[TOC]
This document is for getting and building the netCDF C library and utilities, version 4.3.0. Other libraries that depend on the netCDF C library, such as the Fortran and C++ libraries, are available as separate distributions that can be built and installed after the C library is successfully installed. The netCDF-Java library is also a separate distribution that is currently independent of the netCDF C library.
- For information regarding the netCDF-Fortran libraries, see \subpage building_netcdf_fortran.
The easiest way to get netCDF is through a package management program, such as rpm, yum, adept, and others. NetCDF is available from many different repositories, including the default Red Hat and Ubuntu repositories.
When getting netCDF from a software repository, you will wish to get the development version of the package ("netcdf-devel"). This includes the netcdf.h header file.
Pre-release libraries for Windows may be found here: \ref winbin.
Starting with netCDF-C version 4.3.1, the netCDF-C source code is hosted at the Unidata GitHub repository, available at http://github.com/Unidata/netcdf-c.
Two options are available for building from source:
- The latest release.
- The developer snapshot.
The latest release may be downloaded from github at the following location:
Source files are available in .tar.gz and .zip formats.
The developer snapshot may be cloned from github directly by using the git command.
$ git clone http://github.com/Unidata/netcdf-c netcdf-c
Note:
The developer snapshot release contains bug-fixes and new features added since the last full release. It may also contain portability bugs.
Once you have downloaded and unpacked the distribution, see the following section on \ref building.
The netCDF-C library and utilities require third-party libraries for full functionality. (See \ref architecture).
- \ref build_default
- \ref build_classic
- \ref build_hdf4
- \ref build_parallel
- \ref building_netcdf_fortran
- \ref configure_options
- HDF5 1.8.9 (netcdf-4 support)
- zlib 1.2.5
- curl 7.18.0 (DAP support)
- \ref netCDF-CMake
- \subpage winbin
The usual way of building netCDF requires the HDF5, zlib, and curl libraries. (And, optionally, the szlib library). Versions required are at least HDF5 1.8.9, zlib 1.2.5, and curl 7.18.0 or later. (Optionally, if building with szlib, get szip 2.0 or later.)
HDF5 1.8.9 and zlib 1.2.7 packages are available from the netCDF-4 ftp site. If you wish to use the remote data client code, then you will also need libcurl, which can be obtained from the curl website.
Make sure you run ``make check'' for the HDF5 and zlib distributions. They are very well-behaved distributions, but sometimes the build doesn't work (perhaps because of something subtly misconfigured on the target machine). If one of these libraries is not working, netCDF will have serious problems.
Note that for building netCDF, it is not necessary to build the HDF5 Fortran, C++, or Java API's. Only the HDF5 C library is used.
Optionally, you can also build netCDF-4 with the szip library (a.k.a. szlib). NetCDF cannot create szipped data files, but can read HDF5 data files that have used szip. 8 There are license restrictions on the use of szip, see the section on licensing terms in the web page on szip compression in HDF products. These license restrictions seem to apply to commercial users who are writing data. (Data readers are not restricted.) But here at NetCDF World Headquarters, in Sunny Boulder, Colorado, there are no lawyers, only programmers, so please read the szip documents for the license agreement to see how it applies to your situation.
If ``make check'' fails for either zlib or HDF5, the problem must be resolved before the netCDF-4 installation can continue. For HDF5 problems, see the HDF5 help services.
Build zlib like this:
$ ./configure --prefix=/home/username/local
$ make check install
Then you build HDF5, specifying the location of the zlib library:
$ ./configure --with-zlib=/home/username/local --prefix=/home/username/local
$ make check install
In all cases, the installation location specified with the --prefix
option must be different from the source directory where the software
is being built.
Note that for shared libraries, you may need to add the install directory to the LD_LIBRARY_PATH environment variable. See the netCDF FAQ for more details on using shared libraries.
If you are building HDF5 with szip, then include the --with-szlib=
option, with the directory holding the szip library.
