netCDF-C 4.6.0

We are pleased to announce the netCDF-C 4.6.0 release. Highlighted changes from the 4.5.0 release are as follows:

• [Enhancement] Full support for using HDF5 dynamic filters, both for reading and writing. See the file docs/filters.md.
• [Enhancement] Reversed a handful of 4.5.0 changes which enforced documented-yet-previously-unenforced specifications, as these broke long established workflows.
• [Enhancement] Added an option to enable strict null-byte padding for headers; this padding was specified in the spec but was not enforced. Enabling this option will allow you to check your files, as it will return an E_NULLPAD error. It is possible for these files to have been written by older versions of libnetcdf. There is no effective problem caused by this lack of null padding, so enabling these options is informational only. The options for configure and cmake are --enable-strict-null-byte-header-padding and -DENABLE_STRICT_NULL_BYTE_HEADER_PADDING, respectively. See Github #657 for more information.
• [Enhancement] Reverted behavior/handling of out-of-range attribute values to pre-4.5.0 default. See Github #512 for more information.
• [Bug] Fixed error in tst_parallel2.c. See Github #545 for more information.
• [Bug] Fixed handling of corrupt files + proper offset handling for hdf5 files. See Github #552 for more information.
• [Bug] Corrected a memory overflow in tst_h_dimscales, see Github #511, Github #505, Github #363 and Github #244 for more information.

netCDF-C 4.5.0

We are very happy to announce netCDF 4.5.0. In addition to general bug fixes and improvements, the improvements from the previous release candidate are listed below. For a full list of changes since the 4.4.1.1 release, please see the full Release Notes.

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• Corrected an issue which could potential result in a hang while using parallel file I/O. See Github #449 for more information.
• Addressed an issue with ncdump not properly handling dates on a 366 day calendar. See GitHub #359 for more information.

netCDF-C 4.5.0 - Release Candidate 3

We are pleased to announce the third release candidate for netCDF 4.5.0. Assuming no further bug reports (won't that be nice!) we should have the full release out soon. In addition to general bug fixes, the main improvements from rc2 are as follows:

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• [Update] Due to ongoing issues, native CDF5 support has been disabled by default. You can use the options mentioned below (--enable-cdf5 or -DENABLE_CDF5=TRUE for configure or cmake, respectively). Just be aware that for the time being, Reading/Writing CDF5 files on 32-bit platforms may result in unexpected behavior when using extremely large variables. For 32-bit platforms it is best to continue using NC_FORMAT_64BIT_OFFSET.
• [Bug] Corrected an issue where older versions of curl might fail. See GitHub #487 for more information.
• [Enhancement] Added options to enable/disable CDF5 support at configure time for autotools and cmake-based builds. The options are --enable/disable-cdf5 and ENABLE_CDF5, respectively. See Github #484 for more information.
• [Bug Fix] Corrected an issue when subsetting a netcdf3 file via nccopy -v/-V. See Github #425 and Github #463 for more information.
• [Bug Fix] Corrected --has-dap and --has-dap4 output for cmake-based builds. See GitHub #473 for more information.
• [Bug Fix] Corrected an issue where NC_64BIT_DATA files were being read incorrectly by ncdump, despite the data having been written correctly. See GitHub #457 for more information.
• [Bug Fix] Corrected a potential stack buffer overflow. See GitHub #450 for more information.

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Release Tarball - https://github.com/Unidata/netcdf-c/releases
Windows Installer Downloads - http://www.unidata.ucar.edu/software/netcdf/docs_rc/winbin.html
Documentation - http://www.unidata.ucar.edu/software/netcdf/docs_rc

netCDF-C 4.5.0 - Release Candidate 2

We are pleased to announce the second release candidate for netCDF 4.5.0. Assuming no further bug reports (won't that be nice!) we should have the full release out soon. In addition to general bug fixes, the main improvements from rc1 are as follows:

• [Bug Fix] Addressed an issue with how cmake was implementing large file support on 32-bit systems. See GitHub #385 for more information.
• [Bug Fix] Addressed an issue where ncgen would not respect keyword case. See GitHub #310 for more information.

The documentation and release code may be downloaded via the following links. We look forward to any feedback and suggestions. Once the official 4.5.0 release is out, we will move forward with the next versions of the Fortran and C++ interfaces.

