Introduction to UnZip
The UnZip package contains ZIP
extraction utilities. These are useful for extracting files from ZIP
archives. ZIP
archives are created with PKZIP or Info-ZIP utilities, primarily in a DOS environment.
Note
Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.
Caution
The previous version of the UnZip package had some locale related issues. Currently there are no BLFS editors capable of testing these locale issues. Therefore, the locale related information is left on this page, but has not been tested. A more general discussion of these problems can be found in the Program Assumes Encoding section of the Locale Related Issues page.
Package Information
Additional Downloads
UnZip Locale Issues
Note
Use of UnZip in the JDK, Mozilla, DocBook or any other BLFS package installation is not a problem, as BLFS instructions never use UnZip to extract a file with non-ASCII characters in the file's name.
These issues are thought to be fixed in the patch. But since none of the editors have data to test this, the following workarounds are retained in case they might still be needed.
The UnZip package assumes that filenames stored in the ZIP archives created on non-Unix systems are encoded in CP850, and that they should be converted to ISO-8859-1 when writing files onto the filesystem. Such assumptions are not always valid. In fact, inside the ZIP archive, filenames are encoded in the DOS codepage that is in use in the relevant country, and the filenames on disk should be in the locale encoding. In MS Windows, the OemToChar() C function (from User32.DLL
) does the correct conversion (which is indeed the conversion from CP850 to a superset of ISO-8859-1 if MS Windows is set up to use the US English language), but there is no equivalent in Linux.
When using unzip to unpack a ZIP archive containing non-ASCII filenames, the filenames are damaged because unzip uses improper conversion when any of its encoding assumptions are incorrect. For example, in the ru_RU.KOI8-R locale, conversion of filenames from CP866 to KOI8-R is required, but conversion from CP850 to ISO-8859-1 is done, which produces filenames consisting of undecipherable characters instead of words (the closest equivalent understandable example for English-only users is rot13). There are several ways around this limitation:
1) For unpacking ZIP archives with filenames containing non-ASCII characters, use WinZip while running the Wine Windows emulator.
2) Use bsdtar -xf from libarchive-3.7.2 to unpack the ZIP archive. Then fix the damage made to the filenames using the convmv tool (https://j3e.de/linux/convmv/). The following is an example for the zh_CN.UTF-8 locale:
convmv -f cp936 -t utf-8 -r --nosmart --notest \
</path/to/unzipped/files>
Installation of UnZip
First apply the patch:
patch -Np1 -i ../unzip-6.0-consolidated_fixes-1.patch
Now compile the package:
make -f unix/Makefile generic
The test suite does not work for target “generic”.
Now, as the root
user:
make prefix=/usr MANDIR=/usr/share/man/man1 \
-f unix/Makefile install
Command Explanations
make -f unix/Makefile generic: This target begins by running a configure script (unlike the older targets such as linux and linux_noasm) which creates a flags file that is then used in the build. This ensures that the 32-bit x86 build receives the right flags to unzip files which are larger than 2GB when extracted.