After HDF5 is done, build netcdf, specifying the location of the HDF5, zlib, and (if built into HDF5) the szip header files and libraries in the CPPFLAGS and LDFLAGS environment variables. For example:
$ CPPFLAGS=-I/home/username/local/include LDFLAGS=-L/home/username/local/lib ./configure --prefix=/home/username/local
$ make check install
The configure script will try to find necessary tools in your
path. When you run configure you may optionally use the --prefix
argument to change the default installation directory. The above
examples install the zlib, HDF5, and netCDF-4 libraries in
/home/username/local/lib, the header file in /home/username/local/include, and the
utilities in /home/username/local/bin. If you don't provide a --prefix
option, installation will be in /usr/local/, in subdirectories lib/,
include/, and bin/. The installation location specified with the
--prefix option must be different from the source directory where the
software is being built.
It is possible to build the netCDF C libraries and utilities so that only the netCDF classic and 64-bit offset formats are supported, or the remote data access client is not built. (See \ref netcdf_format) for more information about the netCDF format variants. See the netCDF-DAP site for more information about remote client access to data on OPeNDAP servers.)
To build without support for the netCDF-4 formats or the additional netCDF-4 functions, but with remote access, use:
$ ./configure --prefix=/home/username/local --disable-netcdf-4
$ make check install
(Replace /home/username/local with the name of the directory where
netCDF is to be installed. The installation location specified with
the --prefix option must be different from the source directory where
the software is being built.)
Starting with version 4.1.1 the netCDF C libraries and utilities have supported remote data access, using the OPeNDAP protocols. To build with full support for netCDF-4 APIs and format but without remote client access, use:
$ ./configure --prefix=/home/username/local --disable-dap
$ make check install
To build without netCDF-4 support or remote client access, use:
$ ./configure --prefix=/home/username/local --disable-netcdf-4 --disable-dap
$ make check install
If you get the message that netCDF installed correctly, then you are done!
The netCDF-4 library can (since version 4.1) read HDF4 data files, if they were created with the SD (Scientific Data) API.
For this to work, you must build the HDF4 library with the configure option
--disable-netcdf
to prevent it from building an HDF4 version of the netCDF-2 library that conflicts with the netCDF-2 functions that are built into the Unidata netCDF library.
Then, when building netCDF-4, use the
--enable-hdf4
option to configure. The location for the HDF4 header files and library must be set in the CPPFLAGS and LDFLAGS options.
For HDF4 access to work, the library must be build with netCDF-4 features.
Here's an example, assuming the HDF5 library has been built and installed in H5DIR and you will build and install the HDF4 library in H4DIR (which could be the same as H5DIR):
# Build and install HDF4
$ cd ${HDF4_SOURCE_DIRECTORY}
$ ./configure --enable-shared --disable-netcdf --disable-fortran --prefix=${H4DIR}
$ make
$ make install
$ # Build and install netCDF with HDF4 access enabled
$ cd ${NETCDF_SOURCE_DIRECTORY}
$ CPPFLAGS="-I${H5DIR}/include -I${H4DIR}/include" \
$ LDFLAGS="-L${H5DIR}/lib -L${H4DIR}/lib" \
$ ./configure --enable-hdf4 --enable-hdf4-file-tests
$ make check
$ make install
For parallel I/O to work, HDF5 must be installed with –enable-parallel, and an MPI library (and related libraries) must be made available to the HDF5 configure. This can be accomplished with the mpicc wrapper script, in the case of MPICH2.
The following works to build HDF5 with parallel I/O on our netCDF testing system:
CC=mpicc ./configure --enable-parallel
make check install
If the HDF5 used by netCDF has been built with parallel I/O, then netCDF will also be built with support for parallel I/O. This allows parallel I/O access to netCDF-4/HDF5 files. Note that shared libraries are not supported for parallel HDF5, which makes linking more difficult to get right. "LIBS=-ldl" is also sometimes needed to link successfully with parallel HDF5 libraries. (See /ref netcdf_formats for more information about the netCDF format variants.)
