Introduction

This document briefly describes wgrib2, a utility and library for interacting with, reading, writing, and manipulating GRIB2 files.

Wgrib2 is maintained as a collaboration between Climate Prediction Center (CPC) and the Environmental Modeling Center (EMC).

Installation

Download the tarball from the release page and unpack it, and cd into the main directory of the library. Then run the following commands, substituting your directory locations for the CMAKE_INSTALL_PREFIX (where wgrib2 will be installed), and the CMAKE_PREFIX_PATH (where the build will look for dependencies):

mkdir build && cd build
cmake .. -DCMAKE_INSTALL_PREFIX=install -DCMAKE_PREFIX_PATH="/usr/local/NCEPLIBS-g2c;/usr/local/NCEPLIBS-ip" <Additional CMake options>
make
make install

Additional CMake build options can be used to configure the build by setting them with -D<OPTION>=<VALUE>.

Common CMake Options

Option	Description	Default	Additional Requirements
BUILD_LIB	Build wgrib2 library	ON	N/A
BUILD_SHARED_LIB	Build wgrib2 library as a shared library	ON	N/A
MAKE_FTN_API	Build Fortran API	OFF	BUILD_LIB = ON
USE_NETCDF	Read and write NetCDF files	OFF	NetCDF-c
USE_IPOLATES	Use NCEPLIBS-ip library (required for grid interpolation)	OFF	NCEPLIBS-ip v5.2.0+
USE_G2CLIB_HIGH	Use NCEPLIBS-g2c high-level decoder (needed for '-g2clib 2' option)	OFF	NCEPLIBS-g2c 2.2.0+
USE_G2CLIB_LOW	Use NCEPLIBS-g2c low-level decoders for PNG (packing type 41) and Jpeg2000 (packing type 40)	OFF	NCEPLIBS-g2c 2.2.0+ with desired decoders enabled
USE_AEC	Use AEC to enable encoding/decoding of GRIB2 data with CCSDS packing (packing type 42)	OFF	libaec v1.0.6+
USE_OPENMP	Use with OpenMP	OFF	OpenMP-c
USE_PROJ4	Use with Proj.4 library	OFF	N/A
USE_REGEX	Enable regular expression matching options	ON	Regex Library (may be unavailable on non-POSIX systems)

Less Common CMake and CTest Options

Option	Description	Default
CMAKE_INSTALL_PREFIX	Installation path	/usr/local
ENABLE_DOCS	Enable generation of doxygen-based documentation	OFF
BUILD_WGRIB	Build original wgrib code for GRIB1. This code is no longer supported - use at your own risk.	OFF
FTP_TEST_FILES	Fetch and test with files on FTP site.	OFF
FTP_LARGE_TEST_FILES	Fetch and test with very large files on FTP site.	OFF
FTP_EXTRA_TEST_FILES	Test with more large files fetched via FTP.	OFF
USE_TIGGE	Enable use of TIGGE gribtables	ON
USE_UDF	Enable User-Defined functions	OFF
USE_WMO_VALIDATION	Use WMO Validation Tables (unofficial templates)	OFF
DISABLE_ALARM	Disable alarm for non-compatible systems	OFF
DISABLE_STAT	Disable POSIX feature	OFF
BUILD_EXTRA	Build user-contributed code. This code is no longer supported - use at your own risk.	OFF
USE_MYSQL	Use with BUILD_EXTRA = ON to enable user-contributed MySQL options. It is user's responsibility to ensure MySQL is available.	OFF

Documentation for Previous Versions of wgrib2

Legacy Web Docs