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			672 lines
		
	
	
		
			28 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
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XZ Utils Installation
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=====================
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    0. Preface
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    1. Supported platforms
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       1.1. Compilers
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       1.2. Platform-specific notes
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            1.2.1. AIX
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            1.2.2. IRIX
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            1.2.3. MINIX 3
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            1.2.4. OpenVMS
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            1.2.5. Solaris, OpenSolaris, and derivatives
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            1.2.6. Tru64
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            1.2.7. Windows
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            1.2.8. DOS
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            1.2.9. z/OS
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       1.3. Adding support for new platforms
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    2. configure options
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       2.1. Static vs. dynamic linking of liblzma
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       2.2. Optimizing xzdec and lzmadec
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    3. xzgrep and other scripts
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       3.1. Dependencies
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       3.2. PATH
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    4. Troubleshooting
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       4.1. "No C99 compiler was found."
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       4.2. "No POSIX conforming shell (sh) was found."
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       4.3. configure works but build fails at crc32_x86.S
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       4.4. Lots of warnings about symbol visibility
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       4.5. "make check" fails
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       4.6. liblzma.so (or similar) not found when running xz
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0. Preface
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----------
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    If you aren't familiar with building packages that use GNU Autotools,
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    see the file INSTALL.generic for generic instructions before reading
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    further.
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    If you are going to build a package for distribution, see also the
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    file PACKAGERS. It contains information that should help making the
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    binary packages as good as possible, but the information isn't very
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    interesting to those making local builds for private use or for use
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    in special situations like embedded systems.
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1. Supported platforms
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----------------------
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    XZ Utils are developed on GNU/Linux, but they should work on many
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    POSIX-like operating systems like *BSDs and Solaris, and even on
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    a few non-POSIX operating systems.
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1.1. Compilers
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    A C99 compiler is required to compile XZ Utils. If you use GCC, you
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    need at least version 3.x.x. GCC version 2.xx.x doesn't support some
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    C99 features used in XZ Utils source code, thus GCC 2 won't compile
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    XZ Utils.
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    XZ Utils takes advantage of some GNU C extensions when building
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    with GCC. Because these extensions are used only when building
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    with GCC, it should be possible to use any C99 compiler.
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1.2. Platform-specific notes
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1.2.1. AIX
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    If you use IBM XL C compiler, pass CC=xlc_r to configure. If
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    you use CC=xlc instead, you must disable threading support
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    with --disable-threads (usually not recommended).
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1.2.2. IRIX
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    MIPSpro 7.4.4m has been reported to produce broken code if using
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    the -O2 optimization flag ("make check" fails). Using -O1 should
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    work.
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    A problem has been reported when using shared liblzma. Passing
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    --disable-shared to configure works around this. Alternatively,
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    putting "-64" to CFLAGS to build a 64-bit version might help too.
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1.2.3. MINIX 3
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    The default install of MINIX 3 includes Amsterdam Compiler Kit (ACK),
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    which doesn't support C99. Install GCC to compile XZ Utils.
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    MINIX 3.1.8 and older have bugs in /usr/include/stdint.h, which has
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    to be patched before XZ Utils can be compiled correctly. See
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    <http://gforge.cs.vu.nl/gf/project/minix/tracker/?action=TrackerItemEdit&tracker_item_id=537>.
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    MINIX 3.2.0 and later use a different libc and aren't affected by
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    the above bug.
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    XZ Utils doesn't have code to detect the amount of physical RAM and
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    number of CPU cores on MINIX 3.
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    See section 4.4 in this file about symbol visibility warnings (you
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    may want to pass gl_cv_cc_visibility=no to configure).
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1.2.4. OpenVMS
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    XZ Utils can be built for OpenVMS, but the build system files
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    are not included in the XZ Utils source package. The required
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    OpenVMS-specific files are maintained by Jouk Jansen and can be
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    downloaded here:
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        http://nchrem.tnw.tudelft.nl/openvms/software2.html#xzutils
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1.2.5. Solaris, OpenSolaris, and derivatives
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    The following linker error has been reported on some x86 systems:
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        ld: fatal: relocation error: R_386_GOTOFF: ...