• Release Tarball - https://github.com/Unidata/netcdf-c/releases
• Windows Installer Downloads - http://www.unidata.ucar.edu/software/netcdf/docs_rc/winbin.html
• Documentation - http://www.unidata.ucar.edu/software/netcdf/docs_rc

netCDF-C 4.5.0 - Release Candidate 1

The following list captures the main changes/improvements/bug fixes since version 4.4.1.1:

4.5.0-rc1 - June 5, 2017

• [Enhancement] DAP4 is now included. Since dap2 is the default for urls, dap4 must be specified by
  (1) using "dap4:" as the url protocol, or
  (2) appending "#protocol=dap4" to the end of the url, or
  (3) appending "#dap4" to the end of the url
  Note that dap4 is enabled by default but remote-testing is
  disbled until the testserver situation is resolved.
• [Enhancement] The remote testing server can now be specified with the --with-testserver option to ./configure.
• [Enhancement] Modified netCDF4 to use ASCII for NC_CHAR. See Github Pull request #316 for more information.
• [Bug Fix] Corrected an error with how dimsizes might be read. See Github #410 for more information.
• [Bug Fix] Corrected an issue where 'make check' would fail if 'make' or 'make all' had not run first. See Github #339 for more information.
• [Bug Fix] Corrected an issue on Windows with Large file tests. See Github #385 for more information.
• [Bug Fix] Corrected an issue with diskless file access, see Pull Request #400 and Pull Request #403 for more information.
• [Upgrade] The bash based test scripts have been upgraded to use a common test_common.sh include file that isolates build specific information.
• [Upgrade] The bash based test scripts have been upgraded to use a common test_common.sh include file that isolates build specific information.
• [Refactor] the oc2 library is no longer independent of the main netcdf-c library. For example, it now uses ncuri, nclist, and ncbytes instead of its homegrown equivalents.
• [Bug Fix] NC_EGLOBAL is now properly returned when attempting to set a global _FillValue attribute. See GitHub #388 and GitHub #389 for more information.
• [Bug Fix] Corrected an issue where data loss would occur when _FillValue was mistakenly allowed to be redefined. See Github #390, GitHub #387 for more information.
• [Upgrade][Bug] Corrected an issue regarding how "orphaned" DAS attributes were handled. See GitHub #376 for more information.
• [Upgrade] Update utf8proc.[ch] to use the version now maintained by the Julia Language project (https://github.com/JuliaLang/utf8proc/blob/master/LICENSE.md).
• [Bug] Addressed conversion problem with Windows sscanf. This primarily affected some OPeNDAP URLs on Windows. See GitHub #365 and GitHub #366 for more information.
• [Enhancement] Added support for HDF5 collective metadata operations when available. Patch submitted by Greg Sjaardema, see Pull request #335 for more information.
• [Bug] Addressed a potential type punning issue. See GitHub #351 for more information.
• [Bug] Addressed an issue where netCDF wouldn't build on Windows systems using MSVC 2012. See GitHub #304 for more information.
• [Bug] Fixed an issue related to potential type punning, see GitHub #344 for more information.
• [Enhancement] Incorporated an enhancement provided by Greg Sjaardema, which may improve read/write times for some complex files. Basically, linked lists were replaced in some locations where it was safe to use an array/table. See Pull request #328 for more information.

netCDF-C 4.4.1.1

This is the official release of netCDF-C 4.4.1.1. This is a maintenance release which contains several important bug fixes. The Unidata/netCDF team recommend migrating to netCDF 4.4.1.1 as soon as is possible to avoid a potential, albeit rare, data loss issue in ncgen (as described below or detailed at #323).

• Documentation for netCDF may be found at http://www.unidata.ucar.edu/software/netcdf/documentation/4.4.1.1
• Windows installer files may be found at http://www.unidata.ucar.edu/software/netcdf/documentation/4.4.1.1/winbin.html
• Source downloads are available from https://github.com/Unidata/netcdf-c/releases/v4.4.1.1
• Tarball and zip archives are available from http://www.unidata.ucar.edu/downloads/netcdf/index.jsp

Changes from version 4.4.1

Below is a list of notable changes from the previous release.

• [Bug] Fixed an issue where ncgen would potentially crash or write incorrect netCDF4 binary data under very specific circumstances. This bug did not affect data written on 32-bit systems or by using the netCDF library; it was specific to ncgen. This would only happen when writing a compound data type containing an 8-byte data type followed by a 4-byte data type and the 4-byte data type was not properly aligned; this would possibly result in incorrect padding. This did not affect 32-bit systems, or data written directly by the library. See GitHub #323 for more information.
• [Documentation] Updated documentation related to netCDF variable names and DAP2 access to reflect the undefined behavior potentially observed when DAP2 reserved keywords are used as netCDF variable names. See GitHub #308 for more information.
• [Bug] Fixed an issue with nc_inq_type() not returning proper value in some circumstances. See GitHub #317 for more information.
• [Bug] Corrected an issue related to test failures when --disable-utilities or -DENABLE_UTILITIES=OFF are specified when building with autotools or cmake, respectively. See GitHub #313 for more information.
• [Bug][Enhancement] Corrected a behavioral issue with the _NCProperties attribute taking up too much space. See GitHub #300 and GitHub #301 for more information.
• [Bug] Corrected behavior for nc-config so that, if nf-config is found in system, the proper fortran-related information will be conveyed. See [GitHub #296](https://github.com/Unidata/netcdf-c/issues/296] for more information.

netCDF-C 4.4.1

This is the official release of netCDF-C 4.4.1.

