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         HDF5 Build and Install Instructions for Cygwin
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This document is a instruction on how to build, test and install HDF5 libary on 
Cygwin.  See detailed information in hdf5/INSTALL. 

NOTE: hdf5 can be built with CMake, see the INSTALL_CMake.txt file for more guidance.

Preconditions:
--------------

1. Installed Cygwin 1.7.25 or higher

   To install the Cygwin net release, go to http://www.cygwin.com and 
   click on "setup-x86.exe" (32-bit installation) under the heading
    "Current Cygwin DLL version". This will download a GUI 
   installer called setup-x86.exe which can be run to download a complete 
   Cygwin installation via the internet. Then follow the instructions 
   on each screen to install Cygwin.

   Cygwin uses packages to manage installing various software. Users can 
   choose to install or uninstall certain packages by running setup.exe.
   http://www.cygwin.com/packages/ provides detailed information about 
   Cygwin packages.

   Most required dependencies can be satisfied by installing all packages in
   the "Devel" category.  However, please verify that you have installed all
   packages listed below.

2. Compilers, Libraries and Utilities Installed

   2.1 Compilers Supported
    
    The following compilers are supported by HDF5 and included in the Cygwin
    package system:
       gcc (4.7.3 and 4.9.2), which includes:
            gcc4-core    : C compiler
            gcc4-g++     : C++ compiler
            gcc4-fortran : fortran compiler
            

   2.1.1 Using Compilers Not Supported
       
       By default the current configuration uses vendor compilers; to use
        another compiler run the following commands before running
        configure: 
 
        setenv CC   "foo -flags"
        setenv FC  "fffoo -flags"

       For example, if users want to use pgf90 as fortran compiler, then 

            setenv FC pgf90

        See the configure help page (configure --help) for a list of
        environment variables that have an affect on building the
        library.
        
    2.2 HDF5 External Library Dependencies

    2.2.1 Zlib

         zlib-1.2.5 or later is supported and tested on Cygwin.

    2.2.2 Szip
       The HDF5 library has a predefined compression filter that uses
       the extended-Rice lossless compression algorithm for chunked
       datasets.  For information on Szip compression, license terms,
       and obtaining the Szip source code, see:

          https://portal.hdfgroup.org/display/HDF5/Szip+Compression+in+HDF+Products


    
    2.3 Additional Utilities
    
    The following standard utilities are also required to build and test HDF5:
        
        bison           : yacc implementation
        flex            : flex utility
        make            : make utility
    
    2.4 Alternate Build Process
    
    Download the CMake package and follow the notes in the "INSTALL_CMake.txt" 
    file to build HDF5 with the CMake utilities.
        
        
        
Build, Test and Install HDF5 on Cygwin
--------------------------------------

1. Get HDF5 source code package
   Users can download HDF5 source code package from HDF website
   (https://www.hdfgroup.org/downloads/hdf5/). 
     
2. Unpacking the distribution

   The HDF5 source code is distributed in a variety of formats which
   can be unpacked with the following commands, each of which creates 
   an `hdf5-1.10.x' directory.

   2.1 Non-compressed tar archive (*.tar)

            $ tar xf hdf5-1.10.x.tar

   2.2 Gzip'd tar archive (*.tar.gz)

            $ gunzip < hdf5-1.10.x.tar.gz | tar xf -

   2.3 Bzip'd tar archive (*.tar.bz2)

            $ bunzip2 < hdf5-1.10.x.tar.bz2 | tar xf - 

2. Setup Environment

    In Cygwin, most compilers and setting are automatically detected during
    the configure script.  However, if you are building Fortran we recommend 
    that you explicitly set the "FC" variable in your environment to use the 
    gfortran compiler.  For example, issue the command:
    
            $ export FC=gfortran
            
4. Configuring 
     
   Notes: See detailed information in hdf5/release_docs/INSTALL, 
          part 5. Full installation instructions for source 
          distributions

   The host configuration file for cygwin i686-pc-cygwin is located 
   in the `config' directory and are based on architecture name, 
   vendor name, and operating system which are displayed near the 
   beginning of the `configure' output. The host config file influences
   the behavior of configure by setting or augmenting shell variables. 
     