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    This can be worked around by passing gl_cv_cc_visibility=no
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    as an argument to the configure script.
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    test_scripts.sh in "make check" may fail if good enough tools are
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    missing from PATH (/usr/xpg4/bin or /usr/xpg6/bin). Nowadays
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    /usr/xpg4/bin is added to the script PATH by default on Solaris
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    (see --enable-path-for-scripts=PREFIX in section 2), but old xz
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    releases needed extra steps. See sections 4.5 and 3.2 for more
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    information.
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1.2.6. Tru64
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    If you try to use the native C compiler on Tru64 (passing CC=cc to
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    configure), you may need the workaround mention in section 4.1 in
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    this file (pass also ac_cv_prog_cc_c99= to configure).
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1.2.7. Windows
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    If it is enough to build liblzma (no command line tools):
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      - There is experimental CMake support. As it is, it should be
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        good enough to build static liblzma with Visual Studio.
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        Building liblzma.dll might work too (if it doesn't, it should
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        be fixed). The CMake support may work with MinGW or MinGW-w64.
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        Read the comment in the beginning of CMakeLists.txt before
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        running CMake!
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      - There are Visual Studio project files under the "windows"
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        directory. See windows/INSTALL-MSVC.txt. In the future the
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        project files will be removed when CMake support is good
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        enough. Thus, please test the CMake version and help fix
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        possible issues.
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    To build also the command line tools:
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      - MinGW-w64 + MSYS (32-bit and 64-bit x86): This is used
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        for building the official binary packages for Windows.
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        There is windows/build.bash to ease packaging XZ Utils with
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        MinGW(-w64) + MSYS into a redistributable .zip or .7z file.
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        See windows/INSTALL-MinGW.txt for more information.
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      - MinGW + MSYS (32-bit x86): I haven't recently tested this.
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      - Cygwin 1.7.35 and later: NOTE that using XZ Utils >= 5.2.0
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        under Cygwin older than 1.7.35 can lead to DATA LOSS! If
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        you must use an old Cygwin version, stick to XZ Utils 5.0.x
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        which is safe under older Cygwin versions. You can check
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        the Cygwin version with the command "cygcheck -V".
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    It may be possible to build liblzma with other toolchains too, but
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    that will probably require writing a separate makefile. Building
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    the command line tools with non-GNU toolchains will be harder than
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    building only liblzma.
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    Even if liblzma is built with MinGW(-w64), the resulting DLL can
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    be used by other compilers and linkers, including MSVC. See
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    windows/README-Windows.txt for details.
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1.2.8. DOS
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    There is a Makefile in the "dos" directory to build XZ Utils on
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    DOS using DJGPP. Support for long file names (LFN) is needed at
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    build time but the resulting xz.exe works without LFN support too.
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    See dos/INSTALL.txt and dos/README.txt for more information.
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1.2.9. z/OS
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    To build XZ Utils on z/OS UNIX System Services using xlc, pass
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    these options to the configure script: CC='xlc -qhaltonmsg=CCN3296'
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    CPPFLAS='-D_UNIX03_THREADS -D_XOPEN_SOURCE=600'. The first makes
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    xlc throw an error if a header file is missing, which is required
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    to make the tests in configure work. The CPPFLAGS are needed to
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    get pthread support (some other CPPFLAGS may work too; if there
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    are problems, try -D_UNIX95_THREADS instead of -D_UNIX03_THREADS).
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    test_scripts.sh in "make check" will fail even if the scripts
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    actually work because the test data includes compressed files
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    with US-ASCII text.
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    No other tests should fail. If test_files.sh fails, check that
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    the included .xz test files weren't affected by EBCDIC conversion.
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    XZ Utils doesn't have code to detect the amount of physical RAM and
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    number of CPU cores on z/OS.
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1.3. Adding support for new platforms
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    If you have written patches to make XZ Utils to work on previously
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    unsupported platform, please send the patches to me! I will consider
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    including them to the official version. It's nice to minimize the
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    need of third-party patching.
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    One exception: Don't request or send patches to change the whole
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    source package to C89. I find C99 substantially nicer to write and
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    maintain. However, the public library headers must be in C89 to
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    avoid frustrating those who maintain programs, which are strictly
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    in C89 or C++.
