the January 1995 version, made available courtesy of Jake Coughlin; we don't have the June 1995 update or anything newer. IBM graciously placed their changes in the public domain, and Info-ZIP thanks them for it.
Technical information on zipfiles and other assorted Info-ZIP documentation is available from:
Technical information and documentation for deflate/inflate and zlib are available from :
Further information on where to find Info-ZIP stuff, including BBSes and commercial online services, is available in:
Information about commercial use, modification and redistribution of Zip, UnZip, WiZ and MacZip is available in:
It's basically BSD-like, but note that there may still be a few remaining files in some of the packages that are covered by different licenses.
Return to the Info-ZIP Home Page.
Copyright © 1995-2006
UnZip is maintained by Christian Spieler.
|Primary ftp site hosted by LEO.|