The following works to build netCDF-4 with parallel I/O on our netCDF testing system:
$ H5DIR=/where/parallel/HDF5/was/installed
$ CPPFLAGS="-I${H5DIR}/include"
$ CC=mpicc
$ LDFLAGS=-L${H5DIR}/lib
$ LIBS=-ldl
$ ./configure --disable-shared --enable-parallel-tests
$ make check install
If parallel I/O access to netCDF classic and 64-bit offset files is also needed, the parallel-netcdf library should also be installed. (Note: the previously recommended replacement pnetcdf.h should no longer be used.) Then configure netCDF with the "--enable-pnetcdf" option.
For static build, to use netCDF-4 you must link to all the libraries, netCDF, HDF5, zlib, szip (if used with HDF5 build), and curl (if the remote access client has not been disabled). This will mean -L options to your build for the locations of the libraries, and -l (lower-case L) for the names of the libraries.
For example, one user reports that she can build other applications with netCDF-4 by setting the LIBS environment variable:
LIBS='-L/X/netcdf-4.0/lib -lnetcdf -L/X/hdf5-1.8.9/lib -lhdf5_hl -lhdf5 -lz -lm -L/X/szip-2.1/lib -lsz'
For shared builds, only -lnetcdf is needed. All other libraries will be found automatically.
The ``nc-config --all'' command can be used to learn what options are needed for the local netCDF installation.
For example, this works for linking an application named myapp.c with netCDF-4 libraries:
cc -o myapp myapp.c `nc-config --cflags --libs`
These options are used for autotools-based builds. For cmake options, see
Note: --disable prefix indicates that the option is normally enabled.
| Option | Description | Dependencies | |
|---|---|---|---|
| --disable-doxygen | Disable generation of documentation. | doxygen | |
| --disable-fsync | disable fsync support | kernel fsync support | |
| --enable-valgrind-tests | build with valgrind-tests; static builds only | valgrind | |
| --enable-netcdf-4 | build with netcdf-4 | HDF5 and zlib | |
| --enable-netcdf4 | synonym for enable-netcdf-4 | ||
| --enable-hdf4 | build netcdf-4 with HDF4 read capability | HDF4, HDF5 and zlib | |
| --enable-hdf4-file-tests | test ability to read HDF4 files | selected HDF4 files from Unidata ftp site | |
| --enable-pnetcdf | build netcdf-4 with parallel I/O for classic and 64-bit offset files using parallel-netcdf | ||
| --enable-extra-example-tests | Run extra example tests | --enable-netcdf-4,GNU sed | |
| --enable-parallel-tests | run extra parallel IO tests | --enable-netcdf-4, parallel IO support | |
| --enable-logging | enable logging capability | --enable-netcdf-4 | |
| --disable-dap | build without DAP client support. | libcurl | |
| --disable-dap-remote-tests | disable dap remote tests | --enable-dap | |
| --enable-dap-long-tests | enable dap long tests | ||
| --enable-extra-tests | run some extra tests that may not pass because of known issues | ||
| --enable-ffio | use ffio instead of posixio (ex. on the Cray) | ||
| --disable-examples | don't build the netCDF examples during make check (examples are treated as extra tests by netCDF) | ||
| --disable-v2 | turn off the netCDF version 2 API | ||
| --disable-utilities | don't build netCDF utilities ncgen, ncdump, and nccopy | ||
| --disable-testsets | don't build or run netCDF tests | ||
| --enable-large-file-tests | Run tests which create very large data files | ~13 GB disk space required, but recovered when tests are complete). See option --with-temp-large to specify temporary directory | |
| --enable-benchmarks | Run benchmarks. This is an experimental feature. The benchmarks are a bunch of extra tests, which are timed. We use these tests to check netCDF performance. | sample data files from the Unidata ftp site | |
| --disable-extreme-numbers | don't use extreme numbers during testing, such as MAX_INT - 1 | ||
| --enable-dll | build a win32 DLL | mingw compiler | |
| --disable-shared | build shared libraries | ||
| --disable-static | build static libraries | ||
| --disable-largefile | omit support for large files | ||
| --enable-mmap | Use mmap to implement NC_DISKLESS |
Starting with netCDF-C 4.3.0, we are happy to announce the inclusion of CMake support. CMake will allow for building netCDF on a wider range of platforms, include Microsoft Windows with Visual Studio. CMake support also provides robust unit and regression testing tools. We will also maintain the standard autotools-based build system in parallel.
