/*!  \page grib_get grib_get
\section DESCRIPTION 
 Get values of some keys from a grib file.
	It is similar to grib_ls, but fails returning an error code 
	when an error occurs (e.g. key not found).

\section USAGE 
 grib_get 
 [options] grib_file grib_file ...

\section OPTIONS 
-f  \n Force. Force the execution not to fail on error.
 \n \n -p key[:{s/d/i}],key[:{s/d/i}],... \n 
		Declaration of keys to print.
		For each key a string (key:s), a double (key:d) or an integer (key:i)
		type can be requested. Default type is string.
 \n \n -F format \n 
		C style format for floating-point values.
 \n \n -l Latitude,Longitude[,MODE,file] \n 
		Value close to the point of a Latitude/Longitude.
		Allowed values for MODE are:
		4 (4 values in the nearest points are printed) Default
		1 (the value at the nearest point is printed)
		file (file is used as mask. The closer point with mask value>=0.5 is printed)
 \n \n -P key[:{s/d/i}],key[:{s/d/i}],... \n 
		As -p adding the declared keys to the default list.
 \n \n -w key[:{s/d/i}]{=/!=}value,key[:{s/d/i}]{=/!=}value,... \n 
		Where clause.
		Messages are processed only if they match all the key/value constraints.
		A valid constraint is of type key=value or key!=value.
		For each key a string (key:s), a double (key:d) or an integer (key:i)
		type can be specified. Default type is string.
 \n \n -n namespace \n 
		All the keys belonging to namespace are printed.
 \n \n -s key[:{s/d/i}]=value,key[:{s/d/i}]=value,... \n 
		Key/values to set.
		For each key a string (key:s), a double (key:d) or an integer (key:i)
		type can be defined. By default the native type is set.
 \n \n -V  \n Version.
 \n \n -W width \n 
		Minimum width of each column in output. Default is 10.
 \n \n -m  \n Mars keys are printed.
 \n \n -M  \n Multi-field support off. Turn off support for multiple fields in single grib message.
 \n \n -g  \n Copy GTS header. 
 \n \n -G  \n GRIBEX compatibility mode.
 \n \n -T T | B | M | A \n Message type. T->GTS, B->BUFR, M->METAR (Experimental),A->Any (Experimental).
			The input file is interpreted according to the message type.
 \n \n -7  \n Does not fail when the message has wrong length
 \n \n -X offset \n 
		Input file offset in bytes. Processing of the input file will start from "offset".
 \n \n -i index \n 
		Data value corresponding to the given index is printed.
 \n \n 
\section grib_get_examples grib_get examples
-# grib_get fails if a key is not found.\n 
\verbatim 
>grib_get -p gribname ../data/tigge_pf_ecmwf.grib2
\endverbatim 
-# To get the step of the first GRIB message in a file: \n
\verbatim 
>grib_get -w count=1 -p step ../data/tigge_pf_ecmwf.grib2
\endverbatim 
*/