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2. configure options
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--------------------
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    In most cases, the defaults are what you want. Many of the options
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    below are useful only when building a size-optimized version of
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    liblzma or command line tools.
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    --enable-encoders=LIST
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    --disable-encoders
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                Specify a comma-separated LIST of filter encoders to
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                build. See "./configure --help" for exact list of
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                available filter encoders. The default is to build all
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                supported encoders.
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                If LIST is empty or --disable-encoders is used, no filter
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                encoders will be built and also the code shared between
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                encoders will be omitted.
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                Disabling encoders will remove some symbols from the
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                liblzma ABI, so this option should be used only when it
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                is known to not cause problems.
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    --enable-decoders=LIST
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    --disable-decoders
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                This is like --enable-encoders but for decoders. The
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                default is to build all supported decoders.
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    --enable-match-finders=LIST
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                liblzma includes two categories of match finders:
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                hash chains and binary trees. Hash chains (hc3 and hc4)
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                are quite fast but they don't provide the best compression
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                ratio. Binary trees (bt2, bt3 and bt4) give excellent
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                compression ratio, but they are slower and need more
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                memory than hash chains.
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                You need to enable at least one match finder to build the
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                LZMA1 or LZMA2 filter encoders. Usually hash chains are
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                used only in the fast mode, while binary trees are used to
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                when the best compression ratio is wanted.
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                The default is to build all the match finders if LZMA1
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                or LZMA2 filter encoders are being built.
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    --enable-checks=LIST
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                liblzma support multiple integrity checks. CRC32 is
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                mandatory, and cannot be omitted. See "./configure --help"
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                for exact list of available integrity check types.
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                liblzma and the command line tools can decompress files
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                which use unsupported integrity check type, but naturally
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                the file integrity cannot be verified in that case.
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                Disabling integrity checks may remove some symbols from
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                the liblzma ABI, so this option should be used only when
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                it is known to not cause problems.
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    --enable-external-sha256
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                Try to use SHA-256 code from the operating system libc
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                or similar base system libraries. This doesn't try to
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                use OpenSSL or libgcrypt or such libraries.
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                The reasons to use this option:
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                  - It makes liblzma slightly smaller.
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                  - It might improve SHA-256 speed if the implementation
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                    in the operating is very good (but see below).
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                External SHA-256 is disabled by default for two reasons:
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                  - On some operating systems the symbol names of the
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                    SHA-256 functions conflict with OpenSSL's libcrypto.
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                    This causes weird problems such as decompression
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                    errors if an application is linked against both
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                    liblzma and libcrypto. This problem affects at least
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                    FreeBSD 10 and older and MINIX 3.3.0 and older, but
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                    other OSes that provide a function "SHA256_Init" might
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                    also be affected. FreeBSD 11 has the problem fixed.
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                    NetBSD had the problem but it was fixed it in 2009
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                    already. OpenBSD uses "SHA256Init" and thus never had
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                    a conflict with libcrypto.
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                  - The SHA-256 code in liblzma is faster than the SHA-256
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                    code provided by some operating systems. If you are
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                    curious, build two copies of xz (internal and external
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                    SHA-256) and compare the decompression (xz --test)
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                    times:
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                        dd if=/dev/zero bs=1024k count=1024 \
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                            | xz -v -0 -Csha256 > foo.xz
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                        time xz --test foo.xz
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    --disable-xz
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    --disable-xzdec
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    --disable-lzmadec
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    --disable-lzmainfo
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                Don't build and install the command line tool mentioned
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                in the option name.
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                NOTE: Disabling xz will skip some tests in "make check".
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                NOTE: If xzdec is disabled and lzmadec is left enabled,
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                a dangling man page symlink lzmadec.1 -> xzdec.1 is
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                created.
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    --disable-lzma-links
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                Don't create symlinks for LZMA Utils compatibility.
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                This includes lzma, unlzma, and lzcat. If scripts are
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                installed, also lzdiff, lzcmp, lzgrep, lzegrep, lzfgrep,
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                lzmore, and lzless will be omitted if this option is used.
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    --disable-scripts
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                Don't install the scripts xzdiff, xzgrep, xzmore, xzless,
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                and their symlinks.