This release provides compatibility with libhdf5 1.10.0+; previous versions of netCDF will generate binary files which cannot be read on systems using older versions of libhdf5. A summary of changes between this official release and the previous release candidate are as follows:

• [File Change] Starting with release 4.4.1, netCDF-4 files created will have superblock version 0 instead of superblock version 2, as was observed in previous netCDF versions. This is due to a workaround required to avoid backwards binary incompatibility when using libhdf5 1.10.x or greater. Superblock versions 0 and 2 appear to be forward and backward compatible. Other than a different superblock number the data should remain consistent.
• [Enhancement] Added better error reporting when ncdump/nccopy are given a bad constraint in a DAP url. See GitHub #279 for more information.

Full release notes are available here.

netCDF-C 4.4.1-rc3

This is the third release candidate for netCDF-C 4.4.1. It contains various improvements and bug fixes over the previous release candidate. The notes for this release may be seen below, and the full list of release notes may be seen here. Notable improvements are as follows:

4.4.1-RC3 - June 17, 2016

• [Bug Fix] Corrected an issue where adding a _FillValue attribute to a variable would result in other attributes being lost. See GitHub #239 for more details.
• [Bug Fix][Parallel I/O] Corrected an issue reported by Kent Yang at the HDF group related to Collective Parallel I/O and a potential hang.
• [Bug Fix] Misc. bug fixes and improvements.

netCDF-C 4.4.1-rc2

This is the second release candidate for netCDF-C 4.4.1. It contains various improvements and bug fixes over the first release candidate. The notes for this release may be seen below, and the full list of release notes may be seen here.

4.4.1-RC2 - May 13, 2016

• [Enhancement] Added provenance information to files created. This information consists of a persistent attribute named _NCProperties plus two computed attributes, _IsNetcdf4 and _SuperblockVersion. Associated documentation was added to the file docs/attribute_conventions.md. See GitHub pull request #260 for more information.
• [Bug Fix] Cleaned up some dead links in the doxygen-generated documentation.
• [Bug Fix] Corrected several issues related to building under Visual Studio 2014.
• [Bug Fix] Corrected several test failures related to HDF5 1.10.0
• [Bug Fix] Reverted SOVersion current to 11 from 12; it was incorrectly incremented in netCDF-C release 4.4.1-RC1.
• [Enhancement][Windows] Updated included libhdf5 version from 1.8.15 to 1.8.16 for pre-built Windows/Visual Studio installers.

netCDF-4.4.1-rc1

This is the first release candidate for netCDF 4.4.1. It contains many improvements and bug fixes, and addresses one very important issue. This is the first release which will write backwards-compatible netCDF4 files properly when linked against HDF5 1.10.0. See #250 for full details.

See the file RELEASE_NOTES.md for full release notes. Here is a summary of changes made so far:

Changes from 4.4.0 to 4.4.1-rc1

• [Bug Fix][Enhancement] Fixed an issue with netCDF4 files generated using version 1.10.0 of the HDF5 library. The 1.10 release potentially changed the underlying file format, introducing a backwards compatibility issue with the files generated. HDF5 provided an API for retaining the 1.8.x file format, which is now on by default. See GitHub Issue #250 for more information.
• [Bug Fix] Corrected an issue with autotools-based builds performed out-of-source-tree. See GitHub Issue #242 for more information.
• [Enhancement] Modified nc_inq_type() so that it would work more broadly without requiring a valid ncid. See GitHub Issue #240 for more information.
• [Enhancement] Accepted a patch code which added a hashmap lookup for rapid var and dim retrieval in nc3 files, contributed by Greg Sjaardema. See GitHub Pull Request #238 for more information.
• [Bug Fix] Accepted a contributed pull request which corrected an issue with how the cmake-generated nc-config file determined the location of installed files. See GitHub Pull Request #235 for more information.
• [Enhancement] Added an advanced option for CMake-based builds, ENABLE_SHARED_LIBRARY_VERSION. This option is ON by default, but if turned off, only libnetcdf.dylib will be generated, instead of files containing the SOVERSION in the file name. This is a requested feature most people might not care about. See GitHub #228 for more information.
• [Bug Fix] Corrected an issue with duplicated error codes defined in multiple header files. See GitHub #213 for more information.
• [Bug Fix] Addressed an issue specific to Visual Studio 2015 on Windows. On very large files, some calls to the fstat class of functions would fail for no apparent reason. This behavior was not observed under Visual Studio 2013. This has now been mitigated. See GitHub #188 for more information.
• [Enhancement] Updated nc-config to report whether logging is enabled in netcdf. Additionally, if f03 is available in an installed netcdf-fortran library, it will now be reported as well.
• [Bug Fix] Addressed an issue where netcdf_mem.h was not being installed by cmake. See GitHub #227 for more information.
• [Bug Fix] Addressed an issue where ncdump would crash when trying to read a netcdf file containing an empty ragged VLEN variable in an unlimited dimension. See GitHub #221 for more information.