   In short,
     
   To configure HDF5 C Library, using 
            
            $ ./configure
                   
   To configure HDF5 C/C++ Library, using

            $ ./configure --enable-cxx
                   
   To configure HDF5 C/Fortran Library, using

            $ ./configure --enable-fortran
                   
   To configure HDF5 C with Szip library, using

            $ ./configure  --with-szlib="path to szlib"
           
       For example, if szip library was installed in the directory 
       /cygdrive/c/szip, which is parent directory of "include" and
       "lib", then the following command will configure HDF5 C library 
       with szip enabled:
           
            $ ./configure --with-szlib=/cygdrive/c/szip
                   
   To configure HDF5 C without Zlib,
     
       To disable zlib, using

           $ ./configure --without-zlib
           
   Two ways to configure HDF5 C with specified Zlib
     
      Using

           $ ./configure --with-zlib=INCDIR,LIBDIR

       For example, if the zlib library is installed in
       /cygdrive/c/usr, which is the parent directory of directories
       "include" and "lib", 

 $ ./configure --with-zlib=/cygdrive/c/usr/include,/cygdrive/c/usr/lib

      Through the CPPFLAGS and LDFLAGS Variables
           
       For example, if zlib was installed in the directory 
       /cygdrive/c/usr then using the following command to configure 
       HDF5 with zib

           $ CPPFLAGS=-I/cygdrive/c/usr/include \
           $ LDFLAGS=-L/cygdrive/c/usr/lib \
           $ ./configure

    To specify the installation directories, using 

            $ ./configure --prefix="path for installation"
                 
       By default, HDF5 library, header files, examples, and 
       support programs will be installed in /usr/local/lib,
       /usr/local/include, /usr/local/doc/hdf5/examples, and
       /usr/local/bin. To use a path other than /usr/local specify 
       the path with the `--prefix=PATH' switch as in the above
       command.

    Combination of Switches 

       All of the above switches can be combined together. For 
       example, if users want to configure HDF5 C/C++/Fortran 
       library with szip library enabled, with zlib library at 
       /cygdrive/c/usr/, and install HDF5 into directory 
       /cygdrive/c/hdf5 using gcc/g++ as C/C++ compiler and gfortran
       as fortran compiler
     
           $ ./configure
             --with-szlib=/cygdrive/c/szip
             --with-zlib=/cygdrive/c/usr/include,/cygdrive/c/usr/lib
             --prefix=/cygdrive/c/hdf5
             --enable-cxx
             --enable-fortran 
             <"If no more switches, then hit Enter">

       Notes: The command format above is for readilibity. In practice,
              please type in the command above with at least one
              space between each line, No "Enter" until users finish 
              the switches and want to run the configure. 

 
     or do it through CPPFLAGS and LDFLAGS variables:
     
           $ CPPFLAGS=-I/cygdrive/c/usr/include \
           $ LDFLAGS=-L/cygdrive/c/usr/lib \

           $ ./configure
             --with-szlib=/cygdrive/c/szip
             --prefix=/cygdrive/c/hdf5
             --enable-cxx
             --enable-fortran 
             <"If no more switches, then hit Enter">
                          
5. Make and Make Check

   After configuration is done successfully, run the following series of
   commands to build, test and install HDF5
    
            $ make          > "output file name"
            $ make check    > "output file name"
            
   Before run "make install", check output file for "make check", there
   should be no failures at all.

6. Make Install

            $ make install  > "output file name"
   
     
7. Check installed HDF5 library

   After step 6, go to your installation directory, there should be 
   three subdirectories: "bin" "include" and "lib".

8. Known Problems 
   
   dt_arith tests may fail due to the use of fork. This is a known issue
   with cygwin on Windows.

   "make check" fails when building shared lib files is enabled.  The default
   on Cygwin has been changed to disable shared.  It can be enabled with
   the --enable-shared configure option but is likely to fail "make check" 
   with GCC compilers.

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For further assistance, contact: 

   HDF Forum:     https://forum.hdfgroup.org/
   HDF Helpdesk:  https://portal.hdfgroup.org/display/support/The+HDF+Help+Desk
   