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    --disable-doc
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                Don't install the documentation files to $docdir
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                (often /usr/doc/xz or /usr/local/doc/xz). Man pages
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                will still be installed. The $docdir can be changed
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                with --docdir=DIR.
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    --disable-assembler
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                liblzma includes some assembler optimizations. Currently
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                there is only assembler code for CRC32 and CRC64 for
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                32-bit x86.
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                All the assembler code in liblzma is position-independent
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                code, which is suitable for use in shared libraries and
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                position-independent executables. So far only i386
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                instructions are used, but the code is optimized for i686
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                class CPUs. If you are compiling liblzma exclusively for
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                pre-i686 systems, you may want to disable the assembler
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                code.
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    --enable-unaligned-access
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                Allow liblzma to use unaligned memory access for 16-bit
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                and 32-bit loads and stores. This should be enabled only
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                when the hardware supports this, i.e. when unaligned
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                access is fast. Some operating system kernels emulate
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                unaligned access, which is extremely slow. This option
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                shouldn't be used on systems that rely on such emulation.
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                Unaligned access is enabled by default on x86, x86-64,
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                and big endian PowerPC.
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    --enable-small
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                Reduce the size of liblzma by selecting smaller but
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                semantically equivalent version of some functions, and
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                omit precomputed lookup tables. This option tends to
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                make liblzma slightly slower.
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                Note that while omitting the precomputed tables makes
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                liblzma smaller on disk, the tables are still needed at
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                run time, and need to be computed at startup. This also
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                means that the RAM holding the tables won't be shared
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                between applications linked against shared liblzma.
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                This option doesn't modify CFLAGS to tell the compiler
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                to optimize for size. You need to add -Os or equivalent
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                flag(s) to CFLAGS manually.
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    --enable-assume-ram=SIZE
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                On the most common operating systems, XZ Utils is able to
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                detect the amount of physical memory on the system. This
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                information is used by the options --memlimit-compress,
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                --memlimit-decompress, and --memlimit when setting the
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                limit to a percentage of total RAM.
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                On some systems, there is no code to detect the amount of
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                RAM though. Using --enable-assume-ram one can set how much
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                memory to assume on these systems. SIZE is given as MiB.
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                The default is 128 MiB.
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                Feel free to send patches to add support for detecting
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                the amount of RAM on the operating system you use. See
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                src/common/tuklib_physmem.c for details.
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    --enable-threads=METHOD
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                Threading support is enabled by default so normally there
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                is no need to specify this option.
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                Supported values for METHOD:
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                        yes     Autodetect the threading method. If none
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                                is found, configure will give an error.
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                        posix   Use POSIX pthreads. This is the default
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                                except on Windows outside Cygwin.
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                        win95   Use Windows 95 compatible threads. This
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                                is compatible with Windows XP and later
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                                too. This is the default for 32-bit x86
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                                Windows builds. The `win95' threading is
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                                incompatible with --enable-small.
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                        vista   Use Windows Vista compatible threads. The
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                                resulting binaries won't run on Windows XP
 | 
						|
                                or older. This is the default for Windows
 | 
						|
                                excluding 32-bit x86 builds (that is, on
 | 
						|
                                x86-64 the default is `vista').
 | 
						|
 | 
						|
                        no      Disable threading support. This is the
 | 
						|
                                same as using --disable-threads.
 | 
						|
                                NOTE: If combined with --enable-small, the
 | 
						|
                                resulting liblzma won't be thread safe,
 | 
						|
                                that is, if a multi-threaded application
 | 
						|
                                calls any liblzma functions from more than
 | 
						|
                                one thread, something bad may happen.
 | 
						|
 | 
						|
    --enable-sandbox=METHOD
 | 
						|
                There is limited sandboxing support in the xz tool. If
 | 
						|
                built with sandbox support, it's used automatically when
 | 
						|
                (de)compressing exactly one file to standard output and
 | 
						|
                the options --files or --files0 weren't used. This is a
 | 
						|
                common use case, for example, (de)compressing .tar.xz
 | 
						|
                files via GNU tar. The sandbox is also used for
 | 
						|
                single-file `xz --test' or `xz --list'.