In addition to providing new build options for netCDF-C, we will also provide pre-built binary downloads for the shared versions of netCDF for use with Visual Studio.
The following packages are required to build netCDF-C using CMake.
- netCDF-C Source Code
- CMake version 2.8.12 or greater.
- Optional Requirements:
- HDF5 Libraries for netCDF4/HDF5 support.
- libcurl for DAP support.
There are four steps in the Build Process when using CMake
- Configuration: Before compiling, the software is configured based on the desired options.
- Building: Once configuration is complete, the libraries are compiled.
- Testing: Post-build, it is possible to run tests to ensure the functionality of the netCDF-C libraries.
- Installation: If all tests pass, the libraries can be installed in the location specified during configuration.
For users who prefer pre-built binaries, installation packages are available at \ref winbin
The output of the configuration step is a project file based on the appropriate configurator specified. Common configurators include:
- Unix Makefiles
- Visual Studio
- CodeBlocks
- ... and others
| Option | Autotools | CMake |
|---|---|---|
| Specify Install Location | --prefix=PREFIX | -D"CMAKE_INSTALL_PREFIX=PREFIX" |
| Enable/Disable netCDF-4 | --enable-netcdf-4 --disable-netcdf-4 |
-D"ENABLE_NETCDF_4=ON" -D"ENABLE_NETCDF_4=OFF" |
| Enable/Disable DAP | --enable-dap --disable-dap |
-D"ENABLE_DAP=ON" -D"ENABLE_DAP=OFF" |
| Enable/Disable Utilities | --enable-utilities --disable-utilities |
-D"BUILD_UTILITIES=ON" -D"BUILD_UTILITIES=OFF" |
| Specify shared/Static Libraries | --enable-shared --enable-static |
-D"BUILD_SHARED_LIBS=ON" -D"BUILD_SHARED_LIBS=OFF" |
| Enable/Disable Tests | --enable-testsets --disable-testsets |
-D"ENABLE_TESTS=ON" -D"ENABLE_TESTS=OFF" |
| Specify a custom library location | Use CFLAGS and LDFLAGS | -D"CMAKE_PREFIX_PATH=/usr/custom_libs/" |
A full list of basic options can be found by invoking cmake [Source Directory] -L. To enable a list of basic and advanced options, one would invoke cmake [Source Directory] -LA.
The easiest configuration case would be one in which all of the dependent libraries are installed on the system path (in either Unix/Linux or Windows) and all the default options are desired. From the build directory (often, but not required to be located within the source directory):
$ cmake [Source Directory]
If you have libraries installed in a custom directory, you may need to specify the CMAKE_PREFIX_PATH variable to tell cmake where the libraries are installed. For example:
$ cmake [Source Directory] -DCMAKE_PREFIX_PATH=/usr/custom_libraries/
The compiler can be executed directly with 'make' or the appropriate command for the configurator which was used.
$ make
Building can also be executed indirectly via cmake:
$ cmake --build [Build Directory]
Testing can be executed several different ways:
$ make test
or
$ ctest
or
$ cmake --build [Build Directory] --target test
Once netCDF has been built and tested, it may be installed using the following commands:
$ make install
or
$ cmake --build [Build Directory] --target install
For further information regarding netCDF and CMake, see \ref cmake_faq