ecCodes is an evolution of GRIB-API and will replace it in the futurehas replaced it at ECMWF. Users are strongly advised to start the migration process.
GRIB-API is entirely included in ecCodes without any major change to its Fortran 90, Python and C interfaces. . The functions with the "grib_" prefix are included in the ecCodes library.
However there are some minor changes and rationalisations described below.:
API Changes
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The following functions have been removed: The following C function signatures have changed: |
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In the Fortran interface, for GRIB keys whose value is MISSING, GRIB-API returns -1 whereas ecCodes returns the constant CODES_MISSING_LONG. An example of such a key is "Ni" (the number of points per latitude) for Reduced Gaussian Grids. Please check your code and make sure you are not comparing with -1. |
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In the Fortran interface of GRIB-API, the function grib_keys_iterator_next returns 1 if the next iterator exists and 0 if there are no more elements. But in ecCodes this function returns CODES_SUCCESS (=GRIB_SUCCESS) if the next iterator exists and an integer value if there are no more elements. See example here. |
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We have also removed the Fortran 77 library (libgrib_api_f77.a) and the API examples. |
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section_length[3] section1Length ;
The names of the files in the definitions/mars directory have also changed. Previously they had the prefix "grib1" but this was misleading as they pertain to all editions. So the new files have the prefix "grib" e.g.
definitions/mars/grib.oper.fc.def
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The "include" statements now require the relative path from the top-level of the definitions directory so instead of
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include "grib2/template.4.statistical.def"
The migration from GRIB-API to ecCodes should not affect user software and will be managed in installation and linking phases. Nevertheless, very significant changes in the library have been performed to implement the encoding of different types of messages and in particular for BUFR.
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Some more tests are needed to be fully confident that ecCodes can replace GRIB-API in an operational environment, but we don't have experience at the moment of problems with the GRIB decoding/encoding part of ecCodes. We strongly advise the users to do their own migration tests and send feedback to software.support@ecmwf.int.