 | 
						|
 | 
						|
                Supported METHODs:
 | 
						|
 | 
						|
                        auto    Look for a supported sandboxing method
 | 
						|
                                and use it if found. If no method is
 | 
						|
                                found, then sandboxing isn't used.
 | 
						|
                                This is the default.
 | 
						|
 | 
						|
                        no      Disable sandboxing support.
 | 
						|
 | 
						|
                        capsicum
 | 
						|
                                Use Capsicum (FreeBSD >= 10) for
 | 
						|
                                sandboxing. If no Capsicum support
 | 
						|
                                is found, configure will give an error.
 | 
						|
 | 
						|
    --enable-symbol-versions
 | 
						|
                Use symbol versioning for liblzma. This is enabled by
 | 
						|
                default on GNU/Linux, other GNU-based systems, and
 | 
						|
                FreeBSD.
 | 
						|
 | 
						|
    --enable-debug
 | 
						|
                This enables the assert() macro and possibly some other
 | 
						|
                run-time consistency checks. It makes the code slower, so
 | 
						|
                you normally don't want to have this enabled.
 | 
						|
 | 
						|
    --enable-werror
 | 
						|
                If building with GCC, make all compiler warnings an error,
 | 
						|
                that abort the compilation. This may help catching bugs,
 | 
						|
                and should work on most systems. This has no effect on the
 | 
						|
                resulting binaries.
 | 
						|
 | 
						|
    --enable-path-for-scripts=PREFIX
 | 
						|
                If PREFIX isn't empty, PATH=PREFIX:$PATH will be set in
 | 
						|
                the beginning of the scripts (xzgrep and others).
 | 
						|
                The default is empty except on Solaris the default is
 | 
						|
                /usr/xpg4/bin.
 | 
						|
 | 
						|
                This can be useful if the default PATH doesn't contain
 | 
						|
                modern POSIX tools (as can be the case on Solaris) or if
 | 
						|
                one wants to ensure that the correct xz binary is in the
 | 
						|
                PATH for the scripts. Note that the latter use can break
 | 
						|
                "make check" if the prefixed PATH causes a wrong xz binary
 | 
						|
                (other than the one that was just built) to be used.
 | 
						|
 | 
						|
                Older xz releases support a different method for setting
 | 
						|
                the PATH for the scripts. It is described in section 3.2
 | 
						|
                and is supported in this xz version too.
 | 
						|
 | 
						|
 | 
						|
2.1. Static vs. dynamic linking of liblzma
 | 
						|
 | 
						|
    On 32-bit x86, linking against static liblzma can give a minor
 | 
						|
    speed improvement. Static libraries on x86 are usually compiled as
 | 
						|
    position-dependent code (non-PIC) and shared libraries are built as
 | 
						|
    position-independent code (PIC). PIC wastes one register, which can
 | 
						|
    make the code slightly slower compared to a non-PIC version. (Note
 | 
						|
    that this doesn't apply to x86-64.)
 | 
						|
 | 
						|
    If you want to link xz against static liblzma, the simplest way
 | 
						|
    is to pass --disable-shared to configure. If you want also shared
 | 
						|
    liblzma, run configure again and run "make install" only for
 | 
						|
    src/liblzma.
 | 
						|
 | 
						|
 | 
						|
2.2. Optimizing xzdec and lzmadec
 | 
						|
 | 
						|
    xzdec and lzmadec are intended to be relatively small instead of
 | 
						|
    optimizing for the best speed. Thus, it is a good idea to build
 | 
						|
    xzdec and lzmadec separately:
 | 
						|
 | 
						|
      - To link the tools against static liblzma, pass --disable-shared
 | 
						|
        to configure.
 | 
						|
 | 
						|
      - To select somewhat size-optimized variant of some things in
 | 
						|
        liblzma, pass --enable-small to configure.
 | 
						|
 | 
						|
      - Tell the compiler to optimize for size instead of speed.
 | 
						|
        E.g. with GCC, put -Os into CFLAGS.
 | 
						|
 | 
						|
      - xzdec and lzmadec will never use multithreading capabilities of
 | 
						|
        liblzma. You can avoid dependency on libpthread by passing
 | 
						|
        --disable-threads to configure.
 | 
						|
 | 
						|
      - There are and will be no translated messages for xzdec and
 | 
						|
        lzmadec, so it is fine to pass also --disable-nls to configure.
 | 
						|
 | 
						|
      - Only decoder code is needed, so you can speed up the build
 | 
						|
        slightly by passing --disable-encoders to configure. This
 | 
						|
        shouldn't affect the final size of the executables though,
 | 
						|
        because the linker is able to omit the encoder code anyway.
 | 
						|
 | 
						|
    If you have no use for xzdec or lzmadec, you can disable them with
 | 
						|
    --disable-xzdec and --disable-lzmadec.
 | 
						|
 | 
						|
 | 
						|
3. xzgrep and other scripts
 | 
						|
---------------------------
 | 
						|
 | 
						|
3.1. Dependencies
 | 
						|
 | 
						|
    POSIX shell (sh) and bunch of other standard POSIX tools are required
 | 
						|
    to run the scripts. The configure script tries to find a POSIX
 | 
						|
    compliant sh, but if it fails, you can force the shell by passing
 | 
						|
    gl_cv_posix_shell=/path/to/posix-sh as an argument to the configure
 | 
						|
    script.
 | 
						|
 | 
						|
    xzdiff (xzcmp/lzdiff/lzcmp) may use mktemp if it is available. As
 | 
						|
    a fallback xzdiff will use mkdir to securely create a temporary
 | 
						|
    directory. Having mktemp available is still recommended since the
 | 
						|
    mkdir fallback method isn't as robust as mktemp is. The original
 | 
						|
    mktemp can be found from <http://www.mktemp.org/>. On GNU, most will
 | 
						|
    use the mktemp program from GNU coreutils instead of the original
 | 
						|
    implementation. Both mktemp versions are fine.
 | 
						|
 | 
						|
    In addition to using xz to decompress .xz files, xzgrep and xzdiff
 | 
						|
    use gzip, bzip2, and lzop to support .gz, bz2, and .lzo files.
 | 
						|
 | 
						|
 | 
						|
3.2. PATH
 | 
						|
 | 
						|
    The method described below is supported by older xz releases.
 | 
						|
    It is supported by the current version too, but the newer
 | 
						|
    --enable-path-for-scripts=PREFIX described in section 2 may be
 | 
						|
    more convenient.
 | 
						|
 | 
						|
    The scripts assume that the required tools (standard POSIX utilities,
 | 
						|
    mktemp, and xz) are in PATH; the scripts don't set the PATH themselves
 | 
						|
    (except as described for --enable-path-for-scripts=PREFIX). Some
 | 
						|
    people like this while some think this is a bug. Those in the latter
 | 
						|
    group can easily patch the scripts before running the configure script
 | 
						|
    by taking advantage of a placeholder line in the scripts.
 | 
						|
 | 
						|
    For example, to make the scripts prefix /usr/bin:/bin to PATH:
 | 
						|
 | 
						|
        perl -pi -e 's|^#SET_PATH.*$|PATH=/usr/bin:/bin:\$PATH|' \
 | 
						|
                src/scripts/xz*.in
 | 
						|
 | 
						|
 | 
						|
4. Troubleshooting
 | 
						|
------------------
 | 
						|
 | 
						|
4.1. "No C99 compiler was found."
 | 
						|
 | 
						|
    You need a C99 compiler to build XZ Utils. If the configure script
 | 
						|
    cannot find a C99 compiler and you think you have such a compiler
 | 
						|
    installed, set the compiler command by passing CC=/path/to/c99 as
 | 
						|
    an argument to the configure script.
 | 
						|
 | 
						|
    If you get this error even when you think your compiler supports C99,
 | 
						|
    you can override the test by passing ac_cv_prog_cc_c99= as an argument
 | 
						|
    to the configure script. The test for C99 compiler is not perfect (and
 | 
						|
    it is not as easy to make it perfect as it sounds), so sometimes this
 | 
						|
    may be needed. You will get a compile error if your compiler doesn't
 | 
						|
    support enough C99.
 | 
						|
 | 
						|
 | 
						|
4.2. "No POSIX conforming shell (sh) was found."
 | 
						|
 | 
						|
    xzgrep and other scripts need a shell that (roughly) conforms
 | 
						|
    to POSIX. The configure script tries to find such a shell. If
 | 
						|
    it fails, you can force the shell to be used by passing
 | 
						|
    gl_cv_posix_shell=/path/to/posix-sh as an argument to the configure
 | 
						|
    script. Alternatively you can omit the installation of scripts and
 | 
						|
    this error by passing --disable-scripts to configure.
 | 
						|
 | 
						|
 | 
						|
4.3. configure works but build fails at crc32_x86.S
 | 
						|
 | 
						|
    The easy fix is to pass --disable-assembler to the configure script.
 | 
						|
 | 
						|
    The configure script determines if assembler code can be used by
 | 
						|
    looking at the configure triplet; there is currently no check if
 | 
						|
    the assembler code can actually actually be built. The x86 assembler
 | 
						|
    code should work on x86 GNU/Linux, *BSDs, Solaris, Darwin, MinGW,
 | 
						|
    Cygwin, and DJGPP. On other x86 systems, there may be problems and
 | 
						|
    the assembler code may need to be disabled with the configure option.
 | 
						|
 | 
						|
    If you get this error when building for x86-64, you have specified or
 | 
						|
    the configure script has misguessed your architecture. Pass the
 | 
						|
    correct configure triplet using the --build=CPU-COMPANY-SYSTEM option
 | 
						|
    (see INSTALL.generic).
 | 
						|
 | 
						|
 | 
						|
4.4. Lots of warnings about symbol visibility
 | 
						|
 | 
						|
    On some systems where symbol visibility isn't supported, GCC may
 | 
						|
    still accept the visibility options and attributes, which will make
 | 
						|
    configure think that visibility is supported. This will result in
 | 
						|
    many compiler warnings. You can avoid the warnings by forcing the
 | 
						|
    visibility support off by passing gl_cv_cc_visibility=no as an
 | 
						|
    argument to the configure script. This has no effect on the
 | 
						|
    resulting binaries, but fewer warnings looks nicer and may allow
 | 
						|
    using --enable-werror.
 | 
						|
 | 
						|
 | 
						|
4.5. "make check" fails
 | 
						|
 | 
						|
    If the other tests pass but test_scripts.sh fails, then the problem
 | 
						|
    is in the scripts in src/scripts. Comparing the contents of
 | 
						|
    tests/xzgrep_test_output to tests/xzgrep_expected_output might
 | 
						|
    give a good idea about problems in xzgrep. One possibility is that
 | 
						|
    some tools are missing from the current PATH or the tools lack
 | 
						|
    support for some POSIX features. This can happen at least on
 | 
						|
    Solaris where the tools in /bin may be ancient but good enough
 | 
						|
    tools are available in /usr/xpg4/bin or /usr/xpg6/bin. For possible
 | 
						|
    fixes, see --enable-path-for-scripts=PREFIX in section 2 and the
 | 
						|
    older alternative method described in section 3.2 of this file.
 | 
						|
 | 
						|
    If tests other than test_scripts.sh fail, a likely reason is that
 | 
						|
    libtool links the test programs against an installed version of
 | 
						|
    liblzma instead of the version that was just built. This is
 | 
						|
    obviously a bug which seems to happen on some platforms.
 | 
						|
    A workaround is to uninstall the old liblzma versions first.
 | 
						|
 | 
						|
    If the problem isn't any of those described above, then it's likely
 | 
						|
    a bug in XZ Utils or in the compiler. See the platform-specific
 | 
						|
    notes in this file for possible known problems. Please report
 | 
						|
    a bug if you cannot solve the problem. See README for contact
 | 
						|
    information.
 | 
						|
 | 
						|
 | 
						|
4.6. liblzma.so (or similar) not found when running xz
 | 
						|
 | 
						|
    If you installed the package with "make install" and get an error
 | 
						|
    about liblzma.so (or a similarly named file) being missing, try
 | 
						|
    running "ldconfig" to update the run-time linker cache (if your
 | 
						|
    operating system has such a command).
 | 
						|
 |